Organ growth and fermentation profiles of broilers differing in body growth rate.

This study sought to determine the relationship among broiler performance, organ development, and indicators of microbiota colonization. A total of 1,200 two-day-old male Ross 308 broiler chicks, divided among 3 cohorts of equal size, were housed in battery cages, and allotted based on body weight. On study d 11, birds were weighed, and birds with BW gain within the 10th and 90th percentiles were assigned to the Slow and Fast groups, respectively. Birds (n = 30 for each group) selected on d 11 were provided water and a corn-soybean meal-based diet ad libitum while maintained individually through study d 25 (i.e., a 14-d growth period). Parameters regarding growth performance, organ and intestine weights and lengths, and intestinal volatile fatty acid concentrations were measured. All data were analyzed by one-way ANOVA using the Mixed procedure of SAS. Fast birds exhibited greater (P < 0.001) BW gain and feed intake than slow birds, but feed conversion ratio (FCR) did not differ (P = 0.19). Additionally, Slow birds had higher (P < 0.05) relative weights (% of BW) for nearly all organs on d 11 and 25, most notably the gizzard, proventriculus, pancreas, and liver. Conversely, intestinal sections were longer (P < 0.05) in the Fast birds. Measurement of gut histomorphology did not show any notable differences between growth rate groups in terms of villi height, crypt depth, or their ratio for either time-point (P > 0.05). In terms of volatile fatty acid concentrations of luminal contents, acetate concentrations were 10.2% higher (P < 0.001) in the ileum of the Slow birds compared with Fast birds on d 25. Overall, the findings suggest that total BW gain is influenced by the development of metabolically active organs, as supported by lower weight gain in Slow birds with relatively larger organ weights and shorter intestinal lengths than their Fast counterparts. The general lack of differences in fermentation end-product concentrations in luminal contents does not rule out influence of the microbiota on growth rate of broilers, which warrants further investigation.

Oral gamma-cyclodextrin-encapsulated tributyrin supplementation in young pigs with experimentally induced colitis.

Disruption of intestinal integrity and barrier function due to tissue inflammation has negative implications on overall growth and well-being in young pigs. In this study, we investigated the effects of oral gamma-cyclodextrin-encapsulated tributyrin (TBCD) in young pigs experiencing dextran sodium sulfate (DSS)-induced colitis. Pigs (n = 32 boars) were weaned from the sow at postnatal day (PND) 2, allotted to treatment based on the litter of origin and body weight (BW), and reared artificially over a 26-d feeding period. Treatment groups included: 1) nutritionally adequate (control) milk replacer, no DSS (Control n = 8), 2) control milk replacer plus oral DSS (DSS, n = 7), and 3) control diet supplemented with 8.3 g of TBCD per kg of reconstituted milk replacer plus oral DSS (TBCD + DSS, n = 8). Colitis was induced by administering DSS at 1.25 g of DSS/kg BW daily in a reconstituted milk replacer from PND 14-18. Milk replacer and water were provided ad libitum throughout the 26-d study. All the data were analyzed using a one-way ANOVA using the MIXED procedure of SAS. Control and DSS pigs had similar BW throughout the study, while TBCD + DSS pigs exhibited decreased (P < 0.05) BW starting at approximately PND 15. Additionally, average daily gain (ADG) before and after initiation of DSS dosing, along with over the total study duration, was decreased (P < 0.05) in pigs receiving TBCD + DSS compared with the Control. Milk disappearance was decreased (P < 0.05) in TBCD + DSS pigs when compared with Control and DSS groups. Both the concentration and molar ratio of cecal butyrate concentrations were increased (P < 0.05) in TBCD + DSS pigs compared with the Control group. The DSS and TBCD + DSS treatments also increased (P < 0.05) butyrate concentrations in the luminal contents with the proximal colon compared with Control. TBCD + DSS and DSS pigs had increased (P < 0.05) mucosal width in the distal colon compared with Control, thereby indicating heightened intestinal inflammation. Overall, oral supplementation of encapsulated tributyrin increased the concentration of butyrate in the colon, but was unable to mitigate the negative effects of DSS-induced colitis.

There are negative implications in young pigs when the integrity and function of the intestine are disrupted due to colonic inflammation. Volatile compounds have been used as dietary supplements to alleviate intestinal inflammation, but little work has been completed on the use of encapsulated tributyrin in newly weaned pigs. In this study, pigs received 1 of 3 treatments: 1) a standard milk replacer without the induction of intestinal inflammation, 2) the same standard milk replacer with the induction of intestinal inflammation, or 3) milk replacer supplemented with encapsulated tributyrin with the induction of intestinal inflammation. Throughout the study period, growth performance was decreased in pigs receiving supplemental tributyrin compared with other treatments. Additionally, experimentally induced colitis increased butyrate concentrations in the cecum, while tributyrin supplementation increased butyrate concentrations in the proximal colon. Pigs undergoing intestinal inflammation had increased thickness of the mucosal layer in the distal colon compared with sham-challenged pigs. Overall, the supplementation of encapsulated tributyrin increased colonic butyrate concentrations, but did not mitigate the negative effects of inflammation in the large intestine.

Effects of lysine biomass supplementation on growth performance and clinical indicators in broiler chickens.

Production of crystalline amino acids (AA) through microbial fermentation concomitantly provides an AA-enriched biomass that may serve as a cost-effective supplement for broiler chickens. We investigated the effects of feeding a fermentation biomass product containing approximately 62% Lys on growth performance, organ growth, and clinical outcomes of broilers. Beginning at 2 d post-hatch, a total of 360 Ross 308 chicks were randomly assigned to 1 of 5 treatments provided to 12 replicate cages of 6 birds. Practical corn-soybean meal-based dietary treatments included: negative control (NC; no supplementation of L-Lys, 1.01 and 0.86% standardized ileal digestible Lys in starter and grower phases, respectively), NC + 0.23% L-Lys HCl (positive control; PC), and NC supplemented with 0.30, 0.90, or 1.50% Lys biomass (LB) in both phases. Feed and water were provided ad libitum throughout the study. Individual bird and feeder weights were recorded on study day 0, 10, 21, and 35. At study conclusion, birds from each treatment were randomly selected to collect blood and tissue samples. The PC and 0.30% LB diets elicited similar overall (day 0-35) body weight gain and birds were heavier (P < 0.001) than the NC and other LB treatments. The PC, 0.30% LB, and 0.90% LB groups had better (P < 0.001) overall feed conversion ratio than NC. Some LB-supplemented treatments elicited increased (P < 0.001) relative spleen and ileum weight compared with NC and PC. Heterophils were increased (P < 0.001) in LB treatments compared with PC and NC. Lymphocytes were decreased (P < 0.001) in LB treatments compared with NC, and 1.50% LB was similar to PC. This resulted in an increased (P < 0.001) heterophil-to-lymphocyte ratio in some LB treatments, which may have resulted from general AA supplementation or the LB product. Collectively, these results suggest that addition of up to 0.30% LB restored growth performance when added to a Lys-deficient practical diet and elicited results identical to the Lys-adequate PC diet with no negative clinical effects.