Uso da somatotropina recombinante bovina em búfalas leiteiras I: produção e composição físico-química do leite

Abstract

RESUMO Objetivou-se avaliar a influência da somatotropina recombinante bovina (rbST) sobre a produção e os constituintes do leite de búfalas entre 63 e 154 dias em lactação. Foram utilizadas 22 búfalas, distribuídas em dois grupos experimentais: grupo rbST -aplicação de 500 mg de rbST a cada 14 dias; grupo controlesem aplicação de rbST. A cada sete dias, foi aferida a produção de leite de todas as búfalas e coletada uma amostra para análise físico-química. As variáveis produtivas e as oriundas de análises laboratoriais foram avaliadas como medidas repetidas no tempo, utilizando-se o comando Repeated gerado pelo procedimento GLM do SAS. A média dos parâmetros estudados para os grupos rbST e controle foram, respectivamente: produção de leite -6,54 vs. 6,68 kg; gordura -6,31 vs. 6,34%; proteína 3,86 vs. 3,81%; lactose -4,96 vs. 5,02%; sólidos totais -16,05 vs. 16,03%; extrato seco desengordurado -9,75 vs. 9,74%; contagem de células somáticas -329,90 vs. 171,68 (x 1000/mL); e elecondutividade -2,87 vs. 2,81mS/cm. A utilização de 500mg de rbST administrados quinzenalmente, entre 63 e 154 dias em lactação não alterou a produção de leite, a proporção dos constituintes e a CCS do leite de búfalas leiteiras.Palavras-chave: búfalos, hormônio do crescimento, produção de leite, constituintes do leite rbST and Control were: Milk yield -6,54 vs. 6,68 kg; Fat -6,31 vs. 6,34%; Protein -3,86 vs. 3,81%; Lactose -4,96 vs. 5,02%; Milk solids -16,05 vs. 16,03%; Defatted dry matter -9,75 vs. 9,74%; Somatic Cells Count -329,90 vs. 171,68 (x 1000/mL) ABSTRACT This study aimed to evaluate the effect of recombinant bovine somatotropin (rbST) on milk yield and the proportion of buffalo milk components during lactation. Twenty-two buffaloes randomly distributed in two experimental groups were used: Group rbST -application of 500mg rbST every 14 days, between 63 and 154 days in milk (DIM); Control Group -without treatment. Weekly, the milk yield of buffaloes was measured and a sample was collected for physicochemical analysis. The response variables were evaluated as repeated measures, using the Repeated procedure through the GLM procedure of SAS. Means of each variable after

The Influence of Recombinant Bovine Somatotropin (rbST) on the Metabolic Profile and Milk Composition of Lactating Murrah Buffalo

“…Comparing this study with data from the literature in relation to the concentration of lactose and total solids in milk, the results were in accordance with those reported by several authors [7,17,44], who also did not find any significant difference for these parameters of milk.…”

“…Regarding the constitution of milk from cows supplemented with rbST, most papers did not find changes in their physico-chemical characteristics [21,40,41], and the industrial yield of milk was similar to that obtained from untreated animals [40,42]. In this study, fat values were below that reported in the literature, but they were not affected by rbST treatment, corroborating the papers on buffaloes that did not observe changes in fat content during treatment with rbST [9][10][11]17]. An explanation for the lack of a direct connection between the administration of rbST and the levels of milk fat was the energy status of the animal, since animals in positive energy balance may show no change in the percentage of milk fat different compared to animals in negative energy balance, which may show an increase in the concentration of milk fat.…”

“…It was observed that the administration of rbST promoted increases in production that ranged from 3 to 40% [19]. The impact of the use of rBST on increasing milk production in buffaloes was quite variable, as observed in the literature; some authors observed significant increases in milk production [11,15,20], while others did not observe an increase in milk production [17].…”

“…This impact on milk production is not directly related to the dose of hormone used since there is research that shows an increase in production with low doses of 250 mg of rBST [15] and research that does not show an increase in production with high doses of 500 mg of rBST [17]. Responses to bST are highly dependent on overall management practices before and after initiation of treatment [7], particularly with the energy density of the diet [16].…”

“…In studies assessing the influence of rbST in milk composition, alterations in fat and protein were not found when the animals were in a positive energy balance [9][10][11]17], while the somatic cell count showed enormous variation, which does not allow any statement about the effects of the treatment [10].…”