Avaliação das características do líquido ruminal, hemogasometria, atividade pedométrica e diagnóstico de laminite subclínica em vacas leiteiras

The objectives of this study were to evaluate the characteristics of ruminal fluid, blood gas analysis, pedometer activity and suclinical laminitis occurrence, through the presence of secondary foot diseases in high production dairy cows, from a commercial herd. 200 Holstein cows originating from the same farm, located in Araçatuba/SP, Brazil, were divided into four groups, which are established from the daily milk production. Initially clinical examination of the cows was procedure, followed by sampling of rumen fluid, by esophageal tube. Fluid was evaluated for pH, color, odor, consistency, sedimentation, flotation and methylene blue reduction test. Venous blood samples were also collected for blood gas analysis, in addition to collecting data from pedometrics (number of steps) and daily milk production. Data were tabulated and submitted to correlation analysis. No animal had reported changes in rumen pH. Non-acid base imbalance were found, since the values of blood pH, PCO2, TCO2, HCO3- and BE were normal during hemogasimetric analysis. The pedometric was effective as a screening method to cows with foot diseases. It demonstrated reduction in the number of steps due to pain, correlated with lower milk production. However, the identification of foot lesions was only possible through specific digital clinical examination. The occurrence of 49.5 % of herd foot problems was due to the risk factors present in the farm. The abrasive concrete and inadequate facilities, also associated with the possible occurrence of sub-acute ruminal acidosis, were observed as risk factors. However, sub-acute ruminal acidosis was undiagnosed by the methods used. The correlation between the values of ruminal pH, and blood gas analysis pedometrics showed efficient for the early diagnosis of foot diseases and also in establishing the etiology of these diseases. Subclinical laminitis occurred primarily in cow's herd, considering the multifactorial etiology of this disease, occurrence and distribution of foot diseases diagnosed.

Polimorfismos nos genes DGAT-1 e A2M e suas associações com produção e qualidade do leite de búfalas da raça Murrah

Pós-graduação em Genética e Melhoramento Animal - FCAV

Prevalência de Mycoplasma bovis em rebanhos de vacas leiteiras do interior do estado de São Paulo

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Comportamento ingestivo de vacas leiteiras alimentadas com silagem de milheto ou milho

The objective of this study was to evaluate the ingestive behavior of dairy cows fed corn and millet silage with a 5 mm particle size without inoculant, millet silage with a 5 mm particle size with inoculant, millet silage with a 20 mm particle size without inoculant, millet silage with a 20 mm particle size with inoculant. Five cows Holstein x Gir, with approximately 100 days of lactation at the beginning of the experiment and a mean body weight of 550 kg, producing an average of 15 kg of milk per day were used. The animals were arranged in a randomized 5 x 5 Latin square. The total feeding time, rumination time, chewing time, number of alimentary bolus, rumination time for bolus and number of chews was determined. The variables that make up the feeding behavior were not affected when the cows were fed different millet silages compared with corn silage. Cows fed corn silage and millet silage of 5 mm particle size had a higher intake of dry matter and neutral detergent fiber. A particle size between 5 and 20 mm, the presence or absence of inoculum and the type of silage with DM at 28%, does not affect the total feeding time, ruminating and resting of cows with an average production of 15.2 kg per day. The presence of the inoculant does not affect the intake of dry matter and neutral detergent fiber. Cows fed diets containing corn silage or pearl millet silage with a 5 mm particle size fed more DM.

Indicadores de qualidade do leite bovino orgânico em duas propriedades leiteiras certificadas do Estado de São Paulo

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Produção de leite, duração da lactação e intervalo de partos em búfalas mestiças Murrah

This study aimed to evaluate the potential for milk production (MP), lactation length (LL) and calving interval (CI), analyze the environmental component affecting these traits, and to estimate the heritability and repeatability for milk production in crossbreds of Murrah buffalo cows in the state of Alagoas, Brazil. Data was composed of 487 observations of MP from 136 lactations recorded between the years of 2000 and 2010. In the analysis of variance for PL, the fixed effects were season (1- October to March, 2 -April to September) and year of the beginning of lactation, calving order and the LL (covariate). For the analysis of LL only the fixed effect of year of the beginning of lactation was included, and finally for the CI analysis, year of the beginning of lactation and calving order. The estimates of covariance were obtained using unicharacteristic analysis by Bayesian inference method, applyingan animal model, through Gibbs sampling. The additive genetic, permanent environment and residual effects were included as random effects in the model. The averages (sd) of MP, LL and CI were 2,218.03 kg (408.18), 282.59 days (39.48) e 422.49 days (91.05), respectively. All the effects included in the models were important (P<0.01). The estimates of heritability and repeatability for PL were 0.29 and 0.69, respectively. The results suggest that there is a moderate genetic variability among individuals for PL, indicating the possibility to obtain gain using selection.

