Evaluation of Different Feeds for Their Potential to Generate Methane and Change Methanogen Diversity

Optimization of the dietary formulation is the most effective way to reduce methane. Nineteen feed ingredients (brans, vegetable proteins, and grains) were evaluated for their potential to generate methane and change methanogen diversity using an in vitro ruminal fermentation technique. Feed formulations categorized into high, medium and low production based on methane production of each ingredient were then subjected to in vitro fermentation to determine the real methane production and their effects on digestibility. Methanogen diversity among low, medium and high-methane producing groups was analyzed by PCR-DGGE. The highest methane production was observed in Korean wheat bran, soybean and perilla meals, and wheat and maize of brans, vegetable protein and cereal groups, respectively. On the other hand, corn bran, cotton seed meal and barley led to the lowest production in the same groups. Nine bacteria and 18 methanogen 16s rDNA PCR-DGGE dominant bands were identified with 83% to 99% and 92% to 100% similarity, respectively. Overall, the results of this study showed that methane emissions from ruminants can be mitigated through proper selection of feed ingredients to be used in the formulation of diets

Hemato-biochemical and Cortisol Profile of Holstein Growing-calves Supplemented with Vitamin C during Summer Season

Effect of vitamin C (VC) on biochemical, hematological and cortisol profile of growing Holstein calves during summer was investigated. Eighteen calves between 14 and 16 weeks of age were divided equally into two groups. One group received a diet supplemented with VC (20 g/d) for 60 days, while other non-supplemented diet fed group served as a control (CON). The temperature humidity index (THI) was recorded and computed during the experiment. From days 0 to 60, the THI exceeded 70. Blood samples were collected from the jugular vein of each calf at days 0, 15, 30, 45 and 60. Serum albumin and total protein decreased (p<0.05) in CON and VC calves with age. Serum glutamic-oxaloacetic transaminase concentrations were not affected by treatments. Serum creatinine, albumin and glutamic-pyruvic transaminase concentrations were higher in calves in the VC group than the CON group. While red blood cells, hemoglobin and hematocrit were lower (p<0.05) in VC calves, mean corpuscular volume, mean corpuscular hemoglobin, red blood cell distribution width and mean platelet volume were higher (p<0.05) in these VC supplemented calves. Leukocyte parameters including white blood cells and full term for lymphocytes were not affected by the treatments. Also, serum cortisol was not affected by treatments. At day 15, 30 and 45, the total VC in plasma was higher (p<0.05) in calves fed with VC. In conclusion, serum cortisols were not affected by plasma VC concentration, while some blood parameters were positively influenced in calves fed with VC

Effect of γ-aminobutyric acid producing bacteria on in vitro rumen fermentation, growth performance, and meat quality of Hanwoo steers

Objective: The present study aimed to evaluate the effects of γ-aminobutyric acid (GABA)- producing bacteria (GPB) on in vitro rumen fermentation and on the growth performance and meat quality of Hanwoo steers.Methods: The effects of GPB (Lactobacillus brevis YM 3-30)-produced and commercially available GABA were investigated using in vitro rumen fermentation. Using soybean meal as a substrate, either GPB-produced or commercially available GABA were added to the in vitro rumen fermentation bottles, as follows: control, no additive; T1, 2 g/L GPB; T2, 5 g/L GPB; T3, 2 g/L autoclaved GPB; T4, 5 g/L autoclaved GPB; T5, 2 g/L GABA; and T6, 5 g/L GABA. In addition, 27 Hanwoo steers (602.06±10.13 kg) were subjected to a 129-day feeding trial, during which they were fed daily with a commercially available total mixed ration that was supplemented with different amounts of GPB-produced GABA (control, no additive; T1, 2 g/L GPB; T2, 5 g/L GPB). The degree of marbling was assessed using the nine-point beef marbling standard while endotoxin was analyzed using a Chromo-Limulus amebocyte lysate test.Results: In regard to in vitro rumen fermentation, the addition of GPB-produced GABA failed to significantly affect pH or total gas production but did increase the ammonia nitrogen (NH3-N) concentration (p&lt;0.05) and reduce total biogenic amines (p&lt;0.05). Animals fed the GPB-produced GABA diet exhibited significantly lower levels of blood endotoxins than control animals and yielded comparable average daily gain, feed conversion ratio, and beef marbling scores.Conclusion: The addition of GPB improved in vitro fermentation by reducing biogenic amine production and by increasing both antioxidant activity and NH3-N production. Moreover, it also reduced the blood endotoxin levels of Hanwoo steers.</jats:p