DIRECT-FED MICROBIALS (DFMS) IN HORSES AND POULTRY: EFFECTS ON DIGESTIBILITY, NUTRITIONAL VALUE OF ANIMAL PRODUCTS AND ANIMAL HEALTH.

Abstract

The objective of the research described in this thesis is to evaluate the effect of Direct-Fed Microbial (DFM) in horses and poultry, on digestibility and nutritional value of animal products and animal health. To achieve this objective, three different trials were designed; in the first trial was investigated the effects of live yeast on apparent digestibility in horses, in the second trial was studied the effects of the inclusion of some probiotics in broiler chickens infected with Eimeria spp. and in the last trial the effects of inclusion of selenium-enriched yeast in the diet of laying hens on production performances, health parameters, eggshell quality, and selenium tissue deposition were investigated. In the first study proposed were investigated the effects of the administration of live yeast (LY) in a high-fibre diet on nutrients digestibility in mature horses. Six Italian Standardbred mares (weight: 544 ± 14 kg; age: 15.30 ± 3.9 years) in two-period crossover design were fed a basal diet (2.5% body weight [BW]) in a 70:30 forage:concentrate ratio with (LY) or without (CTR) the administration of 4.6 × 1010 colony forming unit (CFU)/d of Saccharomyces cerevisiae (MUCL 39885). An adaptation to the diet of 14 days, and an 18-day administration phase, with fecal collection in the last 3 days were performed for each period. Yeast was top-dressed twice a day during the concentrate meal (12:30 AM and 09:00 PM). Change in BW was measured at the beginning of each experimental phase and the diet adjusted accordingly, and individual feed intake was recorded daily. Concentrate samples were collected at the beginning of each confinement period and individual hay samples were obtained for each confinement day 38 hours before fecal collection. No influence of LY was observed on BW change (P = .64), feed intake (P = .48), hay intake (P = .48), or concentrate intake (P = .47). S cerevisiae supplementation improved apparent digestibility of dry matter (64.5% vs. 60.1%, P = .03), organic matter (66.1% vs. 61.6%, P = .04), neutral detergent fiber (42.5% vs. 35.9%, P = .04), and acid detergent fiber (36.5% vs. 28.0%, P = .03) with a positive trend on crude protein (P = .08). In the present study, the administration of LY to horses significantly improved the digestion of the fiber fractions of the diet. The aim of the study was to investigate the effects of the inclusion of a probiotics mix (108 cfu/g of Bacillus coagulans, B. subtilis and Cl. butyricum) on growth performance, health status, and intestinal morphology of broiler chickens infected with Eimeria spp. for a complete production cycle from hatching to slaughter. A total number of 900 Hubbard male chickens, 1d old and coming from the same hatchery, were divided in 18 pens located in 3 identical rooms (6 pens per room). At the beginning of the trial, the animals were homogeneously distributed by body weight to 3 experimental dietary treatments consisting of a basal diet plus: PC= probiotics 0.05% (108 cfu/g of Bacillus coagulans, B. subtilis and Cl. butyricum) + a…