TLRI Litter-bed Pig House/Farm

Contents

I.� Introduction ...................................................................... 1�

II.�Research summary on TRLI litter-bed pig house ............ 3�

III.�Construction and management of TRLI litter-bed pig houses ............................................................................ 12�

1.�Segmented management and pen construction .......... 12�

2.�Estimation for number of pig pen for various stages 14�

3.�Reconstruction of existing pig house ........................ 16�

4.�Daily management of pig .......................................... 17�

5.�Cleanup of litter/manure mixture .............................. 19�

6.�Composting of litter/manure mixture ........................ 20�

IV.�Collection and recycling of wastewater in pig farms ..... 28�

V.�Anaerobic or incineration treatment of pig carcass and sow’s postpartum disorders ........................................... 30�

VI.Conclusions.................................................................... 32�

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I. Introduction General livestock house construction books seldom mentioned animal

wastes disposal, and visa versa. Since farm wastes caused public hazard problems, livestock farmers realized that it was very difficult to setup a waste disposal system with the existing farm facility. The issue of how to deal with livestock wastes prior to house construction is essential when efficiency is concerned. In addition, if livestock farm wastes are processed according to the "waste or wastewater" concept, then the organic matter, biochemical oxygen demand (BOD), suspended solids (SS), etc. and others contained in these so-called waste or wastewater have to be treated until the prescribed standards before emission. Although technically it is not difficult for these wastewater treatment facilities to meet emission standards prescribed by the government, it is certainly bound to increase pig production costs, reducing the pig-farming competitiveness. In fact, livestock wastes treatment is an inseparable part of livestock production system, and farmers should seek improvements from housing, feeding management or farming operations. For example, farmer may decrease the housing clean frequency or even not clean, and thus decrease water consumption, or recycle the waste water after treated, or apply the separation technique to separate the solid and liquid of animal waste, and then convert the solid organic slurry into fertilizer, or even feed, i.e., feed utilization as treatment means which is not only minimizing treatment costs but can also have a multiplier effect.

At the end of 1992, the effluent standards of livestock industry in Taiwan were BOD <200 mg/L and <400 mg/L for large-scale and small scale farms, respectively. Swine slurry was treated only by simple solid-liquid separation, and followed by 12 to 15 days of hydraulic retention time (HRT) for anaerobic fermentation; the treated waste water could reach the above effluent standards. However, more harsh effluents standards for BOD imposed during 1993 and 1997 and chemical oxygen demand (COD) was also included in effluents standards since then. Therefore, the third-step of active sludge process was proposed adding to meet the governmental regulation which included aerobic treatment for anaerobic discharged liquids. However, more stringent effluent standards for animal industry was announced in 1998, including effluents standards to BOD <80 mg/L, COD 250 <mg/L and SS <150 mg/L. It is possible to conform to the above effluents standard under standard operation procedure using three-stage wastewater treatment protocol, but could not guaranteed all year long due to organism treatment system sensitive to environmental changes, such as suddenly heavy rain, cold, power outage, and any other factors with short-term impact on treated water. Thus, farmer might be subjected to fines from the Environmental agencies without extra step, aquatic plants decontaminating process. In addition, more and more stringent environmental standards are to be expected, especially in regards of

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nitrogen and phosphorus removal problems for livestock manure. Because of this, Dr. Chia-Mo Hong who was a senior research and advisory scientist from Taiwan Livestock Research Institute (TLRI), realized that new animal waste treatment strategy would become urgent, especially for pig manure treatment. Based on more than 50 years’ professional experience, Dr. Hong proposed a water emission-free litter-bed pig houses concept to solve the pollution problem fundamentally for pig industry.

What is a litter-bed pig house? Basically, putting litter in the pig house and handling swine slurry at the same time is the basic definition for litter-bed pig house. For example, before the 1960s, most Taiwan sideline pig farms had a 30 to 50 cm deep recess on one end of the pig house for stacking straw, rinse water for washing and pig manure. When the pigs were sold or the recess was filled, the manure was cleared to briefly manufacture manure-compost by heaping; the so obtained fertilizer was used on agricultural lands. In addition, woody sawdust pig house was implemented in Japan. Allegedly the construction of this type of pig house is quite simple, with many advantages such as low construction costs, labor-saving, no water emissions, etc. In summary, the litter-bed pig house should include the traditional Taiwan 1960s pig house (Figure 1) and the Japanese woody sawdust pig house (Figure 2).

The litter-bed pig houses program was initiated in 1987 by Dr. Hong when he was a researcher in Taiwan Livestock Research Institute. The program started with pig houses, and was for the most part completed in 1991; the litter-bed farrowing, nursing and piglet houses trials were completed from 1992 to 1995. In 1997, the TLRI research team completed the reconstruction of the five abandoned pig houses into a TLRI litter-bed facility. A total of 6 research papers, 6 conference papers and 13 technique bulletins/magazine articles were published since then to 2002. In addition, part of results was also shown as special chapter in three books. The research team consists of 15 personnel, 3 are still working at TLRI, 4 have passed away, while the rest are either retired or have transferred. However, based on Dr. Hong’s lifelong research and counseling experience in Taiwan's pig industry, TLRI litter-bed pig house knowhow and related technology are already mature, and it had also been promoted for field implementation in rural areas, but due to lack of optimum timing it was not shown its effectiveness in Taiwan. Results showed TLRI litter-bed pig house reduced NT$900 per pig production when compared with that of three-stage wastewater treatment in 2009, and thus implied positive impact on pig industry. Estimate of water loss volume by three-stage wastewater treatment in 1990 with more than ten millions pig production annually, is about the equivalent of the Sun Moon Lake Reservoir's (138,300 m3) available water capacity. Furthermore, pig daily water consumption is considerable, and thus "animal and human competition for

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water in the future" is not an alarmist. From a newspaper report: "The Day After Tomorrow... water shortage will become common; water being more expensive than gasoline is not a out of the question; more than half of Taiwan's reservoirs is undergoing eutrophication; the world's most expensive water is in German with NT$87.9/m3; water shortage will be the tipping point of the next wave of economic crisis..." and other such warnings, all show that TLRI litter-bed pig houses are suitable not only for Taiwan, but also can be the global pig house. In addition, how to strive to collect the farm's water resources, especially the storage and recycling of rainwater and the overflow from of water dispensers, are all action that have been ignored by the pig industry in the past. Also, in addition to the animal wastes, other internal procedures such as postpartum sows and carcasses handling are also issues to be explored by environmentally friendly pigs farms, this bulletin will cover the facilities that a both sustainable and environmentally friendly pig farm should possess, and provide a reference to pig farmers when building the farm.

