A meta-analysis of 19 floor-pen trials (579 replicate pen observations) in diverse geographies, basal diets, seasons, and medication programs was carried out to evaluate the effects of 2 precision glycan microbiome metabolic modulators ( MMM1 and MMM2 ) on the performance of broiler chickens. In each trial, negative-control ( NC ) diets were compared with either MMM1 (14 trials) or MMM2 (8 trials), supplemented at an intended dose of 500 g/MT from hatch to 31 to 42 d. A dose response of MMM2 was evaluated in 8 trials at doses of 100, 250, 500, and 1,000 g/MT, not all present in each trial. Linear mixed-effect models were constructed for the final BW, cumulative feed intake, feed conversion ratio ( FCR ) corrected by mortality and BW ( cFCR ), and mortality, with Treatment as the fixed effect, nested random effects of Trial and Block, and adjustments for heterogeneity of variances. A significance level of P < 0.05 was used. In one of the studies, cecal content samples were collected at 42 d for analysis of microbiome gene abundance. Microbiome metabolic modulator 2 exhibited a reduction of the cFCR of 0.06 g feed/g BW gain compared with the NC and 0.03 g feed/g BW gain compared with MMM1, whereas MMM1 reduced the cFCR by 0.03 g feed/g BW gain compared with NC. Both MMM1 and MMM2 increased the final BW compared with the NC by 43 and 48 g/bird, respectively, with no difference among them. Compared with NC, feed intake was increased by MMM1 (+51 g/bird) and reduced by MMM2 (−74 g/bird). A one-directional dose response of the MMM2 ingredient was observed for the final BW (increasing) and cFCR (decreasing), whereas the feed intake response reached a minimum at 500 g/MT. The metagenomic analysis confirmed an increase in the abundance of genes belonging to the acrylate pathway, which is involved in propionate production, as well as arginine-N-succinyl transferase which is involved in the catabolism of arginine, in response to MMM2. Differential glycan structures of the MMM had an impact on the size and consistency of performance effects in broilers.

A dietary glycan-based precision biotic (Glycan PB) was evaluated on the performance, welfare indicators, and litter characteristics of broiler chickens. In Trial 1, the main effects of Glycan PB dose (0, 250 and 500 g/metric ton (MT)) and xylanase supplementation (0 or 100 g/MT) were tested, as was their interaction. In Trial 2, pens located inside a commercial house were used to test the effect of Glycan PB supplementation (500 g/MT) versus a control diet. In Trial 1, Glycan PB supplementation at 250 and 500 g/MT improved feed conversion ratio (FCR) by 7 and 11 points when compared to diets without Glycan PB (p < 0.001). At 35 d, Glycan PB reduced the pH and ammonia concentration in diets with xylanase. In Trial 1, the supplementation with 500 g of Glycan PB/MT of feed reduced litter scores (p < 0.05). In both trials, 500 g of Glycan PB/MT of feed increased the proportions of birds without footpad lesions (Trial 1: 72.2% vs. 82.7%; p < 0.001; Trial 2: 14 to 27.3% (p = 0.05) or gait defects (Trial 1: 96.1% vs. 98.4%; p < 0.001) and decreased the proportion of birds with footpad lesions (Trial 2: 86% vs. 72.7%; p = 0.05).

This study evaluated the supplementation of a precision biotic (PB) on the enterohepatic health markers and growth performance of broiler chickens undergoing an enteric challenge. In the first study, three treatments were used: Unchallenged Control (UC); Challenged Control (CC; dietary challenge and 10× dose of coccidia vaccine); and a challenged group supplemented with PB (1.3 kg/ton). In the second study, three treatments were used: control diet, diet supplemented with Avilamycin (10 ppm), and a diet supplemented with PB (0.9 kg/ton). All the birds were exposed to natural challenge composed by dietary formulation and reused litter from a coccidiosis positive flock. In Trial 1, PB decreased ileal histological damage, increased villi length, and the expression of SLC5A8 in ileal tissue versus CC; it reduced ileal expression of IL-1β compared to both UC and CC treatments. PB increased the expression of cell cycling gene markers CCNA2 and CDK2 in the ileum compared to CC. In Trial 2, PB improved the growth performance, intestinal lesion scores and intestinal morphology of broiler chickens. These results indicate that birds supplemented with PB are more resilient to enteric challenges, probably by its action in modulating microbiome metabolic pathways related to nitrogen metabolism and protein utilization.

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