No abstract

The objective of this study was to describe barn management practices and to evaluating cow locomotion, hygiene and hock lesion prevalence of dairy cows housed in Compost Barns (CB) located in the subtropical region of Brazil. The CB has demonstrated satisfactory results in relation to animal comfort and productivity. However, modifications to the initial American recommendations are being made by producers in order to adapt it to different conditions. Thirty dairy farms were analyzed regarding structural measurements and layout, management practices, bedded pack and herd characteristics. The main results highlighted were the resting space of 14.6 m2 cow-1, most of the farms (87%) had newly built facilities and only 43.3% were built in E-W direction. Most farms did not have ridge opening and 60 % had fans in the bedded pack area, which is mostly stirred twice a day. About a third of the farms used CB only during the hottest hours of the day or rainy periods, with pasture access the remainder of the time. The bedded pack material averaged 48.4% DM, pH of 8.68, C:N of 5.90 and deep bedding temperature of 42.52 ⁰C. Locomotion scoring showed majority of the cows with  a normal gait (95.5% of cows scoring 1 or 2 for locomotion). Hock lesions were observed in 15.5% of the animals and 84.0% of the cows were clean or only slightly dirty. This study indicates characteristics or issues to start an improvement process on CB usage in Brazilian subtropical region. The cow comfort was considered adequate, based on results of cow locomotion, lesions and hygiene scoring.

O uso de aditivos na alimentação de ruminantes ainda é um dilema. Diante do avanço das pesquisas voltadas à nutrição de precisão, foram descobertos uma gama de substâncias. Estes produtos atuam positivamente sobre as características do alimento ou diretamente no desempenho animal e seu uso é permitido desde que não prejudiquem o valor nutritivo da ração. Aproximadamente quatro fatores devem ser considerados ao determinar se um aditivo alimentar deve ser usado: resposta esperada, retorno econômico, pesquisa disponível e respostas de campo. No entanto, a permissão do uso no Brasil é regulamentada pela IN 44/ 2015, e vai muito além destes fatores. Atualmente os aditivos agrupados em quatro categorias (tecnológico, zootécnico, sensorial ou nutricional) e inúmeros grupos funcionais. Nos últimos anos os nutricionistas têm afirmado que a maioria de seus clientes usam algum tipo de aditivo na ração, por este motivo há necessidade de se conhecer as alternativas, bem como as características do regulamento que administra o uso das substâncias.

The objective was to classify the dairy farms that use Compost bedded pack barn (CB) in the Brazilian subtropical region, in terms of farm structure, building aspects, environmental and compost bedded pack characteristics, and reports the variability among them. Additionally, this research identifies structural and management factors that interfere in the compost bedded pack quality. Farms (n = 30) were visited (January-March 2017), located on Subtropical region of Brazil, where CB measurements, managements and herd observations were performed. The cluster analysis was performed with the kmeans methodology to define the groups, and through iterations, the optimal number of groups was determined according to the Silhouette method. Descriptive statistics were used for the different groups of farms. The clustering analysis, based on 12 variables, resulted in the formation of three groups: “Conventional and adapted CB” (n=18, with new and adapted barns, of different sizes, full time using, with adequate pack characteristics or not), “Large conventional CB” (n = 6, larger barns, more similar to American models, full time using) and, “CB of partial use” (n = 6, used in hottest hours of the day or rainy season, with better pack characteristics among groups, although do not have fans ventilation and the bedded pack is stirring only once a day). The CB systems are heterogeneous, and the barns are characterized by their distinct sizes or period of utilization. The group “CB of partial use” presented better bedded pack characteristics even with less intensive bedding management, and without fan ventilation in the barns.

Objective. The aims of this study were to assess whether colostrum quality is modified by genetic, physiological and management characteristics in the pre-partum period, as well as evaluate whether quality and composition of colostrum is altered in the freezing process. Material and methods. In the experiment I, colostrum and blood samples of 35 cows (18 Holstein and 17 Jerseys) were collected. In the experiment II, six colostrum samples of Holstein cows were collected and frozen during 60 days. Results. The mean immunoglobulin (Ig) concentration was 77.65 mg/ml to Jersey and 82.77 mg/ml to Holstein. The genetic, parturition order, and the interaction between these factors were no significant on IgG concentration in the colostrum. Also, it was observed an effect genetic of cow in the weight on calf at birth and on three days of age (p<0.0001). Regarding transmission of calf passive immunity, no effects of cow breed and calving order were observed on plasma protein concentration of calf, as well as after three days of freezing. Calves of Holstein (83%) and Jersey (82%) breed showed total serum protein levels above 5.5 g/dL. Holstein cows housed in individual paddocks with diet supplementation provided better quality of colostrum (93.57 mg Ig/mL). Over time, the percentage of fat reduced at freezing, that reduced over time (p<0.05) in Experiment II. Conclusions. The pre-partum management exerts influence on colostrum quality, and the freezing not interfere on centesimal and immunological quality of colostrum, with exception the fat, that decrease along the time.