Influence of low pasture allowance during pregnancy on the attachment between ewes and their lambs at birth and during lactation

• DOI: 10.1016/j.applanim.2017.10.016
• Publication Date: 2017-10-31T23:00:10Z
• Authors: Aline Freitas-de-...; Angélica Terrazas; Rodolfo Ungerfeld; Maria José Hötzel; Agustín Orihuela; Raquel Pérez-Clar...
• Keywords: 2. Zero hunger; 0402 animal and dairy science; 04 agricultural and veterinary sciences

Abstract Nutrient restriction during pregnancy may negatively affect ewe-lamb attachment at birth. We hypothesised that the difference in the attachment at birth could persist during lactation and, consequently, the emotional response of lambs to a short-term maternal separation test during late postpartum would be affected. The aim of this study was to compare the ewe-lamb attachment behaviours at birth and the behavioural response to a short-term maternal separation test of 3-month-old lambs born from dams that grazed on high or low natural pasture allowance from day 30 to day 143 of gestation. A complementary aim was to determine if milk yield and lambs’ BW would be affected by the dams’ pasture allowance during pregnancy. Forty-one multiparous single-lambing Corriedale ewes were randomly assigned to two natural pasture allowances: a) high (group HPA: n = 22): the ewes grazed on 14–20 kg of dry matter (DM)/100 kg of body weight (BW)/day; and b) low (group LPA; n = 19): ewes grazed on 6–10 kg of DM/100 kg of BW/day. From day 100 of gestation until lambing, the ewes were collectively provided with 300 g/animal/day of rice bran. From day 143 of gestation until lambs were 3 months old, all animals grazed on natural pasture with unlimited forage availability. Body condition score (BCS) of ewes and BW of ewes and lambs were recorded during the experiment, and udder size was recorded at lambing. Mother-lamb attachment behaviours were recorded at birth and ewes’ milk yield was determined at 3 months of age, when lambs were subjected to a short-term maternal separation test. During the treatments, the HPA ewes had greater BCS and BW than the LPA ewes (p