The dynamics of mitochondrial-linked gene expression among tissues and life stages in two contrasting strains of laying hens

The cellular energy metabolism is one of the most conserved processes, as it is present in all living organisms. Mitochondria are providing the eukaryotic cell with energy and thus their genome and gene expression has been of broad interest for a long time. Mitochondrial gene expression changes under different conditions and is regulated by genes encoded in the nucleus of the cell. In this context, little is known about non-model organisms and we provide the first large-scaled gene expression analysis of mitochondrial-linked genes in laying hens. We analysed 28 mitochondrial and nuclear genes in 100 individuals in the context of five life-stages and strain differences among five tissues. Our study showed that mitochondrial gene expression increases during the productive life span, and reacts tissue and strain specific. In addition, the strains react different to potential increased oxidative stress, resulting from the increase in mitochondrial gene expression. The results suggest that the cellular energy metabolism as part of a complex regulatory system is strongly affected by the productive life span in laying hens and thus partly comparable to model organisms. This study provides a starting point for further analyses in this field on non-model organisms, especially in laying-hens.

Allium-Based Phytobiotic for Laying Hens’ Supplementation: Effects on Productivity, Egg Quality, and Fecal Microbiota

The poultry industry is constantly demanding novel strategies to improve the productivity and health status of hens, prioritizing those based on the holistic use of natural resources. This study aimed to assess the effects of an Allium-based phytobiotic on productivity, egg quality, and fecal microbiota of laying hens. One hundred and ninety-two 14-week-old Lohmann Lite LSL hens were allocated into an experimental farm, fed with a commercial concentrate with and without the Allium-based phytobiotic, and challenged against Salmonella. Productivity, egg quality, and fecal microbiota were monitored for 20 weeks. Results showed that the phytobiotic caused an increase on the number of eggs laid (p < 0.05) and in the feed conversion rate (p < 0.05); meanwhile, egg quality, expressed as egg weight, albumin height, haugh units, egg shell strength, and egg shell thickness remained unchanged (p > 0.05), although yolk color was decreased. Fecal microbiota structure was also modified, indicating a modulation of the gut microbiota by increasing the presence of Firmicutes and Bacteroidetes but reducing Proteobacteria and Actinobacteria phyla. Predicted changes in the functional profiles of fecal microbiota suggest alterations in metabolic activities that could be responsible for the improvement and maintenance of productivity and egg quality when the phytobiotic was supplemented; thus, Allium-based phytobiotic has a major impact on the performance of laying hens associated with a possible gut microbiota modulation.

Modulating effect of growth hormone on the functional state of cultured cells from hen preovulatory follicles

Somatotropic hormone (STH) is an important positive modulator of ovarian function in mammals. Local production of STH and the expression of the corresponding specific receptors were also detected in hen ovarian follicles, which indicates the participation of this hormone in the endocrine/paracrine control of folliculogenesis in birds. Nevertheless, the role of STH in the regulation of growth of avian follicles at the final stage of maturation is still not clear.Objective: To study in vitro the effect of STH on the proliferative activity and apoptotic changes of granulosa and theca cells from preovulatory follicles of domestic hens.Materials and methods. Young laying hens aged 34-35 weeks with a long clutch were used in the experiments. Granulosa and theca cells were isolated from the largest yellow follicle in the hierarchy (F1). The cells were cultured in a medium containing 10% fetal bovine serum until a monolayer was formed, and then for 24 h in the medium without serum in the absence (control) or in the presence of STH at various concentrations (1-100 ng/ml). The proliferative activity and apoptotic changes in the cells were assessed by immunocytochemical assay, based on the expression level of proliferating cell nuclear antigen PCNA and pro-apoptotic protein Bax, respectively.Results. The proportion of PCNA-positive granulosa cells increased 1.3-1.8 times (P<0.01-0.05) as compared to control with increasing the content of STH in the medium to 10-100 ng/ml. Furthermore, within this concentration range, the studied hormone reduced 1.2-1.6 times (P<0.05) the relative number of granulosa cells with the positive reaction to Bax. The sensitivity of theca cells to the growth-stimulating effect of STH was lower than that of granulosa cells. Such the effect of STH led to an increase in the proportion of PCNA-positive thecal cells by 1.2-1.3 times (P<0.05) and was detected only at concentrations of 25 and 100 ng/ml. Meanwhile, STH (25-100 ng/ml) increased 1.3 times (P<0.05) the level of Bax expression in theca cells.Conclusions. The results of the present study indicate the stimulating effect of STH in vitro on the proliferative activity of granulosa and theca cells from the most mature hen preovulatory follicle. In addition, STH is able to reduce the expression of the pro-apoptotic protein Bax in granulosa cells and increase this expression in thecal cells. Thus, the data obtained indicate the possible participation of STH in the regulation of growth and development of follicles at the final stage of maturation during the period of maximum egg-laying intensity in laying hens.

