Effect of Cow-Calf Supplementation on Gene Expression, Processes, and Pathways Related to Adipogenesis and Lipogenesis in Longissimus thoracis Muscle of F1 Angus × Nellore Cattle at Weaning.

The aim of this study was to identify differentially expressed genes, biological processes, and metabolic pathways related to adipogenesis and lipogenesis in calves receiving different diets during the cow-calf phase. Forty-eight uncastrated F1 Angus × Nellore males were randomly assigned to two treatments from thirty days of age to weaning: no creep feeding (G1) or creep feeding (G2). The creep feed offered contained ground corn (44.8%), soybean meal (40.4%), and mineral core (14.8%), with 22% crude protein and 65% total digestible nutrients in dry matter. After weaning, the animals were feedlot finished for 180 days and fed a single diet containing 12.6% forage and 87.4% corn-based concentrate. Longissimus thoracis muscle samples were collected by biopsy at weaning for transcriptome analysis and at slaughter for the measurement of intramuscular fat content (IMF) and marbling score (MS). Animals of G2 had 17.2% and 14.0% higher IMF and MS, respectively (p < 0.05). We identified 947 differentially expressed genes (log2 fold change 0.5, FDR 5%); of these, 504 were upregulated and 443 were downregulated in G2. Part of the genes upregulated in G2 were related to PPAR signaling (PPARA, SLC27A1, FABP3, and DBI), unsaturated fatty acid synthesis (FADS1, FADS2, SCD, and SCD5), and fatty acid metabolism (FASN, FADS1, FADS2, SCD, and SCD5). Regarding biological processes, the genes upregulated in G2 were related to cholesterol biosynthesis (EBP, CYP51A1, DHCR24, and LSS), unsaturated fatty acid biosynthesis (FADS2, SCD, SCD5, and FADS1), and insulin sensitivity (INSIG1 and LPIN2). Cow-calf supplementation G2 positively affected energy metabolism and lipid biosynthesis, and thus favored the deposition of marbling fat during the postweaning period, which was shown here in an unprecedented way, by analyzing the transcriptome, genes, pathways, and enriched processes due to the use of creep feeding.

Effects of Ionophores on Ruminal Function of Beef Cattle.

Ionophores have been widely used in the beef and dairy industry for decades to improve feed efficiency and performance by altering ruminal fermentation dynamics, increasing the level of propionate. Ionophores can also reduce ruminal proteolysis and ammonia synthesis, thus increasing the influx of protein into the small intestine in cattle, leading to improvements in performance and efficiency responses. Ionophores indirectly impact ruminal methanogenesis by decreasing the substrate used to produce methane. Despite the consistent benefits of using ionophores in cattle nutrition, their utilization is under public scrutiny due to concerns related to microbial adaptation. However, there is inconsistent evidence supporting these concerns, whereas ionophores are still an important dietary tool to enhance productivity and profitability in beef production systems.

Effects of Temperament on the Reproduction of Beef Cattle.

Temperament is often defined as the behavioral expression of animals in response to human interaction. Cattle temperament can be evaluated using an association of chute score and exit velocity, with cattle then classified as adequate or excitable temperament. To assess the impacts of temperament on various beef systems, these evaluation criteria were associated with productive and reproductive parameters of Bos taurus and B. indicus-influenced cattle. Consistently across studies, excitable cattle had greater plasma cortisol compared to animals with adequate temperament. Studies also reported that excitable beef females have poorer reproductive performance compared to calmer cohorts, including reduced annual pregnancy rates, decreased calving rate, weaning rate, and kg of calf weaned/cow exposed to breeding. Acclimating B. indicus × B. taurus or B. taurus heifers to human handling improved behavioral expression of temperament and hastened puberty attainment. However, similar benefits were not observed when mature cows were acclimated to human handling. Collectively, temperament of beef females measured via behavioral responses upon human handling impacts their reproductive and productive responses independent of breed type, and should be considered for optimal beef cattle production.

Omega-6 Fatty Acids: A Sustainable Alternative to Improve Beef Production Efficiency.

