The combined effects of purified fiber and dietary threonine on chick growth, and gut health, when infected with coccidiosis

chick;cellulose;pectin;threonine;Eimeria maxima

Wils, Emma ; Dilger ; Ryan N.

关键词: chick;    cellulose;    pectin;    threonine;    Eimeria maxima;   

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/34389/Wils-Plotz_Emma.pdf?sequence=1&isAllowed=y

美国|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

Three experiments were conducted to determine the combined effects of purified dietary fiber and dietary threonine (Thr) on chick growth and intestinal health. The objectives of the first two experiments were to define the individual effect of purified fiber on nutrient digestibility, dietary Thr requirements, and intestinal structure of young chicks. Additionally, a third experiment was conducted to investigate the immune-modulating properties of purified fiber and dietary Thr during an Eimeria maxima coccidiosis infection. In Experiment 1, chicks received corn/soybean meal (SBM) based diets containing 7% added silica sand (control), cellulose, or high-methoxy pectin through d 14 post-hatch. Inclusion of pectin reduced (P < 0.05) weight gain by 32% when compared to other treatments, and resulted in a reduction (P < 0.05) in DM digestibility, as well as AMEn, compared with the control diet.. Based on the energy values attributed to pectin and cellulose, dietary treatments in Experiment 2 and 3 were designed to be isocaloric. In Experiment 2, effects of purified fiber on dietary Thr requirements were determined using a Thr-deficient basal (3.2 g/kg diet) diet containing 7% added silica sand (control), cellulose, or pectin, and one of 7 graded levels of supplemental Thr (0 to 7.2 g/kg of diet). Dietary supplemental Thr requirements in the presence of silica sand (control), cellulose, and pectin were estimated at 778, 737, and 576 mg of supplemental Thr intake over the 14-d feeding period, respectively, based on body weight gain. In Experiment 3, diets were based on the same semi-purified basal diet used in Experiment 2, but the fiber-containing diets were supplemented with 1.8 or 5.3 g of Thr/kg diet [75 and 125% of the previously determined Thr requirement (6.8 g Thr/ kg diet) in Experiment 2]. In Experiment 3, body weight gain, feed intake, and gain:feed increased (P < 0.01) with the addition of 5.3 g of Thr/ kg diet. Eimeria.iiimaxima schizonts were only present in intestinal tissue sampled from infected birds (P < 0.01). Cecal content weights were highest (P < 0.01) in pectin-fed birds. Cecal tonsil IFNG and mucosal scrapings IL-12 were increased (P < 0.01) in the control diet with infection. These findings suggest that both fiber source and dietary Thr concentration affected growth performance and intestinal health indices in young chicks, which may directly impact poultry feeding strategies.