Effect of Source and Level of Zinc Supplementation on Productive and Reproductive Performance of New Zealand White Rabbits

Abstract: This study was carried out to investigate the effect of dietary Zn supplementation in inorganic (zinc sulfate, ZnSO4) and organic (zinc methionine, Zn-Met) forms at two levels (100 or 200 ppm/kg) on productive performance, evaluation of the experimental diets, immune response, genitalia organs development, semen characteristics and fertilizing ability of rabbit bucks on New Zealand White rabbits. One hundred male New Zealand White rabbit (at 6 weeks of age, 808 ± 11g average body weight) were divided into five homogenous groups. The 1st group was fed basal diet as a control, the 2nd and the 3rd groups were fed on the same diet supplemented with 100 or 200 mg Zn/kg diet as zinc sulfate (ZnSO4, inorganic form) and the 4th and the 5th groups were fed on the same diet supplemented with 100 or 200 mg zinc methionine (Zn-Met, organic form).The aim of the experiment was to study the effect of source of zinc (organic and inorganic form) and the level of zinc supplementation on productive performance, growth performance (live body weight, body weight gain, feed intake, feed conversion ratio, live rabbit percentage, digestibility coefficients of DM, OM, CP, CF and EE, nutritive values as DCP and TDN, and efficiency of immune response of growing New Zealand White (NZW) male rabbits.
Eighteen ejaculates from each buck (two ejaculates/day, three times in the 1st week of 7th, 8th and 9th months of age) were collected and evaluated for semen quality. At the 1st week of 7th, 8th and 9th months of age), five bucks of each group were bred with 20 receptive nulliparous female rabbits. Results of testosterone concentration in blood, sperm cell concentration, motility (%), live sperm (%) and intact acrosome (%) were significantly (P<0.01) higher in Zn-supplemented groups, especially in an organic form (Zn-Met) as compared to the control group. Results revealed improved (P<0.01) in semen characteristics with advancing age in Fertilizing ability of bucks was increased significantly (P<0.05) from 60.0% (36/60) in the control group to 66.67% (40/60), 75.0% (45/60), 75.0% (45/60) and 80.0% (48/60) in bucks groups fed diets supplemented with 100 mg ZnSO4 and 200 mg ZnSO4, 100 mg Zn-Met and 200 mg Zn-Met/kg diet, respectively. Inclusion 200 mg Zn-Met/kg diet improved insignificantly fertilizing ability of bucks compared to 100 mg Zn-Met/kg diet. Results revealed positive correlation between testosterone concentration and sperm cell concentration, motility, live sperm, intact acrosome percentages and fertilizing ability rate (r= 0.649, 0.598, 0.550, 0.548 and 0.731, respectively; P<0.001). It can be concluded that dietary Zn supplementation, especially in an organic form of rabbit bucks improved testosterone concentration and semen characteristics, which could result in better fertility.
Key words: Rabbit, zinc inorganic & organic, growth, blood, semen quality, fertility.
Publication year 2014
Pages PP. 145
Availability location مكتبة معهد بحوث الانتاج الحيوانى شارع نادى الصيد- الدقى- الجيزة
Availability number 1290
Organization Name
Country Egypt
Author(s) from ARC
Agris Categories Animal physiology - Reproduction
Blood. Fertility. Growth. Immunity. Production. Rabbits.
Proposed Agrovoc semen quality;Organic zinc;Inorganic zinc;
Publication Type PhD Thesis