Figure 1 Taiwanese style litter-bed

pig house in the early of 1960s.

Figure 2 Japanese style woody sawdust pig house.

II. Research summary on TRLI litter-bed pig house In May 1984, Dr. Hong observed the very simple construction of woody sawdust pig house when he visited an experimental pig farm in Shizuoka, Japan. The pig house was about 70 m2 in area for 70 pigs, with no cement on floor; only soil covered with 50 cm thick layer of manure compost and sawdust. After the pigs are sold the compost, sawdust and manure are cleared the outside for heaping as compost; during the raising the pigs are never washed with water. According to the experimental farm’s staff, pigs raised in the woody sawdust houses gained more weight than those of control group (cement floor) in the winter, but the summer comparison test were conducting. Since this raising system is similar to Taiwan traditional raising style in the early stage which wastes are treated inside the pig house. Taiwan's traditional pig farms were very small scale, consisting of only 5 to 6

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pigs, and thus could be accepted in spite of malodorous problems. However, this is no longer suitable for large-scale farming. Therefore, Dr. Hong conducted the litter-bed pig houses preliminary test after returning to Taiwan. In 1987 he furthered proposed a research plan to conduct a series of experiments at TLRI on pig raising system, including Japanese woody sawdust style, Taiwan traditional flat concrete floor house, and a mixture of flat floor and litter-bed pig house. The objectives of this study were to investigate the optimum space and depth of litter-bed for indoor processing pig wastes. The research was completed in 1991 and results suggested that 1 m2 cement floor area and 0.4-0.6 m2 litter-bed (0.5 m2 in average) with depth 0.4 m per pig were required. It also needs to be noted that if moisture content of litter-bed is greater than 40%, biological agents should be added to suppress the malodor. Comparison between litter-bed and Japanese woody sawdust pig houses in Taiwan is shown in Table 1. When the room temperature of Taiwan traditional flat concrete floor house was 32 , the TLRI litter-bed pig house showed 34 of the maximum temperature compared with that of 47 observed in Japanese woody sawdust pig houses. The reason was due to the low moisture content in mixture of pig manure and rice husk in TLRI litter-bed pig house, which was kept below 40%, and thus neither fermentation heat nor stench, occurred. Pigs may be the smartest domestic animals in the world. Pigs raised in TLRI litter-bed pig house will move to the cement floor instead of litter-bed during hot days. Therefore, one can install automatic water sprayer on the top of the cement floor and further combine with ventilators or fans for one-way blow to reduce pig house temperature. Conversely, Japanese woody sawdust pig house mainly paved with woody sawdust and the relative humid were at about 60%. Therefore, aerobic composting fermentation¸ more heat and serious stench will be expected. Although a series of pig feeding experiments were conducted thereafter, some issues still needed to be clarified, including the causes of slower daily gain and lower daily feed intake observed in summer than in winter for litter-bed housing pigs, whether it was simply due to seasonal effects, or the effect of litter-bed, or the raising density of 1 m2 concrete floor was not enough. Also, technicians in charged were the same for litter-bed and cement groups with the same cleaning tools, which might resulted in undetectable housing effects due to cross-contamination between litter-bed and concrete floor parasites. Therefore, the research team continued to modify and conduct the experiment. Experiment design included three raising groups, 1.5 m2/pig cement floor (low-density) , 1.0 m2/pig cement floor (high-density), and 1.0 m2 cement floor plus 0.5 m2 litter-bed per pig. Also, the cement floor groups and litter-bed group pigs were located in different barns with separate management and cleaning tools. The results of growth performances are shown in Table 2. Deworming was also schedule before and at mid-term of experiment. Parasite tests were performed prior to the mid-term deworming

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and before the pigs sold; the results were shown in Table 3. This study was conducted between January and March 1990, which was in the cold winter of Taiwan. Results indicated that even in the cold season, pigs of high density raising group (with 1 m2/pig cement floor) showed significantly adverse outcomes compared with those of litter-bed ones. Therefore, it might imply that litter-bed pig house was also favorable in summer season. However, pig raising density should be reduced in summer regardless of the litter-bed or flat cement floor housing systems due to negative impact of heat and humidity on daily gain and feed intake. Although no significant difference of feed intake and feed conversion rate among groups was found, the consistent trend was found, i.e., less feed waste and better feed conversion rate obtained in the litter-bed group.

Although deworming was performed before and at mid-term of experiment, it was impossible to be parasite-free as shown in Table 3. Litter-bed and high density cement floor groups had higher parasitic infection rate when compared to low density cement floor group pigs with no hazardous events occurring. In general, no significant difference was found when comparison was made between litter-bed and cement floor housing pigs. However, litter-bed housing pigs did show better daily gain than those of cement floor raising pigs in winter. Also, litter-bed raising system did not clean the pig house; pig consumed 4.8% less feed in average per pig, which is equivalent to 11.5 kg less feed wastage. Comparison results on hygiene inspections of carcass and panel test indicated that no significant difference between litter-bed and cement floor pig groups. A bag-type picking appliance was also developed to clear litter and manure mixture from litter-bed, and further extended to field test on farm shown in Figure 3. Meanwhile, field test of Japanese style woody sawdust (left) and TLRI litter-bed (right) pig houses was also conducted in Tainan County’s Mingde prison (Figure 4). Litter-bed group showed higher daily gain, less disease occurrence, higher survival rate.

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Figure 3 Picking appliance for litter and manure mixture in litter-bed pig

house.

Figure 4 Field test of Japanese woody sawdust (left) and TLRI litter-bed

(right) pig house.

