Abstract The objective of this study was to evaluate whether the addition of a blend based on α-monolaurin mono-, di- and triglycerides of butyric acid, and lysolecithin on the performance even on diets containing reduced inclusion of oil in the diet and without the use of growth-promoting antibiotics of broilers considering the effect on health, performance, and meat. Three treatments were defined: positive control (TP: with enramycin), negative control (TN: no enramycin), and blend (T-FRA: with monolaurin and glycerides of acid butyric minus 0.8% soybean oil). At 21 days, broilers treated with TP and T-FRA obtained the lower feed conversion ratio (FC); at 35 days, T-FRA broilers obtained lower FC than TN broilers. Cholesterol levels were higher in the blood of T-FRA broilers. On day 42, levels of ROS and TBARS were lower in the intestine, muscles, and liver of T-FRA broilers. Moreover, glutathione S-transferase and total non-enzymatic antioxidants were greater at the intestinal and muscular levels. The T-FRA broilers had a lower percentage of lipids in the meat. The MIC indicated that 111mg of the blend/mL inhibited the growth of E. coli; however, the counts of total coliforms and E. coli in the feces and the broilers’ litter did not differ between treatments. In conclusion, the addition of the blend T-FRA in broiler diets was able to improve the feed conversion and maintain the other performance parameters even considering a reduction of 0.8% in the inclusion of oil.

Embora o ácaro Varroa destructor tenha sido introduzido no Brasil há mais de 30 anos, ainda não foram registrados casos de mortalidade de colônias de abelhas. Nas abelhas africanizadas, a taxa de infestação obtida pelo ácaro varroa é baixa, não causando danos à apicultura brasileira. A baixa capacidade reprodutiva do parasita em células de crias de operárias das abelhas africanizadas é considerado um fator importante na manutenção do equilíbrio entre o parasita e o hospedeiro. No entanto, a possível introdução de um novo haplótipo do ácaro Varroa destructor no Brasil, ocorrida recentemente, pode estar aumentando a capacidade reprodutiva desse ácaro. A habilidade reprodutiva das fêmeas do ácaro foi avaliada em mais de mil de células de crias de operárias de abelhas africanizadas aos 17-18 dias de idade, em dois períodos. A porcentagem de fêmeas férteis do ácaro aumentou de 56% nos anos de 1980 a 86% em 2005-2006. A diferença na porcentagem de fêmeas que produziram deutoninfas, descendentes fêmeas que podem alcançar o estágio adulto ao emergir das operárias, foi ainda maior; em 2005-2006, 72% das fêmeas que invadiram células de crias de operárias deixaram pelo menos um descendente viável, comparado com 35% em 1986-1987.

Varroa destructor has been in Brazil for more than 30 years, but no mortality of honeybee colonies due to this mite has been recorded. Africanized bee infestation rates attained by varroa have been low, without causing measurable damage to Brazilian apiculture. The low reproductive ability of this parasite in Africanized bee worker brood cells has been considered an important factor for maintaining the host-parasite equilibrium. Nevertheless, the possible substitution of the haplotype of the mite Varroa destructor that has occurred recently in Brazil could affected the reproductive ability of the population of this parasite in Brazil. The reproductive ability of worker of the mite females was evaluated in over one thousand 17-18day-old Africanized worker brood cells each of the two periods. The percentage of fertile mites increased from 56% in the 1980s to 86% in 2005-2006. The difference in the percentage of females that produced deutonymphs, female progeny that can reach the adult stage at bee emergence, was even greater. In 2005-2006, 72% of the females that invaded worker brood had left at the least one viable descendant, compared to 35% in 1986-1987.