The effect of plane of nutrition during pregnancy of Greek dairy ewes on the development of mammary gland and on subsequent milk production

The present study was undertaken to investigate the effect of plane of nutrition during pregnancy on the development of the mammary gland, on various plasma biochemical parameters (glucose, free fatty acids, beta-hydroxybutyric acid) hormones (insulin, thyroxin) and on some important physiological traits, like feed intake, body weight and milk yield after parturition in Greek dairy ewes. Two experiments were conducted. In the first, pregnant ewes were randomly divided into two groups with different levels of nutrition. Group A ewes met 110% of their maintenance plus pregnancy energy requirements for two foetuses while group B ewes met 90% of their maintenance energy requirements. After parturition, food was given ad libitum to all the ewes. In the second experiment, pregnant Chios ewes were fed as in the first but were slaughtered at the 140(th) day of pregnancy. Various morphological and biochemical parameters of mammary gland were then measured. It was concluded that the plane of nutrition during pregnancy had a significant effect on ewes' body weight, on the development of mammary gland and on milk yield.