Table 1 Comparison between TLRI litter-bed and Japanese woody sawdust pig house in Taiwan

Item TLRI litter-bed pig house Japanese woody sawdust pig houseFloor area 2/3 cement floor + 1/3 litter-bed Paved with woody sawdust Material of litter-bed rice husk or woody sawdust woody sawdust mainly Litter-bed humidity RH <40% RH 60%-70% Inoculum No need Biological agents required Maximum temperature of litter-bed

34 (Room temperature + 2

47Room temperature + 15

NH3 content in air (on litter-bed)

15-20 ppm 15-50 ppm

H2S content in air (on litter-bed)

Non-detectable Non-detectable

Litter-bed cleanup After pigs sold After pigs sold or multi-use Pig house disinfection Disinfection after litter compost

cleanup Disinfection not possible

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Table 2 Effects of TLRI litter-bed pig house on pig production performances

*Litter-bed group

Cement floor **Low-density group ***High-density group

Number of pigs (head) 20 20 20 On-test weight (kg) 38.90 39.50 38.88 Off-test weight (kg) 103.65 99.45 91.69

Averaged daily gain (kg/day) 0.771a 0.714a,b 0.629b Feed intake daily (kg/head) 2.51 2.40 2.19 Feed efficiency 3.25 3.36 3.53 *Raising space: 1 m2 cement floor + 0.5 m2 × 50 cm (depth of litter-bed) per pig **Raising space: 1.5 m2 cement floor per pig ***Raising space: 1 m2 cement floor per pig

Table 3 Parasite infection rate in pig Oundworm Nodular worm Whipworm Coccidia

% *Litter-bed group

Mid-term 100 75 12.5 0 Before sold 75 50 25 0

**Low-density cement floor group

Mid-term 87.5 37.5 12.5 0 Before sold 0 25 0 0

***High density cement floor group

Mid-term 58.3 8.3 16.7 0 Before sold 58.3 41.7 0 0

Note: 1. Number of infected/Number of tested: 8/20 for litter-bed and low-density cement floor groups; 12/23 for high-density cement floor group.

2. *, **, ***: Definition is same as Table 2.

The litter-bed farrowing pen experiment was completed during 1992 to 1995. Survival rate and weight gain were essential for nursing piglets, and thus, the corresponding diary included date and cause(s) of dead piglet for further analysis in addition to daily management. Comparison between TLRI litter-bed and traditional farrowing pens was conducted in Mr. Yang Zhi’s pig farm of Erlun Township, Yunlin County, Taiwan and encouraging results were obtained. Higher piglet survival rate and heavier body weight at 8 weeks age were observed in TLRI litter-bed group than those in traditional farrowing pens. Positive impact of TLRI litter-bed farrowing pen on survival rate of piglet was even more significant for weak piglet(s) at birth. Results obtained

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from experimental farm were consistent with that of field test. The modified traditional high-bed farrowing pen with piglet creep area on both sides was shown in Figure 5. Piglet creep area was modified from the mesh bed to stainless steel bed with 15 cm depth.

Figure 5 (Left) TLRI litter-bed farrowing pen, (Right) Field test of pig house (left: Mr. Z. M. Yang, right: Dr. C. M. Hong).

The TLRI litter-bed pig houses showed exciting results in both experimental and field tests, and also highly recommended and subsidies support by Dr. K. S. Hsu, Chief of Pollution Prevention Division, Council of Agriculture. Unfortunately, it was not in the right timing. Most pig farmers had just completed the three-stage slurry treatment facilities to compliance with environmental standards, thus it was impossible for farmers to abandon these facilities and reconstruct the pig house again. From the TLRI’s standpoint, the research team could not ask farmers to do so, and only some chicken farmers in Erlun Township, Yunlin County, converted chicken coop into TLRI litter-bed style with subsidies from the Grains Foundation. Although there are more than ten years since renovations of chicken coop, no further extension or promotion in litter-bed pig houses was conducted.

In addition, Dr. Hong retired in July 1999. Therefore, in 1997 five obsoleted pig houses of experimental farm in TLRI were planned for miniature litter-bed pig farm with litter-bed facility and 20 to 25 breeding sows capacity. As shown in Figure 6, the management room, rice husk storage room, breeding rooms, and boar pens were on the upper right; the gestation and farrowing pens were on the middle right; the bottom right space

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was for compost storage. The two houses on the left were the growing and finishing pens. The whole complex including wastewater storage tank (on the middle left) was a farrow-to-finish litter-bed design with independent slurry and rainwater ditches. After the wastewater flowed into the storage tank, it was extracted to the compost storage for compost moisture adjustment. The rainwater was directly discharged outside the farm. Due to low roofs of traditional pig houses and 40 cm depth in litter-bed, heat protection facilities were needed in summer. Heat-protecting nets were installed at a little higher position than roof between pig houses, which could prevent from the summer sunlight and lower indoor air temperature (Figure 7). In addition, automatic sprinklers for temperature control were also installed on the roof (Figure 8). The sprinklers could be activated automatically when pre-set temperature reached in the pig houses. Also, ventilators and exhaust fans (Figure 9) are another auxiliary facilities to control the inside temperature of pig house, which could also be activated automatically when necessary.

Figure 6 Schematic diagram of TLRI litter-bed pig house with slurry ditches and rainwater ditch.

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Figure 7 Heat-protecting nets was installed between pig houses to prevent from the

summer sunlight, and maintain cool indoor.

Figure 8 Automatic sprinklers on the roof of pig house.

Figure 9 Automatic ventilators and

exhaust fans inside the pig house.

TLRI litter-bed experimental farm maintained 20 to 25 LY hybrid sows to produce LYD hogs since completion of pig house in 1997. Primary results of 28 litters (March 1997 to July 2000) indicated that litter size born alive, survival rate at 3-week-old and 70-day-old were 9.2 piglets, 97.7% and 96.1%, respectively. Hog reached market weight of 105-112 kg at 198-200 days of age as shown in Table 4. In addition, the aims of annually emissions-free and no malodor could be also achieved.

