A Meta-Analysis of the Effects of Dietary Yeast Mannan-Rich Fraction on Broiler Performance and the Implication for Greenhouse Gas Emissions from Chicken Production.

Dietary supplementation of yeast-derived mannan-rich fraction (MRF) could improve the gastrointestinal health and production efficiency of broilers, and, consequently, lower the environmental impacts of chicken production. The objective of this meta-analysis was to quantify the retrospective effects of feeding MRF (Actigen®, Alltech Inc., Nicholasville, KY) on the production performance of broilers. The meta-analysis database included 27 studies and consisted of 66 comparisons of MRF-supplemented diets vs. basal (i.e., negative control) and antibiotic-supplemented (i.e., positive control) diets. A total of 34,596 broilers were involved in the comparisons and the average final age of the birds was 35 days. Additionally, the impact of feeding MRF on the carbon footprint (feed and total emission intensities) of chicken production was evaluated using the meta-analysis results of broiler performance (MRF vs. basal diets) to develop a scenario simulation that was analyzed by a life cycle assessment (LCA) model. A database of all trials (MRF vs. basal and antibiotic diets) indicated that feeding MRF increased (p < 0.01) average daily feed intake (ADFI; +3.7%), final body weight (FBW; +3.5%), and average daily gain (ADG; 4.1%) and improved (p < 0.01) feed conversion ratio (FCR; -1.7%) without affecting (p > 0.05) mortality. A subdatabase of MRF vs. basal diets indicated that dietary MRF increased ADFI (+4.5%), FBW (+4.7%), and ADG (+6.3%) and improved FCR (-2.2%) and mortality (-21.1%). For the subdatabase of MRF vs. antibiotic diets, both treatments exhibited equivalent effects (p > 0.05) on broiler performance parameters, suggesting that MRF could be an effective alternative to in-feed antibiotics. Subgroup analysis revealed that different study factors (year of study, breed/strain, production challenges, and MRF feeding duration) influenced the effect of dietary MRF on broiler performance. Simulated life cycle analysis (LCA) indicated that feeding MRF decreased feed and total emission intensities, on average, by -2.4% and -2.1%, respectively. In conclusion, these results demonstrate that dietary MRF is an effective nutritional solution for improving broiler performance, an effective alternative to in-feed antibiotic growth promoters, and reduces the environmental impact of poultry meat production.

Yeast mannan rich fraction positively influences microbiome uniformity, productivity associated taxa, and lay performance.

BACKGROUND: Alternatives to antibiotic as growth promoters in agriculture, such as supplemental prebiotics, are required to maintain healthy and high performing animals without directly contributing to antimicrobial resistance bioburden. While the gut microbiota of broiler hens has been well established and successfully correlated to performance, to our knowledge, a study has yet to be completed on the effect of prebiotic supplementation on correlating the mature laying hen productivity and microbiota. This study focused on establishing the impact of a yeast derived prebiotic, mannan rich fraction (MRF), on the cecal microbiota of late laying hens. This study benefitted from large sample sizes so intra- and intergroup variation effects could be statistically accounted for. RESULTS: Taxonomic richness was significantly greater at all taxonomic ranks and taxonomic evenness was significantly lower for all taxonomic ranks in MRF-supplemented birds (P < 0.005). Use of principal coordinate analyses and principal component analyses found significant variation between treatment groups. When assessed for compositional uniformity (an indicator of flock health), microbiota in MRF-supplemented birds was more uniform than control birds at the species level. From a food safety and animal welfare perspective, Campylobacter jejuni was significantly lower in abundance in MRF-supplemented birds. In this study, species associated with high weight gain (an anticorrelator of performance in laying hens) were significantly lower in abundance in laying hens while health-correlated butyrate and propionate producing species were significantly greater in abundance in MRF-supplemented birds. CONCLUSIONS: The use of prebiotics may be a key factor in controlling the microbiota balance limiting agri-food chain pathogen persistence and in promoting uniformity. In previous studies, increased α- and ß-diversity indices were determinants of pathogen mitigation and performance. MRF-supplemented birds in this study established greater α- and ß-diversity indices in post-peak laying hens, greater compositional uniformity across samples, a lower pathogenic bioburden and a greater abundance of correlators of performance.

The Effect of including a Mixed-Enzyme Product in Broiler Diets on Performance, Metabolizable Energy, Phosphorus and Calcium Retention.

