title: Effect of average litter weight in pigs on growth performance, carcass characteristics and meat quality of the offspring as depending on birth weight.
abstract: Offspring born from normal litter size (10 to 15 piglets) but classified as having lower than average birth weight (average of the sow herd used: 1.46 ± 0.2 kg; mean ± s.d.) carry at birth negative phenotypic traits normally associated with intrauterine growth restriction, such as brain-sparing and impaired myofiber hyperplasia. The objective of the study was to assess long-term effects of intrauterine crowding by comparing postnatal performance, carcass characteristics and pork quality of offspring born from litters with higher (>1.7 kg) or lower (<1.3 kg) than average litter birth weight. From a population of multiparous Swiss Large White sows (parity 2 to 6), 16 litters with high (H = 1.75 kg) or low (L = 1.26 kg) average litter birth weight were selected. At farrowing, two female pigs and two castrated pigs were chosen from each litter: from the H-litters those with the intermediate (HI = 1.79 kg) and lowest (HL = 1.40 kg) birth weight, and from L-litters those with the highest (LH = 1.49 kg) and intermediate (LI = 1.26 kg) birth weight. Average birth weight of the selected HI and LI piglets differed (P < 0.05), whereas birth weight of the HL- and LH-piglets were similar (P > 0.05). These pigs were fattened in group pen and slaughtered at 165 days of age. Pre-weaning performance of the litters and growth performance, carcass and meat quality traits of the selected pigs were assessed. Number of stillborn and pig mortality were greater (P < 0.05) in L- than in H-litters. Consequently, fewer (P < 0.05) piglets were weaned and average litter weaning weight decreased by 38% (P < 0.05). The selected pigs of the L-litters displayed catch-up growth during the starter and grower-finisher periods, leading to similar (P > 0.05) slaughter weight at 165 days of age. However, HL-gilts were more feed efficient and had leaner carcasses than HI-, LH- and LI-pigs (birth weight class × gender interaction P < 0.05). Meat quality traits were mostly similar between groups. The marked between-litter birth weight variation observed in normal size litters had therefore no evident negative impact on growth potential and quality of pigs from the lower birth weight group.
authors.affiliation: 1 Agroscope Liebefeld-Posieux, Research Station ALP, 1725 Posieux, Switzerland.
authors.forename: C E
authors.initials: CE
authors.lastname: Pardo
authors.forename: M
authors.initials: M
authors.lastname: Kreuzer
authors.forename: G
authors.initials: G
authors.lastname: Bee
mesh_terms: D000818:Animals; D001724:Birth Weight; D005260:Female; D008297:Male; D008460:Meat / Q000032:analysis*; D034421:Sus scrofa / Q000254:growth & development / Q000502:physiology*; D013557:Switzerland; D014886:Weaning