Teores de proteína bruta no concentrado e níveis de suplementação para vacas leiteiras em pastagens de capim-braquiária cv. marandu no período da seca

Abstract

Avaliou-se a resposta de 40 vacas meio-sangue Holandês/Zebu em pastagem de Brachiaria brizantha à suplementação com concentrados contendo diferentes teores de proteína bruta. Além da pastagem, foram fornecidos diariamente 5,0 kg de cana-de-açúcar por animal. Utilizou-se como testemunha o fornecimento exclusivo de 200 g de suplemento mineral contendo 10% de fósforo. Foram comparados três concentrados contendo 50,0; 28,6 e 20% de proteína bruta na matéria natural, fornecidos nas quantidades de 2,0; 3,5 e 5,0 kg/vaca/dia. O delineamento experimental utilizado foi em blocos casualizados com dez repetições. Os suplementos foram fornecidos em duas porções diárias, após as ordenhas, em baias individuais. Após a ordenha e suplementação matinal, as 40 vacas foram mantidas no pasto até a ordenha da tarde. A cada 21 dias pós-parto, até os 84 dias, foram feitas avaliações da produção de leite, do peso vivo e do escore corporal. A maior produção de leite ocorreu aos 63 dias pós-parto, quando foram fornecidos 3,5 kg de concentrado. Como resposta produtiva, foram obtidos valores de 1,04; 1,20; e 0,63 kg de leite por kg de concentrado, respectivamente, para o fornecimento de 2,0; 3,5 e 5,0 kg, em relação ao controle. Os animais do grupo controle tiveram maior perda de peso vivo e de escore corporal, enquanto entre os demais não houve diferença.

Performance and nutritional parameters of lactating cows on pasture receiving castor bean meal

“…For the digestibility of NDFcp (Table 6), there was no effect of castor bean meal inclusion; however, there was a lower digestibility than that found in the literature (PIMENTEL et al, 2011;SILVA et al 2009), which is due to the amount of EE consumed. The excess of this nutrient, according to Jenkins and Mcguire (2006), has a toxic effect on the microorganism, inhibiting the cellular growth, mainly the cellulolytic bacteria that acts mainly in the digestion of the cellular wall, and also the excess of fat can generate a fiber encapsulation, making it difficult the microbial adhesion to the cell wall.…”

“…This difference may be due to the heterogeneity of castor bean byproducts. The low DMI in relation to the other studies with pastured dairy cattle (PIMENTEL et al, 2011) is related to the low availability and allowance of forage (Table 3), due to the climatic conditions, mainly the lack of rainfall, which was expected during the course of the experiment. According to Silva et al (2009), the availability of forage is directly related to the total DMI, so when the animal is subjected to forage shortage, it results in a reduction in DMI, and the animal needs to increase the grazing time.…”

Performance and nutritional parameters of lactating cows on pasture receiving castor bean meal

“…For the digestibility of NDFcp (Table 6), there was no effect of castor bean meal inclusion; however, there was a lower digestibility than that found in the literature (PIMENTEL et al, 2011;SILVA et al 2009), which is due to the amount of EE consumed. The excess of this nutrient, according to Jenkins and Mcguire (2006), has a toxic effect on the microorganism, inhibiting the cellular growth, mainly the cellulolytic bacteria that acts mainly in the digestion of the cellular wall, and also the excess of fat can generate a fiber encapsulation, making it difficult the microbial adhesion to the cell wall.…”

“…This difference may be due to the heterogeneity of castor bean byproducts. The low DMI in relation to the other studies with pastured dairy cattle (PIMENTEL et al, 2011) is related to the low availability and allowance of forage (Table 3), due to the climatic conditions, mainly the lack of rainfall, which was expected during the course of the experiment. According to Silva et al (2009), the availability of forage is directly related to the total DMI, so when the animal is subjected to forage shortage, it results in a reduction in DMI, and the animal needs to increase the grazing time.…”

Milk Potential of Pantaneira Cows, a Local Breed, at Organic System

“…However, there was no effect on the concentration of digestible energy. In assessing levels of supplementation for grazing dairy cows, Pimentel [ 28 ] found an increase in digestibility with an increase in concentrate offered. The digestibility of NDF and ADF increased with decreasing concentrate in the diet.…”

Suplementação proteica de vacas leiteiras mantidas em pastagem de Tifton 85 durante o período de seca

