RESUMO. Foram analisados 474 rebanhos de bovinos leiteiros da região Norte do Paraná. Os rebanhos foram caracterizados quanto à produtividade média, ao grupo genético predominante, ao sistema de exploração e de ordenha utilizado. De cada propriedade foram colhidas mensalmente duas amostras compostas de leite, do tanque ou do latão, perfazendo um total de 21.957, para a determinação dos teores de gordura, de proteína e de contagem de células somáticas (CCS), no Laboratório de Análises Centralizadas do Programa de Análise de Rebanhos Leiteiros do Paraná. Com o objetivo de determinar a influência de fatores ambientais e raciais na CCS e constituintes do leite, bem como a influência da CCS sobre os teores de proteína e de gordura, os dados foram submetidos à análise de variância pelo método dos quadrados mínimos (proc glm), análise de regressão (proc reg) e análise de correlação (proc corr), no pacote estatístico SAS. Os efeitos estudados para a CCS mostraram-se altamente significativos (p<0,0001), com exceção do sistema de ordenha (p<0,05). Dos efeitos estudados para a proteína e para a gordura, a produção do rebanho não mostrou efeito significativo sobre o teor de proteína (p>0,05). O efeito da CCS sobre os teores de proteína e de gordura láctea foi estatisticamente relevante (p<0,0001). Com o aumento da CCS, ocorreu diminuição no teor de proteína e aumento no teor de gordura, embora apenas 0,53% e 3,02% da variação desses sólidos, respectivamente, possam ser creditados à CCS.Palavras-chave: bovinos leiteiros, gordura, produtividade, proteína, sistema de produção.ABSTRACT. Influence of racial and nutritional management factors on somatic cells count and milk composition of Holstein and mixed breed cows in the north of Paraná State, Brazil. 474 milking herds from the north region of Paraná State were analyzed in this study. The herds were characterized for average productivity, genetic group, exploration and milking systems. Two milk samples (bulk or brass) were collected monthly from each farm, totalizing 21.957 samples. They were processed to determine fat, protein and somatic cells count (SCC) at Centralized Analyses Laboratory from Milking Herds Analyses Program of Paraná State. The data was submitted to analysis of variance (proc glm), regression analysis (proc reg) and correlation analysis (proc corr) in SAS to determine the influence of environmental and racial factors on SCC and milk composition, as well as SCC influence on protein and fat levels. Except for the milk system (p>0.05), all other studied effects were highly significant (p<0.0001) on SCC. For the studied effects on protein and fat, the only one showing no significance (p>0.05) was the herd average production, on protein level. The effect of SCC on milk protein and fat was statistically relevant (p<0.0001). With the increase of SCC, there was a reduction in protein level and an increase in fat level, although only 0.53% and 3.02% of the variation of these solids, respectively, can be credited to SCC.Key words: dairy cattle, milk fat, milk protei...
This observational study verified the effects of monochromatic lighting for three monochromatic light spectra on the production and quality of laying hen eggs and blood parameters, as probable indicators of environmental stress. Lohmann®29-week-old birds were divided into groups of 20 animals, housed in three experimental houses with different lighting treatments (blue, green and red), and monitored for 90 days. Were analysed 4,443 eggs, and the values of the following measurements were extracted: egg weight (g), albumen height (mm), shell resistance (kgf/cm²), shell thickness (mm), Haugh unit, specific gravity (g/cm³), and egg shape. Blood samples were collected from the birds at the beginning and at the end of the study period. The levels of total plasma protein and the heterophile/lymphocyte ratio remained within the normal range. Laying hens housed under blue and red lighting had higher egg production (per hen) and showed better egg quality results. Red lighting stood out for providing significantly better shell resistance than other treatments. Glucose differed between treatments, with a drop in blood glucose levels as the environment light wavelength increased. The quality of the eggs was affected differently by the sources of monochromatic lighting. Correct lighting management promotes better health for birds and increased egg production and quality.
Milk and its derivatives are among the foods most consumed by the population, capable of meeting important nutritional needs of humans. As the consumer market is increasingly demanding in terms of quality of the milk produced, the difficulty in maintaining and controlling these points is an issue present in several studies. Quality can be influenced from the type of production system in which the milk is produced, passing through nutritional and sanitary management, to the environment in which the animals remain during their productive life. This chapter presents a brief characterization of the dairy production chain in Brazil and the federal legislation that governs the production and quality of the milk produced. Some results of research on milk quality in shared tanks carried out by the Kamby Research Group with small rural producers in the Tupã/SP region are also presented. Finally, factors that affect the quality of milk and future actions to improve the dairy production chain are pointed out.
En establecimientos caprinos para la conservación de la leche es común aplicar la tecnología de congelación, ya sea para venta directa o para la elaboración de quesos. En este trabajo se estudió la congelación a -18 ºC como método de conservación de la leche caprina durante 6 meses. Se evaluó el efecto de la congelación en leche cruda y en leche pasteurizada. Se utilizaron dos métodos de descongelado: baño María (27 °C) y heladera (4 °C). En los días 0, 60, 120 y 180 se analizó la composición (% materia grasa, % proteínas totales, % lactosa, % sólidos totales y % sales), parámetros fisicoquímicos (pH, acidez y densidad), parámetros microbiológicos (recuento de mesófilos aerobios totales, coliformes totales, Staphylococcus coagulasa positiva), recuento de células somáticas y la estabilidad a la oxidación (según tiempos de inducción a la oxidación por Rancimat). Se concluye que no se afectó la calidad de la leche de acuerdo a los parámetros de este estudio durante la congelación por el período de 6 meses. Como método de conservación podría ser una alternativa para los establecimientos rurales. No se encontró diferencia en los métodos de descongelación evaluados. Palabras clave: Conservación, leche caprina, congelación.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.