Abstract:

The study examined the effect of bovine somatotropin (bST) in mid-lactating Nili-Ravi buffaloes (n = 18) given varying levels of Enzose (corn dextrose) in a urea-treated wheat straw (UTWS) based ration on nutrient intake, digestibility, nitrogen (N) utilisation, milk yield, and its composition in a completely randomised design with a 2 x 3 factorial arrangement. The control ration contained 60% UTWS and 40% concentrate. The other 2 rations were formulated to replace 50% or 100% concentrate portions of the ration with Enzose of equivalent energy. Enzose is a liquid derived from the enzymatic conversion of corn starch to dextrose, and is light amber in colour. These rations were offered to buffaloes administered 0 or 250 mg bST, biweekly, for a period of 100 days. The bST administration increased (P < 0.05) dry matter (DM), crude protein (CP), nitrogen (N) retention, neutral detergent fibre (NDF), and acid detergent fibre (ADF) intakes. Buffaloes fed a ration containing 50% Enzose as replaced by concentrate had higher DM, CP, NDF, and ADF intakes than those fed 100% Enzose. The NDF and ADF digestibilities, daily milk yield, and milk fat% were also increased by bST administration while the reverse was true for buffaloes fed replacement of 100% concentrate. Overall N balance was not affected either by bST administration or Enzose addition to the ration. Enzose interacted (P < 0.05) with bST for milk yield and milk ash contents. The bST administration in buffaloes increased milk production by 37%. Up to 50% concentrate can be replaced with Enzose in the ration.

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