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Table 4 Growth performances of TLRI litter-bed pig housing LD Hybrid LYD Hybrid Barrow Gilt Barrow Gilt

Weight (kg) At birth 1.9±0.1 (49) 1.8±0.1 (53) 1.7±0.0 (84) 1.6±0.0 (71)3-week-old 5.8±0.1 (49) 5.5±0.1 (52) 5.9±0.1 (81) 5.5±0.1 (71)70-day-age 20.7±0.7(26) 20.1±0.6 (34) 21.0±0.6 (43) 20.2±0.6 (34)150-day-age 82.8±3.0 (10) 80.0±3.1 (9) 80.0±2.0 (20) 78.7±2.1 (16)At sold 104.8±2.3 (27) 102.2±2.6 (22) 112.1±1.9 (41) 105.6±2.1 (34)

Weight gain (kg/day) Birth to 3 weeks of age 0.19±0.01 (49) 0.18±0.01 (52) 0.20±0.00 (81) 0.18±0.00 (71)3 weeks to 70 days of age 0.30±0.01 (26) 0.29±0.01 (34) 0.31±0.01 (43) 0.30±0.01 (34)

70-150 days of age 0.75±0.03 (10) 0.73±0.03 (9) 0.73±0.02 (20) 0.74±0.02 (16)70 days of age to sell 0.71±0.04 (5) 0.71±0.04 (5) 0.68±0.04 (5) 0.71±0.04 (5)

Age at 110 (barrow)/90(gilt) kg (days) 188.2±8.3 (10) 172.7±8.6 (9) 192.0±5.5 (20) 165.9±5.8 (16)Age at sold (days) 197.7±2.5 (27) 198.1±2.8 (22) 199.6±2.0 (41) 197.8±2.2 (34)Value in the parentheses is the number of pigs evaluated. (Shen et al., 2001)

Dr. Hong summarized the comprehensive study results on TLRI litter-bed pig houses as follows: (1) Neither pig house cleaning nor wastewater treatment is needed; annual

water-emissions free can be reached. (2) Feed wastage could be reduced 4.8% or 11.5 kg per growing-finishing pig. (3) No malodor from litter-bed, no need to use biological agents. (4) Pig gain weight is favorable compared to those raised in flat floor house in

winter; there is no high temperature drawback as observed in Japanese woody sawdust pig houses in summer.

(5) Each growing-finishing pig can provide 80 kg of mature compost, with easy transport and fertilizing advantages.

The above mentioned experiments and research processes will not be detailed in this article, and readers can refer to the following articles for further information: Hong, C. M. 1999. Pig excretion, and animal waste processing technology (in Chinese). TLRI Technical Report No. 60. This work was reprinted in 2000, and in 2013 a 3rd Edition was printed again (self-published by Hong C.M.).

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III.Construction and management of TRLI litter-bed pig houses The design of litter-bed pig farms is similar to general commercial farms

with minor change in pig pen as described above. However, it should be paid more attention in litter clean; particularly the water used to clean, rainwater and the overflow from dispensers must be separated, collected and fully utilized. Furthermore, the mechanical operation space for litter-bed clearing and avoiding rainwater entering the pig house should be taken into account. Design for segmented feeding and management are quite similar to conventional pig farm.

1. Segmented management and pen construction Litter-bed pig pens can be simplified to two types: cement floor plus

litter-bed pen for hog (Figure 10) and farrowing/nursing pen for sow and piglet (Figure 11). The former approach is suitable for nursing piglet, growing and finishing pig, boars, pending sows (group raising), and pregnant sows (group raising), with cement floor areas and litter-bed area/depth varied based on corresponding stage.The latter is suited only for the farrowing and nursing stages. Therefore, three segmented sections are recommended for dry sows, farrowing/nursing and hogs, or to further divide the hog section into growing and finishing sections, and thus form four sections. However, the three segmented sections operation is more suited to small scale farm.

Figure 10 Schematic representation of hog (nursing, growing and

finishing) and breeding pig (boar, pending and pregnant sows group raising) pens.

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Figure 11 Schematic representation of farrowing (nursing) pen.

According to the above practices for all stages mentioned and boar pens, the size and depth of litter-bed recommended were shown in Table 5. Rectangular pen with optimum length and width ratio (not too wide) is suitable for pig feeding, exercise, rest and defecation separately. The litter-bed should be slightly higher than the ground; to avoid water logging occurred when rainwater enters the housing. The feeders are in the front; the water dispenser is outside the housing and centered behind the litter-bed, to avoid the retention of overflow water into litter-bed. In addition, the three sides of the cement floor, i.e., the enclosure walls in between the pens and the wall facing the feeders, are favorable to be sealed off. However, fences are preferable for three sides of the litter-bed, i.e., the space in between the pens and the water dispenser side, as they can induce pigs to discharge wastes in the litter-bed. In Taiwan, litter-bed should be located at southward in open pig houses, so it can be kept warm in winter and cool in summer by the wind direction. The roofs of litter-bed pig houses should be elevated by 0.25-0.4 m higher than the average pig houses, because the cement floor of litter-bed pig houses is also higher than average by 0.25-0.4 m. To avoid immersing litter-bed in rainwater, both sides of the litter-bed should have rain sheds. Schematic representation of farrowing pens is shown in Figure 11. The cement floor is paved under the sow stall and long 0.5 m in front of the creep through area at both sides; the rest is litter-bed with 10 cm in depth. In addition, the rear of the sow stall has a 60 cm × 60 cm grid-like cast iron plate cover, so that the sow wastes can flow into the pits.

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Table 5 Cement floor area, litter-bed area and depth of pen recommended for various

stages of pig Pig house for Cement floor area (m2/head) Litter-bed area (m2/head)×depth(m2/head)Boar 7.0~9.0 0.6~0.8×0.4 Sow 2.0~2.4 0.6~0.8×0.4 Growing pig 0.8~1.0 0.3~0.5×0.25 Finishing pig 1.0~1.2 0.5~0.6×0.4 Farrowing sow 4.0~5.3(including litter-bed) 1.7~2.3×0.1(divided into both sides of

creep area)

2. Estimation for number of pig pen for various stages More flexible estimate is applied when the number of pig pens required

in the farms is computed. Using the segmented practices mentioned above to estimate the number of retention days for each stage are shown as follows:

Dry sow stage Dry sow stage refers to sows from weaning to one week before the next

farrowing. The estimated days for sows from weaning to the next estrus is about 21 days, and deducting the 2 weeks of moving into the farrowing/nursing house during pregnancy as 107 days, and accounting 7 days for pig house cleanup and disinfection, the total is 135 days.

