Óleos essenciais em dietas de poedeiras comercias sobre desempenho e qualidade de ovos brancos

Abstract

The search for safe foods and animal products that respect welfare and environmental criteria has gained momentum in the last decade. In this context, research aimed at replacing antimicrobials in animal diets is being developed with the purpose of reducing economic and health problems and providing safe and quality products to the consumer. Therefore, considering the importance of eggs as a protein source in human nutrition, this study was carried out with the objective of evaluating the effects of adding a blend of essential oils (cinnamaldehyde + carvacrol + thymol) to the diet of commercial laying hens on performance parameters and egg white quality. The experiment was carried out in a completely randomized design, with five diets and six replicates of 10 birds. The diets were: diet 1: without antimicrobial and essential oil; diet 2: with antimicrobial; diet 3: with the inclusion of 50 g/t of essential oils; diet 4: 75 g/t of essential oils inclusion and diet 5: inclusion of 100 g/t of essential oils. The performance variables analyzed were: body weight, weight gain, feed intake, feed conversion and egg quality parameters. For the egg quality variables, an evaluation period was characterized every 28 days, with weighing of birds and feed leftovers in order to obtain the values for body weight and feed intake and internal and external egg quality. Egg production, mortality, temperature and relative humidity were monitored daily. Temperatures were measured using a digital thermohygrometer, black globe thermometer and dry and wet bulb thermometers. With the values obtained, it was possible to determine the Globe Temperature and Humidity Index (ITGU). The average black globe temperature and ITGU ranged from 30 to 36 °C and 80 to 87, respectively. Laying hens exposed to hot weather reduce feed intake and body weight, but do not alter egg production percentage. The inclusion of 75 and 100 g/t of essential oils (cinnamaldehyde + thymol + carvacrol) provides heavier eggs and heavier egg yolks in the period from 45 to 60 weeks of age. In a heat stress environment, the addition of 50 g/t of essential oils (cinnamaldehyde + thymol + carvacrol) promotes the production of eggs with thicker shells.