A total of 199 sows from parities 0 to 6 were allotted to 2 experimental groups, control group (C) and high group (H), at d 40 of pregnancy. The sows of the C group were fed 2.5 to 3.0 kg/d throughout gestation and H sows received an extra feed allowance of 1.5 kg/d for gilts and 2.0 kg/d for multiparous sows above the C amount from d 45 to 85 of gestation.The male progeny of C and H sows were followed during the nursery and growing-finishing periods and were classified according to BW into 5 groups per treatment.
At the beginning and end of the experimental period backfat thickness (BF) was measured. Pigs were weighed every week in the nursery phase and every 3 weeks in the growing-finishing phase to calculate ADG by pen. Carcass, meat quality and muscle fiber characteristics (samples from the longissimus thoracis (LT) muscle were taken) were studied at market BW in pigs from group 4 (second lightest group at weaning).
In general, H sows gained more (P<0.001) BF during the experimental period compared with C sows. During the nursery period, pigs born to H sows showed greater ADG and G:F than did pigs born to C sows (P<0.05) and they showed significantly greater pH24 (P<0.01) in the semimembranosus muscle. In addition, H group pigs showed smaller lightness values in the LT muscle (P<0.01). Increasing the maternal feeding amount during midpregnancy led to a smaller total number of muscle fibers in the LT muscle of progeny compared with the progeny of C sows (P=0.01). Maternally supplemented pigs showed fewer primary and secondary fibers than did pigs born to C sows (P<0.01). Pigs born to H sows had a smaller percentage of type IIB fibers (P<0.01), greater percentages of type I and IIA fibers (P<0.05) and greater mean cross-sectional area of muscle fibers (P<0.05) compared with pigs born to C sows.
Results from the present study confirm the existence of effects of maternal nutrition on fetal development, at least in terms of muscle tissue development and meat quality, although with no beneficial effects were found for the postnatal growth performance of the progeny.
A Cerisuelo, MD Baucells, J Gasa, J Coma, D Carrión, N Chapinal and R Sala. 2009. Journal of Animal Science, 87:729-730