Hossain et al . Iranian Journal of Applied Animal Science (2015) 5(2), 309-315 309 Influence of Body Condition Score on Yield and Composition of Milk in Crossbred Dairy Cows INTRODUCTION Body condition score (BCS) is the visual assessment of the amount of muscle and fat covering the specific areas of the bones of cattle. This is an accepted, noninvasive, subjec- tive, quick, and inexpensive method to estimate the degree of fatness in dairy cows (Waltner, 1993). As it independ- ently measures the body weight and frame size, this is truly an indicative measure of body fatness (Wildman et al. 1982). Essentially, there are five key areas on the body re- gions of cows that need to be assessed for BCS namely, the area between the tail head and pin bones, inside of the pin bones, backbone, hips and curvature between the hips and pin bones. There are different scoring scales, but the most common system in use for dairy cows in the US uses a scale of 1 to 5 with 1 being emaciated, 2 thin, 3 average, 4 fat and 5 obese (Wildman et al. 1982; Flamenbaum et al. 1995). It is common to divide the scale into 0.25 point in- crements (Ferguson et al. 1994; Wildman et al. 1982; Edmonson et al. 1989). The study was carried out for a period of 150 days on 120 Holstein Friesian crossbred dairy cows between mid to late lactation to quantify the influence of body condition score (BCS) on yield and composition of milk. Total 12 dairy farms having same housing systems and holding at least 20 crossbred dairy cows per farm between mid to late lactation were selected for this study purposes. BCS of individual cows was re- corded in a 1-5 scale. Milk samples were collected from individual cow. Samples collected from cows hav- ing same BCS were mixed together to make composite sample. Chemical analyses of the samples were carried out in triplicate for fat, protein, lactose, ash, total solids (TS) and solids not fat (SNF). Results indi- cated that, BCS significantly (P<0.05) affected milk yield, milk fat and ash content in crossbred Holstein Friesian dairy cows. Highest milk yield (13.45±1.80 kg/day) was recorded with moderate BCS (3.00) fol- lowed by lower (2.75 to 2.25) and higher (3.25 to 4.00). Milk protein, lactose, TS, SNF and specific gravity (SG) increased non significantly (P>0.05) with increasing BCS up to 4.0. Correlation coefficient matrix indicated that BCS was negatively correlated with milk yield. However, there was a positive relationship of BCS with milk protein, lactose, TS, SNF and SG even though the strength of association was variable. KEY WORDS body condition score, crossbred dairy cow, milk composition, milk yield. M.E. Hossain 1* , T. Chanda 2 , G.K. Debnath 3 , M.M. Hasan 4 , A.H. Shaikat 4 and M.A. Hoque 4 1 Department of Animal Science and Nutrition, Faculty of Veterinary Medicine, Chittagong Veterinary and Animal Science University, Khulshi, Chittagong, Bangladesh 2 Department of Dairy and Poultry Science, Faculty of Animal Science and Veterinary Medicine, Patuakhali Science and Technology University, Patuakhali, Bangladesh 3 Department of Dairy and Poultry Science, Faculty of Veterinary Medicine, Chittagong Veterinary and Animal Science University, Khulshi, Chittagong, Bangladesh 4 Department of Physiology, Pharmacology and Biochemistry, Faculty of Veterinary Medicine, Chittagong Veterinary and Animal Science University, Khulshi, Chittagong, Bangladesh Received on: 27 Sep 2013 Revised on: 3 Nov 2013 Accepted on: 16 Nov 2013 Online Published on: Jun 2015 *Correspondence E‐mail: me.hossain‐dasn@cvasu.ac.bd © 2010 Copyright by Islamic Azad University, Rasht Branch, Rasht, Iran Online version is available on: www.ijas.ir Research Article