Global beef production must increase in the next decades to meet the demands of a growing population, while promoting sustainable use of limited natural resources. Supplementing beef cattle with omega-6 fatty acids (FAs) is a nutritional approach shown to enhance production efficiency, with research conducted across different environments and sectors of the beef industry. Omega-6 FA from natural feed ingredients such as soybean oil are highly susceptible to ruminal biohydrogenation. Hence, our and other research groups have used soybean oil in the form of Ca soaps (CSSO) to lessen ruminal biohydrogenation, and maximize delivery of omega-6 FA to the duodenum for absorption. In cow-calf systems, omega-6 FA supplementation to beef cows improved pregnancy success by promoting the establishment of early pregnancy. Cows receiving omega-6 FA during late gestation gave birth to calves that were healthier and more efficient in the feedlot, suggesting the potential role of omega-6 FA on developmental programming. Supplementing omega-6 FA to young cattle also elicited programming effects toward improved adipogenesis and carcass quality, and improved calf immunocompetence upon a stress stimulus. Cattle supplemented with omega-6 FA during growing or finishing periods also experienced improved performance and carcass quality. All these research results were generated using cattle of different genetic composition (Bos taurus and B. indicus influenced), and in different environments (tropical, subtropical, and temperate region). Hence, supplementing omega-6 FA via CSSO is a sustainable approach to enhance the production efficiency of beef industries across different areas of the world.

Supplementing Trace Minerals to Beef Cows during Gestation to Enhance Productive and Health Responses of the Offspring.

Nutritional management during gestation is critical to optimize the efficiency and profitability of beef production systems. Given the essentiality of trace minerals to fetal developmental processes, their supplementation represents one approach to optimize offspring productivity. Our research group investigated the impacts of supplementing gestating beef cows with organic-complexed (AAC) or inorganic sources (INR) of Co, Cu, Mn, or Zn on productive and health responses of the progeny. Calves born to AAC supplemented cows had reduced incidence of bovine respiratory disease and were >20 kg heavier from weaning until slaughter compared to unsupplemented cohorts. Complementing these findings, heifer progeny born to AAC supplemented cows had accelerated puberty attainment. Collectively, research demonstrates supplementing trace minerals to gestating beef cows may be a strategy to enhance offspring productivity in beef production systems.

Silvopastoral system is an alternative to improve animal welfare and productive performance in meat production systems.

Climate change is a reality and global surface temperature is projected to rise substantially in the next 80 years. Agriculture practices will have to adapt to climate change, and also help to mitigate this effect using, among other strategies, forest conservation and management. Silvopastoral systems have been adopted in tropical climate livestock areas but their benefits on thermal comfort and reproductive performance of beef cows are not completely known. Therefore, our aims were to compare the microclimate of silvopastoral and intensive rotational unshaded grazing systems in different months and to evaluate physiological variables (Exp. 1 and 2), metabolism, and in vitro embryo production (Exp. 2) in crossbred beef females. Our hypothesis is that the silvopastoral system can improve the thermal comfort of beef heifers and cows and, consequently, also improve dry matter intake, body weight gain, and in vitro embryo production when compared to the unshaded rotational grazing system. In Exp 1, the silvopastoral system decreased body temperature and increased welfare and performance of heifers. In Exp. 2, the silvopastoral system enhanced the body weight but did not affect metabolism and the general reproductive performance, but increased the recovery rate of oocytes in primiparous cows.

Administering an Appeasing Substance to Gir × Holstein Female Dairy Calves on Pre-Weaning Performance and Disease Incidence.

