Selection indexes for Nellore production system in the Brazilian Pantanal

Abstract

The objective was to develop selection indexes for Nellore cattle raised in full-cycle production system in the Brazilian Pantanal. The resulting offspring are retained as replacements or sold at two years of age. Preliminary analyses explored effects of scale on economic values (EV). However, given the available data, these effects were very small. Presented herein are results from a simulated system consisting of 5,000 cows with all animals maintained on pasture as is typical in Pantanal. The EV were determined by approximating the partial derivatives of the profit function, changing one trait at a time, by one unit, while keeping the other traits constant. Traits in the breeding objective were mature cow weight, direct and maternal weaning weight, postweaning average daily gain, subcutaneous fat depth, longissimus muscle area, and stayability. Economic values were calculated on the basis of number of animals (per head), number of animal units, and arroba of carcasss weight. Regardless of the basis, maternal weaning weight and subcutaneous fat depth made negligible contributions to the breeding objective. Proportions of variation in the breeding objectives (per head, per animal unit, per arroba) explained by cow weight, direct weaning weight, postweaning average daily gain, stayability, and longissimus muscle area were:

Classificação do Desempenho dos Rebanhos de Seleção Nelore por meio de Aprendizado de Máquina

“…Ou seja, compõem aspectos importantes para o aumento da eficiência da cadeia produtiva da pecuária de corte, do nascimento dos animais até o abate. A combinação destas características compondo índice para os diferentes rebanhos poderá ter aspecto importante na condução futura do projeto, inclusive com a inserção dos pesos econômicos das características para estruturar um índice de seleção próprio para os rebanhos, adequados ao sistema e ambiente no qual os rebanhos são manejados (Portes, et al, 2021). Para realizar o aprendizado com os métodos J48, RF e LMT foram utilizado 80% da base de dados para "ensinar" o algoritmo (1357 animais).…”

Biosecurity assessment of commercial pig farms in Santa Catarina, Brazil

“…In the state of Paraná, Brazil, Stoffel & Rambo (2022) found that R$541,112.40 was the investment necessary for an integrated pig finishing farm designed to produce 1,365 animals per production batch. However, in the country, most studies on pig farms focus on the analysis of production costs (Araújo et al, 2016;Portes et al, 2019;Alves et al, 2022) and not on needed investments. In addition to this lack of studies, the reality of pig production in the state of Santa Catarina is quite diverse, which leads to the conclusion that any attempt to estimate a common figure would only be an approximation.…”