1Colegio de Postgraduados, Montecillo, Estado de México
2Ingeniería Agronómica y Zootecnia, Benemérita Universidad Autónoma de Puebla
3Universidad Autónoma Metropolitana, Unidad Xochimilco
4Universidad Autónoma Metropolitana, Unidad Iztapalapa
5Facultad de Medicina Veterinaria y Zootecnia, Universidad Autónoma del Estado de México
6Faculty of Agriculture (El-Shatby), Alexandria University, Egypt
Centro Nacional de Investigación Disciplinaria en Fisiologia y Mejoramiento Animal, INIFAP, Ajuchitlán, Qro, 76280, México
*Corresponding author: asalem70@yahoo.com
Online published on 15 May, 2014.
The aim of this study was to evaluate the effect on the productive performance, apparent digestibility of DM, serum phosphorus and phosphorus balance in Holstein calves which received a high concentrate diet with different doses of exogenous phytase for a period of 60d. The experiment was conducted with a completely randomized design with three treatments of eight calves each, the treatment included dietary supplementation of exogenous phytase at 0, 12 and 24 g/ton. Phytase inclusion increased (P<0.05) average daily gain when phytase was supplemented at 24 (850g) as compared to 0 (816g) or 12 (809g) g/ton. However, it had no effect (P>0.05) on DM intake, feed conversion and DM digestibility. Adding phytase in the diet decreased phosphorus excretion in faeces (P<0.05) showing a significant linear increase with increasing level of supplementation (the values being 9.96, 9.14 and 8.13 g/d) which, in turn, increased the P retention (4.69, 5.37 and 6.45 g/d, resectively, for the three groups). In conclusion, supplementation of phytase could improve the growth performance of calves without any discernible effects on feed intake or digestibility of nutrients.
Calves, Growth, Holstein, Phytase
