EFFECT OF STARTING BODY FAT CONTENT OF LEGHORN-TYPE LAYING HENS ON THE CHANGES IN THEIR BODY FAT CONTENT, EGG PRODUCTION AND EGG COMPOSITION DURING THE FIRST EGG LAYING PERIOD

The experiment was carried out with 60 TETRA BLANCA laying hens chosen from 250 TETRA BLANCA pullets based on their body fat content, predicted at 16 weeks of age by means of computer tomography (CT). Pullets with the highest (n=20), lowest (n=20) and average (n=20) body fat content were chosen for the investigation. Changes in the body fat content of the experimental animals were followed by means of computer tomography in vivo, scanning the hens at every fourth week of the experiment, between 20 and 72 weeks of age. Eggs produced by these birds, were collected at 32, 52 and 72 weeks of age and, after breaking them, their yolk, albumen and egg shell ratio was determined and their dry matter, crude protein and crude fat content was chemically analyzed. Based on the results it was established that the body fat content of the hens started the egg production with high body fat content being higher than that of the hens started the egg production with average or low body fat content during the whole experimental period. The differences in the body fat content of the two extreme groups were statistically proven between 24 and 48 weeks of age (P0.05) by the starting body fat content of the hens

Multiple Effects of Egg Weight, in Ovo Carbohydrates, and Sex of Birds on Posthatch Performance in Broilers

Chickens raised for their meat (Gallus gallus domesticus) tend to have a critical phase of life right after hatching due to the management of modern production systems. Early nutrition strategies such as in ovo intervention can be an alternative means to support growth and gut health by compensating for the energy deficit after pipping out of the egg. In the current study, 1200 Ross 308 eggs were used to examine the effects of a complex carbohydrate solution of disaccharides and glucose applied in ovo on hatchability, the hatching time of different-sized eggs, and the development, performance, and carcass characteristics of broilers of both sexes. The eggs were divided into three treatment groups: intact (NT), in ovo saline (ioS), and in ovo carbohydrate mixture (ioCH). The incubation protocol was performed according to the recommendations of Aviagen (2019), and the in ovo process was carried out on day 17 by manually injecting 0.5 mL of the solutions into the amniotic fluid. After hatching, the birds were kept in floor pens until day 35 and fed ad libitum in a three-phase feeding program. Body weight, average daily weight gain, feed intake and conversion, and carcass characteristics were measured during the trial. In ovo carbohydrates reduced hatchability by 15%, while growth performance and the weight of thigh and breast muscle were enhanced significantly (p < 0.05) compared with ioS as a possible outcome of carbohydrate-to-muscle satellite cell proliferation and protein accumulation. However, further study is needed to refine the in ovo carbohydrate supplementation method to minimize the mortality of embryos during hatching