Traits Defining Sow Lifetime Maternal Performance

Abstract

Declining sow performance with increasing parity or an increase in the number of poor- quality pigs potentially impacts on farm productivity. This study investigated the phenotypic and genetic background of the sow’s influence on (i) the number of pigs not meeting the industry standards (tail-enders) and (ii) changes in performance with parity. Data were available for 3592 sows and their litters (13,976 litters) from a pig production system in NSW, Australia. The mean, standard deviation (SD), and slope for trait values over time were estimated for the sow characteristic traits: number of born-alive (NBA) and stillborn (SB) piglets and body condition of sow recorded with a caliper (CAL), along with maternal effects on piglet performance, represented by: average piglet birth weight (APBW), number of weaned piglets (WEAN), and tail-enders (TEND). Traits were analyzed in ASReml 4.2, by using an animal model. The number of tail-enders produced by a sow is a heritable trait, with a heritability estimate of 0.14 ± 0.04. Sow characteristics and maternal effects on piglet performance expressed by mean and slope had similar heritability estimates, ranging from 0.10 ± 0.03 to 0.38 ± 0.05, whereas estimates for SD traits were generally not different from zero. The latter suggests individual variability in sow characteristics or maternal performance between parities is largely not genetic in origin. This study demonstrated that more attention is required to identify contributions to the problem of tail-enders, and that slope traits could potentially be useful in the breeding program to maximize lifetime performance.

Assessing reproductive performance and predictive models for litter size in Landrace sows under tropical conditions

“…In summary, the observed litter size patterns in this Landrace population, with the highest NBA occurring at the 4th parity, align with findings from various studies conducted in different geographic locations and with different sow breeds [ 2 , 10 , 31 ]. While the specific parity at which the peak NBA is observed may vary among populations [ 32 , 33 ], the consistent trend of reduced litter size in 1st parity sows is a recurring observation [ 10 , 31 – 34 ]. Similarly, patterns of NPL and PPL exhibited variations among populations [ 1 , 10 , 32 , 33 ], particularly in the 1st parity, likely due to differences in genetic backgrounds, management practices, and environmental conditions, all of which can influence the puberty and fertility of replacement gilts.…”

“…While the specific parity at which the peak NBA is observed may vary among populations [ 32 , 33 ], the consistent trend of reduced litter size in 1st parity sows is a recurring observation [ 10 , 31 – 34 ]. Similarly, patterns of NPL and PPL exhibited variations among populations [ 1 , 10 , 32 , 33 ], particularly in the 1st parity, likely due to differences in genetic backgrounds, management practices, and environmental conditions, all of which can influence the puberty and fertility of replacement gilts.…”

Indicators of functional integrity in production animals

“…For production animals, measures of functional competence based on longevity (stayability) may contribute to assessments of the rate of biological aging (e.g. Hu et al 2021;Friggens et al 2022;Vargovic et al 2022). For example, a novel indicator of functional capacity during aging may be encoded in the persistence of production over successive years or parities.…”

“…Units of production suitable for analysis could include 305-day milk yield, birth weight, litter size, weaning weight of offspring, weaning percentage, and annual wool yield. Additional measures of reproductive performance that vary with parity in pigs include live births, still births, and the number of runts in a litter (Vargovic et al 2022). The premise here is the same as for telomere length and DNA methylation, namely, that accelerated decline in performance with age or parity is indicative of a greater than average burden of wear and tear and hence indicates accelerated biological aging.…”

Effects of Growth Hormone-Releasing Hormone (GHRH) Plasmid Treatment on the Reproductive Productivity of Sows in Primiparous and Multiparous Sow Breeds

“…It encompasses the reproductive efficiency and prolific breeding performance of female pigs. Litter size is an important metric, which denotes the number of piglets born per sow [10], and is a direct determinant of the economic viability and sustainability of pig farming operations.…”