Lúcia Treptow Marques

Fornecimento de suplementos com diferentes níveis de energia e proteína para vacas Jersey e seus efeitos sobre a instabilidade do leite

Objetivou-se avaliar o efeito de suplementos contendo tres combinacoes de energia e proteina sobre a producao leiteira, as caracteristicas fisico-quimicas do leite, o peso e a condicao corporal e o perfil bioquimico sanguineo de vacas. Foram utilizadas 24 vacas lactantes em campo natural, distribuidas em delineamento completamente casualizado, recebendo um dos seguintes suplementos: baixos niveis de energia e proteina; baixo nivel de energia e alto nivel de proteina; ou altos niveis de energia e proteina. Em comparacao ao suplemento com baixos niveis de energia e proteina, aquele com altos niveis de energia e proteina reduziu a instabilidade do leite na prova do alcool, aumentou em 50% a producao de leite e em 18% o escore de condicao corporal das vacas. Alem disso, ocasionou aumento dos componentes do leite e do perfil bioquimico sanguineo das vacas: 13% no teor de lactose; 9% no de extrato seco desengordurado; 21% nos niveis plasmaticos de glicose; 24% no teor de fosforo; 16% no nivel de creatinina; 9% no teor de magnesio; e reduziu em 40% o teor de nitrogenio ureico. O suplemento com altos niveis de energia e proteina foi mais eficiente que os demais em melhorar a estabilidade do leite na prova do alcool, o escore de condicao corporal e os teores de alguns componentes quimicos do leite e do sangue.

Produção leiteira, composição do leite e perfil bioquímico sanguíneo de vacas lactantes sob suplementação com sal aniônico

The objective of this work was to evaluate the inclusion of anionic salt in the diet on the physical characteristics and chemical composition of milk, biochemical blood profile, milk yield, body weight and condition. It was used 20 Jersey cows, distributed into two diets, a diet with no addition of anionic salt and one diet with addition of 0.25 kg/day of ammonium chloride. It was used a completely randomized design. Cows supplemented with anionic salt presented lower urinary pH and increase of blood contents of urea, calcium and magnesium. With the anionic diet, milk precipitated with lower ethanol concentration and it presented lower density, percentages of lactose, protein and immunoglobulin, but higher ionic calcium content. Supply of anionic diet during lactation resulted in metabolic acidosis, which altered the blood biochemical profile and milk physical-chemical characteristics.

Leite instável não ácido: um problema solucionável?

This paper aimed to present the main results about the unstable non acid milk (LINA). The proportion of milk samples with thermal stability below the Brazilian dairy industry standard is a serious problem, with highest occurrence at short food supply periods. It is a multi factorial problem, which causing factors are related to test execution (ethanol concentration used), to management (feeding, climate, human-animal relation), to animal (stress susceptibility, productive potential, lactation stage, sanitary condition, digestive and metabolic disorders), among others. There are doubts to the accuracy and precision of the alcohol test to detect stability problems. Dairy industry needs a fast, low price and easy test, but that can identify milk suitable to thermal processing. An adequate animal’s management besides realistic parameters of milk test might contribute to improve milk stability.

Suplementação de vacas holandesas em estádio avançado de lactação

The trial aimed to verify the effects of two feeding supplements: low and high level supplementation given to cows at an extended lactation stage upon productive aspects, physical-chemical composition of milk and blood biochemical profile. Twelve lactating Holstein cows, with 514kg of body weight, body condition score of 3.5, yielding 13L milk cow-1 day-1 and approximately 349 days of lactation were used. Treatments were low or high level of supplementation for lactating cows grazing natural range pasture. Cows body weight and body condition score, individual milk yield, physical and chemical characteristics and somatic cells count, besides biochemical blood profile were evaluated. Increased nutrient supply augmented body weight gain, body condition score, fat corrected milk, milk fat and total solids contents, but did not change the others milk components nor blood biochemical profile. Increasing nutrient supply for cows at an extended lactation might be a valuable option to match milk productivity and improved physical aspects of dairy cows kept on grazing systems, without adverse effects upon milk components yield.