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Review: Optimizing ruminant conversion of feed protein to human food protein
- G. A. Broderick
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Ruminant livestock have the ability to produce high-quality human food from feedstuffs of little or no value for humans. Balanced essential amino acid composition of meat and milk from ruminants makes those protein sources valuable adjuncts to human diets. It is anticipated that there will be increasing demand for ruminant proteins in the future. Increasing productivity per animal dilutes out the nutritional and environmental costs of maintenance and rearing dairy animals up to production. A number of nutritional strategies improve production per animal such as ration balancing in smallholder operations and small grain supplements to ruminants fed high-forage diets. Greenhouse gas emission intensity is reduced by increased productivity per animal; recent research has developed at least one effective inhibitor of methane production in the rumen. There is widespread over-feeding of protein to dairy cattle; milk and component yields can be maintained, and sometimes even increased, at lower protein intake. Group feeding dairy cows according to production and feeding diets higher in rumen-undegraded protein can improve milk and protein yield. Supplementing rumen-protected essential amino acids will also improve N efficiency in some cases. Better N utilization reduces urinary N, which is the most environmentally unstable form of excretory N. Employing nutritional models to more accurately meet animal requirements improves nutrient efficiency. Although smallholder enterprises, which are concentrated in tropical and semi-tropical regions of developing countries, are subject to different economic pressures, nutritional biology is similar at all production levels. Rather than milk volume, nutritional strategies should maximize milk component yield, which is proportional to market value as well as food value when milk nutrients are consumed directly by farmers and their families. Moving away from Holsteins toward smaller breeds such as Jerseys, Holstein-Jersey crosses or locally adapted breeds (e.g. Vechur) would also reduce lactose production and improve metabolic, environmental and economic efficiencies. Forages containing condensed tannins or polyphenol oxidase enzymes have reduced rumen protein degradation; ruminants capture this protein more efficiently for meat and milk. Although these forages generally have lower yields and persistence, genetic modification would allow insertion of these traits into more widely cultivated forages. Ruminants will retain their niches because of their ability to produce valuable human food from low value feedstuffs. Employing these emerging strategies will allow improved productive efficiency of ruminants in both developing and developed countries.
Animal production and farm size in Holmes County, Ohio, and US agriculture
- Martin H. Bender
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- Journal:
- American Journal of Alternative Agriculture / Volume 18 / Issue 2 / June 2003
- Published online by Cambridge University Press:
- 30 October 2009, pp. 70-79
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- June 2003
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Animal production in US agriculture during 1997 was compared with Holmes County, Ohio, in which half the farms belonged to the agrarian Amish whose small farms have been successful. To compare the intensity of animal production in regard to land that was already devoted solely to domestic feed, the two systems were scaled so that their average farm sizes contained equal land areas devoted to domestic feed and then their animal production per farm was adjusted by the same scaling. By breeding populations, as well as large imports of feed, feeder pigs, calves, and broiler chicks. Holmes County produced three times more milk, four times more broilers, about the same amount of eggs and cattle, and twice the pigs per scaled farm, and hence per given land area, as in the US. Despite the average farm size in Holmes County having been 40% smaller than in Ohio overall, this production yielded more than twice the energy and protein per scaled farm, or per given land area, compared to the US, and required almost twice the feed and 85% as much grazed pasture forage per farm. This was in accord with the fact that feed consumption in Holmes County was twice its harvested crop production, implying a net feed import equal to its crop production. The latter fact was the main contribution to the productivity of Holmes County in excess of the US, and also suggested there would be serious problems in widespread adoption of intensive animal production in regard to agricultural markets, soil fertility and farm nutrient losses through manure application. Energy conversion efficiency for the five animal products and breeding populations was greater in Holmes County than the US (10 and 7%, respectively) and likewise for protein (22 and 13%). Besides imported feed, the higher efficiency of Holmes County was also due to its greater emphasis on milk production, which has benefited from USDA milk price support, modern dairy genetics and dairy nutrition programs. The lower overall efficiency of the US has been partly a result of the fact that beef production and breeding, judged by feed alone, have been the least efficient of the five animal products in energy conversion and nearly the least for protein, regardless of the fact that among the five products, beef cattle are the only animals that nationally derived much of their nutrition from the large national area of grazing land.