Breeding for a better survival of piglets in organic farming: consequences on maternal cortisol and neonate metabolic status
Résumé
Neonatal mortality is high in pig farming, and even higher in organic farming. A strategy for reducing this mortality is to select more maternal sows, producing fewer but more robust piglets. We selected a Large-White maternal line over two successive generations for limited litter size and increased piglet survival in organic conditions. In the present study, we explored whether this selection influenced the physiology of the mothers and offspring in two different farrowing conditions (loose or restrained sows at farrowing). We collected saliva from sows of the G1 (n=48) and G2 (n=33) generations around their 2nd farrowing (at 8h and 13h on days 108 and 112 of gestation and day 4 of lactation (D4), at 8h on D11). Blood was collected from a subset of piglets aged of 24 ± 6 h (n=81 from 28 G1 litters and n=96 from 32 G2 litters). Gestation length increased by 0.86 days (P=0.017). The genetic trend for lower litter size at birth was observed in first parity (G1: 16.25 to G2: 14.43 ± 0.62) but not afterwards (more than 16 total born), and survival rate on D49 was not different (70.86% in G1, 67.04% in G2). G2 sows had lower salivary cortisol than G1 sows on 4 out of the 7 sampling times (P<0.01), and restraint had no influence. Piglet weight at 24h was comparable for G1 and G2, and positively correlated with plasma concentrations of lactate (P<0.05), glucose (P<0.01), albumin (P<0.001), and hydroperoxides (P<0.01). G2 piglets had higher levels of albumin (P<0.05) and hydroperoxides (P<0.001) and lower plasma antioxidant capacity (P<0.001) than G1 piglets. Blocking sows around farrowing induced lower lactate but in G1 only (P
Domaines
Sciences du Vivant [q-bio]Origine | Fichiers produits par l'(les) auteur(s) |
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