Association between Egyptian calves performance and growth hormone and IGF-1 levels under different housing types

Abstract

This study was planned to examine the climatic effects of three housing types on the performance of Egyptian calves and its relationship with growth hormone (GH) and Insulin-like growth factor-1 (IGF-1). To achieve this goal, 18 weaned calves, three months old, and had average body weight (BW) 79.81 ± 7.42 kg were used to obtain animals' performance data throughout 540 days of age. Animals were divided into three equal groups, as follows: 1st, semi-open type shaded roofed with concrete slab and topped with three rows of rice straw bales (CS); 2nd, semi-open type shaded roofed with a layer of an iron sheet (PS); 3rd, opened type without shading or roof and exposed to the direct solar radiation (WS). Results indicated that thermo-regulatory, hematological parameters, GH, and IGF-1 levels were found to be significantly (P< 0.01) affected by the housing types provided. The CS housing type showed significant (P< 0.01) improvement in average daily gain (ADG) and feed conversion compared to other types. Closed positive correlations were observed among age, BW, ADG, and IGF-1 concentration. However, GH concentration recorded negative correlations with the previous traits. Reproductive performance parameters were improved significantly with CS housing type compared to others. It could be concluded that using CS housing type provides more comfortable climatic conditions for Egyptian calves than other housing types under middle Egypt conditions. Also, data of IGF-1 concentration may be a useful aid in selection strategies for improved growth and reproductive efficiency.