Probiotics and prebiotics in animal feeding for safe food production

The goal of this review was to analyze published data related to mitigation of enteric methane (CH 4 ) emissions from ruminant animals to document the most effective and sustainable strategies. Increas- ing forage digestibility and digestible forage intake was one of the major recommended CH 4 mitigation practices. Although responses vary, CH 4 emissions can be reduced when corn silage replaces grass silage in the diet. Feeding legume silages could also lower CH 4 emissions compared to grass silage due to their lower fiber concentration. Dietary lipids can be effec- tive in reducing CH 4 emissions, but their applicabil- ity will depend on effects on feed intake, fiber digest- ibility, production, and milk composition. Inclusion of concentrate feeds in the diet of ruminants will likely decrease CH 4 emission intensity (Ei; CH 4 per unit animal product), particularly when inclusion is above 40% of dietary dry matter and rumen function is not impaired. Supplementation of diets containing medium to poor quality forages with small amounts of concen- trate feed will typically decrease CH 4 Ei. Nitrates show promise as CH 4 mitigation agents, but more studies are needed to fully understand their impact on whole-farm greenhouse gas emissions, animal productivity, and animal health. Through their effect on feed efficiency and rumen stoichiometry, ionophores are likely to have a moderate CH 4 mitigating effect in ruminants fed high-grain or mixed grain-forage diets. Tannins may also reduce CH 4 emissions although in some situations intake and milk production may be compromised. Some direct-fed microbials, such as yeast-based products, might have a moderate CH 4 -mitigating effect through increasing animal productivity and feed efficiency, but the effect is likely to be inconsistent. Vaccines against rumen archaea may offer mitigation opportunities in the future although the extent of CH 4 reduction is like- ly to be small and adaptation by ruminal microbes and persistence of the effect is unknown. Overall, improv- ing forage quality and the overall efficiency of dietary nutrient use is an effective way of decreasing CH 4 Ei. Several feed supplements have a potential to reduce CH 4 emission from ruminants although their long-term effect has not been well established and some are toxic or may not be economically feasible.

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Special topics--Mitigation of methane and nitrous oxide emissions from animal operations: I. A review of enteric methane mitigation options.

Can enteric methane emissions from ruminants be lowered without lowering their production

Animal production is a significant source of greenhouse gas (GHG) emissions worldwide. Depending on the accounting approaches and scope of emissions covered, estimates by various sources (IPCC, FAO, EPA or others) place livestock contribution to global anthropogenic GHG emissions at between 7 and 18 percent. The current analysis was conducted to evaluate the potential of nutritional, manure and animal husbandry practices for mitigating methane (CH4) and nitrous oxide (N2O) – i.e. non-carbon dioxide (non-CO2) – GHG emissions from livestock production. These practices were categorized into enteric CH4, manure management and animal husbandry mitigation practices. Emphasis was placed on enteric CH4 mitigation practices for ruminant animals (only in vivo studies were considered) and manure mitigation practices for both ruminant and monogastric species. Over 900 references were reviewed; and simulation and life cycle assessment analyses were generally excluded. In evaluating mitigation practices, the use of proper units is critical. Expressing enteric CH4 energy production on gross energy intake basis, for example, does not accurately reflect the potential impact of diet quality and composition. Therefore, it is noted that GHG emissions should be expressed on a digestible energy intake basis or per unit of animal product (i.e. GHG emission intensity), because this reflects most accurately the effect of a given mitigation practice on feed intake and the efficiency of animal production. EntErIC CH4 MItIgAtIon prACtICEs Increasing forage digestibility and digestible forage intake will generally reduce GHG emissions from rumen fermentation (and stored manure), when scaled per unit of animal product, and are highly-recommended mitigation practices. For example, enteric CH4 emissions may be reduced when corn silage replaces grass silage in the diet. Legume silages may also have an advantage over grass silage due to their lower fibre content and the additional benefit of replacing inorganic nitrogen fertilizer. Effective silage preservation will improve forage quality on the farm and reduce GHG emission intensity. Introduction of legumes into grass pastures in warm climate regions may offer a mitigation opportunity, although more research is needed to address the associated agronomic challenges and comparative N2O emissions with equivalent production levels from nitrogen fertilizer. Dietary lipids are effective in reducing enteric CH4 emissions, but the applicability of this practice will depend on its cost and its effects on feed intake, production and milk composition. High-oil by-product feeds, such as distiller’s grains, may offer an economically feasible alternative to oil supplementation as a mitigation practice, although their higher fibre content may have an opposite effect on enteric CH4, depending on basal diet composition. Inclusion of concentrate feeds in the diet of ruminants will likely decrease enteric CH4 emissions per unit of animal product, particularly when above 40 percent of dry matter intake. The effect may depend on type of ‘concentrate’ inclusion rate, production response, impact on fibre digestibility, level of nutrition, composition of the basal diet and feed processing.

