Colostrum production of Alentejano and Large-White × Landrace sows: consumption, passive immunity and mortality of piglets

Colostrum production and composition of 45 Alentejano (AL) and 45 crossed (Large–White × Landrace, LL) sows together with consumption and passive immunization of piglets, were evaluated. Piglets were weighed at birth, 24h, and 21 and 28 days of age. Colostrum was collected, chemically analysed and immunoglobulin G (IgG) determined. On piglets, serum IgG concentrations were determined at 2d and 28d of age. Alentejano piglets consumed 19% less colostrum than LL piglets (267 vs 328 g; p<0.001), but when adjusted for birth weight, the difference between genotypes was not significant (p=0.891). Alentejano sows produced less colostrum (1985±139 g vs 3761±139 g, p<0.001) than LL sows, even after adjustment for litter birth weight. IgG concentrations were higher in AL colostrum at 12 h and 36 h after the onset of farrowing. They were higher in AL than in LL piglets (p=0.025) and higher at 2d than at 28d of age (p<0.001). Mortality rate of piglets until d21 post–farrowing was higher in AL genotype (27% vs 16.1%, p<0.001). In both genotypes main factors influencing piglet mortality were birth weight and colostrum intake (g/kg birth weight). Higher mortality in AL than in LL genotype was attributable to the higher proportion (28.7% vs 11.6%, p<0.001) of light piglets. It is concluded that for similar birth weight, both AL and LL piglets have a similar ability to ingest colostrum and that AL sows are less able to produce colostrum than LL sows. IgG concentrations of colostrum and of piglets serum were higher in AL than in LL genotype