| The broiler studied was from a commercial line of broiler chicken (AV), and the feasible study of cool temperature brooding in broiler was carried out at KaoHe Zai Form in Harbin. The broilers were randomly divided into three groups. The control groupefined as group C) was raised at 32-34 X? in the first week. The cool temperature group 1 efined as group 1) and 2 efined as group 2) were raised at 3 1-33 C in 1-3 days and 30-3 1 C at 4-7 days; From the beginning of the second week, every group was raised at the different brooding temperature regime. The breeding temperature of group C, group 1 and group 2 were respectively reduced to 20 C at 35 days, 28 days and 21 days. Through the observation and analysis of the production performance and development of viscera apparatus related to metabolism ., power of immune and biochemical index, we estimated comprehensively the effect of cool temperature brooding in broilers.(1) Data, collected from the first experiment, analysis showed that the mean body weight of birds at 7 weeks of age was 2799.18g, 2824.18g and 2850.12g in the group C, group 1 and group 2 respectively. And the mean body weight of birds at 7 weeks of age was correspondingly 2704. 62g, 2801 .41 g and group 2 in the group C, group 1 and group 2 respectively in the second experiment It indicated that the mean body weight of birds at 7 weeks of age of the cool temperature group was better than that of the group C.(2) Data, collected from the first experiment, analysis showed that the livability of birds at 7 weeks of age was 92.33%, 94.33% and 91% in the group C, group 1 and group 2 respectively. And the livability of birds at 7 weeks of age was correspondingly 92.47%, 94 and 93.01% % in the group C, group 1 and group 2 respectively in the second experiment It indicated that the livability of birds of the cool temperature group at 7 weeks of age was better than that of the group C, especially that the group 1 was 1-2 percentage higher than that of the group C.(3) Data, collected from the first experiment, analysis showed that the FCR of birds in 1-7 weeks of age was 1.95, 1.98 and 1.89 % in the group C, group 1 and group 2 respectively. And the FCR of birds in 1-7 weeks of age was correspondingly 2.18, 2.1 1 and 2.13 in the group C, group 1 and group 2 respectively in the second experiment. It indicated that the FCR of birds in 1-7 weeks of age of the cool temperature group was better than that of the group C.(4) Data, collected from the first and second experiments, analysis showed the weight of birds of the thyroid gland and adrenal gland at 7 weeks of age hadn't significant difference between the group 1 and the group C, which showed that the resigned temperature of the group 1 didn't influence significantly on the metabolic function of the thyroid gland and adrenal gland; And the weight of birds of the thymus gland at 7 weeks of age of the groupl was higher than that of the group C (p0.05), which showed that the weight of the thymus gland had an increasing trend with the decreasing of brooding temperature; the weight of birds of the spleen at 7 weeks of age of the group 1 was lower than that of the group C(p<0.05), which showed that thevariational discipline of the thymus gland and the spleen in the group 1 wasn't consistent with that of the cold stress, it was a cool adaptation for broilers in this brooding temperature. (5) Data, collected from the first and second experiments, analysis showed that there was a trend that the plasma T3 -, T4 concentration at 7 weeks of age was higher than that of T3 T4 at 5 weeks of age, which was consistent with the increasing trend of body weight And in the first experiment, there was a trend that the plasma T4 s T3 concentration at 5 weeks of age of the group 1 and the group 2 was lower than that of the control group, and the group 1 was lower than the group 2. And in the second experiment, there was a trend that the plasma T4 concentration at 5 and 7 weeks of age of the group 1 was higher than that of the group C, and the group 2 was lower than...
|
PDF Full Text Request