Fatores de influência na produção de leite bovino sobre os níveis da contagem bacteriana total

The objective of this study was to evaluate the influence of milking procedures on the levels of total bacterial count (TBC) in bovine milk. In the first study the influences of procedures for hygienic milking, cleaning of milking equipment and milk cooling tanks on the TBC levels were evaluated. Four bulk samples of milk were collected from each tank in eight properties for TBC analysis, employing the flow cytometry method. A questionnaire was applied in each property to assess the current situation of milking procedures on each production system that took part on this research, followed by training of employees in good agricultural practices in the production of milk and monitoring of the TBC measurements. The methodology for analysis of longitudinal data was considered, focusing on random effects models. The results showed that the handling procedures for milking and the cleanliness of the cooling tank contributed to a further reduction in the levels of TBC raw milk cooling tanks. The second study aimed to describe the percentage of the properties that comply with the Normative Instruction Nº 51 (Brazil s IN 51) with regard to total bacterial count (TBC) in bovine milk. The study was conducted from January 2010 to July 2011. Milk samples were collected from the eight properties selected for TBC analysis by the flow cytometry method. Again, on each property a questionnaire was applied to assess the current situation of milking procedures on each production system that took part on this research, followed by training of employees in good agricultural practices in the production of milk and monitoring of the TBC measurements. The methodology of marginal models based on Generalized Estimate Equations (GEEs) was followed in the statistical analysis. The results showed that the handling procedures of the milking and the cleanliness of the cooling tanks contributed to a considerable percentage of the properties that reached the limits of TBC established by IN 51

Caracterização dos sistemas de produção de leite bovino na microrregião Seridó do estado do Rio Grande do Norte

The objective was to contribute to a reading of the characteristics and diversity of production systems from bovine milk in the microregion Seridó of Rio Grande do Norte, discuss the social, economic, environmental and husbandry-related primary activity of milk production. We randomly selected 28 agricultural establishments that performed the activity of dairy bovine culture with subsequent applicat ion of a structured questionnaire during September and October 2011. Data were analyzed with application of measures of descriptive analysis and determination of the index rural development (IRD). The results showed that 53.57% of the interviewees were owners of the land, the median area of the properties amounted to 135 hectares, the median number of animals in the herd was 51 head, with minimum 11 and maximum of 350 heads establishments in the sample, 85.72% of establishments had maximum 23 cows in lactation, 100% performed manual milking with suckling calves, average productivity of 3.91 liters / cow / day, 92.86% of the interviewees did not produce silage and / or hay, 64.29% had no access to technical assistance, the average age of interviewees was 51 ± 10.85 years, 78.57% had only elementary education. The average of the IRD computed in the test sample amounted to 0.43 ± 0.11 on a scale 0-1. The sites were grouped into 04 classes, based on your IRD. The average IRD in each dimension was 0.43, 0.55 and 0.34, respectively for economic / husbandry, social and environmental. The determination of the rate of rural development - IDR found for the sample could add establishments hierarchically. It is necessary that the inclusion of best practices in herd management, bookkeeping zootechnical, technical assistance and reorganization practices in land and environmental preservation

Levantamento exploratório da composição e frações proteicas do leite bovino em propriedades leiteras

The direct relationship with the processing, industrial yield and price of milk, the importance of the centesimal composition of milk and their protein fractions has increased for both the dairy industry and for the producers, so it is important to identify the possible causes on variation of these components. The aim of this study was to evaluate the effect of the seasons, order of calving and lactation phase on milk composition and protein fractions in dairy farms in the Agreste and Leste meso-regions, of Rio Grande do Norte State (RN). Milk samples were taken in seven milk farms directly from the bulk tanks except for one farm where samples were taken from higher milking cows producers and heifers. The experiment was done in seven properties with milk samples taken directly from the bulk tanks and in one property were collected from higher production cows and heifers. Composition analyses were carried out for both experiments and sensorial trial was performed for the second experiment only. The data results were submitted to analysis of variance (ANOVA) and Tukey test performed for 5% significance level. In the first experiment was observed response of the seasons, dry and rainy season; while in the second, the effect of the order of calving and lactation phase had influence on milk composition and protein fractions. There was significant response (p < 0.05) for season effects but due to farms. The rainy season had higher averages in the protein, lactose, total solids and nonfat dry extract. Multiparous cows had higher CCS, NUL and PCAS milk contents; while, first calving heifers showed higher average for the sensory attribute, color of milk. The final third of lactation was responsible for the elevation of the levels of almost all milk components and their protein fractions