Archivos Latinoamericanos de Producción Animal, es la publicación oficial de la Asociación Latinoamericana de Producción Animal Thirty-nine weanling rabbits (New Zealand x English spot;30 days of age) were used in a four-week trial to evaluate the partial replacement of wheat grain for Leucaena leaf meal (Leucaena esculenta; LEU) on performance, carcass dressing percentage, and organ weights in fattening rabbits. Treatments consisted of partial replacement of wheat for 0%, 7.5%, or 15.0% of LEU in growing-finishing diet for fattening rabbits. Partial replacement of wheat grain with increasing levels of LEU did not influence (P>0.10) performance, carcass dressing percentage, and internal organs weights. It is concluded that this feeding strategy might contribute to reduce the food for feed competition while improving locally available forage resources for rabbit production in warm environments with multidimensional poverty. Se utilizaron treinta y nueve conejos de destete (Nueva Zelanda x Mariposa; 30 días de edad) en una prueba de cuatro semanas para evaluar la influencia de la sustitución parcial del grano de trigo por harina de hoja de Leucaena (Leucaena esculenta; LEU) sobre el comportamiento productivo, rendimiento en canal y masa de órganos internos de conejos en engorda. Los tratamientos consistieron en el reemplazo parcial de grano de trigo con 0%, 7.5% ó 15% de LEU en una dieta de crecimiento-finalización para conejos de engorda. El reemplazo parcial de grano de trigo con incrementos en el nivel de LEU no afectó (P>0.10) el comportamiento productivo, rendimiento en canal y el peso de los órganos internos. Se concluye que esta estrategia de alimentación puede contribuir a reducir la competencia por los granos básicos entre el consumo humano y animal, a la vez que mejora el uso de recursos forrajeros locales para la producción de conejo en regiones cálidas con pobreza multidimensional. Trinta e nove coelhos desmamados (Nova Zelândia x Mariposa; 30 dias de idade) foram utilizados em um experimento de quatro semanas para avaliar a influência da substituição parcial do grão de trigo por farinha de folhas de Leucaena (Leucaena esculenta; LEU) no desempenho produtivo, rendimento de carcaça e massa de órgãos internos de coelhos de engorda. Os tratamentos consistiram na substituição parcial do grão de trigo por 0%, 7,5% ou 15% LEU em uma dieta de engorda para coelhos de engorda. A substituição parcial do grão de trigo com aumentos no nível de WBC não afetou (P>0,10) o desempenho produtivo, rendimento de carcaça e peso de órgãos internos. Conclui-se que esta estratégia alimentar pode ajudar a reduzir a competição por grãos básicos entre consumo humano e animal, ao mesmo tempo em que melhora o uso de recursos forrageiros locais para produção de cunicultura em regiões quentes e com pobreza multidimensional.

A Capsicum spp.-based phytogenic solution (PHY) improved the performance and thermal tolerance of heat-stressed (HS) growing pigs. Two trials were conducted to further evaluate the HS pig response to supplemental PHY. Trial 1: The effects on the serum concentrations of amino acids (AAs) and the gene expression of tight junction proteins in the jejunum and ileum were assessed with 42 pigs (Landrace-Hampshire-Duroc; 27.0 ± 4.5 kg BW). There were three treatments (14 replicates): pigs under thermoneutral (TN) conditions fed control diet (TN-C); and HS pigs fed control diet without (HS-C) or with PHY (HS-PHY). Trial 2: Two-period digestion trial with eight ileal-cannulated pigs to analyze apparent ileal digestibility (AID) of AAs. Period 1: All TN pigs, fed the control (TN-C) or PHY-supplemented (TN-PHY) diet. Period 2: All HS pigs, fed the same diet as in period 1 (HS-C and HS-PHY). The control diet was based on wheat–soybean meal. In the jejunum, HS-C pigs had reduced occludin gene expression (p < 0.01) compared to TN-C pigs. HS-PHY pigs increased claudin-2 and tight-junction-protein-1 gene expression compared to HS-C (p < 0.05). In the ileum, HS-C and HS-PHY pigs had reduced occludin gene expression (p < 0.01). The serum concentrations of AAs decreased in HS-C compared to TN-C pigs (p < 0.05); except for arginine and isoleucine, HS-PHY pigs partially recovered serum AA levels. HS tended to reduce (p < 0.10; lysine and methionine) and reduced (p < 0.05) the AID of essential AAs. PHY did not mitigate the HS-associated reduced AA digestibility. In conclusion, these results support the concept that a phytogenic solution improves intestinal integrity and partially restores the post-absorption metabolism of amino acids, independent of the amino acid digestibility of heat-stressed pigs.

