This study determined whether adding condensed tannins to the diet of confined lamb improves performance, metabolism, health, and meat composition and quality. We used 24 Lacaune lambs with an average initial weight of 24.5 ± 0.24 kg. The animals were divided into 12 pens with two animals each. In the treatment group, a black wattle extract was added to the lamb concentrate (2.5 g/kg dry matter), while the control group received only the basal diet (without extract). Black wattle contained 98.6 g/kg of condensed tannin. There was no difference between the performance variables, which included weight gain, feed intake, and feed efficiency. However, the group fed on condensed tannins showed higher carcass yield and a higher percentage of linked intramuscular fat. In meat, a lower proportion of saturated fatty acids combined with higher concentrations of unsaturated fatty acids was observed in lambs of the condensed tannin group. The polyunsaturated fatty acids (PUFA) were no different; however, a higher PUFA/SFA ratio was observed in animals with condensed tannin intake, and a higher proportion of ω6 and ω3 was observed in the meat of these animals. The meat’s protein and ash content did not differ between treatments, as did the meat’s water retention capacity, color, and luminosity. Furthermore, animals that fed on condensed tannins had lower cholesterol levels and higher globulin content. The values of erythrogram variables were lower in lambs that consumed condensed tannins. More significant ruminal bacterial activity was also observed in the group receiving condensed tannins. The antioxidant effect was verified with lower thiobarbituric acid reactive species (TBARS) levels and more significant antioxidant enzyme activity. We conclude that adding condensed tannins improves carcass yield and increases the percentage of fat in the carcass, improving the fatty acid profile, which may be linked to the antioxidant effect, in addition to the health benefits of the consumer of this product.

The objective of the present study was to determine whether the addition of a blend based on the essential oils of cinnamon, oregano, and eucalyptus to the liquid diets of calves would stimulate the immune system combined with anti-inflammatory action, minimize oxidative responses, and alter the intestinal microbiota, consequently enhancing animal growth. Twenty-four male Holstein calves (approximately five days old) were suckled for 60 days, underwent a weaning process, and were followed up until day 75 of the experiment. The calves were divided into control (n = 12) and phytobiotic (n = 12) groups, receiving commercial milk replacer and pelleted concentrate ad libitum. For the phytobiotic group, we added the blend to the liquid diet twice daily at 5 mL/feeding in the first 15 days and 10 mL/feeding until day 60. We detected no differences in weight gain, but animals in the phytobiotic group tended to consume less feed. Calves treated with phytobiotics showed better conversion and feed efficiency than the animals in the control group. Lower leukocyte and lymphocyte counts were observed, as was a higher cholesterol concentration. Immunoglobulin A, ceruloplasmin, and transferrin also differed between groups, with higher IgA and lower levels of acute-phase proteins (ceruloplasmin and transferrin) in calves that consumed the phytobiotic. Higher glutathione S-transferase activity was found in the serum of calves in the treatment group. The intestinal microbiota did not differ between the groups; however, the genera Acinetobacter, Pseudomonas, and Psychrobacter were the most abundant regardless of treatment. We concluded that the blend of oils based on cinnamon, oregano, and eucalyptus improved the calves’ immune and antioxidant systems, improving feed efficiency without affecting the intestinal microbiota.

This study aimed to evaluate whether the addition of a phytobiotic additive formulated based on cinnamon and oregano essential oils (50% free and 50% microencapsulated) combined with turmeric extract and tannins to the diet of cows has beneficial effects on health, productivity, and milk quality. In a completely randomized design, eighteen Jersey cows were used in a compost barn system over 45 days. The cows were divided into two homogeneous groups: one control (without additive; n = 9) and another treatment (with a phytobiotic at a dose of 2 g/cow/day; n = 9). The diet was formulated based on corn silage, hay and concentrate for daily 30 L/cow production. Blood and milk samples were collected at 15-day intervals. There was a treatment × day interaction: cows that consumed the phytobiotic additive produced a more significant amount of milk at days 14, 17, 18, 30, 39 and 45 (p ≤ 0.05). When we corrected milk production for fat percentage, we observed higher milk production in the cows that consumed phytobiotics compared to the control during the experimental period (p = 0.01). The feed intake of cows fed phytobiotics was lower (p = 0.01). Thus, feed efficiency was better in cows that consumed phytogenics. There was a higher percentage of fat in the milk of cows that consumed phytobiotics and a higher amount of polyunsaturated fatty acids compared to the control (p = 0.02). There was an increase in total protein and globulin levels (p = 0.01), which may be associated with the interaction of the antimicrobial, antioxidant, and immunomodulatory properties of the phytobiotic additive. An increase in immunoglobulins (p = 0.01) and a reduction in acute-phase proteins (p ≤ 0.05) were observed in the blood of cows in the phytobiotic group. Lower levels of TNF-α, IL-1β and IL-6 and higher levels of IL-10 in the serum of cows that consumed the phytoactive (p = 0.01) reaffirm the anti-inflammatory effect of the additive. Lower levels of lipid peroxidation (TBARS) and reactive oxygen species (ROS) were observed in the serum of cows in the phytobiotic group. Greater catalase and superoxide dismutase activity was observed in cows that consumed the phytogenic (p < 0.01). Therefore, it can be concluded that the additive in question has antioxidant, immunological, and anti-inflammatory actions and has the potential to improve productive performance when corrected for milk fat.