(1) Background: Ruminants often face stressful situations throughout their productive lives. More specifically, pre-weaning dairy calves are exposed to novel environments, feedstuffs, and pathogens that affect their health and performance. Hence, alternatives that reduce stress and promote growth of pre-weaning dairy calves are warranted. Therefore, this study evaluated the effects of biweekly bovine appeasing substance (BAS) administration on performance and disease incidence in dairy Gir × Holstein female calves prior to weaning. (2) Methods: At birth, 140 female Gir × Holstein calves were randomly assigned to receive BAS (SecureCattle; (IRSEA Group, Quartier Salignan, France; n = 70) or placebo (BAS carrier, diethylene glycol monoethyl ether; CON; n = 70) biweekly until weaning (70 days of age). Calves were allocated into individual housing at random, with no physical contact between treatments to avoid cross-contamination. Experimental treatments (5 mL) were applied topically to the nuchal skin area of each calf. Throughout the experimental period, all animals were observed daily for medical conditions (diarrhea, pneumonia, and others), medical/pharmacological interventions were recorded, and the costs related to these procedures were analyzed. Concurrently with treatment application, calves were individually weighed, and data were analyzed using animal as the experimental unit. (3) Results: Treatment × day and treatment × period (14-day interval) interactions were observed for body weight (BW) and average daily gain (ADG; p ≤ 0.05), respectively. Calves receiving BAS had greater BW at weaning (p = 0.02) and tended to have a greater BW on day 56 (p = 0.06). Similarly, ADG was greater for BAS from days 42 to 56 (p = 0.04) and tended to be greater from days 56 to weaning (p = 0.10). No differences were observed on the overall occurrence of diseases (p = 0.92), whereas the most common observed diseases were diarrhea and pneumonia. The incidence and mean age at which animals were detected with these diseases did not differ (p ≥ 0.46). Nonetheless, CON calves detected with disease had a reduced ADG vs. BAS-administered counterparts (p < 0.01). No differences were observed between disease-diagnosed BAS vs. healthy CON, but healthy BAS had a greater ADG vs. healthy CON (p = 0.03). A treatment effect was observed for the cost per head of each pharmacological intervention (p = 0.05). (4) Conclusions: In summary, BAS administration at a 14-day interval improved performance and reduced the costs of pharmacological interventions of pre-weaning Gir × Holstein dairy calves.

Performance and economic analysis of broilers fed diets containing acerola meal in replacement of corn / Desempenho e análise econômica de frangos de corte alimentados com dietas contendo farelo de acerola em substituição ao milho

It was aimed with this research to evaluate the performance of broiler chickens fed diets containing increasing levels of acerola meal in replacement of corn and analyze the economic viability of that production system. A total of 980 day-old male Cobb chicks were used, allotted in a completely randomized design, with four treatments - inclusion levels (0%, 5%, 10% and 15%) of acerola meal in replacement of corn – and seven replications with 35 birds per experimental unit. The birds were weighed at 21 and 42 days of age to measure the performance data. In the period between 1 and 21 days of age, differences were observed in the feed intake and feed:gain only, in which the inclusion of acerola meal linearly decreased feed intake and improved feed:gain up to a level of 10.25%. For the total rearing period, the control treatment showed higher body weight. The feed:gain showed linear effect, worsening the results with increasing amounts of acerola meal in the diets. In the same period, there was no significant difference in feed intake and productive efficiency index. With regard to the economic analysis, it was found that the lowest final cost per broiler was observed in diets with 10% of acerola meal inclusion in replacement of corn.

Objetivou-se com a pesquisa avaliar o desempenho de frangos de corte alimentados com dietas contendo níveis cres- centes de inclusão de farelo de acerola em substituição ao milho e analisar a viabilidade econômica deste sistema de produção. Foram utilizados 980 pintos de corte com um dia de idade, machos, da linhagem Cobb, distribuídos num delineamento inteiramente casualizado, com quatro tratamentos – níveis de inclusão (0, 5, 10 e 15%) de farelo de acerola em substituição ao milho - e sete repetições com 35 aves por unidade experimental. Aos 21 e 42 dias de idade, as aves foram pesadas para a mensuração dos dados de desempenho. No período de 1 a 21 dias de idade, foram observadas diferenças somente no consumo de ração e na conversão alimentar, nos quais a inclusão de farelo de acerola diminuiu linearmente o consumo de ração e melhorou a conversão alimentar até o nível de 10,25%. No período total de criação, o tratamento controle apresentou maior peso corporal. A conversão alimentar apresentou efeito linear, piorando os resultados com o aumento da quantidade de farelo de acerola nas dietas. Nesse mesmo período, não houve diferença significativa no consumo de ração e no fator de produção. Quanto à análise econômica, verificou-se que o menor custo final por frango foi observado nas dietas com 10% de inclusão de farelo de acerola em substituição ao milho.