Effect of energy and dose of vitamin E selenium on improving the reproduction performance of Joper brood stock

Production performance in Joper broodstock can be improved through increased feed energy and vitamin E-selenium supplementation. This study used 400 laying hens Isa Brown aged 35 weeks and 15 Sentul rooster aged 68 weeks. This study used a factorial completely randomized design with 2 factors, namely metabolic energy levels (2,700 and 2,800 kcal/kg) and vitamin E-selenium supplementation doses (0, 25, 50, 75 and 100 ppm) where each treatment used 10 laying hens and repeated 4 times. The dose of selenium is 0.001 ppm/mg vitamin E. The energy level has a very significant effect (P < 0.01) on (feed, protein and energy) intake and HDP. The dose level of vitamin E- selenium in feed had a very significant effect (P < 0.01) on HDP and significant (P < 0.05) on (feed, protein and energy) intake and FCR. The interaction between the two has a very significant effect (P < 0.01) on HDP. The average feed intake 113-115 g/day, protein intake 21.90-22.20 g/day and energy intake 308-317 kcal/bird. HDP 76.70-83.00%. The conclusion of this study is that feed with metabolic energy of 2800kcal/kg and vitamin E-selenium supplementation at a dose of 100 ppm can improve the productivity of Joper broodstock.

Use of the feed additive “Toxinon” in feeding of replacement young chickens and laying hens

At the present time of the development of industrial poultry farming, the main tasks are to increase the productivity of poultry, reduce production costs and improve its quality. Under practical conditions, there is a shortage of minerals in compound feed for poultry, which leads to a violation of metabolism in the body, slowing down growth and development, deterioration of the work of organs and systems, a decrease in productivity and its quality, and an increase in the prime-cost of production. The purpose of the research was to study the effectiveness of the use of the feed additive “Toxinon” in feeding of replacement young chickens and laying hens. The research has been carried out under the conditions of OOO “Bogotolskaya Poultry Farm” in the Bogotolsky area in the Krasnoyarsk Territory. Comprehensive studies have been conducted to study the effect of the feed additive “Toxinon” on the growth and development, productivity and metabolism of replacement young chickens and laying hens of the industrial herd of the cross “Haysex brown”. The influence of different dosages of the feed additive “Toxinon” on the growth rate, livestock livability, digestibility and use of feed nutrients, egg productivity, egg quality, hematological and biochemical blood parameters of replacement young chickens and laying hens has been studied. The laying hens of the 3rd experimental group were distinguished by the highest egg productivity during the experiment period, which exceeded the control group in terms of the gross number of eggs by 6,4 %, the intensity of egg production by 5,02 abs.%, egg weight by 3,0 % (P > 0,95), the yield of egg mass on the average laying hen by 9,12 %. At the same time, expenditures of feed in the 3rd experimental group have decreased compared to the control group by 7,3 % for 10 eggs, by 9,2 % for 1 kg of egg mass. It has been found that in feeding replacement young chickens and laying hens, the most effective use of the feed additive “Toxinon” in the dosage of 0,25 % of the weight of the feed mixture (2,5 kg/ton of feed).