Management Effects on Group Sow Housing

Canadian researchers have learned that the productivity in electronic sow feeding (ESF) systems is comparable to sows housed in stalls, provided proper management practices are followed.

Dynamic groups that did not add or subtract animals more often than every five weeks did not affect sow productivity.

Sow productivity equal to stalls can be obtained in an ESF system, but only if animals were past embryo implantation when the group was formed.

In the study at the Prairie Swine Centre Elstow Research Farm, over 800 breedings were compared, with females ranging in age from gilts to Parity 5. New animals were added each reproductive cycle.

Within the ESF systems, small groups of about 35 sows were all added to the pen at the same time (static) vs. larger, dynamic groups of 120 sows, where about 35 sows were removed for farrowing and others added at five-week intervals, and not added weekly as in several other studies.

Researchers also considered two stages of gestation at which to place the animals. Animals were either moved to the ESF 8-10 days post-breeding, or approximately 45 days post-breeding, by which time embryonic implantation should have occurred.

Data was also maintained for sows housed in stalls for their entire gestation period.

Farrowing rate measured combined farrowing rate and litter size (Table 1). Females were classified by parity as gilts, first, second and mature, and included calculation of an adjusted performance assuming a standard distribution of ages in each system.

The farrowing rate of the animals differed with parity, lowest for gilts and not different among the older animals. This difference is common in commercial herds, but was more pronounced in the ESF system. Once gilts were housed individually, the difference was eliminated. There were no differences between the static and dynamic groups for farrowing rate.

Litter size was smaller for gilts than for other parities. The total number of live piglets per 100 sows bred was higher for the post-implant group than for the pre-implant treatment, with stalled animals in the intermediate group.

Researchers: H.W. Gonyou, Y. Z. Li and M.L. Strawford, all of the Prairie Swine Centre. Contact Ken Engele, assistant manager, Information Services, by phone (306) 373-9922, fax (306) 955-2510 or e-mail

Table 1. Farrowing Rate of Gilts and Sows in Stalls and Various Management Programs within an Electronic Sow Feeder System1
Pre-Implant Post-Implant
Stalls Static Dynamic Static Dynamic
Gilt 793 678 681 734 763
1st Parity 898 874 865 929 910
2nd Parity 922 879 956 896 1,008
Mature 948 896 896 982 980
Adjusted2 895 834 845 894 917
Adjusted Sows3 929 886 898 948 968
1Results of five reproductive cycles with new gilts added each cycle.
2Based on a theoretical herd demographic of 25% gilts, 20% 1st parity, 18% 2nd parity and 37% mature(approximates a 15% culling rate per cycle to a maximum sixth parity).
3Based on a theoretical sow herd run without gilts, as we have done for three cycles, with 27% 1st parity, 23%2nd parity and 50% mature (approximates a 15% culling rate to a maximum of six parities).

Curing Water Wastage In Postweaning Pigs

It is often thought that pigs at weaning are substituting water for feed consumption, resulting in a temporary weight loss, as they adapt to eating solid food.

But researchers at Agriculture and Agri-Food Canada have discovered that most water usage after weaning is actually water wastage.

They also found that the use of a push-lever bowl drinker reduces water wastage without hurting water and feed intake or affecting piglet behavior.

Compared to the standard nipple drinker, the push-lever bowl drinker reduces daily water wastage per pig by more than 27 fluid oz. through two weeks after weaning (Table 1). Based on 15 pigs/drinker device, changing one nipple drinker to a push-lever bowl drinker can reduce water loss by about 1,300 gal./year.

Using drinker devices other than the standard nipple drinker may ease piglets' transition to solid food and prevent the development of behavior problems such as excessive water intake and belly nosing.

In the experiment, researchers examined the effect of drinker type on water and food intake, growth rate and belly-nosing behavior in the newly weaned piglet.

Eighteen pens of 15 piglets each (270 piglets) were weaned at about 18 days of age and housed in pens containing a standard nipple, push-lever bowl or a float bowl water source. Performance was monitored by pen through two weeks after weaning. Piglets with the nipple drinker wasted much more water than other piglets, while piglets on the float bowl consumed much less water.