Farrowing/nursing stage Farrowing/nursing stage of sow started two weeks prior to farrowing

date expected until weaning piglets. Hence, this stage included the last two weeks of gestation, four weeks of nursing period, one week for pig house cleanup and disinfection, which end up a total of seven weeks. If after weaned, the piglets are reared until 8 weeks of age before moving into the hog housing; this stage accounts for a total of 11 weeks.

Growing stage Growing stage is defined as piglets weaned at 4 weeks of age with 5-6

kg in weight, until reaches 50 kg weight. The estimated averaged daily gain in this stage is 0.45 kg/day; about 100 days are needed, plus seven days for pig house cleanup and disinfection, for a total of 107 days.

Finishing stage This stage started from 50 kg liveweight to 100 kg marketing weight

with 0.55 kg/day estimated averaged daily gain; it requires 91 days and plus seven days for pig house cleanup and disinfection, for a total of 107 days.

Hog stage Refer to piglets from 8 weeks of age with 12-15 kg liveweight until reaches 100

kg marketing weight. The estimated averaged daily gain of this stage is 0.5 kg /

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day, and thus it requires 176 days, plus seven days for housing cleanup and disinfection, for a total of 183 days.

In addition, when estimating the required number of pens, generally an additional 10% increase in number of pens is required. In the meantime, one quarter of sow number should also be added due to annual replacement gilts consideration when estimating the number of sow pens. Based on the above assumptions, the estimated number of pig pens required for three- and four-stage segmented operations are shown in Tables 6 and 7. However, both tables provide only informative information; farmers should adjust appropriately according to their needs. Also, estimates of pens required shown in tables 6 and 7 were obtained for farrow-to-finish farm under assumption as follows: sows farrow 2 litters annually, with an average of 10 piglets weaned per litter, dry sows in raising group of 4-5 individuals per pen, growing pigs in 20-30 pigs per pen, finishing pigs in 20-30 pigs per pen, and hogs in 20-30 pigs per pen.

Table 6 Number of pens required for three-stage segmented pig farm

Number of sows * Dry sow pen ** Farrowing/nursing pen *** Hog pen Head ��������������Pen����������������

10 2.2 3.8 4.4 20 4.4 7.5 8.8 30 6.5 11.3 13.2 40 8.7 15.0 17.7 50 10.9 18.8 22.1 60 13.1 22.5 26.5 70 15.3 26.3 30.9 80 17.4 30.1 35.3 90 19.6 33.8 39.7

100 21.8 37.6 44.1

*Dry sow, pen = [(Number of sows, head)/(5, head/group)] x [(Dry sow stage, day)/( Dry sow stage, day + Farrowing/nursing stage, day) x 1.1 ] + [(Number of sows, head)/(5, head/group)] x 2.5

**Farrowing/nursing stage, pen = (Number of sows, head) x [(Farrowing/nursing stage, day)/(Farrowing/nursing stage, day + Dry sow stage, day) x 1.1]

***Hog pen, pen = (Number of sows, head) x (2 litter/year) x (10 head/litter) x (Hog stage, day/365,day) (1/25 head/group) x 1.1

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Table 7 Number of pens required for three-stage segmented pig farm Number of sows *Dry sow pen *Farrowing/nursing

pen **Growing pig

pen ***Finishing pig

pen Head �����������������Pen �������������������

10 2.2 3.8 2.6 2.4 20 4.4 7.5 5.2 4.7 30 6.5 11.3 7.7 7.1 40 8.7 15.0 10.3 9.5 50 10.9 18.8 12.9 11.8 60 13.1 22.5 15.5 14.2 70 15.3 26.3 18.1 16.5 80 17.4 30.1 20.6 18.9 90 19.6 33.8 23.2 21.3 100 21.8 37.6 25.8 23.6

* Same as Table 6 **Growing pig pen, pen = (Number of sows, head) x (2 litter/year) x (10 head/litter) x

(Growing period, day/365,day) (1/25 head/group) x 1.1 ***Finishing pig pen, pen = (Number of sows, head) x (2 litter/year) x (10 head/litter) x

(Growing period, day/365,day) (1/25 head/group) x 1.1

3. Reconstruction of existing pig house

Reconstructing conventional pig house to litter-bed style are shown in Figure 12 for reference. The key point is to convert existing one as much as possible into an ideal litter-bed pig pen for more efficient management including less labor required. For example, with most pigs gathered to defecate on the litter-bed could reduce cleaning time and loading; the depth of litter-bed is less than 40 cm, the frequency of cleanup for un-composting litter would be increased.

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Figure 12 Schematic representation of reconstruction existing pig houses into litter-bed facitlity.

4. Daily management of pig

Daily clean is not necessary for litter-bed pig house. The litter and manure mixture should be all cleared at once after pigs are moved out and then disinfected before a new batch is moved in. For daily management, if the cement floor is contaminated with too much slurry, the workers need only to scatter the litter from the litter bed on the manure, and then sweep it all into the litter-bed. However, the most essential is to keep litter-bed dry daily. The manure and bedding mixture will not be fermented easily and thus neither heat nor malodor will be generated when < 40% moisture of litter-bed was maintained. Hence, the litter should not be fully filled at once, but should be added progressively, depending on the humidity of litter-bed. When piglets moved from farrowing pens to the growing and finishing pens, there must prepare wide 30cm high litter-bed available through the drinking water area.

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The main purpose was to train all the piglets can drink the water, even forced them into the drinking area. This is very important and can not be ignored absolutely, please keep that in mind when you're trying to move the piglets into the new house.In addition, the manure produced by sows in the farrowing/nursing pens must be cleaned daily, and moved to the compost house for compost manufacture.

