Early Weaned Pigs Prefer Change in Temperature

Early weaned pigs, like nursery and grower pigs in past experiments, show a preference for warmer temperature settings during the day, cooler settings at night.

Data compiled by researchers Clover Bench and Harold Gonyou, Prairie Swine Center, Saskatoon, Saskatechewan, shows young nursery pigs did not prefer a consistent thermal environment, when given a choice.

Instead, temperature settings for the nursery should be based on size and age of the piglets and the time of day, researchers say. In doing so, producers will find more fuel-efficient and animal-welfare friendly ways of managing the thermal environment of the early weaned piglet.

Temperature preference was studied in early weaned pigs at 12-14 days of age in five consecutive trials during the winter of 2000, and measured over space and time. Each test involved a single nursery room of six pens with eight pigs per pen, and used an infrared heat lamp as a heat reward. One pen controlled the gas heater in the nursery room, using a box with an operating (O) and non-operating (NO1) lever. The infrared heat lamp was positioned over the O lever. A second pen was also equipped with a box mounted with an NO2 lever.

Temperature data was collected every five minutes using thermocouples, which were positioned throughout the room and connected to a data logger. All hits to the O, NO1 and NO2 levers were recorded as they occurred using the data logger.

The early weaned piglets demonstrated temperature preferences. As age increased, average temperatures chosen declined by about 1°F/week.

Average temperature preferences were 79.4°F, 78.3°F and 77.4°F for Days 3-5, 10-12 and 17-19 postweaning, respectively, during the 21-day trial (Figures 1, 2). (This requires Adobe Acrobat Reader, download at: www.adobe.com.)

While the average maximum temperature stayed nearly constant throughout each week of the trial (Figure 1), the average minimum temperature was highest three to five days postweaning. The average minimum temperature kept nearly constant at about 72-73°F. And thermal preferences consistently ranged between 72-84°F.

The overall pattern showed that early weaned piglets preferred the highest temperatures during the day and the lowest readings at night (Figure 2).

Researchers: Clover Bench and Harold Gonyou, Prairie Swine Center. Phone Bench at (306) 373-9922; fax (306) 955-2510; or email bench@sask.usask.ca.

Disease Prevalence Exceeds Expectations

A random sampling of 100 pig farms in Ontario has revealed that some swine diseases are more commonly found in the Canadian province than were expected.

Surveys were conducted in the summers of 2001 and 2002. Blood samples were collected from sows and finisher hogs; manure samples were also taken from finishers. The University of Guelph is carrying out the project; results are still being analyzed.

Pigs were tested for pathogens of food safety concern, including salmonella, E. coli 0157:H7 and Yersinia enterocolitica. Other diseases of public health concern being investigated are swine influenza virus (SIV), giardiasis and toxoplasmosis.

Production issues, reproductive and grow-finish performance, and the prevalence of swine respiratory diseases and porcine proliferative enteritis (ileitis) are also being studied.

Overall, the study found the prevalence of swine pathogens to be surprisingly high. The researchers theorized that this was due to the pathogens' subclinical nature and the difficulty in identifying them. Development of rapid and sensitive tests is resolving those concerns.

For instance, antibodies to SIV (H 1 N 1 subtype), thought to be of limited prevalence, have been detected on 80% of Ontario farms, including high-health herds using strict biosecurity procedures.

Researchers looked at Toxoplasma gondii, a parasite found in pigs that can cause toxoplasmosis in humans and encephalitis in immune-compromised patients. The main source of pig infection is from exposure to cats.

About one-third of participants in the study allowed cats into the pig barn. At least one positive finishing hog was identified on six of 84 farms tested, with 1% of all sera testing positive. All positive farms had cats in the barn.

Levels of other parasites, possibly significant to humans, included: Giardia lamblia, 25%; Cryptosporidium spp., 5%; and Balantidium coli, 76%. Results were based on fecal samples.

The survey revealed that 40% of gilts were negative for parvovirus, which was higher than expected and left them at risk for infection at breeding.

Ileitis was detected in most herds, with a prevalence of 70-90%, depending on which serological test was used.

One disease organism not previously found in North American swine was E. coli 0157:H7. The pathogen, commonly found in cattle, is responsible for the so-called "hamburger disease." Three farms out of 44 tested positive for low levels of the Shiga toxin-producing E. coli. So far there has been no link established between infected pigs and human disease.

This study is considered the first step in reducing or eradicating swine diseases of public health and economic significance.

Researcher: Robert Friendship, DVM, University of Guelph. Phone (519) 824-4120, ext. 4022; fax (519) 763-3117 or e-mail rfriends@ovc.uoguelph.ca.

Feeder Adjustment, Size Of Group Both Impact Nursery Pig Growth

Increasing floor space and providing proper feeder adjustment worked together to maximize growth of early weaned piglets in a trial at the Prairie Swine Center in Saskatoon, Saskatchewan, Canada.

A research team assigned 716, 18-day-old early weaned pigs to three different group sites. The first had 24 pigs/pen (2.5 sq. ft./pig). The second had 20 pigs/pen (3 sq. ft./pig), similar to commercial conditions. Group three had 16 pigs/pen (3.75 sq. ft./pig).

Within each group size treatment, feeders were adjusted to provide five different gap openings: 0.4, 0.5, 0.7, 1 and 1.3 in. during the six-week trial.

The 0.4 in. feeder gap provided only a small bead of feed to the pigs, while the entire trough was covered with feed with the 1.3 in. opening.

The treatment had no effect on weight gain nor feed intake until the second half of the experiment. Body weight, daily gain and feed intake achieved best results when the feeder gap size was set at a minimum 0.7 in. The optimal gap varied depending on each feeder. If the feeders were adjusted correctly, at least 90% of the trough was covered with feed.

In the first half of the trial, younger pigs spent more time eating to compensate for a small gap opening, and daily gain and feed efficiency were lower (Table 1).

Overall, smaller group sizes and more floor space improved final weights, daily gain and feed intake (Table 1). The effect of group size was most dramatic with the smallest (.4 in.) feeder gap. Figure 1 illustrates the interaction between group size and gap adjustment.

Neither floor space allowance nor feeder adjustment affected the level of aggression, measured by skin lesion scores on Day 42. Researchers looked at the extent of tailbiting, side nudging and ear chewing (Table 1).

Feeder adjustment affects not only animal performance, it can also affect feeder use, says the research team. If it is assumed capacity is achieved when the feeder is being used 90% of the time, the maximum capacity of a nursery feeder space would be nine pigs when adjusted to a 0.4 in. gap, but 11 pigs when adjusted to a 1 in. or 1.3 in. gap. Click here to download tables and figures. (This requires Adobe Acrobat Reader, download at: www.adobe.com.)

Researchers: Laura Smith, Denise Beaulieu, John Patience and Harold Gonyou, Prairie Swine Center; R. Dean Boyd, PIC. Phone Beaulieu at (306) 667-7441 or e-mail beaulieu@sask.usask.ca.