Qualidade do leite e sua correlação com técnicas de manejo de ordenha

The study was conducted in 32 dairy production systems (DPS) located in the city of Toledo-Paraná, and aimed at verifying the practices of hygiene applied during milking, as well as,  observing their correlation with the total bacterial count (TBC), the somatic cell count (SCC) and the milk composition. We obtained 24 milk analyses in two years of collecting for each DPS. Along with the milk analysis, we collected some information from DPS by conducting a questionnaire where data were obtained,  regarding to the  practices  of  hygiene  during milking. For the statistical analysis, we used the Pearson correlation, seeking to verify the correlation within the hygiene practices concerning to the milk composition, SCC and TBC. We found, by the average results of analyzes of milk, that most samples were within the standards  established by the current legislation (IN 62). We also observed that there was an interconnection between the current applied practices and the milk composition, SCC and TBC. Regarding to the composition, the total solids content was more influenced by the fat and protein components. SCC showed negative correlation with lactose, while TBC was negatively correlated with the price paid for the collected milk, the milk storage time, and the use of uniform in milking. We concluded that applying hygienic practices during milking can be an important tool for maintaining the quality of milk.O estudo foi realizado em 32 sistemas de produção leiteiros (SPL) localizados na cidade de Toledo/PR, e teve por objetivo verificar as práticas de higiene aplicadas durante a ordenha e observar sua correlação em relação com a contagem bacteriana total (CBT), contagem de células somáticas (CCS) e composição do leite. Foram obtidas 24 análises de leite referentes a dois anos de coleta para cada SPL. Juntamente com as análises de leite, foram coletadas informações dos SPL através da realização de um questionário, onde foram obtidos dados referentes às práticas de higiene aplicadas durante a ordenha. Para a análise estatística foi utilizado a análise de correlação de Pearson, onde buscou-se verificar a correlação entre as práticas de higiene em relação a composição do leite, CCS e CBT. Verificou-se pelos resultados médios das análises de leite que a maioria das amostras encontrava-se dentro dos padrões estabelecidos pela legislação atual (IN 62). Observou-se também que as práticas aplicadas durante a ordenha obtiveram correlação em relação à composição do leite, CCS e CBT. Em relação à composição, o teor de sólidos totais foi mais influenciado pelos componentes gordura e proteína. A CCS apresentou correlação negativa com a lactose, enquanto a CBT correlacionou-se negativamente com o preço pago pelo leite coletado, tempo de armazenamento do leite e uso de uniforme na ordenha. Conclui-se o emprego de práticas de higiene durante a ordenha são importantes ferramentas para manter a qualidade do leite

Tifton 85 bermudagrass (Cynodon sp.) silage as a replacement for Tifton 85 hay to feed lactating cows

The objective of the study was to evaluate the replacement of Tifton 85 hay (TH) for Tifton 85 silage (TS) in the diets of lactating cows. Five Holstein cows in middle of lactation were allocated in a 5 × 5 Latin square design and each experimental period lasted 18 days (12 days for adaptation and six days for collection). Treatments consisted of replacement of 0, 25, 50, 75, and 100% of TH for TS. The intake and digestion of nutrients, microbial protein synthesis, milk yield and composition, and the economic viability of the diets were evaluated. The intakes of dry matter, organic matter, and ether extract had a positive linear effect and the digestibility of dry matter, organic matter, crude protein, neutral detergent fiber, acid detergent fiber decreased linearly with increasing participation of TS. Milk production and composition and microbial protein synthesis were not affected. Regarding economic viability, the treatment with 100% hay produced better results, with better gross margin. The Tifton 85 silage can be used as a replacement for Tifton 85 hay up to 100% without changing the milk production and composition of Holstein cows

Avaliação nutricional do resíduo da extração do amido da mandioca seco na alimentação de bovinos

