부산대학교 도서관

The diet of growing buffalo heifers altering in energy levels can potentially impact growth performance and its relative parameters. The present study was conducted with objectives to evaluate the influence of varying dietary energy levels on dry matter intake (DMI), live weight gain, average daily gain (ADG), feed efficiency (FE), structural measurements and body condition score (BCS) in growing pre-pubertal Nili-Ravi buffalo heifers. Eighteen heifers at an age of 220 ± 8 days, weighing 140.5 ± 2.8 Kg and BCS of 2.9 ± 0.1 were randomly assigned to one of the three dietary treatments (n=6 heifers/treatment). Experimental duration was 16 weeks including 14 weeks of data collection and a 2 week pre-experimental adaptability where TMR of NRC 100% recommendations was offered. Three treatments were; 1-ME100%, 2- ME 112% and 3- ME 125% TMR diets containing dietary ME levels of 100%, 112% and 125% of NRC 2001 recommendations for pre-pubertal growing heifers, respectively. These higher levels of energy were achieved by increasing the concentrate level as well as by adding by-pass fat in respective diets. Formulated TMR's were isonitrogenous, made for 150 to 250 Kg live BW heifers, and aimed to achieve a target ADG of 0.8 kg/d. Offering was individual, at 2.8% live BW in two equal feedings and adjusted every fortnight while orts were collected daily. Body weight, BCS and structural measurements were taken at start and biweekly thereafter. Total DMI and DMI as a % of BW were lower (P≤0.05) for the ME 125% as compared to the ME 112% and ME 100%. The heifers fed ME112% gained more weight (total and ADG) (P≤0.05) than those fed ME100%. Whereas, FE improved with increasing level of energy in the diets above NRC (2001) recommendations. Structural measurements and BCS of heifers remained unaffected (P>0.05) for all the treatments. The cost per unit gain in ME100% and ME112% treatments was comparable; whereas, it was higher (P≤0.05) in ME125% treatment. The results of present study implicate that a target ADG of 800 g can be achieved by feeding TMR with 12% higher energy level than the NRC recommendations. Feeding TMR diet with ME 112% of NRC also improved FE in pre-pubertal Nili-Ravi buffalo heifers at a comparative cost. [ABSTRACT FROM AUTHOR]