Use of a crush-reducing device to decrease crushing of suckling piglets by sows.
Weanling pigs tend to avoid wind, and suckling piglets are thought to be more sensitive to wind than weanlings, owing to their thinner s.c. fat layer. We developed a crush-reducing device based on the anticipated behavior of suckling piglets toward wind and evaluated the performance of the device through field testing. The crush-reducing device consisted of six photo sensors, a controller, six solenoid valves, and an air compressor. In this study, 206 sows and their suckling piglets (Landrace xYorkshire) were investigated to ascertain the individual effects of several factors. Some of the newborn piglets were cross-fostered before the crush-reducing device was implemented. Litter weights were measured on d 0 and 4 to determine the influence of the crush-reducing device on the weights of suckling piglets. The crushing of suckling piglets by sows was affected by season (P < 0.01) and litter size (P < 0.05), but not by the parity of the sows; however, the number of crushed piglets per litter was less (P < 0.01) in the crush-reducing device group (0.05 +/- 0.02 crushed piglets/litter) than in the control group (0.23 +/- 0.04 crushed piglets/litter), regardless of litter size or season. The BW gain of suckling piglets did not differ between the control and the crush-reducing device groups. Based on these results, the crush-reducing device is expected to decrease the number of crushed piglets per litter without influencing the BW gain of suckling piglets, thereby greatly contributing to the productivity of pig breeders.
Crushing of piglets by sows: effects of litter features, pen features and sow behaviour
Abstract Crushing of piglets by sows in farrowing pens was studied in a 2×2 experiment to evaluate the effect of different pen design features. Pens had either concrete or plastic-coated expanded metal flooring, and half of the pens were fitted with a horizontal bar 23 cm above the floor, bisecting the pen. The bar was intended to prevent the sow from rolling suddenly onto her side, a movement known to crush piglets in open pens. Ninety-eight litters were analyzed during the first 3 days after birth when most crushing occurs. Of the 927 viable, live-born piglets, 95 (10.2%) died during the study, and 75 of these deaths were due to crushing as indicated by post mortem analysis. A high incidence of crushing was associated with larger litter size at birth, lower average piglet weight gain in early lactation, and older (high parity number) sows; however, these variables were interrelated, with older sows tending to have larger litters with lower early weight gains. Pens with a bar had significantly less crushing during the last 2 days of the study (Days 2–3), but this was fully offset by a non-significant tendency for more crushing in these pens on Days 0–1. Video recordings were analyzed for 16 sows with multiple crushings. Of eight types of sow body movement recorded, two caused most of the crushing: lying down from a standing position (54% of crushings observed), and rolling from lying on the udder to lying on the side (33% of crushings observed). Pen design features influenced how often the different movements were performed and how often these movements crushed piglets, but pen design did not affect the total number of movements or the total number of piglets crushed. Although the comparisons in the study did not result in significant differences in the incidence of crushing, the method shows promise as a way to identify design features that reduce the incidence of dangerous movements.
Effects of oral doses of corn oil and other factors on preweaning survival and growth of piglets.
Piglets were provided supplemental energy as oral doses of corn oil to find whether such treatment might improve survival or weight gains. A total of 1,840 piglets from 182 litters was used. Piglets were allotted to dosed and control treatments within litter on the basis of body weight. Dosed piglets received a total of 8 ml of corn oil in four doses during the first 48 h postpartum. The survival rate to weaning was high and not affected (P greater than .10) by the corn oil doses. Deaths of piglets low in birth weight were delayed by the fat doses, suggesting some utilization. The fat doses did not affect piglet weight gain. Factors affecting preweaning survival and growth of piglets were also evaluated using data from the same piglets. Specific factors investigated were sex, parity of dam, birth weight, litter size and the mean and standard deviation of piglet birth weights within litters. Male piglets were heavier at birth than females, but there was no sex effect on weight at 7 d or at weaning. Small males were less likely to survive to 3 d than were small females. Litters from primiparous sows were smaller at birth and weaning, but had lower percentages of stillbirths and of preweaning deaths than did those from multiparous sows. Piglets from primiparous sows were more uniform in birth weight. Piglets that were heavier at birth grew faster and were more likely to survive. Litter size affected growth but not survival of piglets. A heavier average birth weight in the litter reduced slightly the growth rate of individual piglets. An increase in variability of piglet birth weight within a litter was associated with an increase of the percentages of stillbirths and of preweaning mortality. A few litters accounted for a major portion of the mortality. Much of the variation in piglet mortality and growth was not explained by factors considered.