Reproductive qualities of boars in the assessment of adaptive capabilities when using introductory crossbreeding of different variants

Background. The article deals with the study of the reproductive performance of breeding boars of Poltava meat breed when using different variants of introductory crossbreeding. At the same time, the objectives of using introductory crossbreeding determine the dynamics of changes.

By introductory crossing in the breed new genotypes were created with Finnish Landrace pigs (in order to improve productive qualities) and fast-ripening meat pigs (in order to increase the adaptive capacity of animals to natural and climatic conditions of the farm). To conduct research we formed four groups according to the principle of pair-analogs: Group I – boars descendants of introductory crossbreeding, with a share of blood of the fast-ripening meat breed 25%, Group II – boars descendants of introductory crossbreeding, with a share of blood of the Finnish Landrace breed 25%, Group III – boars descendants of introductory crossbreeding, with a share of blood of the fast-ripening meat breed 50%, Group IV – boars descendants of introductory crossbreeding, with a share of blood of the Finnish Landrace breed 50%. We evaluated boar development indicators (live weight, body length, age at 100 kg live weight, thickness of the bailiffs follower) and indicators characterizing reproductive capacity (number of inseminated and farrowed breeding sows, fertilizing capacity of the boar, multiple fertility of farrowed breeding sows, weight of one piglet at weaning at 45 days).

Infusion of Finnish Landrace blood in order to improve meat qualities leads in boars of Poltava meat breed to a violation of adaptive capabilities, manifested in an increase in the age of achieving a live weight of 100 kg and a decrease in reproductive performance, not actively involved in the selection process. Increasing the level of bloodlines of breeding boars up to 50% for Finnish Landrace breed is not reasonable in these natural and climatic conditions and will require additional costs to improve efficiency.

The infusion of blood of the soon-to-be ripe meat breed to boars of Poltava meat breed with the purpose of improvement of adaptive qualities leads to strengthening of adaptive properties of the organism, by means of increase of protective capabilities and increase of reproductive indicators.

Purpose. The aim of the study is to investigate reproductive qualities of boars in the evaluation of adaptive capabilities when using introductory crossbreeding of different variants

Materials and methods. The data of 40 breeding boars-producers of Poltava meat breed, belonging to genetic groups with the infusion of blood of Finnish Landrace and soon-breeding meat breed, were used in the work. All animals belonged to the elite and first classes. The age of the animals was 24 months.

We evaluated boar development indicators (live weight, body length, age at 100 kg live weight, thickness of the rump) and indicators characterizing reproductive capacity (number of inseminated and farrowed sows, fertilizing capacity of the boar, multiple fertility of farrowed sows, weight of one piglet at weaning at 45 days, weight of one piglet at weaning at 45 days).

Results. As a result of the study it was found that in boars of Poltava meat breed of all examined groups the obtained average values of live weight and body length did not differ significantly from each other.

The study revealed that the use of introductory crossbreeding using 25% bloodlines for the two improving breeds did not cause significant changes in the average number of sows inseminated and interviewed. Increasing the proportion of bloodlines up to 50% resulted in multidirectional significant differences depending on the breeds used. Thus, the use of Finnish Landrace breed decreased the value of both studied indicators by 20.96 head (64.6%) (p≤0.05) and 15.77 head (66.4%) (p≤0.05), respectively.

When the proportion of bloodlines of the fast-ripening meat breed increased from 25% to 50%, boars showed a significant increase in the number of farrowing sows by 9.85 head or 41.5% (p≤0.05). This group also showed the highest value of fertilizing ability of boars. The difference amounted to 13.49% (p≤0.05) compared to the group with lower bloodlines. No significant differences were found in groups with Finnish Landrace blood for this indicator.

Conclusion. The infusion of the blood of the fast-ripening meat breed in order to increase the adaptive qualities of the Poltava meat breed and increasing the share of its bloodline up to 50% led to a reliable increase in reproductive indicators (the number of inseminated sows, the number of farrowing sows, the fertilizing ability of the boar), not related to the primary in the breeding process, but determining, among other things, the efficiency of the pig breeding industry.

In the indicators of development, the use of blood of the early maturing meat breed was reflected in the indicator of the thickness of the speck. We found a significant increase in fat thickness with increasing bloodlines of the fast-ripening beef breed. Earlier studies have clearly shown that increased fat thickness can have a favorable effect on reproductive performance. Our study also demonstrated a significant effect of rump thickness on the fertilizing ability of boars. Taking into account that an increase in the thickness of the rump can be considered as an increase in the protective properties of the skin, it gives us the opportunity to talk about the increase in the protective and adaptive (adaptive) capabilities of the organism in this case.