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Title:Methods to reduce rectal temperature decline of newborn piglets and the effect of cross-fostering strategies on piglet pre-weaning growth and mortality
Author(s):Vande Pol, Katherine Diane
Director of Research:Ellis, Michael
Doctoral Committee Chair(s):Ellis, Michael
Doctoral Committee Member(s):Knox, Robert V; Stein, Hans H; Shull, Caleb M
Department / Program:Animal Sciences
Discipline:Animal Sciences
Degree Granting Institution:University of Illinois at Urbana-Champaign
Degree:Ph.D.
Genre:Dissertation
Subject(s):Piglet
pre-weaning mortality
rectal temperature
drying
warming
oxygen
birth weight
farrowing
room temperature
cross-fostering
litter size
weaning weight
weight variation
growth
Abstract:There have been significant increases in the average litter sizes of commercial sows over recent decades. As a result, average piglet birth weight has decreased, and the number of low birth weight piglets (i.e., < 1 kg) has increased. Lower birth weight piglets have higher levels of mortality, particularly associated with hypothermia and starvation. Larger litters often exceed the number of functional teats, increasing competition for teat access, and low birth weight piglets have a reduced ability to compete compared to heavier littermates. The research conducted for this thesis focused on reducing pre-weaning mortality through limiting piglet temperature decline in the early postnatal period and by providing an understanding of the fundamental components of cross-fostering. Five studies were conducted to determine the typical piglet temperature decline in the early postnatal period and evaluate the effect of practical interventions (drying using various methods, warming, drying and warming, or providing supplemental oxygen) on this temperature decline. In addition, the impact of the most effective method at reducing the extent and duration of temperature decline (the combination of drying and warming) was evaluated for piglet pre-weaning mortality. Drying piglets at birth reduced (P ≤ 0.05) piglet temperature decline within the first 2 h after birth, with no differences between drying methods (with a desiccant or paper towels). Warming piglets was as effective (P > 0.05) as drying at minimizing postnatal temperature decline, with the combination of these two approaches being the most effective (P ≤ 0.05) method. Treatment effects were greater (P ≤ 0.05) under cooler than warmer farrowing room temperatures. Drying and warming reduced (P ≤ 0.05) pre-weaning mortality compared to undried Control piglets under cooler (< 25°C), but not warmer (≥ 25°C), farrowing room temperatures. These results suggest that drying and warming of piglets at birth is an effective approach to reducing early postnatal rectal temperature decline, and may reduce pre-weaning mortality except under farrowing room temperatures typically experienced in the summer months. Four studies were carried out to develop an understanding of fundamental components of cross-fostering for effects on piglet pre-weaning mortality (PWM, morbidity and mortality) and growth. In general, rearing piglets with lower birth weight littermates reduced (P ≤ 0.05) PWM and increased (P ≤ 0.05) weaning weights. Reducing within-litter birth weight variation improved performance for low birth weight piglets (i.e. < 1.0 kg), but reduced performance of heavier piglets. Reducing litter size from two above to two piglets below the number of functional teats of the sow reduced (P ≤ 0.05) PWM and tended (P = 0.06) to increase weaning weight. Using piglets from multiple compared to a single litter to form cross-fostered litters reduced (P ≤ 0.05) PWM, with no effects on weaning weights. The results of these studies suggest that increasing the piglet competition within the litter (by increasing litter size or the weight of littermates) results in increased PWM and decreased weaning weights. In addition, PWM was lower when piglets were mixed with those from other litters, however, the biological or behavioral reasons for this effect require further research. The optimum cross-fostering strategy to maximize pre-weaning piglet performance is likely to be dictated by the birth weight distribution of the population in question, and the cost of reducing litter size (which, for example, would require the use of more nurse sows) compared to the benefit of increased piglet performance.
Issue Date:2020-11-25
Type:Thesis
URI:http://hdl.handle.net/2142/109373
Rights Information:Copyright 2020 Katherine Vande Pol
Date Available in IDEALS:2021-03-05
Date Deposited:2020-12


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