Própolis como aditivo nutricional em dietas contendo óleo de soja para vacas em lactação : parâmetros digestivos e estabilidade e qualidade do leite

• Autor(a) principal: Maia, Fábio José
• Data de Publicação: 2013
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Estadual de Maringá (RI-UEM)
• Texto Completo: http://repositorio.uem.br:8080/jspui/handle/1/1608
• topic: Ruminantes; Nutrição; Aditivos; Vacas leiteiras; Produtos à base de própolis; Própolis; Nutrição animal; Atividade antibacteriana; Estabilidade oxidativa; Flavanoides; Polifenois; Extrato de própolis; Brasil.; Ruminants; Nutrition; Additives; Dairy cows; Products based on propolis; Propolis; Animal Nutrition; Antibacterial activity; Oxidative stability; Flavanoids; Polyphenols; Propolis extract; Brazil.; Ciências Agrárias; Zootecnia

The antimicrobial and antioxidant effects of a dried extract made from a product-based propolis on digestibility, ruminal and blood parameters, efficiency of microbial protein synthesis, production, composition, fatty acid composition (FA) and antioxidant capacity of milk were evaluated in two experiments. In the first experiment, three doses of the propolis dry extract were added in diet of dairy cows to evaluate the antioxidant and antimicrobial effects of phenolic compounds present in propolis. Therefore, dry matter intake, total nutrients digestibility, efficiency of microbial protein synthesis, blood parameters, production, composition, FA composition, concentration of total flavonoids and phenolic acids and antioxidant capacity of milk were determined. Four Holstein cows, multiparous, with average body weight of 564.44±61.39 kg and approximately 210 days in milk were assigned in a 4x4 Latin square according to the following treatments: DDF0 - basal diet without the addition of propolis, DDF37 - 37.82 mg/day of apigenin measured in total flavonoids, DDF63 - 63.04 mg/day of apigenin measured in total flavonoids and DDF88 - 88.25 mg/day of apigenin measured in total flavonoids. Soybean oil was used as a source of polyunsaturated fatty acids and added at 2% in diet composition. The doses proposed were based on results obtained in previous experiments, in which an initial dose of propolis based-product was tested for the same parameters evaluated in this study. The supply of soybean oil and propolis affected (P<0.05) dry matter intake. Total digestibility of crude protein, ether extract and total digestible nutrients showed quadratic effect (P<0.05) in relation to the dose of propolis and total digestibility of other nutrients was not affected (P>0.05), as well as other parameters related to nitrogen metabolism in the rumen, which were evaluated by total allantoin excretion, purine absorption and synthesis of microbial crude protein. In general, the addition of propolis did not influence (P>0.05) plasmatic concentrations of blood metabolites related to the metabolism of dietetic protein, carbohydrates and lipids, except for the HDL concentration. There was no effect (P>0.05) of flavonoids doses on milk production or daily production and percentage of fat, protein, lactose and total solids. The increase in total flavonoid intake from the propolis dry extract has changed fatty acid composition of milk fat in diets containing soybean oil as source of polyunsaturated fatty acids. Concentration of phenolic compounds (flavonoids and total polyphenols) and oxidative stability of milk, measured by the iron reduction and concentration of conjugated dienes (CD), were not affected (P>0.05) by doses of propolis. However, there was effect (P<0.05) of propolis dose on the oxidative stability of milk. Based on these results, it was proposed a second trial to evaluate the role of rumen on the metabolism of phenolic compounds and polyunsaturated fatty acids, when propolis dry extract and soybean oil were administered in the rumen and/or abomasum of dairy cows. Four Holstein cows, multiparous, cannulated in rumen, with 570.95±46.78 kg of average body weight and approximately 203 days in milk, were assigned in a 4x4 Latin square according to the following treatments: PR/OR - propolis and soybean oil administered in the rumen, Abo/Abo - propolis and soybean oil perfused in the abomasum, PR/OA - propolis administered in the rumen and oil perfused in the abomasum and PA/OR - propolis perfused in the abomasum and oil administered in the rumen. The site of propolis and oil administration did not affected (P>0.05) the coefficients of total digestibility of nutrients. Propolis in the rumen singly or in combination with soybean oil has maintained the total production of short chain fatty acids, pH and ammonia concentration in the rumen. The local of propolis administration had no effect (P>0.05) on milk production and composition; however, the abomasal oil infusion reduced milk fat concentration. Milk fatty acids composition was altered (P>0.05) by the site of oil infusion but not by propolis. The concentrations of antioxidant compounds and oxidative profile of milk were not affected (P>0.05) by the site of propolis perfusion. The use of propolis- based product in dairy cows diets influences dry matter intake and digestibility of fiber, protein, ether extract and improves milk oxidative stability. Intermediary doses appear to be more recommended to improve the characteristics related to intake and total digestibility of nutrients, while oxidative stability was dose-dependent. Propolis has potential to be used as antimicrobial and antioxidant additive because affects the milk oxidative stability and digestibility of nutrients.