EFFECTS OF DIETARY SUPPLEMENTATION WITH ZINC AND BETAINE ON GROWTH PERFORMANCE AND SOME PHYSIOLOGICAL RESPONSES FOR GROWING RABBITS UNDER HOT CONDITIONS

Document Type : Original Article

Authors

Rabbit Res. Department, Anim. Prod. Res. Inst., ARC, Ministry of Agric., Egypt.

Abstract

Sixty weaned males APRI line rabbit about 35 days with average initial weight 530±10.3 gm were randomly distributed into six experimental groups (10 per each) from June to August (hot season). Group 1 fed the basal diet as control (C). While, groups 2 (R1, basal diet+100mg zinc/kg diet), 3 (R2, basal diet+160 mg betaine/kg diet), 4 (R3, basal diet+320 mg betaine/kg diet), 5 (R4, basal diet+100mg zinc+160 mg betaine/kg diet) and 6 (R5, basal diet+100mg zinc+320 mg betaine/kg diet). Initial body weight, final body weight (FBW), feed intake (FI), body weight gain (BWG), feed conversion ratio (FCR), total protein (TP), albumin (ALB), globulin (GL), red blood cells (RBCs), white blood cells (WBCs), packed cell volume (PCV%), total antioxidant capacity (TAC), malonaldehyde (MAD), thiroxine (T4), triiodotherionine (T3), carcass characteristics and economic study were determined.
Results showed significant (P≤0.05) increases in FBW, BWG and significant (P≤0.05) improving in FCR in all treated groups compared with the control one. Dressing and testes percentages were significant (P≤0.05) increasing compared with the control. Also, RBCs, WBCs, PCV% and lymphocytes were increased in treated groups while neutrophils and eosynophils were decreased compared with the control one. Zinc showed significantly (P≤0.05) increasing lymphocytes and monocytes compared with control. While betaine recorded a decreasing in neutrophils compared with zinc and control groups. There were decreasing in TP, ALB, GL and TAC in control group comparable with all treated groups. Also, control group significantly (P≤0.05) increased in cholesterol and MAD. The economic efficiency values and relative economic efficiency were significantly improved in all treated groups compared with control group.
Conclusively: using fed supplemented with 100 mg zinc/kg feed for growing APRI rabbit could be recommended for realizing best results of growth performance, carcass characteristics and relative economic efficiency% during summer season.

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