This study aimed to evaluate the digestive power of waste of cassava starch extraction dried (WCSEd) and corn, in addition to determining the appropriate level of WCSEd to replace corn in the diet of cattle. Studies to evaluate the in vitro digestibility and in situ degradability were performed. The study used four cattle with rumen cannula, individually fed with diets containing increasing levels (0, 33, 66 and 100%) of WCSEd to replace corn, to evaluate the dry matter and nutrient intake and digestibility, pH and ammonia concentration of rumen fluid. The WCSEd showed differences in the in vitro digestibility of DM, OM and NDF (P < 0.05) compared to corn, but did not change the NDT and in situ degradability. As for in vivo reviews, the DM and nutrient intake was influenced by treatments in decreasing order, resulting in changes in the digestibility of DM, OM and NDT of diet, and a decreased concentration of N-NH3, but the pH was not affected. The residue from the extraction of cassava starch showed lower in vitro digestibility; however, ruminal degradability did not differ from corn. Their use in ruminant feed reduces the intake and degradation of feed, but improves the use of N-NH3 in the rumen.Objetivou-se avaliar a degradabilidade potencial do REAMs e do milho e de determinar o nível adequado de REAMs, em substituição ao milho na ração de bovinos. Foram realizados estudos para avaliação da digestibilidade in vitro e degradabilidade in situ. Utilizou-se quatro bois castrados, canulados no rúmen, alimentados individualmente, com dietas contendo níveis crescentes (0%, 33%, 66% e 100%) de REAMs em substituição ao milho, para avaliação da ingestão e digestibilidade da matéria seca e nutrientes, avaliação do pH e nitrogênio amoniacal do líquido ruminal. O REAMs apresentou diferenças quanto à digestibilidade in vitro da MS, MO e FDN (P < 0,05), quando comparado ao milho, mas não apresentou alteração quanto ao NDT e a degradabilidade in situ. Quanto às avaliações in vivo a ingestão de MS e dos nutrientes foi influenciada de forma decrescente pelos tratamentos, resultando em redução na digestibilidade da MS, MO e no NDT das dietas in vivo, ocorrendo redução na concentração de N-NH3, mas o pH não foi influenciado. O resíduo da extração do amido da mandioca apresentou menor digestibilidade in vitro porem não diferiu do milho quanto a degradabilidade ruminal. Sua utilização na alimentação de ruminantes reduz a ingestão e degradação da ração, porém melhora o aproveitamento do N-NH3 no rúmen.s

Tifton 85 bermudagrass (Cynodon sp.) silage as a replacement for Tifton 85 hay to feed lactating cows

ABSTRACT The objective of the study was to evaluate the replacement of Tifton 85 hay (TH) for Tifton 85 silage (TS) in the diets of lactating cows. Five Holstein cows in middle of lactation were allocated in a 5 × 5 Latin square design and each experimental period lasted 18 days (12 days for adaptation and six days for collection). Treatments consisted of replacement of 0, 25, 50, 75, and 100% of TH for TS. The intake and digestion of nutrients, microbial protein synthesis, milk yield and composition, and the economic viability of the diets were evaluated. The intakes of dry matter, organic matter, and ether extract had a positive linear effect and the digestibility of dry matter, organic matter, crude protein, neutral detergent fiber, acid detergent fiber decreased linearly with increasing participation of TS. Milk production and composition and microbial protein synthesis were not affected. Regarding economic viability, the treatment with 100% hay produced better results, with better gross margin. The Tifton 85 silage can be used as a replacement for Tifton 85 hay up to 100% without changing the milk production and composition of Holstein cows

Use of dried brewers' grains instead of soybean meal to feed lactating cows

ABSTRACT The objective of this study was to determine the optimal level of dried brewers' grains (DBG) to replace soybean meal in diets for lactating Holstein cows. Five cows, around 88±28 days in milk, were distributed in a 5 × 5 Latin square design and fed diets containing different levels of DBG (0, 25, 50, 75, and 100%). The forage:concentrate ratio of the diet was 50:50. Feed intake, dry matter, nutrient digestibility, microbial synthesis, milk production and composition, and the economic viability of the diets were evaluated. There was reduction in dry matter intake and, consequently, in crude protein and non-fiber carbohydrates with increased levels of DBG. This occurred due to physical limitation of rumen caused by increased neutral detergent fiber intake. Ether extract intake also increased with levels of DBG due to higher concentrations of this nutrient in the diet. Apparent dry matter, organic matter, ether extract, and neutral detergent fiber digestibility increased with replacement of soybean meal by DBG. Milk production showed a quadratic effect and the levels of fat, protein, and total solids reduced linearly. Each 1% of soybean meal replaced by DBG in concentrate led to a reduction of 0.04, 0.02, and 0.06 g kg-1 of milk fat, protein, and total solids, respectively. The milk production efficiency increased linearly and the microbial synthesis efficiency was not affected. The economic return increased along with the DBG levels. Thus, DBG levels replacing up to 75% of soybean meal can be used to feed lactating cows, since it provides improvements in digestibility, milk production efficiency, and economic return without affecting microbial efficiency