Microbiome modulation by a precision biotic in broilers chickens: a commercial study validation.

Precision biotics (PBs) are chemically synthesized complex glycans that modulate specific microbiome metabolic functions. The objective of the present study was to evaluate the effect of the supplementation of PB on the growth performance, and cecal microbiome modulation of broiler chickens raised under commercial conditions. A total of 190,000-day-old Ross 308 straight-run broilers were randomly assigned to 2 dietary treatments. There were 5 houses per treatment with 19,000 birds per house. In each house, there were 6 rows of battery cages with 3 tiers. The 2 dietary treatments included a control diet (a commercial broiler diet) and a PB supplemented diet at 0.9 kg/MT. On a weekly basis, 380 birds were randomly selected for body weight (BW) determination. At 42 d of age, the BW and feed intake (FI) of each house were recorded, the feed conversion ratio (cFCR) was calculated and corrected with the final BW, and the European production index (EPI) was calculated. Additionally, 8 birds per house (40 birds/experimental group) were randomly selected to collect cecal content for microbiome analysis. The supplementation of PB significantly improved (P < 0.05) the BW of the birds at 7, 14, and 21 d and numerically improved the BW of the birds by 64 and 70 g at 28 and 35 d of age, respectively. At 42 d, the PB numerically improved BW by 52 g, and significantly improved (P < 0.05) the cFCR by 2.2 points and the EPI by 13 points. The functional profile analysis showed a clear and significant difference in the cecal microbiome metabolism between control vs. PB supplemented birds. A higher abundance of pathways was modulated by PB which were associated with amino acid fermentation and putrefaction, particularly from lysine, arginine, proline, histidine, and tryptophane which led to a significant increase (P = 0.0025) in the Microbiome Protein Metabolism Index (MPMI) compared to nonsupplemented birds. In conclusion, the supplementation of PB efficiently modulated pathways related to protein fermentation and putrefaction, resulting in higher MPMI and improved growth performance of broilers.

Effects of phytonutrients on growth performance, antioxidative status, and energy utilization of broilers fed low energy diets.

Two experiments were conducted to investigate the effects of phytonutrients (PN) on growth performance, antioxidant status, intestinal morphology, and nutrient utilization of birds fed low energy diets. In Exp. 1, a total of 1,440 one-day-old Ross 308 male broiler chickens were randomly divided into 3 treatment groups, with 16 replicates per treatment (48 pens; 30 birds per pen). Birds in treatment 1 were fed diets with normal energy content (NE). Birds in treatment 2 were fed NE diet but with 60 kcal removed (LE). Birds in treatment 3 were assigned to LE diet supplemented with PN (LE + PN). Results indicated that LE diet increased feed conversion ratio (FCR) compared with NE from d 1 to 38, while LE + PN diet prevented this response (P = 0.02). At d 26, birds in the LE + PN group had the highest ileal and jejunal villus height to crypt depth (VH:CD) ratio. At d 39, PN supplementation improved ileal and jejunal VH:CD ratio, compared with LE group. Moreover, birds fed PN diets received a better economic profit. In Exp. 2, 360 one-day-old Ross 308 male broiler chickens were used in a metabolism study. The treatments used in Exp. 2 were the same as those in Exp.1, with 4 replicates (pens) and 30 birds in each replicate. Dietary apparent metabolism energy (AME), energy and protein digestibility were determined between 21 and 28 d of age. Results showed that chickens fed LE + PN diet tended to have greater AME (P = 0.02) and nitrogen-corrected apparent metabolism energy (AMEn) (P = 0.03) than birds fed LE diets. It was concluded that LE + PN showed a potential advantage to improve feed conversion and gut health of broilers, as well as economic profits.

Effects of the different levels of dietary trace elements from organic or inorganic sources on growth performance, carcass traits, meat quality, and faecal mineral excretion of broilers.

This experiment was conducted to evaluate the effects of different sources and levels of trace elements on growth performance, carcass composition and mineral excretion levels of broilers. In a completely randomised experimental design, 900 one-day-old male Ross-308 broilers were assigned to 5 treatments, with 6 replicates of 30 birds each. The control group (CITE) was fed with a basal diet containing regular inclusion levels of inorganic trace elements. Treatment groups were supplied with reduced levels (30% and 50% of the regular level) of inorganic (ITE) or organic trace elements (OTE), respectively. Groups 50% ITE, 30% OTE and 50% OTE diets had equivalent average daily gain (ADG), average daily feed intake (ADFI), feed to gain ratio (F/G ratio) and mortality rate compared with group CITE in any phase. However, compared with group CITE chicks in group 30% ITE have lower ADG and ADFI and higher F/G ratio. The carcass yields were not affected by dietary treatments. Compared with group CITE, in groups 30% ITE, 50% ITE, 30% OTE and 50% OTE the shear force values of the breast muscle were only 71.8%, 83.4%, 63.5% and 59.4% (p < 0.05), respectively. Birds received diets containing reduced levels of trace elements had diminished excretions of Mn and Zn throughout the entire period (p < 0.01). In conclusion, the reduced supplementation of trace elements had no or slightly negative impact on growth performance, carcass yield and meat quality, but decreased faecal mineral excretion. Moreover, the trace element supply as OTE played a limited role on performance and excretion and was only partly beneficial for animal performance in case the trace element supply was reduced to 30%.

