Effect of Photoperiod on the Egg Production, Plasma Luteinizing Hormone, Follicle-Stimulating Hormone, Gonadal Hormones, and Mrna Levels of Lh and Fsh in the Hypothalamic-Pituitary-Gonadal Axis of Pigeons

We investigated the egg production, changes in luteinizing hormone (LH), follicle-stimulating hormone (FSH), gonadal hormones, and their mRNA levels in the hypothalamic-pituitary-gonadal axis of White King pigeons submitted to different photoperiods. The treatments consisted of three photoperiods (8 h light (L):16 h dark (D), 12L:12D, and 16L:8D), with three replicates of twelve pairs of adult pigeons. The birds were exposed the photoperiods for 45 days. Egg production performance was recorded daily. Six pigeon pairs per replicate were selected for plasma collection, and six pigeon pairs per replicate for the resection of the hypothalamic-pituitary-gonadal (HPG) axis. Egg production was significantly improved by long-day lighting (16L:8D), while no differences in egg shape index were detected. Higher average egg weight was obtained in 16L:8D group, whereas broken egg percentage was higher in the 8L:16D group. Female LH level was significantly higher in long-day lighting, and the FSH level significantly lower in short-day lighting. The females in the 16L:8D group had higher estrogen level. The photoperiods had a minor effect on plasma LH and testosterone in males, whereas the FSH level was significantly higher in the 16L:8D group. The level of LH mRNA expression was higher in both females and males of the 16L:8D group. Similar trends in FSH mRNA expression observed in both females and males. The 16L:8D photoperiod not only improved egg production, but also stimulated plasma LH, FSH, gonadal hormones, and promoted LH and FSH mRNA expression in pigeons.(AU)

Effect of Photoperiod on the Egg Production, Plasma Luteinizing Hormone, Follicle-Stimulating Hormone, Gonadal Hormones, and Mrna Levels of Lh and Fsh in the Hypothalamic-Pituitary-Gonadal Axis of Pigeons

We investigated the egg production, changes in luteinizing hormone (LH), follicle-stimulating hormone (FSH), gonadal hormones, and their mRNA levels in the hypothalamic-pituitary-gonadal axis of White King pigeons submitted to different photoperiods. The treatments consisted of three photoperiods (8 h light (L):16 h dark (D), 12L:12D, and 16L:8D), with three replicates of twelve pairs of adult pigeons. The birds were exposed the photoperiods for 45 days. Egg production performance was recorded daily. Six pigeon pairs per replicate were selected for plasma collection, and six pigeon pairs per replicate for the resection of the hypothalamic-pituitary-gonadal (HPG) axis. Egg production was significantly improved by long-day lighting (16L:8D), while no differences in egg shape index were detected. Higher average egg weight was obtained in 16L:8D group, whereas broken egg percentage was higher in the 8L:16D group. Female LH level was significantly higher in long-day lighting, and the FSH level significantly lower in short-day lighting. The females in the 16L:8D group had higher estrogen level. The photoperiods had a minor effect on plasma LH and testosterone in males, whereas the FSH level was significantly higher in the 16L:8D group. The level of LH mRNA expression was higher in both females and males of the 16L:8D group. Similar trends in FSH mRNA expression observed in both females and males. The 16L:8D photoperiod not only improved egg production, but also stimulated plasma LH, FSH, gonadal hormones, and promoted LH and FSH mRNA expression in pigeons.

Effects of dietary copper on growth performance, slaughter Performance and nutrient content of fecal in Growing Goslings from 28 to 70 days of age

A dose-response experiment with four dietary copper concentrations (4.17, 8.17, 12.17 and 16.17 mg/kg) was conducted to estimate the growth performance, slaughter performance, nutrient content of fecal and liver copper concentrations of growing Goslings from 28 to 70 d of age. Two hundred healthy male Yangzhou geese with similar body weight were randomized to four groups with five replicates per treatment and ten geese per replicate. Average daily feed intake, average daily gain and feed conversion ratio of geese for each pen were measured from 28 to 70 d of age. At 70 d of age, two geese were selected randomly from each pen and slaughtered to evaluate carcass quality. Metabolism experiment was conducted with five male geese from each group (one goose per pen) which body weight was close to the mean weight of the group from 64 to 70 d of age. Significant effects of dietary copper was found on body weight, feed conversion ratio, carcass yield, fecal copper concentrations and liver copper concentrations. Body weight, feed conversion ratio and carcass yield showed significant quadratic response to increase dietary copper concentration, while fecal copper concentration and liver copper concentration showed a significant linear response. The result showed that dietary Cu addition can improve growth by increasing the use of the feeding stuff and improving carcass yield in growing Goslings. Furthermore, taking into consideration, the optimal level of Gosling dietary copper was between 8.77 and 11.6 mg/kg from 28 to 70 days of age.(AU)

Effects of dietary copper on growth performance, slaughter Performance and nutrient content of fecal in Growing Goslings from 28 to 70 days of age

A dose-response experiment with four dietary copper concentrations (4.17, 8.17, 12.17 and 16.17 mg/kg) was conducted to estimate the growth performance, slaughter performance, nutrient content of fecal and liver copper concentrations of growing Goslings from 28 to 70 d of age. Two hundred healthy male Yangzhou geese with similar body weight were randomized to four groups with five replicates per treatment and ten geese per replicate. Average daily feed intake, average daily gain and feed conversion ratio of geese for each pen were measured from 28 to 70 d of age. At 70 d of age, two geese were selected randomly from each pen and slaughtered to evaluate carcass quality. Metabolism experiment was conducted with five male geese from each group (one goose per pen) which body weight was close to the mean weight of the group from 64 to 70 d of age. Significant effects of dietary copper was found on body weight, feed conversion ratio, carcass yield, fecal copper concentrations and liver copper concentrations. Body weight, feed conversion ratio and carcass yield showed significant quadratic response to increase dietary copper concentration, while fecal copper concentration and liver copper concentration showed a significant linear response. The result showed that dietary Cu addition can improve growth by increasing the use of the feeding stuff and improving carcass yield in growing Goslings. Furthermore, taking into consideration, the optimal level of Gosling dietary copper was between 8.77 and 11.6 mg/kg from 28 to 70 days of age.