Relationships between prenatal ewe traits, milk production, and preweaning performance of twin lambs1

Abstract

There is limited information on factors affecting twin lamb growth before weaning, which limits the options available to farmers to actively manage lamb growth. Data from 2 multiyear experiments involving 402 twin-bearing Romney ewes were used to evaluate the effects of prenatal ewe traits (live weight at mating and set stocking and BCS at mating and set stocking) and combined twin lamb birth weight on ewe milk production and lamb growth from birth to weaning as well as the proportion of variation in twin lamb growth that could be explained by these variables. Additionally, the effect of accumulated ewe milk yield over a 42-d period (MY; Days 0 to 42) and accumulated milk components (protein, fat, and lactose) on twin lamb growth were investigated. The effects of prenatal variables on MY, birth weight, and combined twin lamb live weight gain from Day 0 to 42 (LWG) were inconsistent across the 2 experiments. In addition, prenatal ewe traits ( < 0.05) explained less than 30% of the variation in MY and lamb growth from birth to weaning in both experiments. Combined twin lamb birth weight was positively ( < 0.001) correlated with MY ( = 0.34 and = 0.43 in Exp. 1 and 2, respectively). Combined twin lamb LWG was dependent on ewe MY ( = 0.43 for Exp. 1 and = 0.30 for Exp. 2). Lactose, fat, and milk CP yields explained 47 and 42% of the variation in lamb LWG in Exp. 1 and 2, respectively. Lactose and milk CP yield positively affected ( < 0.05) LWG in Exp. 1 and 2, respectively. Fat yield had a positive relationship with LWG in Exp. 1 and a negative relationship with LWG in Exp. 2. In conclusion, the measured prenatal ewe traits had a minimal effect on milk yield and twin lamb growth to weaning. Milk yield and composition explained the greatest proportion of variation in LWG. This suggests that farmers should select ewes with higher milk yields to maximize twin lamb growth to weaning. However, less than 50% of the variation in LWG and weaning live weight was explained by the measured ewe and lamb parameters. Therefore, further studies are required to determine additional ewe or lamb variables that control variation in twin lamb growth.

Ewe and lamb pre-weaning performance of Pelibuey and Katahdin hair sheep breeds under humid tropical conditions

“…Few studies have investigated the effect of breed and litter size on ewe milk production and lamb weaning weight in sheep. Danso et al (2016) found that live weight, body condition and mating season of the sheep have minimal effects on milk production and weaning growth of twin lambs. Snowder and Glimp (1991) reported a positive correlation between ewe milk production and lamb growth from birth to 56 days.…”

Milk yield and composition of Katahdin and Pelibuey ewes in tropical conditions

“…In some studies the effect of quantity and quality of milk supply during pre-weaning period on the growth and feed conversion efficiency of lambs after weaning was reported (Danso et al, 2016). The estimation of milk yield contributes a valuable information needed to implement management strategies both for ewes and their lamb as the milk yield influences weaning weight and variations in milking ability among breeds and genetic groups available in tropical areas (Peniche-Gonzalez et al, 2015).…”

Effect of Diet and Type of Pregnancy on Transcriptional Expression of Selected Genes in Sheep Mammary Gland

“…Sheep production is mainly based on pastures and faces serious problems regarding lamb survival and growth from birth until weaning, especially in twin-bearing ewes [1], which is in accordance with the physiological negative energy balance present in peripartum [2,3]. It is known that milk production and its persistence are influenced by the metabolic status of the animals [4].…”