Dosed Exposure to Low Temperature as a Breeding Background in The Selection of Gene Pool Breeds of Chickens for Viral Vaccines Production

Abstract

Background: One of the ways to utilize the potential of local breeds is to use them as producers of raw materials for the bio-industry (production of vaccines and diagnostics for animals and humans). Methods: Breeding of Russian White (PRWC) laying hens in 5 generations was carried out with the aim of increasing the output of allantois-amniotic fluid of embryos with a selective background (cooling of hatching eggs during the sensitive period of embryogenesis). In F5, the thermoregulation capabilities of 7-day-old PRWC chickens were studied in comparison with Amrox chickens under the influence of a daily stress factor (cooling at +10oC for 30 minutes) and raising at +22oC. The level of allantois-amniotic fluid output and biological activity of the Newcastle disease virus in F5 PRWC embryos in comparison with F0 and commercial line embryos was evaluated. Results: Day-old PRWC chicks responded to exposure to low sublethal temperature with muscle shivering, but, unlike Amrox chickens, they were active and retained the reflex of searching for food. PRWC chickens raised at low temperatures up to 7 days of age maintained the same growth rate as chickens raised at a common regime but used less residual yolk, which practically did not decrease the body temperature, and change the level of thyrotrophic hormone in response to the dosed exposure at low temperatures at 7 days of age. The content of doses of the Newcastle disease virus (EID50) in the extraembryonic fluid of F5-embryos of PRWC was 32.3 times higher than that of commercial line ones. Conclusion: PRWC chicks in the early neonatal period are more reactive at low temperature and have better thermoregulation mechanisms. PRWC embryos can be recommended for use in the production of various viral vaccines as well as diagnosticums.

Effects of Colored Polymer Light and Feed Forms on the Performance of Broiler Chickens in the Humid Tropical Climate

“…Water intake was positively correlated with rectal temperature in birds reared under white polymer, as the values of cloacal temperature and water intake were highest throughout the study. This result correlates with the report presented by Vaneekeren N et al and Stanishevshevskaya OL and Fedorava ES [24,11] who stated that one of the ways broilers exchange heat is by increasing their water intake. These results suggest that, higher luminosity stimulated physical activity, the low body temperature allowed better heat exchange, and therefore, there was less need for birds reared under the back polymer light filter to drink water.…”

“…Broiler starter chicks require environmental temperature of 29 -32°C, while environmental temperature of 23 -28°C is needed at the finished phase of the birds [10]. Stanishevshevskaya OL and Fedorava E.S [11] reported that a day-old chicks have difficulty in maintaining their body heat because their thermoregulatory capacity is not well developed. Heat stress has detrimental impacts on physiological function and growth performance, manifesting as lower feed consumption, reduced body weight gain, and lower feed efficiency [12].…”

Unveiling Comparative Genomic Trajectories of Selection and Key Candidate Genes in Egg-Type Russian White and Meat-Type White Cornish Chickens

“…In the time of the Soviet Union, RW was the major layer breed used for egg production [10]. Currently, only a small number of cold-tolerant and disease-resistant RW chickens are kept in the gene pool collection [19,20]. Identifying genomic regions affected by natural and artificial selection in breeds with different genetic backgrounds may give an insight into the history of domestication and selection for economically important traits [76][77][78][79].…”

“…Presently, the small RG population of cold-tolerant RW chickens (25 males and 234 females) is kept in the Genetic Collection of Rare and Endangered Chicken Breeds of the RRIFAGB. In the last two decades, the RW breeding program has been aimed at improved egg production and egg weight and increased yield of vaccine raw material, i.e., extraembryonic (allanto-amniotic) fluid and titers of vaccine viruses in it while maintaining cold tolerance of neonatal chickens [ 15 , 19 , 20 ]. There is also one more RW population maintained at the All-Russian Poultry Research and Technological Institute (ARPRTI) collection farm, Sergiev Posad.…”