Some factors affecting voluntary food intake in buffaloes. 3. Effect of concentrate feeding on intake of roughages fed to lactating buffaloes

Abstract

SummaryThree experiments, each with six lactating Mehsana-Surti buffaloes, were conducted to investigate the effect of supplementary feeding of concentrates on intake of basal rations of berseem hay, maize silage or wheat straw and on the total intake of feeds in 3 × 3 latin square designs.In the berseem hay experiment, concentrate feeding at 16·8 or 26·1% of hay drymatter intake (DMI) resulted in a decrease of hay DMI by 0·77 and 0·65 kg/kg concentrate D.M., respectively. Intake of total digestible nutrients (TDN) and digestible crude protein (DCP) of buffaloes receiving concentrates in addition to hay were not different from those receiving hay alone. The possibility of some chemical factor limiting feed intake has been indicated for these rations in buffaloes. Supplementary feeding had a little effect on milk production.In the maize silage experiment, concentrate feeding at 14·5 and 27·7% of the silage DMI resulted in a similar increase of total DMI, thereby increasing the TDN intake and DCP intake. Appreciable increases in milk yield and solids-not-fat (SNF) content due to supplementation were noted, although milk-fat content tended to be low.Voluntary intake of rations comprising wheat straw fed free choice with three levels of concentrates at 28·7, 48·0 and 68·8 % of straw DMI was studied in the third experiment. Concentrate supplementation had little effect on straw DMI with the result that intakes of total D.M., TDN and DCP on the medium and high proportions of supplements were higher than those on the low proportion. The milk yield, of buffaloes receiving medium and high proportions of concentrates with wheat straw increased significantly over those receiving the low proportion of concentrates. The SNF and milk-fat contents were similar on all the three treatments. The implication of physical factors limiting intake is discussed in the case of maize silage and wheat straw diets.The lactating buffaloes failed to maintain their weights on either sole berseem hay or sole maize silage rations. Supplementary feeding helped buffaloes to register small weight gains on hay rations and substantial gains on silage rations. The buffaloes on wheat straw fed with three proportions of concentrates tended to put on a little weight. Multiple regression using pooled data of Expts 1 and 3 showed that the partial regression coefficient of metabolic body weight (kgW0·76) on TDN intake was not significant but that of 6% fat-corrected milk on TDN intake was, suggesting a close relationship between milk yield and food intake.