Effects of surgical castration, immunocastration and homeopathy on the performance, carcass characteristics and behaviour of feedlotfinished crossbred bullsEfeitos da castração cirúrgica, imunocastração e homeopatia sobre o desempenho, características de carcaça e comportamento de bovinos machos cruzados terminados em confinamento AbstractThe aim of this study was to evaluate total weight gain, carcass yield, rib-eye area, marbling, subcutaneous fat thickness, frequencies of mounting, excitement, dominance behaviour and serum testosterone concentration in feedlot-finished non-castrated bulls, surgically castrated bulls, immunocastrated bulls and bulls treated with homeopathy. The study involved 52 calves, Holstein-Zebu, 20±3 months old, in a completely randomised design divided into four treatments of 13 animals: non-castrated, surgically castrated, immunocastrated and non-castrated with homeopathy. Analysis of variance was performed, and the Tukey test was applied (P<0.05). The Pearson correlation coefficient was estimated and principal components analysis was performed. The castrated animals had lower total weight gain and carcass yield than the animals in the remaining treatment groups. The immunocastrated bulls had a greater subcutaneous fat thickness than the non-castrated bulls. The castrated bulls exhibited lower frequencies of mounting, excitement and dominance behaviour than the animals in the remaining treatment groups. Testosterone levels were lower in the castrated animals. Principal components analysis revealed a moderate magnitude and sharpness in the differentiation of the castrated animals. It was concluded that the immunocastrated animals were similar in performance to the non-castrated animals, while the carcass finish characteristics of the immunocastrated animals were similar to the castrated animals. The castrated animals had lower productive performance than the animals in the remaining treatment groups. The homeopathy animals had performance and carcass finish characteristics similar to the non-castrated animals. Homeopathy and immunocastration did not reduce sodomy and dominance behaviours. ResumoObjetivou-se determinar ganho de peso, rendimento de carcaça, área olho lombo, marmoreio, espessura de gordura subcutânea, frequências de monta, excitação, dominância e concentração sérica de testosterona de bovinos não castrados, castrados cirurgicamente, imunocastrados e tratados com homeopatia terminados em confinamento. Utilizou-se 52 garrotes, 3/4 holandês-zebu, 20±3 meses de idade e 303,78±15,78 Kg, distribuídos inteiramente ao acaso em quatro tratamentos de 13 animais: não castrados, castrados cirurgicamente, imunocastrados e não castrados tratados com homeopatia. Fez-se a análise de variância e quando esta foi significativa (P<0,05), aplicou-se o teste de Tukey. Estimou-se o coeficiente de correlação de Pearson entre as variáveis e realizou a análise de componente principal. Os castrados apresentaram menor ganho de peso e rendimento de carcaça que os demais tratamentos e marmoreio super...

ABSTRACT. This study aimed to evaluate milk composition and metabolic profile of Holstein cows at different calving orders in the beginning, middle, and end of lactation. One hundred ten Holstein cows were housed in a free stall system receiving the same diet and were grouped according to calving order (first, second, third, and fourth calving) and days in milk (DIM): early (1-90 DIM), middle (91-180 DIM), and end of lactation (over 181 DIM) for comparing milk yield, milk composition, and blood metabolic profile between the calving orders within the same lactation period. These parameters were also evaluated between lactation periods of the cows in different calving orders. The calving order, in any lactation stage, had no influence on milk yield per day and blood biochemical profile of Holstein cows receiving the same diet. However, calving order in all stages of lactation influenced milk composition. The first, second, third, and fourth calving order had no effect on the blood biochemical profile of Holstein cows, in any lactation stage. On the other hand, the different stages of lactation influenced milk yield and milk composition of Holstein cows.Keywords: biochemical profile, lactation period, milk quality.Composição do leite e perfil metabólico sanguíneo de vacas holandesas em diferentes ordens de parto e estádios de lactação RESUMO. Objetivou-se avaliar a composição do leite e perfil metabólico de vacas da raça Holandesa em diferentes ordens de parto, no início, meio e fim de lactação. Foram utilizadas 110 vacas mantidas em sistema Free stal, recebendo a mesma dieta. Os animais foram agrupados de acordo com a ordem de parto em diferentes dias em lactação (DEL), início (1-90 DEL), meio (91-180 DEL) e fim de lactação (mais de 181 DEL), para a comparação da produção de leite, composição química do leite e perfil metabólico do sangue entre as ordens de parto dentro do mesmo período de lactação. Estes parâmetros também foram avaliados entre os períodos de lactação das vacas em diferentes ordens de parto. A ordem de parto, em nenhum estádio de lactação, influenciou a produção de leite por dia e o perfil bioquímico do sangue de vacas Holandesas que recebiam a mesma dieta. Entretanto, a ordem de parto em todos estádios de lactação influenciou a composição química do leite. A primeira, segunda, terceira e quarta ordem de parto em nenhum estádio de lactação influenciaram o perfil bioquímico do sangue de vacas Holandesas. Por outro lado, diferentes estádios de lactação influenciaram a produção e composição química do leite.Palavras-chave: perfil bioquímico, período de lactação, qualidade do leite.

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The aim was to conduct a literature review on the estrus detection and its interference on the reproductive efficiency of dairy cattle. Efficient and accurate estrus detection of cattle and artificial insemination in an assertive time are essential to increase pregnancy rate, estrus detection rate, and consequently good reproductive efficiency. Methods of estrus detection that are widely used on farms do not have good rates.  This is because the physiological and behavioral changes of the animals, as well as the period of the duration of the estrus cycle, are being expressed in low intensity and short duration. In addition, they are very variable and difficult to measure. Thus, it is of utmost importance to use electronic methods to improve estrus detection.

The objective of this study was to examine the effects of increasing circulating progesterone in multiparous Holstein cows, using an intravaginal progesterone implant between days 3 and 7 following fixed-time artificial insemination (FTAI). The animals were randomly assigned into two groups: (1) treatment group and (2) control (no treatment). The experiment took place during periods of high and mild temperatures. Pregnancy rates were evaluated by ultrasound at 30 and 60 days after FTAI; embryonic and fetal mortality rates were also evaluated on these dates. The temperature and humidity index on the day of FTAI were different (P < 0.05) during the times of interest, but it did not affect conception rates. Neither the conception rates at days 30 and 60 nor the embryonic and fetal mortality rates differed between the groups during either the high- or mild-temperature periods (P > 0.05). Throughout the experimental period, the serum progesterone concentration was higher in the treatment group than in the control (P < 0.05). We conclude that the intravaginal progesterone implant inserted from days 3 to 7 following FTAI had no effect on conception rates at days 30 and 60 or on embryonic or fetal mortality rates but enhances the serum progesterone concentrations following treatment in multiparous Holstein cows during high- and mild-temperature periods.