Clustering of multi-tissue transcriptomes in gilts with normal cyclicity or delayed puberty reveals genes related to pubertal development†.

In gilts, puberty is marked by standing estrus in the presence of a boar. Delayed puberty (DP; failure to display pubertal estrus) is a major reason for gilt removal. To investigate the physiological determinants underlying DP in gilts, transcriptomic data from tissues relevant to estrus and puberty, such as mediobasal hypothalamus, anterior pituitary gland, ovarian cortex, olfactory bulb, amygdala, and hippocampus, were obtained from age-matched DP (n = 8) and cyclic control gilts at follicular phase (n = 8) and luteal phase (n = 8) of the estrous cycle.

Relationships of genomic estimated breeding values for age at puberty, birth weight, and growth during development in normal cyclic and acyclic gilts.

Managing replacement gilts to reach optimal body weight and growth rate for boar stimulation and first breeding is a key component for sow reproductive longevity and producer profitability. Failure to display pubertal estrus remains a major reason that gilts are culled from the herd. Puberty is metabolically gated so evaluating phenotypic and genetic relationships between birth weight and growth traits with age at puberty and acyclicity can provide valuable insight for efficient gilt development.

gBLUP-GWAS identifies candidate genes, signaling pathways, and putative functional polymorphisms for age at puberty in gilts.

Successful development of replacement gilts determines their reproductive longevity and lifetime productivity. Selection for reproductive longevity is challenging due to low heritability and expression late in life. In pigs, age at puberty is the earliest known indicator for reproductive longevity and gilts that reach puberty earlier have a greater probability of producing more lifetime litters.

Functional genomics of reproduction in pigs: Are we there yet?

Reproductive failure is the main reason for culling females in swine herds and is both a financial and sustainability issue. Because reproductive traits are complex and lowly to moderately heritable, genomic selection within populations can achieve substantial genetic gain in reproductive efficiency. A better understanding of the physiological components affecting the expression of these traits will facilitate greater understanding of the genes affecting reproductive traits and is necessary to improve and optimize management strategies to maximize reproductive success of gilts and sows.

Dam parity structure and body condition during lactation influence piglet growth and gilt sexual maturation through pre-finishing.

Energy demands during lactation greatly influence sow body condition and piglet performance. We hypothesized that primiparous sows or sows with reduced body condition would produce piglets with reduced growth and delayed sexual maturation. Eight weekly farrowing seasons were used to evaluate sow body condition (post-farrowing, PF and weaning, WN) and piglet growth from 157 dams.