Influence of Direct-fed Microbial Blend and Ferula Elaeochytris on in Vitro Rumen Fermentation Pattern and Degradability During Simulated Ruminal Acidosis.

Introduction: The use of probiotics and phytobiotics has attracted interest because of their protective effect against acidosis. Ferula elaeochytris (FE) is considered a good source of bioactive compounds, mainly monoterpene α-pinene. This study aimed to investigate the effect of a direct-fed microbial blend (Pro) and FE on rumen fermentation parameters in vitro under normal and acidosis conditions. Material and Methods: An in vitro experiment using the Hohenheimer Futterwerttest (HFT) gas production system was conducted. An acidosis challenge was made to compare the effectiveness of the probiotics blend and FE extract on ruminal pH regulation. To generate different ruminal fermentation parameters, the design of the trial considered the 2 additives (Pro and FE) × 6 incubation times (2, 4, 8, 12, 24 and 48 h) × 2 conditions (acidosis and normal) × 2 incubation runs for each feedstuff (barley, alfalfa and straw). Results: An acidosis challenge was successfully induced. The Pro and FE additives had no impact on the observed rumen fermentation parameters such as volatile fatty acid concentration or ammonia (P = 0.001). The acidosis condition decreased total in vitro degradability (IVD) by 3.5% and 21.9% for barley and straw, respectively (P < 0.001). The additives had different significant effects on the IVD of nutrients during both normal and acidosis conditions. In alfalfa samples, FE supplementation significantly decreased the IVD of all observed nutrients under the ruminal acidosis condition, although it had no effect during the normal condition. Conclusion: An acidosis challenge was successfully induced and the effect of additives was varied on fermentation parameters and rumen degradability of different feeds either under normal or acidosis conditions.

Use of Camelina sativa and By-Products in Diets for Dairy Cows: A Review.

Camelina sativa, belonging to the Brassicaceae family, has been grown since 4000 B.C. as an oilseed crop that is more drought- and cold-resistant. Increased demand for its oil, meal, and other derivatives has increased researchers' interest in this crop. Its anti-nutritional factors can be reduced by solvent, enzyme and heat treatments, and genetic engineering. Inclusion of camelina by-products increases branched-chain volatile fatty acids, decreases neutral detergent fiber digestibility, has no effect on acid detergent fiber digestibility, and lowers acetate levels in dairy cows. Feeding camelina meal reduces ruminal methane, an environmental benefit of using camelina by-products in ruminant diets. The addition of camelina to dairy cow diets decreases ruminal cellulolytic bacteria and bio-hydrogenation. This reduced bio-hydrogenation results in an increase in desirable fatty acids and a decrease in saturated fatty acids in milk obtained from cows fed diets with camelina seeds or its by-products. Studies suggest that by-products of C. sativa can be used safely in dairy cows at appropriate inclusion levels. However, suppression in fat milk percentage and an increase in trans fatty acid isomers should be considered when increasing the inclusion rate of camelina by-products, due to health concerns.