This study aimed to assess the variation over time in thermal comfort indices and the behavior of physiological parameters related to thermolysis, blood parameters, and semen in natura of buffalo bulls reared in tropical climate. The study was carried out in an artificial insemination station under a humid tropical climate (Afi according to Köppen). Ten water buffalo bulls (Bubalus bubalis) were used during the 5 months (April to August) of study. The environmental Temperature Humidity Index (THId) and the pen microclimate Temperature Humidity Index (THIp) were calculated. Every 25 days, respiratory rate (RR), heart rate (HR), rectal temperature (RT), and Benezra's thermal comfort index (BTCI) were assessed in the morning and in the afternoon. A blood assay was performed every month, while semen was collected weekly. THIp did not vary over the months (P > 0.05) and was higher in the afternoon than in the morning (77.7 ± 2.6 versus 81.8 ± 2.1, P < 0.05). RR, HR, and BTCI significantly increased over the months and were different between the periods of the day (P > 0.05) but within the physiological limits. RT varied between the periods of the day and decreased over the months, being the lowest in August (37.8 ± 0.7 °C), time-impacted hematocrit, mean corpuscular volume, hemoglobin levels, and spermatic gross motility and vigor (P < 0.05). Thus, buffalo bulls reared under a humid tropical climate may have variations in thermal comfort during the hotter periods but are able to efficiently activate thermoregulatory mechanisms and maintain homeothermy, hence preserving their physiological and seminal parameters at normal levels.

A ocorrência da infecção pelo Vírus da Leucose Enzoótica dos Bovinos (BLV) no Estado do Pará, foi estudada através do método de imunodifusão em ágar-gel (AGID) e por um ensaio imunoenzimatico (ELISA) indireto, paralelamente. Os exames foram realizados com amostras de soros sanguíneos oriundos de bovinos de diferentes raças sendo a maioria deles adultos. A prevalência observada foi de 49,8% (359/721) no ELISA e 26,0% (174/668) no AGID. Todos os 14 grupos dos animais estudados pelo ELISA indireto, mostraram a existência da infeção, enquanto que pelo método da AGID, dois grupos de animais foram negativos.

This study presented relevant aspects about the Amazonian environment and how it impacts the thermal comfort of domestic buffaloes (Bubalus bubalis) raised in the Eastern Amazon. Furthermore, strategies for monitoring and mitigating animal heat stress are presented, based on research results with the species. Although domestic buffaloes are considered adaptable animals, exposure to intense solar radiation causes thermal discomfort. This condition is expressed in biophysical indicators, in metabolic, endocrine, behavioral responses, and in body thermographic patterns. Therefore, the biometeorological monitoring of production is crucial to support decision-making regarding environmental management strategies, genetic selection of thermotolerant individuals, and increase in animal welfare. Lastly, the use of silvopastoral systems can help to provide higher thermal comfort, which is a condition that directly impacts the productivity of milk and meat buffaloes when they are raised in tropical regions, such as in the Eastern Amazon.

Ruminant energy supplementation with vegetable oils or fats has been standing out worldwide and oil palm processing has been receiving growing interest. This study assessed the effect of supplementation with saturated and unsaturated fatty acids from the palm oil industry on the lipid profile of seminal plasma and of the sperm membrane, as well as on the morphological and functional characteristics of raw and cryopreserved buffalo semen. Twelve purebred Murrah bulls ( Bubalus bubalis ) were assigned to the experimental groups and fed diets for 120 days with no added lipids (CONT, four bulls), or with an extra amount of 3% lipids from crude palm oil (PALM, four bulls), or from palm oil deodorizer distillate (PODD, four bulls). Semen was collected and cryopreserved every 15 days. The lipid composition of membranes and semen quality were determined after collections. Lipid supplementation did not impact feed intake (P>0.05). Diet enrichment with PALM increased the linoleic acid (C18:2,ω6) in seminal plasma. Lipid supplementation did not increase the polyunsaturated fatty acids in the sperm membrane composition, but significantly increased the lignoceric acid (C24:0). Cryopreserved semen of the supplemented bulls presented higher progressive motility (60.2 vs. 67.9 vs. 65.2%; P<0.05) and sperm viability detected by eosin-nigrosin staining (61.1 vs. 69.4 vs. 67.8%; P<0.05). Palm oil reduced major sperm defects in both raw (12.2 vs. 9.3 vs. 13.2%; P<0.0001) and cryopreserved semen (12.4 vs. 9.4 vs. 11.2%; P<0.0001). The lipids added to the diet did not impact the population of spermatozoa with intact plasma and acrosomal membranes (PI-/PSA-), but significantly increased the percentage of spermatozoa with high mitochondrial potential (25.6 vs. 31.5 vs. 32.0%; P=0.008). The results suggest that lipid supplementation based on crude palm oil or palm oil deodorizer distillate can be safely used to feed buffalo bulls and may increase sperm attributes related to male fertility.

