Camila Ten Kathen Jung

This study evaluated the effects of dietary inclusion of free and protected acid protease on productive performance, milk composition, metabolic profile, nutrient digestibility, and ruminal environment in lactating Jersey cows. Fifteen multiparous cows (67 ± 7.5 days in milk; 27.5 ± 3.5 kg/day) were assigned to a 3 × 3 Latin square (5 squares) design with 21-day periods. Treatments consisted of: control (no enzyme), free protease (4.4 g/day), and protected protease (4.4 g/day). The protected form was developed using alginate-based encapsulation to enhance enzyme stability under ruminal conditions. Protease inclusion did not affect dry matter intake, milk yield, or feed efficiency (p > 0.05). However, free protease increased lactation persistency (p = 0.05) and improved fat-corrected and energy-corrected milk yields (p ≤ 0.02), with intermediate responses observed for protected protease. Milk fat and protein contents were higher in enzyme-fed cows (p ≤ 0.05), while other compositional parameters remained unchanged. Apparent crude protein digestibility was greater in cows receiving free protease (p = 0.037), with no effects on dry matter or fiber digestibility. Protease intake increased total volatile fatty acid concentrations and major fermentation products (acetate, propionate, and butyrate; p ≤ 0.01), indicating enhanced ruminal fermentation. Blood metabolites showed increased total protein and globulin levels in cows fed free protease (p ≤ 0.05), suggesting improved protein metabolism. Microbiota analysis revealed no differences in alpha or beta diversity; however, specific microbial taxa and predicted metabolic pathways were modulated by treatments, particularly in post-ruminal compartments. In conclusion, exogenous protease, especially in free form, improved protein utilization and corrected milk production without disrupting microbial stability. These findings highlight the potential of protease as a nutritional strategy to enhance efficiency in dairy systems through targeted modulation of ruminal function and nutrient metabolism.

The combination of additives in ruminant diets is a growing strategy focused on cow health and productivity; therefore, the additives need to have synergistic effects when combined. Because of this, the objective of this study was to evaluate the effects of combining functional additives (biocholine, live yeasts, Yucca schidigera extract, and exogenous enzymes) on the productive performance, milk quality, rumen environment, oxidative status, and metabolic parameters of lactating Jersey cows maintained in an intensive system as well as verifying whether the effects on metabolism and the rumen environment (volatile fatty acids and microbiota) directly or indirectly influence productive efficiency. Eighteen Jersey cows in their second lactation were used, distributed in a completely randomized design into two groups: control, receiving a basal diet, and treatment, receiving the same diet plus the additive mixture. The experiment lasted 56 days. Dry matter intake, milk production and composition, feed efficiency, apparent digestibility, volatile fatty acid profile, rumen microbiota, hematological and biochemical parameters, and oxidative stress markers were evaluated. The combination of additives was able to increase milk production and production corrected for fat, protein, and energy, without altering dry matter intake, resulting in greater feed efficiency. There was an increase in milk protein content from day 28 onwards. In the rumen, a reduction in the protozoan population and an increase in the proportion of propionic acid were observed, without altering the ruminal pH or the total production of volatile fatty acids. The apparent digestibility of crude protein was higher in the treated group. The consumption of additives also promoted specific changes in the ruminal microbiota, with a greater abundance of microorganisms associated with carbohydrate degradation and less activity of pathways related to denitrification. From a systemic point of view, the treatment reduced markers of oxidative stress (reactive oxygen species—ROS and thiobarbituric acid reactive substances—TBARS), decreased creatine kinase and cholinesterase activity, and increased serum fructosamine concentration, indicating antioxidant, anti-inflammatory effects and improved energy status, respectively. It is concluded that the combination of plant biocholine, yeasts, Yucca schidigera extract, and exogenous enzymes improves productive efficiency, promotes ruminal fermentation, and contributes to greater metabolic and oxidative stability in lactating Jersey cows.

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.