Background: Heat stress reduces semen quality in rams. Objective: To evaluate the productive and reproductive responses of rams and ram lambs with different rectal temperatures under heat stress conditions. Methods: The animals (n = 12, Dorper × Katadhin × Pelibuey crossbreed, aged 235 to 730 days) were assigned to one of three experimental groups: ram lambs with low rectal temperature (RLLRT), ram lambs with high rectal temperature (RLHRT), and Rams. Results: Afternoon rectal temperatures were higher (p ≤ 0.05) in the RLHRT group, and there was no difference (p > 0.05) between the Rams and RLHRT groups. Ejaculate volume and sperm concentration were higher (p ≤ 0.05) in the Rams group than in the RLLRT and RLHRT groups. Mass motility and sperm concentration were lower (p ≤ 0.05) in the RLLRT group than in the RLHRT and Rams groups. Average daily weight gain did not differ (p > 0.05) between the RLLRT and RLHRT groups. Conclusion: The selection of ram lambs with low rectal temperature under heat stress conditions did not provide any benefit in terms of average daily weight gain or ejaculate traits.

Objective: To measure the effect of zin injection, during an estrus synchronization protocol, on pregnancy rate in sheep from the “Valle de Mexicali”.Design/methodology/approach: The experimental units were 157 ewes, which wereallocated in five farms (UP): UP1 (n=19), UP2 (n=27) UP3 (n=20) UP4 (n=71) and UP5(n=21). In each farm, the ewes were randomly assigned to one of three treatments:control, z-100 and z-200. The ewes from control groups were subcutaneously injectedwith 4 mL of olive oil as placebo. The ewes from groups z-100 and z-200 weresubcutaneously injected with 100 and 200 mg of zinc oxide. The response variableswere the preovulatory diameter of the largest follicle and pregnancy rate.Results: The differences between experimental groups on diameter of the largestpreovulatory follicle and pregnancy rates were not significant different (p>0.05). Limitations of the study/implications: The ewe’s reproductive response to zincinjection might be affected by the animal mineral status, it is recommended to carry onsupplementation with base on mineral blood concentrations.Conclusion: The subcutaneous injection with 100 or 200 mg of zinc oxide did not affectthe size of the largest preovulatory follicle and pregnancy rate in ewes.

Exposure of animals to ambient temperature above the thermo neutral zone caused heat stress. Alterations in digestion and absorption of nutrients as well as damage to the small intestine epithelia associated with the production of reactive oxygen species (ROS) may occur in heat stress pigs, resulting in depressed performance. The cells possess an antioxidant system capable of protecting the animals against the effect of heat stress. However, when ambient temperature increases beyond the thermo neutral zone, ROS production also increases provoking an imbalance between ROS and antioxidant production. This review provides relevant information related to the alterations that occur at intestinal, cellular and molecular level in animals exposed to heat stress, and the effect that methionine and arginine as antioxidant amino acids, and their use in diets for heat stress pigs.

The addition of a probiotic to the diet of heat-stressed pigs was evaluated on body temperature, respiratory rate, and productive performance. Eighty pigs of 22 kg BW were assigned to the following treatments: 1) housed in thermoneutral conditions (TN) fed with a conventional diet (TN-C); 2) TN, conventional diet added with probiotic (TN-P); 3) housed under heat stress (HS) conditions, conventional diet (HS-C); 4) HS, diet added with probiotic (HS-P). Twenty pigs were used per treatment. Respiration rate and body temperature were recorded, and productive performance was measured. The body temperature of HS pigs decreased by the addition of the probiotic (P0.05), the respiration rate was higher at 1700 h than at 0700 h (P<0.05). The addition of the probiotic increased daily weight gain and feed efficiency (P<0.01). It is concluded that the addition of probiotic to diets for HS pigs improves their weight gain and feed conversion.