Based on these data, we demonstrated the beneficial effects of TES-TRIS for post-thaw buffalo sperm quality; however, no protective effect was observed for buffalo sperm cryopreserved with the different tested concentrations of Lippia origanoides extract oil. Key words: Powdered Coconut Water. Lippia. Cryopreservation. Spermatozoa. Buffalo. ResumoPara a implantação da inseminação artificial é indispensável à utilização de sêmen congelado, que pode provocar mudanças deletérias na estrutura e na integridade das membranas espermáticas, comprometendo sua função. Para evitar estes danos celulares, há a necessidade de se utilizar meios diluidores e substratos adequados que recuperem o maior número possível de células viáveis pós-descongelação. Para isso, foram avaliados, no experimento I, três diferentes diluidores, o diluidor TES-TRIS, bastante utilizado para bubalinos, e um diluidor a base de água de coco em pó (ACP-112  ), associado ou não ao leite (ACP-112  -Leite), na congelação do sêmen de bubalinos; e no experimento II, foi avaliado o efeito do óleo extraído da Lippia origanoides na proteção dos espermatozóides contra as crioinjúrias decorrentes da congelação do sêmen bubalino. Foram utilizados 10 touros bubalinos para as colheitas de sêmen (10 ejaculados/touro), sendo os ejaculados diluídos em TES-TRIS (controle), ACP-112  e ACP-112  -Leite no experimento I; e no experimento II, os ejaculados foram diluídos no melhor diluidor obtido no experimento I, acrescido de 2.5 µg mL -1 , 5 µg mL -1 e 10 µg mL -1 da planta e o grupo controle, constituído somente do diluidor. O sêmen recém colhido foi analisado quanto as características convencionais, tais como, motilidade, concentração, morfologia e viabilidade. Após a descongelação das amostras foram avaliados novamente, motilidade e viabilidade espermática, e posteriormente, foram realizados os testes de termo-resistência, hiposmótico e de avaliação das membranas dos espermatozóides, através das sondas fluorescentes PI, FITC-PSA e JC-1, utilizando a citometria de fluxo. Os dados obtidos foram submetidos à ANOVA e ao Teste de Tukey a 5%. No experimento I, o diluente TES-TRIS apresentou melhores resultados para as várias características avaliadas quando comparado com o ACP-112  e ACP-112  -Leite (P < 0.05), demonstrando maior proteção deste diluidor às estruturas espermáticas durante a criopreservação do sêmen de bubalinos. No experimento II, as diferentes concentrações do óleo extraído da Lippia origanoides não demonstraram nenhuma diferença (P > 0.05) entre as variáveis avaliadas, quanto à proteção das estruturas espermáticas durante a criopreservação. Com base nestes dados, pôde-se demonstrar os efeitos benéficos do diluidor TES-TRIS na qualidade pós-descongelação dos espermatozóides bubalinos; entretanto, nenhum efeito protetor foi observado sobre os espermatozóides bubalinos criopreservados em associação com o óleo extraído da Lippia origanoides, nas diferentes concentrações utilizadas. Palavras-chave: Água de coco em pó. Lippia. Criopreservação. Espermatozóid...