Productive and reproductive performance at farrowing and at weaning of sows of seven genetic lines

This research aimed to study the effects of genetic line (GL), farrowing room (FR) and number of parity (NP) on the productive and reproductive performance at farrowing and weaning of sows of seven genetic lines. The response variables were total litter size at farrowing (TLSF) and at weaning (TLSW), pigs born alive (PBA), stillbirth (PBD), litter weight at farrowing (LWF) and at weaning (LWW), sow average food intake (FI), and sow weight (SWL), and back fat (BFL) loss during lactation. Besides the fixed effects of GL, NP, and FR, the model also included the covariates TLSF for LWF, and TLSW for LWW. There were significant differences (P<0.0026) among GL for TLSF, PBA, PBD, and FI. Parity was important (P<0.0001) only for FI, and FR was (P<0.038) for PBD. Sows of three or more parities had higher FI (4.5 +/- 0.2 kg) than those of one and two (3.4 +/- 0.2 kg). It is needed more attention at farrowing and during lactation in order to reduce death of piglets both at farrowing and during lactation. Back fat and weight loss of sows during lactation should be reduced in order to avoid deterioration of post-weaning productive and reproductive performance.