ISSUE FOCUS FEED & ADDITIVE MAGAZINE February 2023 29 Rumen pH generally declines after each meal as rumen available carbohydrates are fermented and volatile fatty acids (VFAs) are produced. When VFA production exceeds the ability of the rumen environment to neutralize or absorb the acids, SARA occurs. The size of the meal and the amount of rapidly fermentable carbohydrates can have an impact on the decline in rumen pH. Having smaller and more frequent, meals reduces variability in rumen fermentation patterns as well as the rate of pH decline and the amplitude of the rumen pH. In consideration of these factors, it is safe to conclude that changes in feeding behavior as a result from TMR feedings can increase the risk of SARA. Changing feeding behavior can reduce the risk of cows experiencing SARA. Ruminants however have the biggest capacity to consume human inedible feed, including the digestion of cellulose, with forages as the main source but also feed materials such as sugar beet pulp, citrus pulp and brewers’ grains. Their unique ruminant digestive system allows them to convert “low value” fiber-rich feed components into “high value” animal proteins (milk and meat) not in competition with human foods, goes largely unnoticed. 4. Rumen modifiers Rumen specific live yeast Saccharomyces cerevisiae CNCM I-1077 used as a feed additive, has the ability to enhance fiber degradation through its rumen modifier effects, translated into higher feed efficiency in dairy cows. The effects and modes of action of this live yeast on rumen microbiota have been extensively studied. The main effects attributable to this strain include: 1. stabilization of ruminal pH 2. increase in fiber degradation and the subsequent improvement in digestibility In sacco, trials demonstrate the positive effect of S. cerevisiae CNCM I-1077 on NDFd of more than 200 different forage samples, including: corn silage, straw, rye grass hay, alfalfa hay, annual rye grass (pasture), meadow hay, grass silage, etc. Saccharomyces cerevisiae CNCM I-1077 is found to increase NDF digestibility by 4 to 8 units, depending on the type • Feeding more than once a day resulted in improved rumen NDF digestibility (Dhiman et al., 2002). • Feeding twice a day. The amount of TMR sorting was reduced by increasing the frequency of feed delivery from once to twice a day. In both cases, the dairy cows sorting against long fiber was measured by TMR NDF levels throughout the day, but the twice-a-day feeding cows sorted less (DeVries, 2010; DeVries, 2016). • Pushing up the feed. • Increasing the frequency of feed delivery, which would allow the cows to spend more time at the feedbunk across the day. Smaller, more frequent meals throughout the day will allow more equal access to freshly delivered feed for all cows. • Feedbunk access: insuring a sufficient place at feedbunk will limit competition to access to the feed. • Feeding diets that are higher in NDFd can influence feeding behavior by increasing DMI and decreasing the number of meals. • Particular attention to ensure physically effective fiber supply in the diet is important to minimize potential onset of SARA. • Using rumen modifier in the diet: live yeast Saccharomyces cerevisiae CNCM I-1077 (LEVUCELL SC) is documented to improve fiber degradation in the rumen and stabilize rumen pH at an optimum level. Examples of management practices that could positively influence feeding behavior and improve fiber utilization
RkJQdWJsaXNoZXIy MTUxNjkxNQ==