Drinker type also greatly affected feeding behavior; piglets with the push-lever bowl spent less time at the feeder than other piglets, although there was no difference in feed intake or overall average daily gain.

Piglets with the push-lever bowl also tended to belly nose and perform other nosing behaviors less than piglets with the float bowl.

These results indicate that piglets use more water during the first two days after weaning, but much of that water is wasted rather than satiating needs.

Excessive drinking and water wastage can be solved through the use of push-lever drinkers without negative effects on feed intake and growth rates.

Researcher: Stephanie Torrey, Agriculture and Agri-Food Canada, Dairy & Swine Research & Development Centre, Sherbrooke, Quebec, Canada; and Tina Widowski, University of Guelph, Guelph, Ontario, Canada. Contact Torrey by phone (819) 565-9174, ext. 129, by fax (819) 565-5507 or e-mail

Table 1. Overall Water Consumed, Wasted and Used at the Three Drinker Devices
Drinker type Water (ml/pig/d) Water wasted, %
Consumed Wasted Used
Float 475 295 770 38.3
Nipple 870 1,114 1,981 56.1
Push-lever 774 186 960 19.3

‘Pig-Friendly’ Loading Chute Minimizes Loading Stressors

Pigs marketed on a prototype loading gantry were exposed to fewer stressors, including electric prods and incidence of slips, falls, vocalizations and piling.

Pig mortalities from farm to harvest are estimated to cost the U.S. swine industry over $55 million annually. Switching from a traditional loading chute to a loading gantry will help limit those losses.

Data was collected on 74 semi-loads of crossbred finisher pigs from a single commercial finishing site in Missouri from November 2006 to August 2007.

Two loading protocols were compared in two experiments by a team of Iowa State University (ISU) scientists. The first experiment (44 semi-loads) compared two loading tools on the first pigs (first pull or FP, Table 1) marketed from the finishing facility. The second experiment (30 semi-loads) compared two loading tools on closeout pull (CO, Table 2) or last pigs marketed from the finishing facility.

The first loading tool design (T) was a traditional, metal-covered chute, which was 30.5 in. wide, 7.6 ft. high and 15 ft. long. The T chute featured a flat pivot section on each end to accommodate the angle that the truck backs into the chute, and allowed loading two pigs onto the truck at the same time. The ramp angle to load pigs onto the truck was 19 degrees to the bottom deck; the internal ramp angle was raised 23 degrees for finisher pigs to access the upper trailer deck.

The second design (P) was a prototype-loading gantry, aluminum-covered chute. The chute was 36.56 in. wide, 10 ft. high and 29.7 ft. long. Flooring was Vanberg epoxy-coated metal (feels like concrete), with an inverted stair-step design with 1-in.-high cleats spaced 8 in. apart.

The prototype loading gantry allowed two pigs to climb onto the truck at the same time from a flat plane. The ramp incline was 7 degrees to the truck's bottom deck and 18 degrees to the upper deck.

The second chute features a special lighting design that minimizes shadows. A bumper dock system features a self-extending system that elimantes gaps at the barn and trailer. An electric jack screw system mechanically moves and operates the chute into position as well.

Pigs were loaded using the National Pork Board's Swine Welfare Assurance Program and the American Meat Institute's Animal Handling Audit. Those assessments included facility evaluation, proper loading and transportation procedures, and evaluation of welfare parameters as hogs are loaded onto the trailer.

Researchers found the loading tool does appear to play an integral role in the welfare parameters of pigs at the time of marketing, favoring the P chute, and having a positive influence in stress reduction at the time of load out, regardless of pull at marketing.

Although not addressed statistically, it appears that pigs loaded during the closeout period experienced more prods, slips, falls, vocalizations and pileups when compared to those pigs marketed first.