The growing demand for biofuels, especially ethanol produced from corn, has driven the production of co-products such as dried distillers grains with solubles (DDGS). With a high protein content (around 30%), fiber, and minerals, DDGS presents an economical alternative for animal nutrition, replacing traditional sources like soybean meal while maintaining productive performance and reducing costs. This study evaluated the total replacement of soybean meal with DDGS in the diet of confined Holstein cattle, focusing on weight gain, feed intake, digestibility, feed efficiency, animal health, meat quality, and economic viability. The 24 animals received diets with 80% concentrate, containing either DDGS or soybean meal, and no significant differences were observed in terms of body weight (p = 0.92), feed intake (p = 0.98), or feed efficiency (p = 0.97) between the two treatments. The average daily gain was 1.25 and 1.28 kg for cattle in the DDGS and soybean meal groups, respectively (p = 0.92). Regarding metabolic and digestive parameters, no relevant changes were found in blood levels, except for higher serum cholesterol (p = 0.03) levels in animals fed DDGS. The digestibility of neutral detergent fiber (NDF) (p = 0.03) and acid detergent fiber (ADF) (p = 0.05) was lower in the DDGS group, while the digestibility of ether extract was higher (p = 0.02). Rumen fluid analysis revealed an increase in the production of short-chain fatty acids (p = 0.01), such as acetic and butyric acids (p = 0.01), in the DDG-fed animals. In terms of meat quality, animals fed DDGS produced meat with lower levels of saturated fatty acids (SFA) (p = 0.05) and higher levels of unsaturated fatty acids (UFA) (p = 0.02), especially oleic acid (p = 0.05). This resulted in a healthier lipid profile, with a higher UFA/SFA ratio (p = 0.01). In terms of economic viability, DDGS-based diets were 10.5% cheaper, reducing the cost of production per animal by 7.67%. Profitability increased by 110% with DDGS compared to soybean meal, despite the high transportation costs. Therefore, replacing soybean meal with DDGS is an efficient and economical alternative for feeding confined cattle, maintaining zootechnical performance, increasing meat lipid content and improving fatty acid profile, and promoting higher profitability. This alternative is particularly advantageous in regions with easy access to the product.

The search for natural alternatives that improve the productive efficiency and metabolic state of dairy cows has driven the use of phytogenic compounds such as silymarin, a flavonolignan extracted from Silybum marianum L. Gaertn with recognized antioxidant, anti-inflammatory, and hepatoprotective properties. This study evaluated the effects of silymarin supplementation on the productive performance; milk composition; and ruminal, hematological, biochemical, and oxidative parameters of lactating Jersey cows kept in a confined system with robotic milking. Twelve cows (230 ± 30 days in lactation; 22 ± 3.5 kg/day of milk) were distributed in a crossover design, receiving a control diet (GCON) or a diet supplemented with 5 g/cow/day of silymarin (GSIL) for 28 days in each stage. Silymarin intake did not alter dry matter intake, feed efficiency, or average milk production (p > 0.05), but it increased milk fat content (4.27 × 4.02%; p = 0.05) and, consequently, milk production corrected for 4% fat (24.4 × 23.2 kg/day; p = 0.05). In the rumen environment, cows in the GSIL group showed higher concentrations of acetic acid (57.4 × 48.4 nmol/L), and total short-chain fatty acids (100.2 × 89.4 nmol/L; p = 0.01). Regarding the biochemical profile, silymarin reduced gamma-glutamyltransferase and aspartate aminotransferase activities, as well as haptoglobin levels, indicating a hepatoprotective effect, combined with a lower inflammatory response in the liver. Oxidative status was improved by decreased levels of TBARS (lipid peroxidation) and reactive oxygen species, as well as myeloperoxidase activity in the serum of cows fed silymarin (p ≤ 0.05), but there was no difference between groups for superoxide dismutase activity and glutathione levels. The inclusion of silymarin in the diet of lactating Jersey cows improved the antioxidant and hepatic profile, increased milk fat content, and favored ruminal fermentation, suggesting metabolic and productive benefits in confined systems with high physiological demands.

The objective of the present study was to evaluate different inclusion levels of drymass of the yeast Aspergillus niger (0; 0.125; 0.250; 0.500; 1.00; 2.00; 4.00 and 8.00%) in commercial diets for juveniles of Nile tilapia (16.11 ± 1.74g) in a water recirculation system. The productive performance, organosomatic indexes and carcass composition of these animals were evaluated after 58 days of experiment. A total of 192 juveniles were distributed among 32 tanks made up of eight treatments with four repetitions. A significant difference was observed for the hepatosomatic index at 2.00% of inclusion, which was similar to the other treatments except for the 0.125% inclusion level. The inclusion of A. niger had no negative impacts on performance when compared with the control diet. Since it is a by-product, the use of A. niger can be an alternative in the formulation of diets for tilapia in the initial stages (15-70g).