Newton Pohl Ribas

Contagem de células somáticas em amostras de leite

The goal of this study was to evaluate somatic cell count (SCC) in bulk tank milk samples in the milk delivered to the industry by dairy farmers; also, to allot of the bulk tank milk samples in somatic cell score (SCS) class. Bulk tank milk samples are routinely analyzed at the central laboratory of the Programa de Analise de Rebanhos Leiteiros do Parana (PARLPR) of the Holstein Association, state of Parana, Brazil. The present study was on a data set of the PARLPR containing 257,540 bulk tank milk samples from 32,590 herds delivering milk to 18 dairy industries in the states of Santa Catarina, Parana and Sao Paulo, analyzed between January 1999 and November 2001. General Linear Models procedures were used to study the effects of micro region, year and month of the test, herd and age of the sample on SCC in bulk tank milk samples. Mean and standard deviation for SCC samples in bulk tank milk samples were 486,812 and 401,547 cells/mL, respectively. All factors had a highly significant effect on the SCC. Micro regions were highly variable on the SCC, from 602,000 to 242,000 cells/mL. The highest means were observed in 2001 (483,000 cells/mL). Highest SCC means were observed in January (497,000 cells/mL) and lowest in September (442,000 cells/mL). The effect of age of the sample showed reduction in SCC levels until day four; after day seven samples were highly variable. Sixty-four percent of all samples showed a SCS of five or more.

Sólidos totais do leite em amostras de tanque nos estados do Paraná, Santa Catarina e São Paulo

Objetivou-se, neste trabalho, estudar a variacao dos solidos totais em amostras de leite de tanques de 32.590 rebanhos dos estados do Parana, Santa Catarina e Sao Paulo. Foram analisadas 257.540 amostras de leite de tanques coletadas entre janeiro de 1999 e novembro de 2001, no Laboratorio Central do Programa de Analise de Rebanhos Leiteiros do Parana (PARLPR), da Associacao Paranaense de Criadores de Bovinos da Raca Holandesa. Utilizando-se o metodo dos quadrados minimos, foram estudados os efeitos de rebanho, regiao, mes e ano de analise, idade da amostra e escore de celulas somaticas sobre os solidos totais, em amostras de leite de tanques. As medias ajustadas dos solidos totais por regiao variaram de 11,78 a 12,83%; a maior media foi verificada em maio de 2001 e a menor, em janeiro de 2000; os solidos totais nao demonstraram variacao ate o quinto dia de analise; o efeito de escore de celulas somaticas foi contraditorio, se comparado aos relatados por outros autores. Todos os fatores incluidos no modelo linear foram altamente significativos sobre as caracteristicas analisadas. O coeficiente de correlacao entre solidos totais e seus componentes foi de 0,875 para gordura, 0,653 para proteina, 0,237 para lactose, e 0,643 para solidos nao-gordurosos. A correlacao de solidos totais com contagem de celulas somaticas foi 0,012, e com escore de celulas somaticas, de 0,023.

Genotype × environment interaction for milk yield of Holstein cows among dairy production units in the state of Paraná

It was analyzed 117,082 complete lactation records adjusted for 305 days in milk yield (MY305) of 49,676 Holsteins cows from 308 herds distributed among seven dairy production units in the state of Parana, Brazil. The objective was to verify the genotype × environment interaction to MY305 of Holsteins cows between dairy production units in the state of Parana using the Bayesian inference. All animals were officially controlled by the Servico de Controle Leiteiro Mensal of Associacao Paranaense de Criadores de Bovinos da Raca Holandesa, between January/1992 and December/2003. The (co)variance components and genetic parameters were estimated using one and multiple-trait analysis, where MY305 of each dairy production unit was considered as a different variable. Means and standard deviations for MY305 (kg) for dairy production units of Castro, Carambei, Witmarsum, Arapoti, Sul, Norte and Oeste, were 8,414 ± 1,825; 8,481 ± 2,010; 7,636 ± 1,594; 7,850 ± 1,795; 8,617 ± 2,050; 7,401 ± 1,809 and 7,336 ± 2,456, respectively. The highest heritability estimated was obtained for the Oeste unit (0.39) while Carambei unit presented the lowest value (0.23). Genetic correlations were low (0.09 to 0.57) between dairy production units. Pearson and Spearman correlations were lower for the Oeste unit, when compared with other dairy production units, which ranged from 0.37 to 0.41, and from 0.37 to 0.49, respectively. These results show the presence of genotype × environment interaction between dairy production units in the state of Parana.

Influência da adição de probióticos na dieta sobre o estado sanitário e desempenho de bezerros da raça Holandesa

O experimento foi realizado no Setor de Bovinocultura de Leite da Fazenda Experimental de Iguatemi, Maringa, Parana, com o objetivo de avaliar o efeito do uso de probioticos sobre o indice de diarreia, mortalidade e desempenho (altura e peso) de bezerros. As medicoes de peso e altura foram feitas logo apos o nascimento dos animais, aos 30 e aos 60 dias de idade. Foram utilizados 19 bezerros puros por cruza Holandes, do nascimento aos 60 dias de idade, machos e femeas. Os bezerros foram distribuidos em tres tratamentos: (A) leite integral + probiotico em po soluvel, (B) leite integral + probiotico em po soluvel e pasta probiotica de administracao oral e (C) leite integral. Foram fornecidos feno e concentrado a vontade apos 20 dias de idade. Os indices de diarreia e mortalidade foram nulos para os tres tratamentos. Nao houve diferenca significativa para o ganho medio diario e mudanca nas alturas tomadas nas cernelhas do nascimento aos 60 dias de idade entre os tratamentos A (0,56 kg/dia e 0,055 cm/dia), B (0,41 kg/dia e 0,075 cm/dia) e C (0,51 kg/dia e 0,043 cm/dia).

Curvas de lactação de vacas holandesas do Estado do Paraná, Brasil

A data set from the dairy herd analysis system in the State of Parana, Brazil (PARLPR - APCBRH), containing 27029 lactation records from 422 herds, was used to plot lactation curves. Lactation curves were plotted according to three parity groups and six levels of production. Production at peak increases with increases in herd production level and with increases in lactation number. Daily decline increases with increases in herd production level, in the case of second or greater lactation; for first lactation animals, no trend was identified for this characteristic. The curves, peak and persistency values obtained are to be used as management tools on dairy farms in the State of Parana.

Avaliação da contagem de células somáticas na primeira lactação de vacas holandesas no dia do controle mensal

Data consisting of 172,304 test-day records of first lactation Holstein cows were used to evaluate non-genetic effects on Somatic Cell Count (SCC) and Somatic Cell Score (SCS). Milk samples were collected in Holstein herds supervised by the Dairy Herd Analysis Program, at Parana State, Brazil, between January 1983 and December 1998. The statistical models included the fixed effects of region (Reg), number of milkings (NM), days in milk (DIM), age of cow (AC), month of test-day (MTD), days of storaging of samples before analysis (DS) and the random effects of herd, cow and residual. Data was analyzed by REML using the spatial power procedure. Observed means for SCC (x1000 cel/mL) and SCS ranged from 400,245±468,558 and 3.55±0.82 in 1993 to 241,360±514,969 and 2.41±1.35 in 1998, respectively. DIM, AC, MTD and DS effects were significant for SCC and SCS. The phenotypic correlations between SCC and SCS on consecutive test-days suggest it is possible to estabilish management routines to reduce the presence of clinical and/or subclinical mastitis in first lactation Holstein cows.