In addition to pig manure fully converting to compost for agriculture usage, the feeding and management of pigs raised in litter-bed houses is similar to that of pigs raised in traditional flat floor or high-bed houses. Therefore, it is absolutely prohibited to add copper salts or any heavy metal in the feed to avoid the contaminated compost produced, and thus cause secondary pollution. Although there have not been cases of parasitic infestation occurred in litter-bed pig houses, deworming should still be the focal point in litter-bed pig housing system, and it is recommended to implement deworming program as shown in Figure 13. Also, for daily care it is absolutely prohibited to use water to wash pigs, especially in summer. Some farmer removed the litter from the litter-bed, and converting it into the so-called "immersion-type pig house"; the only problem was that the corresponding farm did not possess slurry treatment facilities, so the whole farm was malodorous. To rationalize fraud, farmer claimed to be a litter-bed farm and deceived inspectors of Environmental agencies, and "timely" covertly discharge wastewater from the farm. To solve Taiwan’s hot summer problem, spray atomized water inside the pig houses in coordination with ventilating modes, and other alternatives as shown in Figures 7, 8 and 9, should be able to mitigate the impact of high temperature problems.

Figure 13 Deworming program.

19

5. Cleanup of litter/manure mixture

Although artificial arm had been used to pick up the litter and slurry mixture in the litter-bed houses, manual cleanup is still the choice to clean the litter/manure mixture from the farrowing/nursing pen. However, it is worth of further development. Mechanical auxiliary cleanup facilities for the litter/manure mixture of boar, sow, growing, finishing, and hog pens should be also considered, such as shovel loaders, and pickup machine developed by National Chung Hsing University in collaboration with TLRI (Figure 3). Furthermore, the mechanical auxiliary cleanup appliance required sufficient space for operation, which should be taken into account by construction of pig house. Denmark style and roll-forward type are commonly converted into litter-bed (Figures 14 and 15) pig houses. When clearing the litter/manure mixture from the former, the entire row of pig pens must be cleared at the same time, the litter-bed’s length must be considered so that the width can provide easy access for machine operation. The pig pens’ rear end of the latter must have enough space for mechanical operations. The advantage of roll-forward type is easy to clean up the mixture from the litter-bed of individual pen as long as pushing the rear fence of pen inward, but its construction costs are slightly higher.

Figure 14 Litter-bed cleanup design modified from Danish style pig house.

Left: ordinary day, Right: litter-bed mixture clearing.

20

Figure 15 Litter-bed pig house with un-composting compost cleanup

facility (roll-forward type). ( indicates a rolled canvas rainshed near the litter-bed and under the eaves)

Results of litter and manure mixture fermentation experiment indicated that 40-50 kg rice husk was used in litter-bed for hogs during growing-finishing period (weighing 15-100 kg) and 220 kg un-composting compost with 66% moisture content was produced per pig (Hong et al., 1990). The further composting process required 5-6 weeks by bagged fermentation process or 3-4weeks by aerobic fermentation, which could produce about 80 kg mature compost per pig with 30% moisture content.

6. Composting of litter/manure mixture The composting fermentation is the only choice for un-compost manure

of litter-bed pig house. The size of composting storage varies on fermentation method, fertilized crops and seasons with estimates of 0.02 m2 fermentation space (1.8 m effective height in composting storage). Regarding the composting facilities for pig slurry and litter, the existing facilities could be utilized without modification, and the moisture adjustment or dehydration stage could be also excluded. The moisture content of the litter/manure mixture in the litter-bed is usually maintained below 40%; to keep the moisture content of compost at about 65%, and thus the dehydration stage could be also bypassed after clearing the litter-bed house. After composting, the mature compost could be sieved for coarse particles and recycled as litter in the litter-bed, and fertilize fine compost particles in the field directly. However, all the compost to the field is another choice. Coarse compost particles along with leaves, leaves, hay, rice husks, and even soil could be recycling in litter-bed pig house.

21

Heaping fermentation

Heaping fermentation can be classified as static heaping and mechanical agitation heaping (Figure 16). Mechanical agitation heaping is further divided into open and closed type. Static heaping is the most commonly used in Taiwan, which uses shovel loaders for compost turning and includes open and boxed styles with and without ventilation function. Boxed heaping can also be covered by canvas to extract the odors from composting tank through a deodorizing tank for deodorization. There is also the bagged method. Open-style mechanical agitation fermentation commonly uses rail type along cranes. The fermentation tank with or without ventilation has several models, including round, oval, straight reciprocating type etc., in coordination with the rotary or ladle agitator. In addition, some uses moving-type compost turning machines. The closed-type fermentation tank can be divided into horizontal and vertical styles, with internal agitator machine and aeration devices. Open-type composting site with completely closed storage space can also be called closed-type. Generally speaking, static heaping required less investment and longer processing period with lump shape finished compost and more variable in quality; while mechanically agitated heaping needs higher facility investment and management costs, but shorter treatment period and more uniform quality of finished compost product would be the feedback.

Composting methods and the characteristics of facilities were outlined in Table 8 for farmers’ reference. However, the static heaping is commonly adapted in Taiwan and the mechanical agitation heaping system is more suitable for large-scale farms.

22

Tabl

e 8

Cha

ract

eris

tics o

f com

post

ing

met

hod

Trea

tmen

t fa

cilit

y

Faci

lity

char

acte

ristic

s In

vest

men

ttSc

ale

Sola

r pow

er

Elim

inat

ing

mal

odor

La

bor

need

ed

Faci

lity

area

Man

agem

ent c

ostT

reat

men

t tim

eLa

rge/

med

ium

Smal

l

Stat

ic h

eapi

ng

Bag

ged

Diff

icul

t D

iffic

ult

Littl

e M

ediu

m

Low

Lo

ng

Littl

e

B

oxed

Ye

s Ye

s M

ediu

m

Med

ium

Lo

w

Med

ium

Li

ttle

Hea

ped

Yes

Diff

icul

t H

eavy

La

rge

Low

Lo

ng

Littl

e

M

echa

nica

l agi

tatio

n ot

atin

g Ye

s Ye

s Li

ttle

Med

ium

H

igh

Shor

t M

ediu

m

Ladl

e Ye

s Ye

s Li

ttle

Med

ium

H

igh

Shor

t M

ediu

m

Mov

ing

Yes

Diff

icul

t M

ediu

m

Larg

e H

igh

Shor

t M

ediu

m

Clo

sed

Diff

icul

t Ye

s Li

ttle

Smal

l H

igh

Shor

t H

igh

Seal

ed

Yes

Diff

icul

t Li

ttle

Med

ium

H

igh

Shor

t H

igh

23

Open fermentation tank

Boxed fermentationtank

Boxed fermentation tank covered with canvas

Bagged compost

Rotary fermentation tank

Ladle fermentation tank

Moving-type compost turner

Vertical hermetic fermentation tank

Figure 16 Composting method for livestock manure.

