This study aimed to evaluate the effect of dietary supplementation with calcium propionate (CaPr) or sodium propionate (NaPr) on growth performance, ruminal fermentation, and meat quality of finishing lambs. Twenty-seven non-castrated Creole male lambs (24.95 ± 2.15 kg body weight (BW); 4.5 ± 0.5 months old) were randomly assigned to three treatments: (a) CON: basal diet without the addition of CaPr or Na Pr; (b) basal diet + CaPr (10 g/kg DM); and (c) basal diet + NaPr (10 g/kg DM). The data were analyzed using a completely randomized experimental design, with each lamb considered an experimental unit (nine replicates/treatment). Dietary supplementation with CaPr or NaPr did not affect (p > 0.05) growth performance or dietary energetics. However, greater (p = 0.05) apparent dry matter digestibility was observed in the lambs that consumed the diet with NaPr10. Dietary supplementation with CaPr or NaPr did not affect (p > 0.05) ruminal pH or ruminal concentrations of ammonia nitrogen, acetate, propionate, butyrate, and total volatile fatty acids. However, ruminal lactate concentration increased (p = 0.01) in lambs consuming the NaPr diet. Hot carcass weight and yield, backfat thickness, meat pH, meat color (L*, a*, and b*), cooking loss, and water holding capacity were not affected by dietary supplementation with CaPr or NaPr. In conclusion, dietary supplementation with 10 g/kg DM of calcium propionate or sodium propionate does not affect growth performance, dietary energetics, ruminal fermentation, and the meat quality of finishing lambs.

This study aimed to evaluate the effects of dietary supplementation with increasing levels of a polyherbal phytogenic additive (PPA) on growth performance, health parameters, and blood metabolites of dairy calves. Forty female Holstein calves (43.35 ± 2.41 kg body weight and 25.1 ± 2.2 d of age) were housed in individual pens and randomly assigned to four treatments (n = 10) with increasing levels of PPA: 0 (CON), 2 (PPA2), 3 (PPA3), and 4 (PPA4) g PPA/d for 67 d. Compared to the CON treatment, supplementation with the PPA2 treatment increased (quadratic effect p = 0.02) the average daily gain and final body weight of the dairy calves. Also, a higher starter intake (SI), and intake of milk + milk replacer was observed (linear and quadratic effect p = 0.0001) in response to supplementation with the PPA2, PPA3, and PPA4 treatments. The evaluated treatments did not affect (p > 0.05) the feed conversion ratio, or the number of cases of diarrhea, pneumonia, and otitis. The evaluated treatments did not affect (p > 0.05) most of the hematological and biochemical blood parameters. However, compared to the CON treatment, supplementation with the PPA2 treatment increased (quadratic effect p < 0.05) the blood concentration of the segmented neutrophils and plasma protein. Likewise, the serum glucose concentration decreased (linear effect p < 0.05) with supplementation of the PPA2, PPA3, and PPA4 treatments. Compared with the CON treatment, the PPA4 supplementation decreased the serum urea concentration (linear effect p = 0.04). In conclusion, supplementation with 2 g/d of PPA can be used as a natural alternative to improve the growth rate and stimulate starter and milk + milk replacer intake in dairy calves without adverse effects on health parameters or blood metabolites.

The objective of this study was to evaluate the effects of dietary inclusion of increasing levels of soybean oil on milk yield, milk composition, and milk fatty acid profile in dairy cows. The experiment was designed as a 4 × 4 double Latin square with 21-day periods and used eight Holstein cows (body weight of 550 ± 19.5 kg and 200 ± 5 days in milk). The treatments evaluated were a basal diet without soybean oil and a basal diet added with 10, 20, or 30 g/kg DM of soybean oil. None of the treatments evaluated affected (p > 0.05) milk yield, dry matter intake, dry matter digestibility, or the concentration of fat, non-fat solids, protein, and lactose in milk. Furthermore, increasing levels of soybean oil included in the diets did not affect (p > 0.05) the milk concentration of butyric, caproic, caprylic, capric, lauric, pentadecanoic, palmitoleic, heptadecanoic, and linoleic fatty acids. However, dietary inclusion of soybean oil decreased (linear effect; p ≤ 0.05) the milk concentration of myristic, palmitic and oleic fatty acids. In contrast, higher concentrations (linear effect; p ≤ 0.05) of stearic fatty acids were observed in the milk of dairy cows fed soybean oil in their diet. In conclusion, dietary inclusion of increasing levels of soybean oil (30 g/kg DM) modifies the fatty acid profile of milk without affecting milk yield or the protein, fat, or lactose content.