Some factors affecting voluntary food intake in buffaloes. 2. Effect of feeding mixed diets

Abstract

Seven non-pregnant Murrah buffalo heifers aged 20-34 months and weighing 170-260 kg were used in a 7 x 4 incomplete latin square design to study the effect of feeding mixed diets on voluntary intake over a period of 84 days. Voluntary intake and rate of passage were determined during the last 10 days and digestibility of feed nutrients during the last 6 days of each 21-day experimental period.Maize stover, dry grass and wheat straw were fed ad libitum mixed with either a fixed quantity of berseem hay (MH, GH and WH rations, respectively) or concentrates (MC, GC and WC rations, respectively) to total co. 0-80% of body weight (BW). Berseem hay fed free choice mixed with limited (0-70% BW) concentrates (HC ration) comprised another treatment. The mean daily total dry-matter intake (DMI g/kgW° 75 ) and total digestible nutrient intake (given in parenthesis) by animals were 62-2 (1-94), 72-2 (2-20), 74-3 (2-30), 75-2 (2-94), 79-5 (2-59), 85-9 (2-78) and 88-5 (2-98), respectively on MH, GH, WH, HC, MC, WC and GC rations. The digestible crude protein intake on the HC ration was higher than on the remaining six rations. Feeding a fixed quantity of either berseem hay or concentrates resulted in lower consumption of basal roughages suggesting that the physical capacity of the gut limited intake.Dry-matter digestibility (%) and mean retention time (h), given in parenthesis, ) and 58-9 (66-0), respectively on MH, GH, WH, HC, MC, GC and WC rations. The digestibilities of D.M. and proximate principles, except crude fibre (CF), of the HC ration were higher than those of the remaining six mixed diets. Concentrate feeding tended to hasten the movement of digesta of the roughage portion of the mixed diet through the digestive tract. The longest mean retention and rumen retention times were associated with the highest digestibilities. The wheat straw-berseem hay mixed diet was as good as dry grass or maize stover-berseem hay mixed diets with regard to its nutrient intake and weight gain by the heifers. approximately equal to the maximal intake of the better quality roughage when fed alone. Hillman Under ordinary farm feeding conditions it is an (1969) observed that the total dry-matter intake accepted practice to feed a good quality roughage (total DMI) of animals fed silage ad libitum together mixed with a poor quality one or, where good with a limited quantity of hay, was increased when quality roughages are not available, to feed a compared with the intake of silage D.M. when silage restricted quantity of concentrates with the poor was fed alone. Similarly, Miller et al. (1965) also quality roughages in order to get optimum pro-noted higher total DMI of cows fed mixed forages, duction. Not much is known about the effect of one in fixed amounts and the other fed ad libitum feeding a fixed quantity of good quality roughage though intake of forage fed ad libitum was deon intake of poor quality roughages fed ad libitum creased. The addition of restricted amounts of and on total intake. Blaxter, Wainman & Davidson concentrates have ...