Egg quality and production performance of laying hens injected with growth hormone and testosterone in the late phase of production

Abstract

In this study, 160 73-week-old laying hens (HyLine W-36) were used to investigate the changes in production performance and egg quality parameters of aged laying hens after injection of different doses of growth hormone (GH) and a fixed dose of testosterone (Ts). The hens were weighed individually, placed in laying cages and then randomly assigned to four treatments with four replicates of 10 birds each, in a completely randomised design. The experiment was started at the 75th week and lasted until the 82nd week of age. The treatments were: 1: injection of 100 µL distilled water (control group), 2: injection of 500 µg Ts/kg liveweight + 50 µg GH/kg liveweight, 3: injection of 500 µg Ts/kg liveweight + 100 µg GH/kg liveweight and 4: injection of 500 µg Ts/kg liveweight + 150 µg GH/kg liveweight. In this study, ovulation rate (egg production percent), egg mass and feed intake were significantly higher in Treatment 3 than the control group (P < 0.05), and in Treatment 4, feed conversion ratio was significantly higher than for the other experimental groups (P < 0.05). In addition, the birds in Treatment 3 showed greater egg weight, albumen height, eggshell weight, eggshell density and eggshell weight per surface area than the control group (P < 0.05). In Treatment 3, egg length significantly increased compared with Treatments 1 and 4 (P < 0.05), and in Treatments 2 and 4, shell breaking strength was significantly lower than for the control group (P < 0.05). In conclusion, our results showed positive effects of GH and Ts administration on egg quality parameters and production performance in aged laying hens. Taken together, in the present study Treatment 3 was found more effective in improving egg quality and production performance of the old laying hens.

Variation and Association of Hen Performance and Egg Quality Traits in Individual Early-Laying ISA Brown Hens

“…The average CVs observed for shell weight and shell thickness suggest uniformity in shell quality across the experimental period. These were similar to those observed in the control group of the study by Mohammadi et al [ 26 ], as well as in the study of early-laying hens reported by Roberts et al [ 18 ]. There was, however, a 15% CV for shell breaking strength.…”

“…The CV of 3% for yolk index from this study suggests uniformity in yolk quality in early-laying hens between 25 and 30 weeks of age. The average yolk index in the current study was higher than that recorded by Mohammadi et al [ 26 ]. Yolk color is an important visual measure of egg quality which is linked to consumer preference [ 27 ].…”

Morphological changes of reproductive organs during egg formation of autochthonous Oravka hens

“…Immediately after slaughtering, whole ovary with follicular hierarchy and oviduct were removed in different stage of egg fromation (Table 1). Ovary weight, the weight of the first, second, third, fourth and fifth largest follicles were measured by Mohammadi and Ansari-Pirsaraei (2016). The oviduct weight, total length of oviduct, length of individual parts of oviduct were considered by modified method of Halaj (1983).…”

Impact of Royal Jelly, Gibberellic Acid and Testosterone Treatments on Some Productive, Egg Quality Traits and Economic Efficiency in Local Chicken Strain, During the Summer Season of Egypt.

“…While the highest values of the LBW and BWG were recorded in the groups injected with 200 μg Ts, or GA 3 , / Kg BW followed by the same level of RJ (20-48 Wks of age) when compared to the control group (Table 3). The increase in weight due to RJ, GA3 and Ts has effects similar to that of estrogen on hen body weight (Hiba, 2010;Elkomy et al, 2007 andMohammadi, 2015). From the oldest to the most recent they were showing that the LBW and BWG of the female chicks injected with 200 μg RJ, GA 3 and Ts increased compared to the control group.…”