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The objective was to evaluate the impact of functional teat number on reproductive throughput in swine. Data included 735 multiparous Landrace × Large White F1 females. Sow underlined traits consisted of total teat number, functional teat number, nonfunctional teat number, and number of functional mammary glands. Weaning traits were calculated for both the biological and the nurse dam. For the biological dam, litter size at weaning included a sow’s biological piglets regardless of cross-fostering. For nurse dam, number weaned included the piglets a sow weaned. For the biological dam, piglet survival was calculated as litter size at weaning / (total number born × 100). Linear regression estimates were calculated in RStudio v. 1.1.456 and variance components were estimated using GIBBS3F90.
Average total number born, number born alive, total teat number, functional teat number, nonfunctional teat number, and number of functional mammary glands were 14.22, 13.12, 14.43, 13.96, 0.42, and 10.7, respectively. An increase in one functional teat number enhanced litter size at weaning by 0.32 piglets and number weaned by 0.33 piglets. Similarly, an increase in one functional teat number improved piglet survival by 1.63% and reduced preweaning mortality by 2.73%. However, an increase in one functional teat number reduced average piglet weaning weight for biological and nurse dams by 35 and 94 g, respectively. Yet an increase in one functional teat number enhanced litter weaning weight for biological and nurse dams by 1.3 and 1.5 kg, respectively. Heritability estimates for total teat number, functional teat number, nonfunctional teat number, number of functional mammary glands, piglet weaning weight, litter weaning weight, litter size at weaning, and piglet survival were 0.25, 0.22, 0.53, 0.18, 0.21, 0.22, 0.16, and 0.18, respectively. Genetic correlation estimates between functional teat number with total teat number, nonfunctional teat number, and number of functional mammary glands were 0.79, 0.09, and 0.28, respectively. Estimated genetic correlations between total teat number with piglet weaning weight, litter weaning weight, litter size at weaning, and piglet survival were 0.37, 0.38, 0.11, and −0.19, respectively. Genetic correlation estimates between functional teat number with piglet weaning weight, litter weaning weight, litter size at weaning, and piglet survival were 0.44, 0.49, 0.39, and 0.35, respectively.
Results suggest increasing functional teat number would enhance both piglet survival and reproductive throughput.
Obermier DR, et al. The impact of functional teat number on reproductive throughput in swine. Translational Animal Science. 2023; 7(1): txad100. https://doi.org/10.1093/tas/txad100