Mitigation of greenhouse gas emissions in livestock production - A review of technical options for non-CO2 emissions

Probiotics/prebiotics have the ability to modulate the balance and activities of the gastrointestinal (GI) microbiota, and are, thus, considered beneficial to the host animal and have been used as functional foods. Numerous factors, such as dietary and management constraints, have been shown to markedly affect the structure and activities of gut microbial communities in livestock animals. Previous studies reported the potential of probiotics and prebiotics in animal nutrition; however, their efficacies often vary and are inconsistent, possibly, in part, because the dynamics of the GI community have not been taken into consideration. Under stressed conditions, direct-fed microbials may be used to reduce the risk or severity of scours caused by disruption of the normal intestinal environment. The observable benefits of prebiotics may also be minimal in generally healthy calves, in which the microbial community is relatively stable. However, probiotic yeast strains have been administered with the aim of improving rumen fermentation efficiency by modulating microbial fermentation pathways. This review mainly focused on the benefits of probiotics/prebiotics on the GI microbial ecosystem in ruminants, which is deeply involved in nutrition and health for the animal.

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Effect of Probiotics/Prebiotics on Cattle Health and Productivity.

Meta-analysis of the influence of Saccharomyces cerevisiae supplementation on ruminal parameters and milk production of ruminants

The aim of this study was to compare rumen pH and time-budget in eight mid-lactation goats receiving two diets in a cross-over design (low-concentrate diet (L): 30% and high-concentrate diet (H): 60% concentrate). Feeding H increased daily intake (4.3 ± 0.08% v. 4.7 ± 0.08% of body weight for L and H, respectively) and daily milk production (3.01 ± 0.130 v. 3.50 ± 0.130 kg/day of 3.5% fat-corrected milk for L and H, respectively). It decreased milk fat and inverted the fat-to-protein ratio (1.07 ± 0.054 v. 0.94 ± 0.054 for L and H, respectively). As suggested by the percentage of time spent with rumen pH below 6.0 (23.4 ± 6.60% v. 39.9 ± 5.88% for L and H, respectively), H was more acidogenic than L. When offered H instead of L, goats spent less time eating (298 ± 17.5 v. 265 ± 17.5 min for L and H, respectively) and ruminating (521 ± 21.0 v. 421 ± 21.0 min for L and H, respectively) but more time resting (352 ± 27.1 v. 459 ± 21.1 min for L and H, respectively) over a 24-h period. They also tended to spend more time drinking (20 ± 2.9 v. 25 ± 2.9 min for L and H, respectively; P = 0.08) when offered H rather than L. These differences in activities were mainly observed during the first hours following feeding. When offered H, goats adapted their feeding behaviour around the feedings, which allowed them to limit the physiological disturbances potentially inducible by H and to increase milk production, without experiencing too much acidosis.

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/4F855C722206451591B47B5A8D43249A/S1751731108003157a.pdf/div-class-title-effect-of-concentrate-percentage-on-ruminal-ph-and-time-budget-in-dairy-goats-div.pdf

Effect of concentrate percentage on ruminal pH and time-budget in dairy goats.

A new segmentation-clustering method to analyse feeding behaviour of ruminants from within-day cumulative intake patterns

Subacute ruminal acidosis is one of the major concerns of ruminant nutrition. It is mainly characterised by very quick and severe disturbances of an equilibrium, during which animals eat and produce around their potential. Bouts of acidosis are very rarely described in the literature. An experiment was performed on 12 cannulated dairy goats fed a high concentrate diet in order to describe these bouts of acidosis and their consequences on intake, production and behaviour of the animals. We performed daily measurements of intake and production and continuous measurements of intake, chewing and rumen pH. Modelling these bouts of acidosis showed that a bout of acidosis is characterised by a very quick pH drop, followed successively by intake and milk yield drops. The pH drop is followed by a few days of high rumen pH, which then slowly returns to pre bout acidosis values. Bouts of acidosis can influence intake and milk production during more than three weeks. Modelling intake using a method based on segmentation/classification showed that intake was disrupted during bouts of acidosis. The animals ate less with a high intake rate but more with a low intake rate. Simultaneous analysis of intake, rumination and rumen pH kinetics showed that the disruption of intake behaviour led to a disruption of rumination behaviour. Furthermore, these changes in feeding behaviour led to more stable kinetics of rumen pH, which did not decrease below 6.0.

Modélisation des épisodes d'acidose sub-clinique et du comportement alimentaire associé : application à la chèvre laitière

There is scarce information on the effect of yeast supplementation in dairy goats. The aim of this study was to determine the effect of live yeast supplementation on ruminal polysaccharidase activities in 12 mid-lactation goats receiving a high-concentrate diet. After three weeks of adaptation to the diet, six goats were yeast-supplemented (group Y) twice daily via rumen cannula during five weeks (10g/d, 2.2.1010 CFU/g Saccharomyces cerevisiae CBS 493.94, Alltech); the other animals were not supplemented (group C). Fibrolytic activity was lower in rumen contents after feeding than before and in nylon bags containing wheat than in those containing hay; the opposite results were obtained for amylolytic activity. Yeasts had no effect on amylase and xylanase activities in rumen contents or nylon bags and in cellulase activity in rumen contents, but tended (P = 0.07) to decrease cellulase activity in bag residues.

Marion Desnoyers

Papers

Meta-analysis of the influence of Saccharomyces cerevisiae supplementation on ruminal parameters and milk production of ruminants

Effect of concentrate percentage on ruminal pH and time-budget in dairy goats.

A new segmentation-clustering method to analyse feeding behaviour of ruminants from within-day cumulative intake patterns

Modélisation des épisodes d'acidose sub-clinique et du comportement alimentaire associé : application à la chèvre laitière

Effect of live yeast supplementation on ruminal polysaccharidase activities in goats fed a high concentrate diet