Combined effects of 3-nitrooxypropanol and canola oil supplementation on methane emissions, rumen fermentation and biohydrogenation, and total tract digestibility in beef cattle. (23rd March 2021)

• Record Type: Journal Article
• Authors: Zhang, Xiu Min; Smith, Megan L; Gruninger, Robert J; Kung, Limin; Vyas, Diwakar; McGinn, Sean M; Kindermann, Maik; Wang, Min; Tan, Zhi Liang; Beauchemin, Karen A
• Is Part Of: Journal of animal science. Volume 99:Number 4(2021)
• Publication Date: 2021-03-23
• Subjects: biohydrogenation -- canola oil -- methane -- 3-nitrooxypropanol -- rumen fermentation; Livestock -- Periodicals; Livestock; Electronic journals; Periodicals; 636.005
• DOI: 10.1093/jas/skab081
• Languages: English
• ISSNs: 0021-8812

Abstract

Abstract: The individual and combined effects of 3-nitrooxypropanol (3-NOP ) and canola oil (OIL ) supplementation on enteric methane (CH4 ) and hydrogen (H2 ) emissions, rumen fermentation and biohydrogenation, and total tract nutrient digestibility were investigated in beef cattle. Eight beef heifers (mean body weight ± SD, 732 ± 43 kg) with ruminal fistulas were used in a replicated 4 × 4 Latin square with a 2 (with and without 3-NOP) × 2 (with and without OIL) arrangement of treatments and 28-d periods (13 d adaption and 15 d measurements). The four treatments were: control (no 3-NOP, no OIL), 3-NOP (200 mg/kg dry matter [DM ]), OIL (50 g/kg DM), and 3-NOP (200 mg/kg DM) plus OIL (50 g/kg DM). Animals were fed restrictively (7.6 kg DM/d) a basal diet of 900 g/kg DM barley silage and 100 g/kg DM supplement. 3-NOP and OIL decreased ( P < 0.01) CH4 yield (g/kg DM intake) by 31.6% and 27.4%, respectively, with no 3-NOP × OIL interaction ( P = 0.85). Feeding 3-NOP plus OIL decreased CH4 yield by 51% compared with control. There was a 3-NOP × OIL interaction ( P = 0.02) for H2 yield (g/kg DM intake); the increase in H2 yield ( P < 0.01) due to 3-NOP was less when it was combined with OIL. There were 3-NOP × OIL interactions for molar percentages of acetate and propionate ( P < 0.01); individually, 3-NOP and OIL decreased acetate and increased propionate percentages with no further effect when supplemented together. 3-NOP slightly increased crude protein ( P = 0.02) and starch ( P = 0.01) digestibilities, while OIL decreased the digestibilities of DM ( P < 0.01) and neutral detergent fiber ( P < 0.01) with no interactions ( P = 0.15 and 0.10, respectively). 3-NOP and OIL increased ( P = 0.04 and P < 0.01, respectively) saturated fatty acid concentration in rumen fluid, with no interaction effect. Interactions for ruminal trans -monounsaturated fatty acids ( t-MUFA ) concentration and percentage were observed ( P = 0.02 and P < 0.01); 3-NOP had no effect on t-MUFA concentration and percentage, while OIL increased the concentration ( P < 0.01) and percentage ( P < 0.01) of t-MUFA but to a lesser extent when combined with 3-NOP. In conclusion, the CH4 -mitigating effects of 3-NOP and OIL were independent and incremental. Supplementing ruminant diets with a combination of 3-NOP and OIL may help mitigate CH4 emissions, but the decrease in total tract digestibility due to OIL may decrease animal performance and needs further investigation.