Growth, Nutrient Utilization and Amino Acid Digestibility of Dairy Calves Fed Milk Replacers Containing Different Amounts of Protein in the Preruminant Period

"H Li, Q Y." Diao,N F Zhang,Z Y Fan

doi:10.5713/ajas.2008.70562

Abstract

This study was designed to examine the effects of different dietary protein levels on growth performance, nutrient utilization, amino acid (AA) digestibility and serum biochemical parameters of preruminant dairy calves. Fifteen healthy new-born calves were randomly allotted to three experimental groups and fed with different milk replacer that contained 18% (LP), 22% (MP) or 26% (HP) of protein. The results showed that final BW, net gain and ADG were significantly higher in the MP group than in LP and HP groups (p 0.05). BUN concentration, on the other hand, decreased as calves grew but increased following the increase of dietary CP content. Furthermore, no significant differences in digestibility of amino acids were observed among these three groups of animals (p>0.05). We concluded that calves fed with milk replacer containing 22% of protein had better growth performance and nutrient utilization as compared to animals treated with milk replacer containing either 18% or 26% of protein.

Highlights

One of the major challenges of rearing preruminant calves on the dairy farm is to reduce feed costs (Babu et al, 2003)
The milk replacers contained 18%, 22%, and 26% of crude protein (CP), and were reconstituted to 12.5% solid content and fed at 10% of body weight (BW) daily; feeding was allocated across three times at 8:30, 14:00, and 20:30 and the amount fed to each calf was adjusted with growth
Growth performance Initial BW did not differ among the three groups

Summary

Introduction

One of the major challenges of rearing preruminant calves on the dairy farm is to reduce feed costs (Babu et al, 2003). One effective strategy is using milk replacer (MR) instead of whole milk for young calves. Protein is the most expensive and key component in formulating rations for animals. The optimum level of protein in the diet remains to be determined. The level of protein in the diet of calves is critical, because excessively low or high protein content can cause animal production, welfare and environmental problems. Several researchers have stated the absolute need to accurately define the protein requirement for dairy calves as well as the optimal protein level in milk replacer (Blome et al, 2003; Lohakare et al, 2006)

Objectives

Methods

Results