Abstract

The present research study was undertaken to investigate the effect of maternal uterine environment on birth weight of lambs. Embryos were transferred within, and reciprocally between, Suffolk and Cheviot sheep to establish four groups of pregnancies: Suffolk in Suffolk (SinS; Large control), Suffolk in Cheviot (SinC; Restricted uterine environment) Cheviot in Suffolk (CinS; Luxurious uterine environment) and Cheviot in Cheviot (CinC; Small control). Birth weight and other morphological characteristics of lambs such as head width, head length, crown-rump length, heart girth, fore leg length, hind leg length and femur length were recorded within 24 h of birth. Various placental parameters were also recorded at lambing. Birth weight of SinC lambs (5.04 ± 0.20 kg) was significantly (P <0.05) lower than SinS lambs (5.93 ± 0.19 kg). All of the body dimensions were also significantly (P <0.05) reduced in SinC compared with SinS lambs. However, neither birth weight nor other morphological parameters were significantly different (P >0.05) between CinC and CinS lambs. Among placental parameters, cotyledon number was significantly (P <0.05) lower in CinS (57.48 ± 6.27) than SinS group (74.17 ± 5.88). These results indicate that a restricted maternal uterine environment affects birth weight probably via alteration to placental characteristics.

RK, Sharma, CMC Jenkinson, HT Blair, PR Kenyon, and TJ Parkinson

Proceedings of the New Zealand Society of Animal Production, Volume 69, Christchurch, 10-14, 2009