24

Deodorizing facility of composting house

Various malodorous components are produced, such as ammonia (NH3), trimethylamine ((CH3)3N), methyl mercaptan (CH3SH), and hydrogen sulfide (H2S) etc. at the beginning 3-5 days of composting process. These malodorous components are harmful to human and animals, and may result in respiratory disorder, suffocation, and poisoning etc. if high concentration occurs. The Air Pollution Control Act and the Occupational Safety and Health Act, with provisions regarding air pollution emission standards and standard allowable concentration of harmful substances in the air of the environment are set to protect workers’ safety and health and to prevent occupational accidents. Many deodorizing methods can be the option.

Currently the most commonly used in Taiwan is the sawdust deodorization protocol recommended by the TLRI. The advantages of this protocol include easy and convenient to set up, material acquisition and handy operation, high deodorizing efficiency, and recycling. The protocol is described as follow, to provide a reference to the industry.

The principle of sawdust deodorizing is to pump the malodorous components through sawdust layer, which absorbs the components and dissolves them in water, practically removing them. Wet sawdust showed better absorption efficient than that of dry one, so the sawdust in the deodorization tank should be sprayed with water to maintain proper humidity for efficient absorption.

Generally a hermetic fermentation tank is used for deodorizing, but closed fermentation tank is expensive. Therefore, an alternative is to seal the fermentation tank using plastic sheets, and install suction blower at only one end for malodor extraction, and then deliver it into the deodorizing tank as shown in Figure 17. It should be noted that no compost house (site) could be closed to avoid insufficient pumping and ventilation occurred, which would be detrimental to working environment. When the exhaust blower with turbo fan start, the static pressure is set at 320 mm Aq and 1 m3 exhaust volume per minute benchmark, in coordination with 1.7 m2 area of deodorizing tank, namely 10 m3 of air volume requires 17 m2 area of deodorizing tank. The static pressure recommended for various materials are shown in Table 9.

The deodorizing tank (Figures 18 and 19) includes tank wall, malodor pumping pipeline, gravel, nylon mesh, and woody sawdust; the bottom of tank is paved and elevated with gravel covered by nylon mesh, and the malodor pumping pipeline is installed. The gravel should be covered by fine woody sawdust for one meter height, and 35-50% moisture content of sawdust is required to maintain satisfied deodorization.

25

The speed of the ammonia from compost site through the sawdust layer is 10 mm/sec. After 100 seconds retention with woody sawdust in the deodorizing tank, only 1 ppm ammonia content remains, which accounts for about 92-100% deodorization efficiency. When the woody sawdust is saturated with malodor absorption, the deodorizing efficiency will decrease rapidly, and new woody sawdust must be replaced. The sawdust’s shelf life (days) could be detected by whether the sawdust surface of deodorizing tank releases malodors or not. The deodorizing efficiency comparison between woody sawdust and soil deodorizing tanks is shown in Table 10.

Table 9 The static pressure recommended for various materials

Method Heaping height (m) Static pressure (mm Aq) Heaping deodorizing tank 1.0 210 Soil deodorizing tank 0.5 110 Rockwool deodorizing tank 2.5 300 Woody sawdust deodorizing tank 1.0 200 *Source: Hong, C. M. 2013. Pig farming excretion, waste resources processing technology.

3rd Ed., P.140.

Figure 17 Schematic representation of heaping deodorizing tank.

26

Figure 18 Woody sawdust deodorizing tank.

Fig. 19 Soil deodorizing tank.

Figure 20 Woody sawdust and soil deodorizing tanks in field test.

27

Tabl

e 10

D

eodo

rizin

g ef

ficie

ncy

of sa

wdu

st a

nd so

il de

odor

izin

g ta

nks

Mal

odor

com

pone

nt

Woo

dy sa

wdu

st d

eodo

rizat

ion

So

il de

odor

izat

ion

Conc

entra

tion

befo

re

deod

oriz

ing

Conc

entra

tion

afte

r de

odor

izin

g

Deo

doriz

ing

effic

ienc

y

Conc

entra

tion

befo

re

deod

oriz

ing

Conc

entra

tion

afte

r de

odor

izin

g

Deo

doriz

ing

effic

ienc

y

pp

m

%

pp

m

%

Am

mon

ia (N

H3)

20~2

00

0 10

0

20~3

60

0 10

0 Tr

imet

hyla

min

e ((

CH

3) 3N

) 16

~200

0

100

8~

180

0 10

0 H

ydro

gen

sulfi

de (H

2S)

*

*

M

ethy

l mer

capt

an (C

H3S

H)

*

*

*Con

cent

ratio

n is

less

than

0.1

ppm

is u

ndet

ecta

ble.

So

urce

: Lin

, T. W

. 199

3. In

stal

latio

n of

deo

doriz

ing

cham

ber a

nd th

e ef

ficie

ncy

of o

dor r

emov

al in

man

ure

com

post

ing.

Tai

wan

Liv

est.

Res

. 26

:7-1

6.

28

IV. Collection and recycling of wastewater in pig farms

Experimental and field results of TLRI litter-bed pig house facilities can indeed save water resources, but it is not enough. The capability of cherishing water resources should have been the one of characteristics for modern farmers. There are almost no pig farms that have taken into account how to collect, store and reuse rainwater. The main reason might be due to cheap water cost and no severe water shortages occurred in Taiwan. However, one should not be too optimistic when is faced with the finite and irreplaceable water resources. Farmers could construct the rainwater storage tanks at the lowest recess of pig farm with the size depending on operation model (e.g., with or without crop grown or fishery pond etc.), available land, and the scale of farm. Also, professionals should be definitely included in the construction for the decision of the rainwater cisterns’ size and depth. For the construction of storage cisterns, Dr. Hong recommended the red mud plastic (RMP) facility due to the significant advantages in cost-saving, durability, and watertight. Furthermore, rainwater, swine slurry, water for clean, overflow from water dispensers, and wastewater after treatment should be absolutely separated on the farm, and cannot be combined use. Also, the stored rainwater can also use for washing pig houses, or even as drinking water for pig, in addition to coordinating with the operation model in animal farming or fisheries.