“…Também Pimentel et al (2011) avaliaram a resposta de vacas meio-sangue Holandês/Zebu, em pastagem de Brachiaria brizantha, à suplementação com concentrados contendo diferentes teores de proteína bruta. Foram comparados três concentrados contendo 50,0; 28,6 e 20,0% de proteína bruta na matéria natural, fornecidos nas quantidades de 2,0; 3,5 e 5,0kg/vaca/dia, respectivamente.…”

Performance and nutritional parameters of lactating cows on pasture receiving castor bean meal

“…For the digestibility of NDFcp (Table 6), there was no effect of castor bean meal inclusion; however, there was a lower digestibility than that found in the literature (PIMENTEL et al, 2011;SILVA et al 2009), which is due to the amount of EE consumed. The excess of this nutrient, according to Jenkins and Mcguire (2006), has a toxic effect on the microorganism, inhibiting the cellular growth, mainly the cellulolytic bacteria that acts mainly in the digestion of the cellular wall, and also the excess of fat can generate a fiber encapsulation, making it difficult the microbial adhesion to the cell wall.…”

“…This difference may be due to the heterogeneity of castor bean byproducts. The low DMI in relation to the other studies with pastured dairy cattle (PIMENTEL et al, 2011) is related to the low availability and allowance of forage (Table 3), due to the climatic conditions, mainly the lack of rainfall, which was expected during the course of the experiment. According to Silva et al (2009), the availability of forage is directly related to the total DMI, so when the animal is subjected to forage shortage, it results in a reduction in DMI, and the animal needs to increase the grazing time.…”

Milk Potential of Pantaneira Cows, a Local Breed, at Organic System

“…However, there was no effect on the concentration of digestible energy. In assessing levels of supplementation for grazing dairy cows, Pimentel [ 28 ] found an increase in digestibility with an increase in concentrate offered. The digestibility of NDF and ADF increased with decreasing concentrate in the diet.…”

Suplementação proteica de vacas leiteiras mantidas em pastagem de Tifton 85 durante o período de seca

“…Também Pimentel et al (2011) avaliaram a resposta de vacas meio-sangue Holandês/Zebu, em pastagem de Brachiaria brizantha, à suplementação com concentrados contendo diferentes teores de proteína bruta. Foram comparados três concentrados contendo 50,0; 28,6 e 20,0% de proteína bruta na matéria natural, fornecidos nas quantidades de 2,0; 3,5 e 5,0kg/vaca/dia, respectivamente.…”

Performance and nutritional parameters of lactating cows on pasture receiving castor bean meal

“…For the digestibility of NDFcp (Table 6), there was no effect of castor bean meal inclusion; however, there was a lower digestibility than that found in the literature (PIMENTEL et al, 2011;SILVA et al 2009), which is due to the amount of EE consumed. The excess of this nutrient, according to Jenkins and Mcguire (2006), has a toxic effect on the microorganism, inhibiting the cellular growth, mainly the cellulolytic bacteria that acts mainly in the digestion of the cellular wall, and also the excess of fat can generate a fiber encapsulation, making it difficult the microbial adhesion to the cell wall.…”

“…This difference may be due to the heterogeneity of castor bean byproducts. The low DMI in relation to the other studies with pastured dairy cattle (PIMENTEL et al, 2011) is related to the low availability and allowance of forage (Table 3), due to the climatic conditions, mainly the lack of rainfall, which was expected during the course of the experiment. According to Silva et al (2009), the availability of forage is directly related to the total DMI, so when the animal is subjected to forage shortage, it results in a reduction in DMI, and the animal needs to increase the grazing time.…”

Milk Potential of Pantaneira Cows, a Local Breed, at Organic System

“…However, there was no effect on the concentration of digestible energy. In assessing levels of supplementation for grazing dairy cows, Pimentel [ 28 ] found an increase in digestibility with an increase in concentrate offered. The digestibility of NDF and ADF increased with decreasing concentrate in the diet.…”

Suplementação proteica de vacas leiteiras mantidas em pastagem de Tifton 85 durante o período de seca

“…Também Pimentel et al (2011) avaliaram a resposta de vacas meio-sangue Holandês/Zebu, em pastagem de Brachiaria brizantha, à suplementação com concentrados contendo diferentes teores de proteína bruta. Foram comparados três concentrados contendo 50,0; 28,6 e 20,0% de proteína bruta na matéria natural, fornecidos nas quantidades de 2,0; 3,5 e 5,0kg/vaca/dia, respectivamente.…”