Matheus Lehnhart de Moraes

This study evaluated the impact of increasing the dilution rate on the outflow of nitrogen (N) compounds in a semi-continuous culture fermenter (RUSITEC). Five semi-continuous culture fermenters were used to test three dilution rates of the liquid phase (3, 5, and 7 %/h) in an incomplete 3 × 3 Latin square design. Three 10-day assays were performed, each consisting of a 5-day adaptation and stabilization period followed by 5 days of sampling. Each fermenter received 10 g of a total mixed ration, and artificial saliva was continuously infused, at the different experimental rates. The liquid effluent was measured and sampled daily for further analysis. Increasing the dilution rate did not affect N degradability or ammonia-N outflow, but linearly increased the outflow of small peptides and decreased the outflow of amino acids (p < 0.05). The sum of free amino acids and small peptides flowing out of the fermenter represented 21 to 54% of the N that disappeared from bags. The outflow of small peptides from fermentation vessels was directly impacted by increased dilution rate of the incubation medium, indicating that they may contribute significantly to the rumen undegradable protein fraction of feedstuffs.

Objective: To investigate the relationship between socioeconomic indicators and the concentration of milk production in the state of Rio Grande do Sul (RS), with the aim of highlighting the importance of the activity. Theoretical Framework: Milk production in RS is characterized by family farming, and several studies have already identified the main milk-producing regions and municipalities. However, few studies have related this activity to socioeconomic indicators, as well as its impact on municipal development. Method: The methodology adopted in this research comprises a multivariate analysis using three variables that characterize dairy farming (Milk production, Number of cows, and Production per km²) and three socioeconomic variables (Territorial area, Municipal HDI, and GDP per capita). Data collection was carried out using historical data from the Brazilian Institute of Geography and Statistics (IBGE), the United Nations Development Programme (UNDP), and the Foundation for Economics and Statistics (FEE). Subsequently, a Principal Component Analysis was conducted using R software. Results and Discussion: The results revealed that Production per area (Thousand liters/km²) is a variable that characterizes milk production in RS municipalities and is correlated with the Municipal HDI. Research Implications: The practical and theoretical implications of this research highlight the socioeconomic importance of dairy farming in RS. Originality/Value: This study contributes to guiding public resources and investors in the dairy supply chain in RS.

The aim of this study was to evaluate the effects of diphenyl diselenide (PhSe) supplementation during the transition period on the metabolism, immunity, oxidative status, and milk production of postpartum dairy cows. Twenty-seven Holstein females were divided into groups: (PhSe) (DDG), which received 3 μmol/kg of (PhSe)₂ in 4 mL of dimethyl sulfoxide (DMSO) subcutaneously, DMSO (DMSOG), and NaCl (NACLG) which received 4 mL of DMSO and 0.9% NaCl. Evaluation of body condition score (BCS), weighing and administrations were performed at 42, 28, and 14 days prepartum, and on the day of calving (0). On days 0, 7, 14, 21, and 35 postpartum, BCS was evaluated, and blood were collected. Colostrum was obtained from the first postpartum milking. Production was measured, and milk was collected on days 7, 14, 21, and 35 postpartum. DDG showed higher values of total protein (TP) and globulins (GLOB) 7 days postpartum and increase from day 0 to days 21 and 35. DDG immunoglobulin G (IgG) was higher on days 21 and 35, and increased between days 7 and 21. In postpartum TP, GLOB and IgG are physiologically reduced, therefore, the results indicate that supplementation of transition females with (PhSe) stimulated postpartum humoral immunity.

