Scielo RSS <![CDATA[Veterinaria México OA]]> vol. 5 num. 4 lang. es <![CDATA[SciELO Logo]]> <![CDATA[Effects of an allostatic modulator on the behavior and blood indicators of young bulls after transport]]> Abstract: An allostatic modulator (AM) composed of ascorbic acid, acetylsalicylic acid, sodium chloride and potassium chloride was dissolved in the drinking water of three groups of young bulls (n = 7) and administered to them for 7 d after 20.42 h of transport (Control (C) = 0 g/head/d, G2 = 30 g/head/d, G3 = 60 g/head/d). The effects of the AM on behavior and blood cellular and biochemical components were measured. G3 animals spent less time lying and more time standing than C animals (P = 0.001 and P = 0.02, respectively), indicating less fatigue. G3 bulls presented a lower frequency of agonistic interactions than those in the G2 group (P = 0.001), suggesting a possible effect on aggression that warrants further evaluation. The AM affected creatinine kinase (CK) activity in the G2 group compared to the C group (P = 0.04), suggesting an effect of AM components that has not been previously reported. Cortisol levels remained unaffected by AM supplementation (P = 0.55). These preliminary findings suggest an effect of supplementing cattle with an AM after long-haul transport. <![CDATA[Effect of resveratrol on the <em>in vitro</em> maturation of ovine (<em>Ovis aries</em>) oocytes and the subsequent development of handmade cloned embryos]]> Abstract: The effect of resveratrol on the in vitro maturation (IVM) of ovine (Ovis aries) oocytes and the development of handmade cloned embryos was evaluated. The nuclear maturation and reactive oxygen species (ROS) levels in the oocytes, as well as the early development and morphological cloned embryo quality, were evaluated under different resveratrol concentrations (0, 0.5, 2 and 5 µM). After IVM, no significant difference was observed in the maturation rate of oocytes treated with 0.5 µM (81.3 %) and 2 µM (72 %) resveratrol compared to that of the control group (0 µM) (74.2 %), but the rate significantly decreased at 5 µM (56 %) (p &lt; 0.05). When the oocyte ROS levels were determined, no significant differences among the groups were observed (p &gt; 0.05). For cloned embryo development, the embryos obtained from the oocytes treated with 0.5 µM resveratrol showed higher (p &lt; 0.05) compacted morula rates (10.7 %) compared to the embryos obtained from the oocytes treated with 0, 2 and 5 µM (6.2, 0 and 0 %, respectively). Regarding embryo morphological quality, the embryos from the oocytes treated with 0.5 µM resveratrol showed a lower rate of poor quality morulae (4.7 %) in comparison to those treated with 0, 2 and 5 µM (23.8, 23.3 and 33.3 %, respectively) (p &lt; 0.05). In conclusion, resveratrol showed no significant improvement on the IVM or ROS levels in domestic ovine oocytes. However, treatment with 0.5 µM resveratrol during IVM improved embryo quality and promoted morulae compaction of Ovis aries handmade cloned embryos. <![CDATA[Can C-phycocyanin be used as a sperm protector?]]> Abstract C-phycocyanin (C-PC) is a biocompound extracted from Arthrospira maxima. It is a chromophore-protein complex, with antioxidant properties. Its ability to prevent oxidative stress allows for diverse medical applications. This study evaluates the use of C-PC as a protein supplement and an antioxidant for in-vitro sperm preservation in a short-term extender. Viability, progressive motility, DNA damage and percentage of reactive oxygen species where assessed in Swine (Sus scrofa domesticus) sperm stored for up to 72 hours at 4 °C. Treatments with C-PC had the following concentrations: 0, 34.5, 69, 138 and 207 µg mL−1. Progressive motility and percentage of sperm with undamaged DNA were unchanged (20%) after storage for 48 hours using the 138 ug mL-1 C-PC concentration. <![CDATA[Addition of calcium propionate to finishing lamb diets]]> Abstract: Calcium (Ca) propionate can be added to ruminant diets as a glucogenic substrate. However, due to its hypophagic effect, it is necessary to establish the optimal dose that can be used to replace grains in finishing diets for lambs. Therefore, the objective of this study was to assess the effect of four concentrations of Ca propionate in lamb diets on productive performance and rumen fermentation. Thirty two Hampshire x Suffolk lambs (23.82 ± 0.40 kg initial body weight), distributed in a completely randomized design, were given a diet with four concentrations of Ca propionate (g kg−1): 0, 10, 20 or 30 g, for 42 days. The results were tested for linear or quadratic responses. The final weight, average daily gain and feed: gain ratio showed quadratic responses (P ≤ 0.01). The optimal dose was established at 13.77 g kg−1 DM. Addition of Ca propionate did not affect variables related to rumen fermentation (pH, total volatile fatty acids, acetate, butyrate or rumen ammonia-N; P ≥ 0.05). Nonetheless, glucose and propionate concentrations showed a quadratic response (P ≤ 0.05). The highest concentrations of propionate in rumen were observed with 15.14 g kg−1 DM. Results indicate that Ca propionate can be included in a dose of up to 13.77 g kg−1 DM in feedlot rations, to attain best lamb performance.