Seasonability of protein and others milk components related with quality payment program

Avaliou-se o efeito da variação da qualidade do leite mediante acompanhamento de amostras provenientes de tanques refrigeradores. As 2.970 amostras foram obtidas de outubro/2005 a setembro/2006. Foram realizadas análises de composição, contagem de células somáticas (CCS) e contagem bacteriana total. As condições climáticas foram avaliadas pela temperatura e umidade do ar coletadas em estações meteorológicas distribuídas em todo o estado de São Paulo. No outono, ocorreram os maiores valores para gordura e proteína do leite, 3,65 e 3,21%, respectivamente. Para contagem de células somáticas, foi observado aumento no verão e contagem bacteriana na época da primavera. Foi identificada a influência da época do ano sobre o preço do leite pago dentro de um programa, com valor de bonificação máxima de 7,9% para o outono. Um dos mais importantes itens relacionados com a penalização foi a CCS, a qual pode interferir na qualidade dos produtos finais por meio de alteração da proporção de caseína/proteínas do soro. O efeito da CCS e o da época do ano devem ser considerados na formulação das tabelas de programas de pagamento.This study evaluated the variation of quality of bulk tank milk using 2,970 samples, collected from October 2005 to September 2006. Milk composition analyses, somatic cell count (SCC), and total bacterial count were performed. Climate conditions were evaluated by temperature and relative air humidity collected at meteorological stations throughout São Paulo state. Autumn season was related to the highest values for protein and fat, 3.65 and 3.21%, respectively. For somatic cell count, it was observed an increase in the count in the summer and for bacterial count in the spring. The influence of season on milk price was observed for dairy producers in a program, with maximum bonus of 7.9% in the autumn. One of the most important parameters related to penalty for lower quality of milk was SCC, since it can affect the quality of some dairies by the alteration of casein/whey protein proportion. Therefore, the effects of SCC and season should be considered into the process of formulation of tables for milk payment program.FAPES

In situ degradability of corn stover and elephant-grass harvested at four stages of maturity

Among tropical forages, corn silage is largely used by farmers trying to explore the maximum genetic potential from the animals. However, other tropical forages, such as elephant-grass (Pennisetum purpureum), are more productive and therefore cheaper to use than corn silage. Our objective was to compare the in situ degradability of elephant-grass with that from corn hybrids, all harvested at four stages of maturity. The experimental design followed a randomized block design with nested subplots. Two corn hybrids: AG5011, ZN8392 were harvested with 25, 30, 35, and 40% dry matter (DM) in the whole plant, and separated in stem + leaf sheath + leaf blade (stover), and cobs. Elephant-grass was harvested with 30, 40, 50 and 60 days after a leveling cut. Dried and ground samples were incubated in nylon bags inside the rumen for 0, 6, 12, 24, 48 and 72 h to estimate the kinetics of ruminal DM and neutral detergent fiber (NDF) degradation. The advance of maturity increased the NDF and acid detergent fiber (ADF) content in elephant-grass, and reduced its DM degradability. However, maturity had little or no effect on fiber content and DM degradability of corn stover. Elephant-grass had a higher NDF degradability than corn stover, and there was no effect of maturity on NDF degradability of either elephant-grass or corn stover. Fiber degradability of elephant-grass was not worse than that of corn stover, and therefore the choice of forage should be made on economical analysis rather than assuming an intrinsic low production potential for elephant-grass based diets

Análise econômica de esquemas alternativos de controle leiteiro Economic analysis of alternative schemes of milk recording

Compararam-se os custos de seis esquemas de controle leiteiro (CL), estabelecidos com base em diferentes freqüências de controles (com possibilidade de controle trimestral supervisionado e aproveitamento do CL da fazenda), no número de ordenhas e na realização de análises qualitativas (composição do leite e/ou contagem de células somáticas). Computaram-se os percentuais que os custos totais do CL representariam na receita bruta mensal do leite (CL/RB) e na receita líquida mensal (CL/RL). O esquema tradicional (freqüência mensal) apresentou o mais elevado custo mensal e os maiores CL/RB e CL/RL. Esquemas com intervalo maior entre controles e amostragem em ordenhas alternadas resultaram na redução dos custos com diárias e quilometragem. O custo mensal do CL variou de 0,68% a 1,8% sobre a receita bruta do leite e de 6,6% a 17,0% sobre a receita líquida.Costs of six different milk recording schemes based on the interval between controls (with the possibility of a three-month interval supervision control and the use of the farmers’ milk recording data), the number of milking recorded and milk quality analyses (milk composition and/or somatic cell counting) were compared. The ratio milk recording costs over gross income (CL/RB) and over net income (CL/RL) were also estimated. The traditional scheme (monthly recording) presented the highest monthly costs and ratios CL/RB and CL/RL. Schemes with longer intervals between controls and alternate sampling presented the lowest costs due to the reduction of travel costs. Monthly milk recording costs over milk gross income and over net income ranged from 0.68% to 1.8% and from 6.6% to 17.0%, respectively