The present study evaluated the effect of increasing levels of wet brewery residue (WBR) as a source of roughage on nutrient intake, performance and ingestive behaviour in lambs finished in confinement. Thirty-two uncastrated male lambs were used, weaned at 50 days of age. The treatments comprised increasing levels of WBR as roughage in the diet: 31, 44, 57 and 70%, on a dry-matter. The concentrate consisted of disintegrated corn, soybean meal, calcitic limestone and mineral salt. There was a quadratic effect (P ≤ 0.05) from the increasing levels of WBR on the intake of DM, OM, CP and TCH. The intake of EE, NDF and ADF increased linearly (P ≤ 0.01), while TDN intake showed a linear reduction (P < .0001) for increases in the level of WBR. There was a quadratic effect (P ≤ 0.010) on the average daily weight gain (ADG) from the addition of WBR to the diet. The time spent on feeding and rumination (P ≤ 0.05), expressed in minutes, showed a linear increase. Feeding rate for DM showed decreasing linear behaviour (P ≤ 0.006), while NDF rumination rate showed increasing linear behaviour (P ≤ 0.013) due to the increased levels of WBR in the diet. There was a linear increase in the time spent on each feeding activity (P ≤ 0.007) with the increase in WBR in the diet. Maximum weight gain is achieved when 46.9% WBR is used as a source of roughage in the diet, and this level can be recommended for terminating lambs in confinement.

Mineral nutrition for dairy cattle has advanced considerably in recent decades. The requirements, as well as the entire metabolism of each mineral element, have been demystified by science, attributing accuracy in the predictions of liquid requirements. These advances also allow us to understand the factors that influence absorption, metabolism and their impact on the animal's organism. Among the mineral elements, the macroelements represent the highest cost in the formulation of supplements and/or mineral cores, and often the excessive supplementation of these can cause serious damage to the cows, in addition to contamination of the environment. In this context, this review summarizes the main advances in mineral macroelements nutrition for dairy cattle, as well as their requirements, main sources, functions, absorption, excess and interactions with other mineral elements.

The aim of this study was to analyse precocity behaviour over nine years in Hereford steers and their crosses, slaughtered with from zero to six teeth. Approximately 144,000 certified carcases in the Carne Pampa programme were analysed between 2010 and 2018. The increase in cold carcase weight per year was evaluated for three periods of the year: the hot season was defined as 26 December to 25 May, the autumn void was defined as 26 May to 25 July, and the cold season from 26 July to 25 December. To assess the behaviour of cold carcase weight over the years per season, the data were submitted to simple linear regression analysis. The average weights per season were compared by the mean value comparison test. The cold season had the highest mean carcase weight, with 239.1 kg, showing an annual increase of 6.45 kg. Analysing the behaviour of mean carcase weight by dentition, animals with zero teeth showed a greater weight increase over the years during the cold season as well as during the autumn void; during the hot season, animals slaughtered with two teeth showed the greater increase in weight. The category that showed the least increase in weight for all three seasons were animals slaughtered with six teeth. It was concluded that over the nine years, there was an increase in slaughter precocity in male cattle certified in the Carne Pampa programme.

This study aimed to evaluate the effect of using different high-grain diets on the carcass characteristics and tissue composition of the meat of feedlot-finished lambs. Thirty-two male castrated Texel lambs born from single births and weaned at approximately 50 days of age were allotted to treatments that consisted of different unprocessed grains, as follows: corn grain, white oat grain, black oat grain, or grain of rice in the husk. The animals were slaughtered upon reaching the pre-established slaughter weight of 32 kg, which corresponds to 60% of the mature weight of their mothers. Lambs fed the high-corn grain diet had higher weights and yields of hot and cold carcass and larger loin-eye areas than those finished in the feedlot receiving high-grain diets based on white oat, black oat, or rice in the husk. Additionally, they had a higher degree of fatness and a thicker subcutaneous fat layer at slaughter, which lead to decreased cooler shrink loss. The neck, shoulder, ribs, and leg cuts were heavier in lambs fed the high-corn grain diet. By contrast, these lambs had a lower proportion of leg, more rib, and higher meat fat content, which may be undesirable for the consumer market. The use of high-corn grain diets, in comparison with high-grain diets based on black oat, white oat, and rice in the husk, may be recommended for finishing lambs in the feedlot when they are slaughtered at similar weights.