Alternative count Bayesian models for genetic evaluation of litter traits in pigs

The results of fattening hybrid pigs of Danish selection

The results of a study of the breed combinations that influence pigs of Danish selection on fattening, meat, and economic indicators are presented. The experimental animals were divided into two groups according to their genotype. The method of groups-analogs was applied. The pigs were similar in terms of conditional heredity, sex, age, and body weight within each group. Five animals from each group were slaughtered at the meat processing plant to study the meat qualities. These studies arose due to the constant search for the most successful and cost-effective options for breed combinations that guarantee the effect of heterosis in hybrid offspring, which determined the scientific novelty and relevance. The dependence on breed combinations of fattening and meat qualities of young pigs obtained by simple two-breed and complex three-breed industrial crossbreeding of breeds of Danish selection has been established. At the final stage of fattening, a significant intergroup difference was established in terms of the average daily increase in body weight in favor of pigs of the breed combination F2 ¼Y ¼L ½D at 5.4% at P > 0.999 compared with analogs of the breed combination F1 ½Y ½L. Crossbreeds of the F2 generation turned out to be more early maturing and reached a body weight of 100 kg in 168.1 days, compared to 173.2 days in crossbreeds of the F1 generation with a difference of 5.1 days (P > 0.95) and a slaughter weight of 110 kg with a difference of 5.5 days (P > 0.95). They also spent less feed by 0.18 feed units per 1 kg of body weight gain, but the intergroup difference was insignificant. At slaughter, the weight of the steamed carcass in the crossbreeds of generation F2 ¼Y ¼L ½D was higher by 6.7 kg (P<0.95), and the slaughter yield was higher by 5.9 % (P > 0.999). It is concluded that the combination of Yorkshire breeds with Landraces and Durocs achieves a high economic effect on pork production since the level of profitability of pork production in three-breed hybrids is higher by 6.6%, respectively than in two-breed ones.

Genetic parameters and litter trait trends of Danish pigs in South Vietnam

OBJECTIVE

The objective of this study was to estimate the genetic parameters and various litter trait trends of Danish pigs in South Vietnam, including the number born alive (NBA), number weaned (NW), and litter weight at the 21st day (LW21).

METHODS

Records of 936 Yorkshire sows with 3361 litters and 973 Landrace sows with 3161 litters were used to estimate the variance components, genetic parameters, and trends of NBA, NW, and LW21. The restricted maximum likelihood method was applied using VCE6 software to obtain the variance components and genetic parameters. Thereafter, the best linear unbiased prediction procedure with an animal model was applied using PEST software to estimate the breeding values of the studied traits.

RESULTS

The heritability estimates were low, ranging from 0.12 to 0.21 for NBA, 0.03 to 0.04 for NW, and from 0.11 to 0.13 for LW21. The genetic correlation between the NBA and NW was relatively strong in both breeds, at 0.77 and 0.60 for Yorkshire and Landrace, respectively. Similarly, the genetic correlation between the NW and LW21 was considerably stronger in Landrace pigs (0.71) than in Yorkshire pigs (0.48). The estimates of annual genetic progress were 0.0431, 0.0233, and 0.0461 for NBA, NW, and LW21 in Landrace pigs and 0434, 0.0202, and 0.0667 for NBA, NW, and LW21 in Yorkshire pigs, respectively.

CONCLUSION

The positive genetic trends estimated for the additive genetic values of the selected traits indicated that the current breeding system has achieved favorable results.

Impact of Bayesian Inference on the Selection of Psidium guajava

Perennial breeding species demand substantial investment in various resources, mainly the required time to obtain adult and productive plants. Estimating several genetic parameters in these species, in a more confidence way, means saving resources when selecting a new genotype. A model using the Bayesian approach was compared with the frequentist methodology for selecting superior genotypes. A population of 17 families of full-siblings of guava tree was evaluated, and the yield, fruit mass, and pulp mass were measured. The Bayesian methodology suggest more accurate estimates of variance components, as well as better results to fit of model in a cross-validation. Proper priori for Bayesian model is very important to convergency of chains, mainly for small datasets. Even with poor priori, Bayesian was better than frequentist approach.