Ewes shorn and unshorn during pregnancy in South Brazil: effects on body condition score and lamb birth weight

Authors

  • Luiz Alberto Oliveira Ribeiro Universidade Federal do Rio Grande do Sul, Faculdade de Veterinária, Departamento de Medicina Animal, Porto Alegre, RS
  • Marcelo Arnt Brito Universidade Federal do Rio Grande do Sul, Faculdade de Veterinária, Departamento de Medicina Animal, Porto Alegre, RS
  • Rodrigo Costa Mattos Universidade Federal do Rio Grande do Sul, Faculdade de Veterinária, Departamento de Medicina Animal, Porto Alegre, RS

DOI:

https://doi.org/10.11606/issn.1678-4456.bjvras.2010.26834

Keywords:

Sheep, Pre-lamb shearing, Lamb birth weight, Body condition score

Abstract

In this work the effects of pre-lamb shearing on the ewe body condition scores (BCS) and lamb birth weights and growth rates were examined. A flock of 64, three year old Border Leicester x Texel ewes (49-54 kg), exposed to rams in March were divided, on day 74 of pregnancy, into two groups each of 32 ewes. The ewes grazed together, on natural pampas grass, at a stoking rate of five ewes/ha and a pasture availability of approximately 800 kg DM/ha. One group was shorn (S), at day 74 of pregnancy (P74) and the other was left unshorn (US). The BCS of the S and US ewes were assessed at the beginning of the experiment (P74), P108 and P135, as well as at lactation (L) on days L15 and L24. The lamb birth weights, and weights at 2 and 3 weeks of life were also recorded. Both groups of ewes showed a marked reduction of BCS during gestation and lactation periods. The S group experienced a significantly (P < 0.05) more severe reduction of BCS. This dropped from 3.3 score units at P74 to 1.79 and 1.22 at P135 and L24. The BCS of the US group were 3.11, 2.19 and 1.21 score units respectively at these times. Shearing pre-lambing increased mean lamb birth weight by 0.71 kg and this was statistically significant (P < 0.05). There were no effects on the lamb weight gain measured at two and three weeks of life. The increase in lamb birth weight produced by shearing ewes during pregnancy, described in this paper, could reduce the lamb perinatal mortality, especially in years with a low forage supply, leading to a critical BCS during gestation. The results suggested also that close attention should be given to the BCS of the ewe flock during pregnancy, a practice that is not common in the southern areas of Brazil.

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Published

2010-04-01

Issue

Section

UNDEFINIED

How to Cite

Ewes shorn and unshorn during pregnancy in South Brazil: effects on body condition score and lamb birth weight. (2010). Brazilian Journal of Veterinary Research and Animal Science, 47(2), 111-116. https://doi.org/10.11606/issn.1678-4456.bjvras.2010.26834