Digestibilidade total e desempenho de bezerras lactentes da raça Holandesa com adição de própolis na dieta

The objective of the present study was to evaluate the effect of  addition of propolis based products  (LLOSA2 and LLOSC1) at two concentrations of propolis (A and C) and two alcoholic contents (1 and 2,) towards the use of lasalocid sodium (positive control) in total tract digestibility and performance of Holstein heifers fed from birth to weaning (60 days) with milk and concentrate diet (20% crude protein). It was used a completely randomized design with three treatments and ten repetitions for performance evaluation, and four replications to estimate the total tract digestibility of the diets at 5% significance level. There was no effect (P>0.05) of the tested additives on dry matter intake of heifers (1048.5 g/day), average daily weight gain (711.3 g/day) and feed conversion (1.5). Similarly, no significant difference (P>0.05) of additives was observed on the digestibility of dry matter (77.4%), crude protein (79.0%) and ether extract (96.9%). Thus, data suggest that the additives based on propolis can be used in replacement of lasalocid in Holstein heifers, as the additives based on propolis did not cause any damage to the nutrient intake, performance, feed conversion and total tract digestibility of tested diets.Objetivou-se avaliar o efeito da adição de produtos à base de própolis (LLOSA2 e LLOSC1) em duas concentrações de própolis (A e C) e dois teores alcoólicos (1 e 2) frente ao uso de lasalocida sódica (controle positivo) na digestibilidade total e desempenho de bezerras Holandês Preto e Branco alimentadas do nascimento ao desmame (60 dias) com leite e  ração concentrada (20% de proteína bruta). Utilizou-se delineamento experimental inteiramente casualizado com três aditivos e dez repetições para avaliação do desempenho; e quatro repetições para a estimativa da digestibilidade total das dietas ao nível de 5% de significância.  Não houve efeito (P>0,05) dos aditivos testados sobre o consumo de matéria seca das bezerras (1048,5 g/dia), ganho de peso médio diário (711,3 g/ dia) e para conversão alimentar (1,5). Do mesmo modo, não houve diferença significativa (P>0,05) dos aditivos sobre as digestibilidades de matéria seca (77,4%), proteína bruta (79,0%) e extrato etéreo (96,9%). Assim, os aditivos à base de própolis podem ser utilizados na substituição da lasalocida sódica em bezerras lactentes Holandês, pois os mesmos não causaram nenhum prejuízo ao consumo de nutrientes, desempenho, conversão alimentar e digestibilidade das dietas testadas

Antioxidant activity and lipid oxidation in milk from cows with soybean oil and propolis extract added to their feed

Abstract The presence of PUFA (polyunsaturated fatty acids) in cow milk, including conjugated linoleic acids (CLA) isomers, makes milk susceptible to lipid oxidation, and may lead to the formation of volatile products responsible for a rancid smell. Consequently, including natural antioxidants in the diet of dairy cattle can assist in preventing lipid oxidation. In this study, soybean oil (a source of PUFA) and different ethanolic extracts of Brazilian propolis were included in the cows' feed, and the antioxidant activity and lipid oxidation of the animals' milk was assessed. Antioxidant activity was analyzed using the DPPH method, potassium ferricyanide reduction and chelating ability. Total phenolic compounds and flavonoids were also determined. Lipid oxidation was assessed by determining conjugated dienes and the production of aldehydes (propanal, pentanal, hexanal and octanal). Increased antioxidant activity was seen in the samples of milk from cows receiving propolis. Similarly, the addition of ethanolic extract of propolis to the diet of dairy cattle increased milk protection for two treatments with propolis against lipid oxidation in terms of production of propanal and hexanal. These results confirm the positive effect of applying this natural additive to the diet of lactating cows, improving the nutritional quality of the milk produced