Effects of levels of threonine and a phytogenic additive in the diets on the performance and gut health of chickens challenged with Eimeria spp.

Author(s)

Jaqueline Moreira Rafael

• Document type: Master's Dissertation
• Press: Piracicaba.
• Institution: Universidade de São Paulo (USP). Escola Superior de Agricultura Luiz de Queiroz (ESALA/BC)
• Defense date: 2015-11-13

Examining board members

José Fernando Machado Menten; Flavio Alves Longo; Carla Cachoni Pizzolante

• Advisor: José Fernando Machado Menten

Abstract

The study of the relationship between the additives and nutrients is essential for improving the use of these substances and the maximum animal performance. The purpose of this study was to examine the effects of levels of threonine and the inclusion of blends of essential oils on the performance and intestinal health (morphology, intestinal microbiota and mucin production) in broilers challenged with Eimeria spp. The treatments followed a 3x2 factorial arrangement with three levels of digestible threonine (100, 110,120% of the Brazilian Tables recommendations), and supplementation or not of a blend of essential oils in the feed in a completely randomized design experiment. The diets based on corn and soybean meal to meet the nutritional requirements were fed ad libitum. Each treatment had six replicates of 45 birds each, totaling 1620 animals. On day 14, all birds were orally gavaged with 10 times the recommended dose of a commercial coccidial vaccine with sporulated live oocysts of Eimeria spp. . Performance was evaluated weekly until 40 days of age. At 21 and 40 days of age, samples of the intestines were collected for morphometry. At 21 days of age samples of the contents of the small intestine and the cecum were collected for analysis of microorganisms. At 40 days of age, the contents of the ileum were collected for determining the mucin production. The data were submitted to analysis of variance at 5%, studying the interaction and the effects of the main factors. At 40 days of age the inclusion of essential oils in the diet decrease the feed intake of the animals, without changing growth and feed conversion . At 21 days of age, 120% of digestible threonine in the diet increased the height of villus in the ileum when compared with 110% of digestible threonine (p<0,05). There was no effect of treatments on the production of mucin in the contents of the ileum. The increasing levels of digestible threonine and essential oils in the diet did not modify the microbiota.It is possible to observe a tendency of change on the frequency of some genera in the cecum of the animals. (AU)

• FAPESP's process: 14/00542-0 - Effects of levels of threonine and a phytogenic additive in the diets on the performance and gut health of chickens challenged with Eimeria spp
• Grantee: Jaqueline Moreira Rafael
• Support Opportunities: Scholarships in Brazil - Master