Which factor is more important: Intensity or duration of episodic heat stress on broiler chickens?

Influence of heat stress on the reproduction rates of sows of the Poltava meat breed, depending on the genotype

The article deals with the issues of the influence of heat stress that occurs in the summer on the indicators characterizing the reproductive qualities. Purebred sows of tested Poltava meat breed of different genotypes were investigated: Group I - individuals-offspring obtained by the method of introductory crossing using the blood of early maturing meat breed (blood content 12.5 %), Group II - individuals obtained by the method of introductory crossing using the blood of the Finnish Landrace (blood content of 12.5 %). It was found that in sows of the Poltava meat breed with the blood of early maturing meat breed, the number of live piglets at birth significantly exceeds the indices of sows with the blood of the Finnish Landrace by 8.27 % at p≤0.05. According to the analysis of Cv, these natural and technological conditions had the greatest influence on the duration of the service period in sows of Group I. Wherein, the least influence of these natural and technological conditions was found for the indicator of the duration of pregnancy. Animals with the blood of an early maturing meat breed were more adaptable to these natural and technological conditions.