Técnicas associadas à biotecnologia da reprodução para minimizar os efeitos do estresse térmico e aumentar a fertilidade em vacas leiteiras de alta produção

The dairy sector has undergone considerable economic losses due to low fertility rates due to adverse effects of heat stress on reproduction of cows. Genetic selection for increased production, coupled with the expanding dairy to tropical areas of the planet, and global warming has further aggravated the problem of heat stress. The effects of heat stress are multifactorial and act directly or indirectly at various levels of reproductive tissues, resulting in low fertility of cows, which in practice, results in reduced reproductive efficiency in the property, reducing the producers’ profit. Some strategies related to breeding biotechnology such as fixed-time artificial insemination, embryo transfer and use of BST, can minimize these effects and improve the reproductive efficiency of the herd

Estresse término na reprodução de vacas leiteiras

Climate change in tropical countries, like Brazil, causes major problems in dairy production due to an increase of heat stress effects. In recent years, milk production in Brazil increased 36.07%. The Southeast region remains a leader in production with herds of high producing Holstein cattle (mostly), which is more susceptible to heat stress. Thermal stress decreases fertility in direct and indirect ways. Conception rates are reduced of 40-60% during cooler months of the year and 10-20% in the warmer months. Negative effects of heat stress involve changes in reproductive hormones, follicular development, oocytes, and embryos, and decreased dry matter intake. Several studies discuss change in reproductive hormones, such as reduction in plasma concentration of GnRH, LH, and oestradiol, which lead to decreased detection of estrus and ovulation. Various methods are being studied to bypass these negative effects and increase the fertility of dairy cows under heat stress. Cooling systems are the most advantageous and can be associated with technologies such as ET and TAI

Deslocamento de abomaso em vacas leiteiras

The genetic selection and the nutritional management to improve milk production make the dairy cattle more susceptible to the development of diseases, such as the abomasal displacement. It is the most frequently detected abomasal problem and it is the main cause of abdominal surgeries in dairy cattle. It is a multifactorial disease that occurs mainly in dairy cattle of high production during the puerperium. The abomasal displacement can occur to the right (DAD) or to the left (DAE), being the former more frequent than the latter. It is related to feeding management and occurs in animals that also have other diseases such as hypocalcaemia, ketosis and retained placenta. The disease causes economical losses in dairy cattle because of the costs with treatment, reduction of production, increase of the interval between the parturition, loss of body weight, early discard of the matrix and mortality. The most usual clinical signs are apathy, dehydration, low to serious ruminal timpanismo (gas accumulation in the abomasum) with reduction or lack of motility, liquid splash sound during the ballottement of the right flank, metallic sound to percussion, presence of a structure similar to distended viscera in the thorax or in the paralombar cavity on the side corresponding to the displacement, and liquefied, dark, scarce and fetid feces. The treatment is surgical, and the most used technique is the omentopexy on the left flank. The hidroelectrolytic correction must be performed and the concomitant diseases must be treated. The prophylaxis consists of adequate nutrition and pre-parturition management, besides reduction of stress and other diseases of the puerperium

Fontes de ácidos graxos insaturados na alimentação de vacas leiteiras no período seco

Pós-graduação em Zootecnia - FCAV

Desempenho de vacas leiteiras em pastejo de alfafa

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Boas práticas de manejo de bezerras leiteiras na fase de cria e potenciais efeitos na recria

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Fatores associados a qualidade do leite, higiene animal e concentração bacteriana na cama de vacas leiteiras confinadas no sistema de compostagem

Pós-graduação em Medicina Veterinária - FMVZ

Óleo funcional na dieta de vacas leiteiras

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Fatores de risco para casos repetidos de mastite clínica em vacas leiteiras de alta produção

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)