The importance of enzymes in the poultry industry is ever increasing because they help to extract as many nutrients as possible from the raw material available and reduce environmental impacts. Therefore, an experiment was conducted to examine the effect of a natural enzyme complex (ASC) on diets low in AME, Ca and P. Male Ross 308 broilers (n = 900) were fed one of four diets: (1) positive control (PC) with no enzyme added (AME 12.55 MJ/kg, AVPhos 4.8 g/kg and AVCal 9.6 g/kg); (2) negative control (NC) with no enzyme added and reduced AME, Ca and P (AME 12.18 MJ/kg, AVPhos 3.3 g/kg, AVCal 8.1 g/kg); (3) negative control plus ASC at 200 g/t; and (4) negative control plus ASC at 400 g/t. Broiler performance, digesta viscosity, tibia mineralization and mineral content were analyzed at d 21. Between d 18 and 20, excreted DM, GE, total nitrogen, Ca, and P were analyzed. ASC at 200 g/t and 400 g/t improved the FCR (p = 0.0014) significantly when compared with that of the NC. There were no significant differences in BW or FI between the treatments. Birds fed ASC at 200 g/t and 400 g/t had significantly improved digesta viscosity (p < 0.0001) compared with that of the PC and NC birds and had significantly higher excreted DM digestibility (p < 0.01) than the NC and the PC birds with 400 g/t ASC. ASC inclusion significantly improved P retention (p < 0.0001) compared to that in the PC. Ca retention was significantly increased by 400 g/t ASC compared to that in the PC and NC (p < 0.001). AME was significantly higher (p < 0.0001) for all treatments compared to that in the NC. There were no significant differences between treatments for any of the bone measurements. This study showed that feeding with ASC can support the performance of broilers when fed a diet formulated to have reduced Ca, P and AME, with the greatest results being seen with a higher level of ASC inclusion.

The Effect of Organic Trace Mineral Supplementation in the Form of Proteinates on Performance and Sustainability Parameters in Laying Hens: A Meta-Analysis.

The effect of supplementing organic trace minerals (OTM), in the form of mineral proteinates (Bioplex® Cu, Fe, Mn, and Zn, Alltech Inc., Nicholasville, KY, USA), in the diets of laying hens was examined using Comprehensive Meta-Analysis (CMA) statistical software. The impact on production performance, egg quality traits, and sustainability parameters related to the carbon footprint of egg production was assessed. Data were obtained from 32 global studies, comprising 107 dietary assessments of 30,992 laying hens. Overall pooled effect size (raw mean difference) of production performance when dietary organic trace minerals were supplemented either in basal diets, partial replacement of inorganic trace minerals (ITM), or total replacement of ITM, indicated that use of Bioplex minerals resulted in 2.07% higher hen-day production (HDP), whilst feed conversion ratio (FCR) was lower by 51.28 g feed/kg egg and 22.82 g feed/dozen eggs, respectively. For egg quality traits, daily egg mass was 0.50 g/hen/day higher and egg weight was 0.48 g per egg greater when Bioplex minerals were incorporated in the diet. The mean difference in egg loss was -0.62%. Eggshell thickness was greater by 0.01 mm, and a higher eggshell strength of 0.14 kgf was observed. Eggshell weight was heavier by 0.20 g, eggshell percentage was higher by 0.15%, and Haugh unit was 1 point higher (0.89). We also carried out a meta-regression of the effects of the study factors (location, year of study, hen breed/strain, age of hens, number of hens, and study duration) on the overall pooled effect size of the production performance and egg quality traits in response to supplementary OTM inclusion, and it indicated that certain factors had a significant (p < 0.05) impact on the results. Finally, a life cycle assessment (LCA) model was selected to evaluate the impact of feeding organic trace mineral proteinates on the carbon footprint (feed and total emission intensities) of the egg production using the data generated from the meta-analysis. Results showed that the inclusion of OTM proteinates resulted in an average drop in feed and total emission intensities per kg eggs of 2.40% and 2.50%, respectively, for a low-global-warming-potential (GWP) diet and a drop of 2.40% and 2.48% for feed and total emissions, respectively, based on high-GWP diet. Based on the overall results, the inclusion of organic trace mineral proteinates in layer diets can benefit production performance and egg quality traits while contributing to a lower carbon footprint.

Meta-analysis and sustainability of feeding slow-release urea in dairy production.

