Body Condition Score At Lambing And Performance Of Santa Ines Ewes With An Offspring During Lactation

The main objective of this study was to evaluate the performance of Santa Ines ewes using their body condition score (BCS) at lambing. Data from 135 adult ewes with singletons were investigated. Ewes were divided into three distinct groups: 1) Below average: BCS < 2.5 points (n = 44); 2) Average: BCS between 2.5 and 3.0 (n = 53); and 3) Above average: BCS > 3.0 (n = 38). The scale for BCS varied from 1 (very thin) to 5 (very fat). The individual BW, BCS, metabolic profile, milk production, and composition of ewes as well as their lambs' performance until weaning were studied. Metabolic profile was monitored relative to lambing at -7, +7, and +60 days. It was observed that ewes with a higher BCS were also heavier; however, there were no differences in the lambs among the groups for weight at birth and weaning (70 days). As there was no difference in milk production and composition, the average daily weight gain of the lambs was similar regardless of the ewe's BCS. The metabolic profile (hemoglobin, total protein, albumin, creatinine, urea, glucose, beta-hydroxibutyrate, cholesterol, and aspartate aminotransferase - AST) were also similar among the groups. However, when the metabolic profile was compared with the different physiological stages relative to lambing, some differences were observed. For example, beta-hydroxibutyrate was greater during the peripartum period, and glucose was greater in the lactation phase. It was concluded that even in a situation of poor BCS, Santa Ines ewes have the physiological capacity to adapt themselves to a negative energy balance similar to the periparturient period. It seems that irrespective of the BCS, ewes prioritized lactation and were able to produce enough milk to nurse their lambs accordingly.