Influence of weaning management at 30, 75 and 180 days of age on non-esterified fatty acids and reproductive performance in beef cows.

This study aimed to investigate the effect of age at weaning of calves on non-esterified fatty acids (NEFA) and reproductive parameters of beef cows. Animals (n = 65) were randomly assigned to three treatments after calving: hyper-early weaning (W30) at 32 ± 0.89 days, early weaning (W75) at 77 ± 0.95 days, and conventional weaning (W180) at 183 ± 0.82 days. Body weight (BW) and body condition score (BCS) were evaluated at parturition (AP) and at 30, 45, 64, 81, 100 and 115 days postpartum (dPP). Blood samples were collected to analyze NEFA levels and progesterone (P4) at 30, 45, 64 and 81 dPP. Higher BW and BCS were observed from 64 to 115 dPP in W30 cows than W180 ones (p < 0.05). Cows subjected to W30 condition had higher levels of NEFA at 30 dPP compared to 64 and 81 dPP (p < 0.05). We also observed that cows from W180 group showed decreased levels of NEFA at 30 dPP compared to 45 (p < 0.01) and 64 dPP (p < 0.05). The highest P4 level was observed at 64 dPP in W30 cows compared to W75 and W180 (p < 0.05). We also observed higher CR of W30 (86%) compared to W180 (47%) at 45 dPP (p < 0.05). The overall pregnancy rate (PR) was higher for W30 (95.5%) than W180 (73.9%). In addition, higher BW at calving and P4 levels at 30 dPP were positively correlated with the possibility of pregnancy (p < 0.05). Improvement in BW and BCS were observed in cows subjected to hyper-early weaning management. However, levels of NEFA decreased as the postpartum period progressed. We concluded that cows who weaned calves hyper-early have greater chances of increasing cyclicity and PRs.

Panorama and ambiguities of cultured meat: an integrative approach.

The purpose of this research was to identify, through a systematic review of the literature, the strengths, weaknesses, threats and opportunities of the production and commercialization of cultured meat, as well as to analyze the challenges to be faced by this new food biotechnology. For this, we analyzed 194 manuscripts published in the Scopus and Web of Science databases that dealt with cultured meat under the perspective of cellular agriculture, employing several nomenclatures. The results indicate that there is still no consensus in the literature about the strengths, weaknesses, threats and opportunities of cultured meat, which constitutes an emerging, multifaceted, and encouraging field of study, and a series of inferences have been made that provide insights into the knowledge analyzed. Finally, we propose an analytical model that combines sub-scenarios from which it becomes possible to understand and anticipate the direction of this new food biotechnology.

Typology of beef production systems according to bioeconomic efficiency in the south of Brazil / Tipologia de sistemas de produção de carne bovina de acordo com a eficiência bioeconômica no sul do Brasil

ABSTRACT: The objective of this study was to evaluate the bioeconomic efficiency of beef cattle production systems in the south of Brazil. A survey was conducted with 33 beef cattle farmers operating with complete cycle production systems in areas larger or equal to 900 ha. Answers were classified in two drivers, technology (TEC) and management (MAN), which were separated into subfactors with their respective components. Multiple correspondence analysis, Tukey test, cluster analysis, and Pearson correlation were the statistics procedures. The TEC components were above normal for Brazilian farmers, but the gross margin is still lower than that needed to generate financial resources for a proper remuneration of cattle farmer. Farmers were classified into three clusters according to bioeconomic efficiency: low (LEL), intermediate (IEL), or high-efficiency level (HEL). The TEC driver differentiated the LEL x HEL clusters and the MAN, mainly expressed in costs, the IEL x HEL. Positive correlation between age at first mating and age at slaughter in the HEL cluster explains the higher costs when compared to IEL because of the use of differentiated feed resources. Investments in technologies related to herd feeding in HEL cluster improved the productivity by only 20% and the cost per hectare by 95 USD ha-1 in comparison to IEL cluster. The main differences between farmers are because of the use of technologies related to feeding and cost management. Therefore, before implementing a new technology, an economic evaluation is necessary.

RESUMO: O objetivo deste estudo foi avaliar a eficiência bioeconômica em sistemas de produção de bovinos de corte no sul do Brasil. A pesquisa foi realizada com 33 pecuaristas que operam com sistemas de produção baseado em ciclo completo, em áreas maiores ou iguais a 900 hectares. As respostas foram classificadas em dois fatores: tecnologia (TEC) e gestão (GES), os quais foram separados em subfatores com seus respectivos componentes. A análise de correspondência múltipla, teste de Tukey, análise de cluster e correlação de Pearson foram os procedimentos estatísticos. Os componentes do TEC estavam acima do normal para os pecuaristas brasileiros, mas a margem bruta ainda é menor do que a necessária para gerar recursos financeiros para uma remuneração adequada ao pecuarista. Os pecuaristas foram classificados em três grupos de acordo com a eficiência bioeconômica: baixo (BNE), intermediário (INE) ou alto nível de eficiência (ANE). O driver TEC diferenciou os clusters BNE x ANE e o GES, expresso principalmente em custos, o INE x ANE. A correlação positiva entre a idade no primeiro acasalamento e a idade ao abate no agrupamento ANE explica os custos mais elevados quando comparados aos INE, devido ao uso de recursos alimentares diferenciados. Os investimentos em tecnologias relacionadas à alimentação de rebanho no agrupamento ANE melhoraram a produtividade em apenas 20% e o custo por hectare em 95 USD ha-1 em comparação ao cluster INE. As principais diferenças entre os pecuaristas se devem ao uso de tecnologias relacionadas à alimentação e ao gerenciamento de custos. Portanto, antes de implementar uma nova tecnologia, uma avaliação econômica é necessária.