The use of the Fourier Transform Infrared spectroscopy to determine adulterants in raw milk

The objective of this study was to develop calibrations to determine the concentration of some milk adulterants by using the automated methodology of Fourier Transform Infrared (FTIR). For construction of calibrations, samples were collected from 100 farms in the states of São Paulo and Minas Gerais. Samples were tainted with three different adulterants commonly used in the adulteration of raw milk: sodium bicarbonate (SB), sodium citrate (SC) and cheese whey (W). Each adulterant was used at three different concentrations (SB: 0.05, 0.10 and 0.25%; SC: 0.025, 0.050 and 0.075% and W: 5, 10 and 20%). For validation, 60 samples were collected in other farms, which were not considered at the development stage of calibration. Adulterants were added at the following concentrations: 0.03, 0.06, 0.10 and 0.12% for SB; 0.02, 0.04, 0.06 and 0.08% for SC and 5, 10 and 20% for W. Performance of each calibration was evaluated in terms of accuracy (Se), detection limit (DL) and determination coefficient (R²). All calibrations presented R² higher than 0.91 with DL of 0.015%; 0.017% and 3.9% for SB, SC and W, respectively. Accuracy was 0.005%, 0.009% and 2.26% for SB, SC and W, respectively. Results show that the FTIR methodology can be used for determining the concentration of sodium bicarbonate, sodium citrate and whey in raw milk. Associated with automated equipment, it is a viable option for monitoring these adulterants, having low operational costs and high analytical performance as additional features

Contagem de células somáticas e produção de leite em vacas holandesas confinadas Somatic cells count and milk yield in confined holstein cows

A relação entre contagem de células somáticas do leite (CCS) e produção de leite é objeto de estudo de inúmeras pesquisas em diversos países, porém, no Brasil a literatura a esse respeito é escassa. Desse modo, o objetivo do presente trabalho é verificar se as perdas na produção de leite devidas ao aumento da CCS são proporcionais à produção, ou absolutas, independendo desta, e a partir de que valor de CCS elas começam a ser evidentes. Para o estudo foram utilizadas 13.725 observações, colhidas mensalmente de seis rebanhos, no período de janeiro de 2001 a junho de 2002. O modelo de análise, para curva de lactação, foi baseado na função gama incompleta, considerando os efeitos de ordem de lactação, rebanho e época do parto. A CCS foi incluída nesse modelo de duas formas: como fator multiplicativo (representando perdas relativas) e como fator aditivo (representando perdas absolutas). A escolha do melhor modelo foi baseada no critério de informação de Schwarz (BIC). Concluiu-se que as perdas são absolutas, evidentes a partir de 17.000 células/mL e, para cada aumento de uma unidade na escala do logaritmo natural a partir desse valor, estimam-se perdas de 238 e 868 mL/dia para primíparas e multíparas, respectivamente.<br>The relationship between milk somatic cells count (SCC) and milk yield has been the aim of countless researches in several countries; however, in Brazil, the literature related to this subject is scarce. Therefore, the objective of this study is to verify if the losses in milk yield due to SCC increase are proportional to the yield, or absolute (independent of it) and starting from which SCC, the losses become evident. For this study, 13.725 observations were used, collected monthly from 6 different herds, from January/2001 up to June/2002. The analysis model, for lactation curve, was based upon the incomplete gama function, considering the effects of lactation order, herd and calving season. The SCC entered in that model in two ways: as multiplicative factor (representing relative losses) and as addictive factor (representing absolute losses). The best model was chosen based on the information criteria of Schwarz (BIC). It is concluded that the losses are absolute, becoming evident from 17.000 cells/mL, and they are 238 and 868 mL/day for each increase of one unit in the natural logarithm scale, starting from that SCC, respectively, for primiparous and multiparous