Researchers: Nick Berry; Anna Johnson; Tom Baas; Ken Stalder; and Locke Karriker, DVM, Iowa State University; and Jeff Hill of Premium Standard Farms, Milan, MO. Contact Johnson by phone (515) 294-2098, fax (515) 294-4471 or e-mail

Table 1. First Pull (FP) Welfare Parameters
Chute Typea
Itemb T P
Electric prods 161.59 96.25
Slips 247.91 96.02
Falls 100.42 20.18
Vocalizations 138.06 69.08
Pileups 3.59 0.01
aT = Traditional chute; P = Prototype loading gantry;
bElectric prods = any time the prod touched any portion of the pig's anatomy; Slips = any time the pig's foot lost contact with the ground in a non-walking manner; Falls = any time a pig lost contact with the ground and a non-limbic portion of the animal touched the ground; Pileups = any time two or more of the pig's feet lost contact with the ground and were on top of another animal.
Table 2. Closeout Pull (CO) Welfare Parameters
Chute Typea
Itemb T P
Electric prods 188.23 108.12
Slips 302.48 106.02
Falls 115.37 24.75
Vocalizations 140.44 79.21
Pileups 4.63 0.10
aT = Traditional chute; P = Prototype loading gantry;
bElectric prods = any time the prod touched any portion of the pig's anatomy; Slips = any time the pig's foot lost contact with the ground in a non-walking manner; Falls = any time a pig lost contact with the ground and a non-limbic portion of the animal touched the ground; Pileups = any time two or more of the pig's feet lost contact with the ground and were on top of another animal.

Electric Prod Use Can Be Costly

Research at Canada's Prairie Swine Centre (PSC) confirms that use of an electric prod to move market hogs elevates stress levels in the animals vs. other means of handling.

A total of 192 hogs near market weight were walked from their finishing pens in groups of six, through a 984-ft.-long handling course that included numerous turns, curves, reversals and partially obstructed alleys.

The course took an average of 10 minutes to complete. Three handling regimens were imposed on the animals.

Hogs in the gentle treatment group were moved with a herding board, quiet voice and gentle slaps at a comfortable walking pace. These hogs were essentially unstressed by the procedure (Table 1).

Hogs in the second group were handled aggressively, at a fast pace, with shouting and slapping, but without use of an electric prod. These animals showed a higher incidence of stress, but none showed extremes that might lead to animal losses.

For the third group, pigs were moved at a fast pace, a louder voice and use of slapping or an electric prod. The use of the electric prod resulted in more than 40% of the pigs showing behavioral and physiological signs of stress, with 4% to the extreme point of stumbling and falling.

“Losses resulting from aggressively handled pigs can approach 4% in a commercial swine operation,” says PSC researcher Harold Gonyou. “For a 600-sow, farrow-to-finish operation marketing 14,000 hogs/year, assuming a 2% loss due to aggressive handling, this would represent lost revenue on 280 market hogs, or approximately $37,000 for that operation.”

In the trials, pigs that were highly stressed had higher temperatures, lower blood pH and higher blood ammonia levels than did pigs with no outward signs of stress.

“Clearly, we should be minimizing the use of the electric prod when handling animals,” points out Gonyou. “Before prodding a pig while it is being loaded, the handler should consider if another means of encouraging movement could be effective, even if it took slightly longer. If one pig is repeatedly being difficult to move, it should be left behind and perhaps herded separately rather than prodding it again.

“If producers find that they must use the electric prod frequently during the load out process, they should consider changes to their load out design and/or handling techniques.”

Researcher: Harold Gonyou, Prairie Swine Centre, Saskatoon, Saskatchewan. Contact Gonyou by phone (306) 373-9922, fax (306) 955-2510 or e-mail Kenneth Engele, assistant manager, Information Services, PSC, at

Table 1. The Incidence of Highly Stressed Pigs in Three Different Handling Treatments
Gentle No-Prod Prodded
No signs of stress 47 41 54
Highly stressed but not falling 1 7 23
Highly stressed and falling 0 0 9
Total number of pigs 48 48 96
Handling time in course (sec.) 701 467 467