Slow-release urea (SRU) is a coated non-protein nitrogen (NPN) source for providing rumen degradable protein in ruminant nutrition. A meta-analysis was conducted to evaluate the effects of replacing vegetable protein sources with SRU (Optigen®, Alltech Inc., USA) on the production performance of dairy cows. Additionally, the impact of SRU supplementation on dairy sustainability was examined by quantifying the carbon footprint (CFP) of feed use for milk production and manure nitrogen (N) excretion of dairy cows. Data on diet composition and performance variables were extracted from 17 experiments with 44 dietary comparisons (control vs. SRU). A linear mixed model and linear regression were applied to statistically analyse the effect of SRU on feed intake and production performance. Feeding SRU decreased (P < 0.05) dry matter intake (DMI, -500 g/d) and N intake (NI, -20 g/d). There was no significant effect (P > 0.05) on milk yield, fat-corrected milk, energy-corrected milk, and milk fat and protein composition. However, SRU supplementation improved (P < 0.05) feed efficiency (+3%) and N use efficiency (NUE, +4%). Regression analyses revealed that increasing SRU inclusion level decreased DMI and NI whereas increasing dietary crude protein (CP) increased both parameters. However, milk yield and feed efficiency increased in response to increasing levels of SRU inclusion and dietary CP. The NUE had a positive relationship with SRU level whereas NUE decreased with increasing dietary CP. The inclusion of SRU in dairy diets reduced the CFP of feed use for milk production (-14.5%; 373.13 vs. 319.15 g CO2 equivalent/kg milk). Moreover, feeding SRU decreased manure N excretion by 2.7% to 3.1% (-12 to -13 g/cow/d) and N excretion intensity by 3.6% to 4.0% (-0.50 to -0.53 g N/kg milk). In conclusion, feeding SRU can contribute to sustainable dairy production through improvement in production efficiency and reduction in environmental impacts.

A Meta-Analysis of the Effects of Slow-Release Urea Supplementation on the Performance of Beef Cattle.

Slow-release urea (SRU) is a coated non-protein nitrogen (NPN) source for ruminant nutrition. This study applied a meta-analytic technique to quantify the effect of a commercial SRU (Optigen®, Alltech Inc., Nicholasville, KY, USA) on the performance of beef cattle. Data were extracted from 17 experiments and analysed using the random-effects model to estimate the effect size of SRU on dry matter intake (DMI), crude protein intake (CPI), live weight gain (LWG) and feed efficiency (FE) of growing and finishing beef cattle. There was no effect of feeding SRU on the overall DMI and CPI of beef cattle. Dietary inclusion of SRU improved the overall LWG (+92 g/d/head) and FE (+12 g LWG/kg DMI/head) of beef cattle. Notably, SRU supplementation in growing cattle exhibited a better improvement on LWG (130 vs. 60 g/d/head) and FE (18 vs. 8 g LWG/kg DMI/head) compared with finishing cattle. Moreover, SRU showed consistent improvements on the LWG and FE of beef cattle under several study factors. Simulation analysis indicated that positive effects of SRU on LWG and FE improved profitability through reduction in feed cost and reduced the emission intensity of beef production. These results indicate that SRU is a sustainable NPN solution in beef cattle production.

Long term dietary supplementation with microalgae increases plasma docosahexaenoic acid in milk and plasma but does not affect plasma 13,14-dihydro-15-keto PGF2α concentration in dairy cows.

The aims of the study were to determine the long-term effects of dietary supplementation with microalgae (SCIM) on milk and blood fatty acid (FA) composition and reproductive hormones in early lactation dairy cows. Sixty Holstein-Friesian dairy cows (30 per treatment) were unsupplemented (Control) or supplemented with 100 g of SCIM (Schizochytrium limacinum sp.) per cow per day from 25 ± 0.5 d post-partum for 98 d. Intake and milk yield were recorded daily, with milk samples collected at weeks 0, 1, 2, 4, 8 and 14, and blood samples collected from 12 representative pairs per treatment at weeks 0, 2, 4, 8, and 14 for subsequent analysis of FA, ß-hydroxybutyrate, non-esterified fatty acids and glucose. At 33 ± 0.9 d postpartum the oestrus cycle of 24 cows (12 per treatment) were synchronized and plasma 13,14-dihydro-15-keto PGF2α (PGFM) concentrations determined following an oxytocin challenge. Data were analysed by repeated measures analysis of variance. There was no effect of treatment on dry matter intake, milk yield or milk fat content, with mean values across treatments of 22.1 and 40.6, and 37.2 g/kg respectively. Milk fat concentration of C22:6 n-3 increased rapidly in cows receiving SCIM, reaching a maximum of 0.38 g/100 g FA by week 14. Similarly, blood concentration of C22:6 n-3 increased to 1.6 g/100 g FA by week 14 in cows fed SCIM. There was no effect of treatment on plasma metabolites, but plasma glucose was lower in cows fed SCIM compared to the Control at week 2, and higher in week 8. There was no effect of treatment on peak plasma PGFM concentration or area under the curve. It is concluded that feeding SCIM rapidly increases blood and milk concentrations of C22:6 n-3 which are maintained over time, but does not improve plasma PGFM in dairy cows.