Dr. Hong reported that in Taiwan the daily water intake with body weight 20-100 kg was 5.1-7.0 L/head in average, and the overflow quantity of water dispenser was 6.2-6.5 L/head, regardless of the pig’s weight. It was obvious that there was a great quantity of overflow from the water dispensers. Therefore, the modification of water dispenser should have been made to recycle the overflow water and installed as shown in Figure 21. In addition, Dr. Hong further developed and patented recycling water dispenser for livestock farm in 1993, which was shown in Figure 22 with its schematic representation in the upper right, the top-down view in the left, the side view in the bottom right. It could be seen from the schematic representation that a water level control pipe in the right side of device was designed to maintain water in the dispenser’s bowl at a constant level; overflow water could be recycled by the control pipe.

29

Estimate of daily overflow per pig regardless of body weight is 6.2-6.5 L. Hence, there was about 23 million m3 overflowed water annually based on ten million heads of hog production in Taiwan at the time, which was equivalent to the available water capacity of the Baihe Reservoir (14.41 million m3) + Kukuan Dam (7 million m3). The recycling water dispenser for livestock was developed in 1993 without field promotion. Therefore, if there is any farmer interested in effectiveness of the device, Dr. Hong is willing to provide technical support with free of charge.

Figure 21 Overflow

recycling device for water dispenser.

Figure 22 Recycling water dispenser for livestock.

After pigs removed out and the litter/manure mixture cleaned up, the pig house still needs to be cleaned; the quantity of cleaning water required is not much, which can be stored separately as adjustment water for composting of litter and manure due to insufficient moisture content of un-compost litter/manure (adjust from <40% to about 65%). However, it can also be supplemented by rainwater or from the water dispenser overflow.

30

V. Anaerobic or incineration treatment of pig carcass and sow’s postpartum disorders

Pig carcasses are currently collected and processed by professional factories, but in the long run, if dead pig with or without suffered from disease(s), postpartum disorders and stillbirth are not allowed to removed out from the farm, which would be benefit not only to disease control but also food safety for human. Taiwan is the global leader in animal carcasses processing technology, and the development of the anaerobic fermentation tank for animal carcass is unique in the world. In coordinated with the application of Horizontal type anaerobic digester facility (Figure 23), research team of TLRI should be proud of the patented device and its field promotion, as well as the application in the industry by technology transfer. Therefore, litter-bed facility coordinate with a simple horizontal type anaerobic digester and carcass anaerobic treatment installation, can fully deal with carcasses and problems resulted from sow’s postpartum disorders on-farm. Furthermore, during 1990 to 1995, TLRI has also promoted the biogas production technology by anaerobic fermentation to Taiwan pig farmers (Figure 24). Therefore, farmers can setup incinerators, and use the biogas generated from incinerating dead pig, and excess biogas can be also for flamethrower to disinfect the cleaned up pig houses or as biogas heating lamps for piglets; and thus become exemplary green farms. Regarding the required volume of above anaerobic fermentation tank facilities (including biogas storage tank) and animal carcasses anaerobic treatment and the information about biogas incinerators, biogas flamethrowers and biogas heating lamps etc., will not be described in this bulletin. For more detail information, please refer to the book entitled in "Pig farming excretion, waste resources processing technology (3rd ed.)".

31

Figure 23 Anaerobic fermentation of animal carcass - sow afterbirth, dead piglets and dead chicken. (Front: anaerobic digester for carcasses; Rear: anaerobic digester)

Figure 24 Applications of biogas developed in Taiwan.

32

VI. Conclusions This bulletin mainly presents the research results of TLRI litter-bed pig

house, the construction and management of the pig housings, the efficient use of water resources in farms, and facilities that modern green pig farms should have been implemented. When compared with existing flat floor pig houses and the three, four-stage slurry treatment facilities in Taiwan, it indeed significantly reduced production costs and enhanced the competitiveness of pig industry. Although the TLRI litter-bed pig house was born ahead of its time, and was greatly misunderstood and unappreciated, its potential for solving the water shortage problem can still be expected in the future.

Although Dr. Hong believes that TLRI litter-bed pig houses are absolutely suitable for pig farmers in Taiwan, and should become the trend of the pig industry globally, it is not appropriate to copy overall by farmers without consideration of individual variation among operation model of farms. Therefore, so called "paradigm" is redundant for senior expert like Dr. Hong. In retrospect of history of pig farming, the evolution of pig house begins with scattered grazing-type (Figure 25) to intensive-fastening module (Figure 26), and then the so-called natural farming which takes into account animal welfare both in Taiwan and globally. As pointed by Dr. Hong, pig farmer can take the TLRI litter-bed pig house as base, except farrowing and nursing stage, with construction adjusted for individual farm’s needs, and the concept of animal welfare, and thus fit the global trend of the future. In addition, the roof of pig barn mounted with solar panels to generate electricity, not only can increase energy conversion, and pigs under the roof can also reduce the summer heat stress in Taiwan, is a win-win strategy, should be the trend in the future. All the related experts were suggested to take it into account.

Figure 25 Grazing type raising for sow herd of TRLI in the 1960s.

33

Fastening pigs under the tree: taken on 1975/05/01 at Hsiao Liuchiu, Pingtung County, Taiwan.

Japan: Battary style pig house

Fastening style raising Bacon Bin produced by Black, Sivalls & Bryson Inc., USA

A fastening type farrowing crate Fastening type farrowing carate made by Yong-Fu Factory, Tainan, Taiwan.

Figure 26 Fastening type pig house (Source: Hong, C. M. 1975. Research on fastening type pig house. Taiwan Livest. Res. 8:63-75 )

Legend: In 1970s, the “ideal pig house” pursued was: to increase space utilization efficiency for land saving, and thus cost-saving for pig house building as well as for coordinating manure cleanup. Finally the animal life support system can be reached.