Effects of 3-nitrooxypropanol on methane emission, digestion, and energy and nitrogen balance of lactating dairy cows.
The objective was to measure effects of 3-nitrooxypropanol (3 NP) on methane production of lactating dairy cows and any associated changes in digestion and energy and N metabolism. Six Holstein-Friesian dairy cows in mid-lactation were fed twice daily a total mixed ration with maize silage as the primary forage source. Cows received 1 of 3 treatments using an experimental design based on two 3 × 3 Latin squares with 5-wk periods. Treatments were a control placebo or 500 or 2,500 mg/d of 3 NP delivered directly into the rumen, via the rumen fistula, in equal doses before each feeding. Measurements of methane production and energy and N balance were obtained during wk 5 of each period using respiration calorimeters and digestion trials. Measurements of rumen pH (48 h) and postprandial volatile fatty acid and ammonia concentrations were made at the end of wk 4. Daily methane production was reduced by 3 NP, but the effects were not dose dependent (reductions of 6.6 and 9.8% for 500 and 2,500 mg/d, respectively). Dosing 3 NP had a transitory inhibitory effect on methane production, which may have been due to the product leaving the rumen in liquid outflow or through absorption or metabolism. Changes in rumen concentrations of volatile fatty acids indicated that the pattern of rumen fermentation was affected by both doses of the product, with a decrease in acetate:propionate ratio observed, but that acetate production was inhibited by the higher dose. Dry matter, organic matter, acid detergent fiber, N, and energy digestibility were reduced at the higher dose of the product. The decrease in digestible energy supply was not completely countered by the decrease in methane excretion such that metabolizable energy supply, metabolizable energy concentration of the diet, and net energy balance (milk plus tissue energy) were reduced by the highest dose of 3 NP. Similarly, the decrease in N digestibility at the higher dose of the product was associated with a decrease in body N balance that was not observed for the lower dose. Milk yield and milk fat concentration and fatty acid composition were not affected but milk protein concentration was greater for the higher dose of 3 NP. Twice-daily rumen dosing of 3 NP reduced methane production by lactating dairy cows, but the dose of 2,500 mg/d reduced rumen acetate concentration, diet digestibility, and energy supply. Further research is warranted to determine the optimal dose and delivery method of the product.
School of Agriculture, Policy and Development, University of Reading, PO Box 237, Earley Gate, Reading, RG6 6AR, United Kingdom. Electronic address: c.k.reynolds@reading.ac.uk.
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CK
Reynolds
School of Agriculture, Policy and Development, University of Reading, PO Box 237, Earley Gate, Reading, RG6 6AR, United Kingdom.
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Humphries
School of Agriculture, Policy and Development, University of Reading, PO Box 237, Earley Gate, Reading, RG6 6AR, United Kingdom.
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Kirton
DSM Nutritional Products Ltd., PO Box 2676, CH-4002 Basel, Switzerland.
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Kindermann
DSM Nutritional Products, Research Centre for Animal Nutrition and Health, BP 170, F-68305 Saint-Louis Cedex, France.
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Duval
DSM Nutritional Products Ltd., PO Box 2676, CH-4002 Basel, Switzerland. Electronic address: c.k.reynolds@reading.ac.uk.
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Steinberg
D000821:Animal Feed / Q000032:analysis; D000818:Animals; D002417:Cattle; D004032:Diet / Q000662:veterinary; D004041:Dietary Fats / Q000032:analysis; D004043:Dietary Fiber; D004063:Digestion; D004305:Dose-Response Relationship, Drug; D004734:Energy Metabolism / Q000187:drug effects*; D005232:Fatty Acids, Volatile / Q000032:analysis; D005260:Female; D005285:Fermentation; D006863:Hydrogen-Ion Concentration; D007774:Lactation / Q000187:drug effects*; D008697:Methane / Q000096:biosynthesis*; D008892:Milk / Q000737:chemistry; D008894:Milk Proteins / Q000032:analysis; D009584:Nitrogen / Q000378:metabolism*; D020005:Propanols / Q000494:pharmacology*; D012417:Rumen / Q000378:metabolism; D003313:Zea mays / Q000737:chemistry
C000603069:3-nitrooxypropanol; D004041:Dietary Fats; D004043:Dietary Fiber; D005232:Fatty Acids, Volatile; D008894:Milk Proteins; D020005:Propanols; D009584:Nitrogen; D008697:Methane
3-nitrooxypropanol; dairy cow; digestion; methane; rumen