Reproductive performance of ewes mated in the spring when given nutritional supplements to enhance energy levels
Animal Reproduction
Reproductive performance of ewes mated in the spring when given nutritional supplements to enhance energy levels
Autor Correspondente: M M Seneda | [email protected]
Palavras-chave: ewes, fertility, flushing, lambing rate, soybean hulls
Resumos Cadastrados
Resumo Inglês:
The objective of this study was to evaluate the
reproductive performance of ewes mated in the spring
when given nutritional supplements to enhance energy
levels. Ewes were assessed for weight and body
condition at the beginning and end of flushing periods.
Lambing rates and rates of proliferation were also
evaluated. Crossbred woolly ewes (n = 46), 36 ± 2
months of age and rated 3.0 ± 0.1 on a body condition
scale that spanned from 1 to 5 were divided into four
treatment groups. One group received no feed
supplements (NFS), while the others were supplemented
for 64 days: 21 days before and 43 days during the
mating season. The latter groups were fed soybean hulls
at 0.6% (S06), 0.9% (S09) and 1.2% (S12) of their body
weight (BW), calculated using dry mass. Ewes were
mated for 50 days with four rams by means of natural
breeding in October and November, which is spring in
Brazil. There was no significant difference among the
treatments based on mean BW of the ewes before and
after the supplementation period (P > 0.05). Similarly,
no differences were found in the rates of proliferation
(P > 0.05). The S09 treatment presented the highest
lambing rate (82%, 9/11), while the NFS treatment
correlated with the lowest rate (42%, 5/12; P < 0.05).
There was a positive linear effect for body condition
score as the supplementation level increased (P < 0.05).
We conclude that a supplementation level of 0.9% BW
seems to improve lambing rates for ewes that undergo
springtime mating.