Effects of feed form and feed particle size on growth performance, carcass characteristics and digestive tract development of broilers.

This study was conducted to evaluate the effects of feed form (mash and crumble-pellet) and feed particle size (fine, medium and coarse) on growth performance, carcass characteristics and digestive tract development of broilers. A total of 1,152 one day-old Ross 308 mixed-sex broilers were used in a factorial arrangement (2 × 3) based on a completely randomized design with six replicates of 32 birds each. Higher average daily gain (ADG) and average daily feed intake (ADFI) were observed (P < 0.01) for birds fed the crumble-pellet diets (CPD) than for those fed the mash diets (MD) during starter, grower and the entire experiment period. From d 1 to 40, birds fed CPD had a higher (P < 0.01) body weight (BW) than those fed MD. Birds fed CPD had a lower (P < 0.01) feed:gain ratio (F:G) during the starter phase than those fed MD. Medium or coarse particle size increased (P < 0.01) ADG and ADFI during the starter phase, but birds fed fine particle size diets had lower (P < 0.01) F:G during the grower phase. In MD, medium and coarse particle sizes resulted in higher (P < 0.05) BW, ADG and ADFI than fine particle size during the whole experiment. In CPD, particle size had no significant effect on growth performance, as indicated by a feed form × particle size interaction (P < 0.05). At 41 days of age, ten birds per treatment were randomly selected and killed for slaughter yields and digestive tract characteristics determination. It was shown that particle size and feed form alone had no significant effect on slaughter yields, so changes was the feed form × particle size interaction. The relative empty weight of the gizzard was greater (P < 0.01) and the relative length of the ileum was longer (P < 0.05) in birds fed MD than in those fed CPD. Overall, CPD improved growth performance during the entire period of the study with effects being less evident during the finisher phase than during the starter and grower phases, and the effect of feed particle size varied depending on feed form.

Association of PPARγ2 polymorphisms with carcass and meat quality traits in a Pietrain x Jinhua F2 population.

The PPARγ2 gene is a key regulator of both proliferation and preadipocyte differentiation in mammals. Herein its genotype and allele frequencies were analyzed using PCR-SSCP in eight pig breeds (N = 416). Two kinds of polymorphisms of the PPARγ2 gene were detected, including a previously reported shift SNP A177G (Met59Val) in exon 1 and a novel silent mutation G876A in exon 5. The results revealed that European pig breeds carry a higher allele A frequency at the A177G locus and a fixed GG genotype at the G876A locus. Allele A at the G876A locus was only found in Jinhua pigs. The association between haplotype (A177G/G876A) and carcass and meat quality traits was analyzed in a Pietrain x Jinhua F2 population (N = 248). The PPARγ2 gene was found to be significantly associated with backfat thickness at the shoulder (p < 0.05), 6-7(th) ribs (p < 0.01), last rib (p < 0.01), gluteus medius (p <0.05) and ham weight (p < 0.01). Significant effects of different haplotypes on ham weight and backfat thickness at the 6-7(th) ribs, last rib, and gluteus medius were also observed.

Association of PPARgama2 polymorphisms with carcass and meat quality traits in a Pietrain x Jinhua F2 population

The PPARγ2 gene is a key regulator of both proliferation and preadipocyte differentiation in mammals. Herein its genotype and allele frequencies were analyzed using PCR-SSCP in eight pig breeds (N = 416). Two kinds of polymorphisms of the PPARγ2 gene were detected, including a previously reported shift SNP A177G (Met59Val) in exon 1 and a novel silent mutation G876A in exon 5. The results revealed that European pig breeds carry a higher allele A frequency at the A177G locus and a fixed GG genotype at the G876A locus. Allele A at the G876A locus was only found in Jinhua pigs. The association between haplotype (A177G/G876A) and carcass and meat quality traits was analyzed in a Pietrain x Jinhua F2 population (N = 248). The PPARγ2 gene was found to be significantly associated with backfat thickness at the shoulder (p < 0.05), 6-7th ribs (p < 0.01), last rib (p < 0.01), gluteus medius (p <0.05) and ham weight (p < 0.01). Significant effects of different haplotypes on ham weight and backfat thickness at the 6-7th ribs, last rib, and gluteus medius were also observed.