This study aimed to evaluate the effect of including extruded-expelled soybean meal (ESBM) as the main protein source in a total mixed ration (TMR) offered to sheep on digestive and metabolic parameters, in comparison to protein sources with known nutritional properties: solvent-extracted soybean meal (SBM; high ruminal degradability) and dried distillers grains with solubles (DDGS; low ruminal degradability). Five Corriedale × Suffolk crossbreed male sheep (33.7 ± 4 kg body weight) fitted with ruminal catheters and duodenal cannulas were used in an incomplete double 3 × 3 Latin square design, comprising three experimental periods of 20 d each. On a dry matter basis, the TMR was composed of corn silage (0.60) and a mixture of concentrate feedstuffs (0.40), which included ground corn and one of three protein sources: ESBM, SBM, or DDGS. The sheep receiving TMR with ESBM showed intermediate organic matter digestibility compared to SBM and DDGS and lower neutral detergent fibre digestibility together with DDGS (p p p <0.05). In conclusion, replacing SBM with ESBM in TMR offered to sheep did not impact most of the rumen fermentation and digestion variables whereas improved the efficiency of N utilisation. In contrast, replacing SBM with DDGS in TMR for sheep has been shown to reduce N losses through urine, increase the duodenal flow of dietary N, and improve N utilisation efficiency.

Background: This experiment evaluated whether the combination of essential oils (thyme, rosemary, orange) with extracts of Cinnamomum and Quillaja saponaria (enriched with tocopherols) in steers’ diet has positive effects on the health, digestibility, growth, oxidative stress, and fatty acid profile of meat. Methods: The experiment included 24 Holstein steers, divided into two groups, randomly divided (treated = phytogenic mixture (n = 12); control = monensin (n = 12)), undergoing a growth phase of 120 days and 90 days of finishing in individual pens, with a monthly collection of blood, rumen fluid, feces, and feed. Results: In the finishing phase (days 150 to 210), there was a tendency (p = 0.07) toward more significant average daily weight gain when cattle consumed a phytogenic mixture than monensin. The use of the phytogenic product showed greater feed efficiency in the period from 150 to 240 days (p < 0.05), with higher levels of short-chain fatty acids (SCFAs), without differences in the composition of these SCFAs between the control and treated groups, with a reduction in apparent digestibility in the treated group. In blood parameters, the treated group showed higher erythrocyte counts (p < 0.05) without changes in leukocytes, lymphocytes, granulocytes, monocytes, and platelets. The phytogenic treatment demonstrated higher total protein and globulin levels, with increased glucose levels on days 30 and 210 (p < 0.05). Ceruloplasmin and haptoglobin levels increased in the treated group without changes in ferritin, transferrin, C-reactive protein, IgA, and heavy-chain immunoglobulins (p < 0.05). A reduction in oxidative stress was observed using the phytogenic agent, with a marked decrease in the levels of reactive oxygen species (ROS) and carbonyl proteins, with a tendency to increase glutathione S-transferase (p < 0.05). In meat, the phytogenic reduced saturated fatty acids with increased polyunsaturated fatty acids and increased the omega 6/omega 3 ratio. Lower levels of thiobarbituric acid reactive substances and ROS were detected in the meat combined with a higher concentration of total thiols in the treated group than in the control group. Conclusions: The use of the phytogenic in steers’ diets has shown to be a viable candidate for replacing monensin, presenting equal or superior performance results with systemic modulating effects on oxidative stress, meat quality, and serum and biochemical parameters that contribute to more substantial health and efficiency.

This study’s objective was to evaluate whether adding a combination of phytoactive (microencapsulated essential oils, minerals, turmeric extract, tannin, prebiotic, and probiotic) to the feed of lactating Jersey cows positively affects the production, composition, and quality of milk, rumen environment, and animal health. Fourteen Jersey cows were divided into two groups (control and phytogenic) for an experiment with two lactation phases of 45 days each (early lactation and mid-lactation). During the experiment, milk production was higher at various times in cows that consumed phytoactive, and these animals had the best feed efficiency. In mid-lactation, phytoactive intake increased nutrient digestibility. The number of lymphocytes in the blood is reduced when cows consume phytoactive substances. Globulin levels increased in these cows fed with the additive, which may be related to a higher concentration of immunoglobulins, especially IgA. Cows fed phytoactives had lower ceruloplasmin and haptoglobin concentrations. Lower serum lipid peroxidation, associated with greater glutathione S-transferase activity, is a good health indicator in cows that consume phytoactive substances. The higher concentration of volatile fatty acids was due to the higher proportion of acetic acid in the ruminal fluid combined with lower butyric acid. Somatic cell counts in milk were lower in cows that consumed phytoactives during mid-lactation, as well as the effect of the treatment on Streptococcus spp. (lower in cows that consumed the additive). We conclude that consuming the additive benefits cows’ health modulates rumen fermentation and nutrient digestibility, and positively affects milk production and quality.