Milk yield and its composition are influenced by flow of substrates from the blood circulation to the mammary tissues. Body condition score (BCS) is an intermediate factor between the feed intake and the productivity status of the animal. Since energy intake does not keep pace with continuously rising milk yield, energy deficit in early lactation leads to a competitive situation among milk yield, fertility and health of the dairy cow as these traits are linked by energy requirement. The present study was designed to investigate the effect of body condition and pregnancy on milk yield and composition in F1 crossbred cows (Holstein-Friesian X local cows). Fifty-eight cows (60 days postpartum) were selected at a large state farm. Pregnancy status was classified as: NP (non-pregnant), T-1 (pregnant trimester-I), T-II (trimester-II) and T-III (trimester-III). Milk yield (MY), milk composition (MC) and BCS were recorded weekly. The study continued up to 9 months postpartum during the year, 2007-2008. Pregnancy significantly affected the MY and MC (P
Key words: Crossbred cattle, Milk composition, Pregnancy, BCS, milk progesterone
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