Identifying the factors impacting on farmers' intention to adopt animal friendly practices.

Brazil, one of the leading countries in livestock production, has not yet developed legislation considering animal welfare issues and most of the actions to improve farm animal welfare (FAW) standards are developed by livestock industries and government focusing in meet the demands of exporting countries. Such actions resulted in FAW protocols and manuals for adoption of best management practices. In this context, farmers' decisions are of particular importance as they may comply with current FAW protocols or even decide to provide better FAW standards than required. A present example of farmers' decisions to provide better FAW standards than required by FAW protocols is in the adoption of environmental enrichment in pig farming. This practice is widely available to pig farmers, however, anecdotal evidence shows that the adoption rate is low. This study uses the theory of planned behavior (TPB) as a framework to identify the socio-psychological factors that influence pig farmers' intention to adopt environmental enrichment on their farms. The TPB hypothesizes that intention is determined by three psychological constructs: attitude, subjective norms, and perceived behavioral control. These three constructs are derived from behavioral, normative, and control beliefs, respectively. Self-identity was added as an additional construct to explain intention. A survey with 185 farmers was conducted. We used Partial-Least-Square Structural Equation Modeling (PLS-SEM) to identify the impact of attitude, subjective norms, perceived behavioral control, and self-identity on farmers' intention to adopt environmental enrichment on their farms. We used MIMIC models to identify the most important beliefs underlying farmers' intention to adopt environmental enrichment in their farms. Results show that the intention of farmers to adopt was mainly determined by their positive perceptions about their own capability to adopt environmental enrichment (perceived behavioral control), followed by their perceptions about the social pressure to adopt it (subjective norms), their positive evaluations of adoption (attitude), and self-identity. The most important behavioral beliefs were 'increase productivity', and 'decrease animals stress'. The most important normative beliefs were 'family', 'neighbor farmers', 'pig buyers', and 'experts'. The most important control belief was 'receive bonus when selling pigs'. These results revealed important implications to design public and private interventions aimed to stimulate the adoption of animal friendly practices.

Genomic selection in dairy cattle simulated populations.

Genomic selection is arguably the most promising tool for improving genetic gain in domestic animals to emerge in the last few decades, but is an expensive process. The aim of this study was to evaluate the economic impact related to the implementation of genomic selection in a simulated dairy cattle population. The software QMSim was used to simulate genomic and phenotypic data. The simulated genome contained 30 chromosomes with 100 cm each, 1666 SNPs markers equally spread and 266 QTLs randomly designated for each chromosome. The numbers of markers and QTLs were designated according to information available from Animal QTL (http://www.animalgenome.org/QTLdb) and Bovine QTL (http://bovineqtl.tamu.edu/). The allelic frequency changes were assigned in a gamma distribution with alpha parameters equal to 0·4. Recurrent mutation rates of 1·0e-4 were assumed to apply to markers and QTLs. A historic population of 1000 individuals was generated and the total number of animals was reduced gradually along 850 generations until we obtained a number of 200 animals in the last generation, characterizing a bottleneck effect. Progenies were created along generations from random mating of the male and female gametes, assuming the same proportion of both genders. Than the population was extended for another 150 generations until we obtained 17 000 animals, with only 320 male individuals in the last generation. After this period a 25 year of selection was simulated taking into account a trait limited by sex with heritability of 0·30 (i.e. milk yield), one progeny/cow/year and variance equal to 1·0. Annually, 320 bulls were mated with 16 000 dams, assuming a replacement rate of 60 and 40% for males and females, respectively. Selection and discard criteria were based in four strategies to obtain the EBVs assuming as breeding objective to maximize milk yield. The progeny replaced the discarded animals creating an overlapping generation structure. The selection strategies were: RS is selection based on random values; PS is selection based on phenotypic values; Blup is selection based on EBVs estimated by BLUP; and GEBV is selection based on genomic estimated breeding values in one step, using high (GBlup) and low (GBlupi) density panels. Results indicated that the genetic evaluation using the aid of genomic information could provide better genetic gain rates in dairy cattle breeding programs as well as reduce the average inbreeding coefficient in the population. The economic viability indicators showed that only Blup and GBlup/GBlupi strategies, the ones that used milk control and genetic evaluation were economic viable, considering a discount rate of 6·32% per year.

Genetic parameter estimation for pre- and post-weaning traits in Brahman cattle in Brazil.

Beef cattle producers in Brazil use body weight traits as breeding program selection criteria due to their great economic importance. The objectives of this study were to evaluate different animal models, estimate genetic parameters, and define the most fitting model for Brahman cattle body weight standardized at 120 (BW120), 210 (BW210), 365 (BW365), 450 (BW450), and 550 (BW550) days of age. To estimate genetic parameters, single-, two-, and multi-trait analyses were performed using the animal model. The likelihood ratio test was verified between all models. For BW120 and BW210, additive direct genetic, maternal genetic, maternal permanent environment, and residual effects were considered, while for BW365 and BW450, additive direct genetic, maternal genetic, and residual effects were considered. Finally, for BW550, additive direct genetic and residual effects were considered. Estimates of direct heritability for BW120 were similar in all analyses; however, for the other traits, multi-trait analysis resulted in higher estimates. The maternal heritability and proportion of maternal permanent environmental variance to total variance were minimal in multi-trait analyses. Genetic, environmental, and phenotypic correlations were of high magnitude between all traits. Multi-trait analyses would aid in the parameter estimation for body weight at older ages because they are usually affected by a lower number of animals with phenotypic information due to culling and mortality.