Sperm viability, serological, molecular, and modified seminal plasma agglutination tests in the diagnosis of Leptospira in the semen and serum of bovine bulls.

The present study investigated the serum microscopic agglutination test (MAT) among 203 bovine bulls with reproduction by natural means, without apparent signs of orchitis or inflammation of accessory reproductive glands. Simultaneously, the semen of all bulls was subjected to sperm viability analysis and PCR based on the 16S rRNA gene. PCR-positive results of semen samples were confirmed by sequencing. A modified seminal plasma agglutination (MSPA) test, replacing the blood serum of all bulls in the MAT with seminal plasma was performed as well. Eight (8/203 = 3.9%) semen samples from bulls were considered nonviable (necrospermia and azoospermia) without relation to the PCR diagnosis. No agglutinin titers were identified in MSPA test. A high frequency (132/203 = 65%) of leptospiral agglutinin titers was identified in the MAT, particularly for the Sejroe serogroup (Hardjo CTG, 100/203 = 49.3%; Wolffi 74/203 = 36.4%; Guaricura 72/203 = 35.5%; and Hardjoprajitno 56/203 = 27.6%). Three (3/203 = 1.5%) semen samples of bulls were positive in the PCR, but these results were not confirmed by sequencing. The high frequency of serovars from the Sejroe serogroup typically adapted to bovines indicates the need for measures for the prophylaxis/control of the pathogen on the sampled farms. Discrepancies among the MAT, sperm viability, and molecular detection of leptospires in semen highlight the need for a combination of methods to diagnose leptospirosis in bovine bulls. To our knowledge, modified seminal plasma agglutination is described for the first time here to investigate anti-Leptospira antibodies produced locally in the genital tract in the diagnosis of bovine leptospirosis among bulls that reproduce by natural means.

Effects of physiological stage and season on infrared thermograms of different body areas of dairy cows raised under tropical conditions.

The objective of this study was to investigate the influence of season and pregnancy stage on the temperature of various body areas of Holstein cows using digital infrared thermography, an effective and non-invasive technique. The temperature was recorded at several areas of the body surface to determine the most reliable body area for measurement of rectal temperature in pregnant and non-pregnant animals. Holstein cows (n = 24) were divided into groups according to their physiological stage. The experimental period was 365 days, containing a dry (April-September) and rainy (October-March) season, with parameters measured every 28 days. Thermographic data for different body areas, rectal thermometry, ultrasonography, and climatic data were collected between 7:00 and 9:00. Thermogram-recorded temperatures significantly differed (P < 0.05) between seasons and reproductive phases. Moreover, significant differences were noted between the temperatures of the flank, lateral udder, and perineal areas across seasons (P < 0.05). The udder, perineal, and rectal temperatures differed according to the reproductive phase (P < 0.05). Significant correlations (P < 0.01) were observed between reproductive phases and rectal, ocular globe, snout, flank, and perineum temperature. The body areas examined by thermographic imaging presented different temperatures, exhibiting physiological variation. Season and physiological stage influenced the temperature of body areas of milk cows.

Efeito da ovariectomia em novilhas Nelore x Angus, Bos taurus indicus x Bos taurus taurus sobre os ganhos de peso / Ovariectomy effect in heifers Nelore x Angus, Bos taurus indicus x Bos taurus taurus on the weight gains

Esse estudo teve o objetivo de avaliar o ganho de peso em novilhas mestiças Nelore x Angus, castradase não castradas, mantidas em pastagem e confinamento. Os animais foram alocados em dois gruposassim constituídos: grupo 1 formado por 30 novilhas não castradas com 18 meses de idade. Grupo 2composto por 30 novilhas castradas com 18 meses de idade. Os animais foram mantidos em pastagem de Brachiaria decumbens e pesados aos 39 e 75 dias. Diferença significativa foi observada entre o ganhomédio diário dos dois grupos – G1 e G2 (75ºdia), respectivamente (0,51 kg e 0,65 kg; P<0,01). No diaseguinte (76ºdia), todos os animais foram transferidos e mantidos por 144 dias no confinamento. Diferençasignificativa foi observada entre o ganho médio diário dos dois grupos – G1 e G2 (144ºdia), respectivamente(0,73 kg e 0,58 kg; P<0,01). Os resultados desse experimento mostraram que novilhas castradasapresentaram um maior ganho diário em pastagem.

This study aimed to evaluate the weight gain in cross breed heifers Nelore X Angus, spayed andnonspayed, kept on pasture and confinement. The animals were allotted in two groups as follows: group1 consisted of 30 nonspayed heifers with 18 months old. Group 2 was composed of 30 spayed heiferswith 18 months old. The animals were allotted in pasture of Brachiaria decumbens and weighted at 39and 75 days. Significant difference was observed between the average daily gain of the two groups ­ G1and G2 (75th day), respectively (0.51 kg and 0.65 kg; P<0.01). The following day (76th day), all animals wereallotted and kept on confinement during 144 days. Significant difference was observed between theaverage daily gain of the two groups ­ G1 and G2 (144th day), respectively (0.73 kg and 0.58 kg; P<0.01).The results of this experiment show that spayed heifers presented a higher daily gain on pasture.

Eficiência da meia dose de cloprostenol na submucosa vulvar nas taxas de induçåo do estro e de prenhez em vacas repeat-breeders Nelore-Chianina / Efficiency of half-dosis of Cloprostenol subvulvar mucous inducing estrus and pregnant rate in cows

Este estudo teve como objetivo avaliar a eficiência do cloprostenol na indução do estro e taxa de gestação em vacas de corte repeat-breeders, comparando a eficiência de meia dose na submucosa vulvar. Foi utilizada dose de 1 mL (250 mg de cloprostenol) na submucosa vulvar no grupo 2 (G2)= 25 vacas; e dose clássica de 2 ml (500 mg de cloprostenol) intramuscular, formado pelo grupo 1 (G1)= 24 vacas meio sangue Nelore-Chianina, totalizando 49 fêmeas repeat-breeders, com escore corporal 3,5 (1 a 5), sem alterações ao exame ginecológico. As vacas se encontravam com 175+-13 dias de período pós-parto, mantidas em estação de cobertura durante 89 dias, entre Dezembro 2003 e Fevereiro de 2004. Foram inseminadas uma vez, seguidas por duas a três coberturas naturais, efetuadas por touros aptos após exame andrológico, acasalados na proporção de 1:20. A aplicação de cloprostenol foi repetida 11 dias após a primeira dose, nas vacas que não apresentaram estro. Realizou-se rufiação 2 vezes ao dia, durante cinco dias após a aplicação de qualquer dose de cloprostenol. As porcentagens totais de estro foram de 79,16 por cento (G1) e 56 por cento (G2). A média de horas para apresentação do estro foi de 81,35h (1ª dose) e 92,8h (2ª dose) para o G1; e de 76,1h (1ª dose) e 71,5h (2ª dose) para o G2. Com relação à média de horas para a manifestação do estro nos grupos G1 e G2 para a 1ª dose, 2ª dose e para o total de vacas no estro, não houve diferença significativa (p>0,05). As inseminações artificiais foram realizadas 12h após a observaçåo do estro e o diagnóstico de gestação aos 53 dias após a última inseminação, por meio de palpação retal, confirmado com ultra-sonografia transretal, sendo diagnosticadas 20 vacas gestantes, dez no G1 e dez no G2, perfazendo 40,8 por cento de gestações. Não houve diferença entre o total de vacas gestantes no dois grupos. Sugere-se a aplicação estratégica da meia dose de cloprostenol na submucosa vulvar para a indução do estro em vacas repeat-breeders, ao término da estação de cobertura.