Feed utilization efficiency

Soybean oil appears to be the preferred plant lipid source regarding fish growth while considerable savings in feed costs could be achieved if used as a partial dietary substitute for fish oil within compound feeds. The same goes to linseed and rapeseed oil but to a lesser extent (Wassef et al., 2009 El-Kerdawy Salama, 1997). Furthermore, the use of palm oil and olive oil in fish feeds has given growth and feed utilization efficiency comparable to fish fed with equivalent levels of fish oil (Caballero et al., 2002 Mourente et al, 2005 Rosenlund, 2001 Torstensen et al., 2000, 2004). 

Many researchers seem to believe that 60% fish oil substitution in compounded fish feeds by plant oils is the preferable percentage in order not to compromise growth performance or feed utilization efficiency of fish (Alexis, 1997 Caballero et al., 2004 Izquierdo et al., 2003, 2005 Montero et al., 2005 Mourente et al., 2005, 2006 Wassef et al., 2009). 

Seefeld, M.D. and R.E. Peterson. 1984. Digestible energy and efficiency of feed utilization in rats treated with 2,3,7,8-tetrachIorodibenzo-p-dioxin. Toxicol. Appl. Pharmacol. 74 214-222. 

Obviously, the overall feed cost depends on the price of the feed as well as its utilization efficiency. This is illustrated in Fig. 2.12. Accordingly, vegetables oils are not competitive with crude oil priced at 50 bbl 1, whereas grains and ligno-... 

The advisability of using certain antibiotics, particularly penicillin and tetracycline, in animal feeds has been questioned because of their use in human medicine. Any use of an antibiotic that is prescribed for humans presents some risks to human health, whether the use is for humans, animals or for other purposes but. the uses also have benefits. Otherwise, they would not persist. Antibiotics are used in animal feeds to increase animal weight, increase efficiency of feed utilization, increase reproductive efficiency and decrease morbidity and mortality. These benefits to animals and animal producers are reflected in decreases in food costs to humans. There are also benefits to human health from use of antibiotics in food animals. By reducing the incidence of animal health problems, use of antibiotics in food animals reduce the transference of animal infections to humans. The contention that the effectiveness of penicillin and tetracycline for use in human medicine is rapidly diminishing as a result of the proliferation of resistant bacteria caused by subtherapeutic use of antibiotics in animal production is not supported by experimental data. Rather, the evidence suggests that a fairly stable level of resistance of the intestinal bacteria in humans has long since been established to penicillin and tetracycline as it has been in animals. 

Reduced hydrocarbon gas make resulting in reduced feed gas consumption and enhanced hydrogen utilization efficiency... 

Fig. 6.4). The avilamycin complex is produced by Streptomyces viridochromo-genes and is composed of factor A as the major component with several other minor components (20). It is used as a feed additive for swine at a level of 20-40 ppm for animals up to 4 months of age and at 10-20 ppm for animals of 4-6 months of age (21, 22). When fed to swine, avilamycin causes an increase in gain rate and efficiency of feed utilization. 

The most widely used and researched growth promotant of this type is the polyether antibiotic monensin (63). Monensin, at levels of 33 p.p.m. in feed, has been shown to increase efficiency of feed utilization in both sheep and cattle fed a variety of rations by up to 12%. Slaughter and carcass analysis data indicate that the main effect of the compound is to increase the efficiency of dietary energy retention in the carcass. Its mode of action is thought to be related to its ability to increase the molar proportion of propionate, at the expense of acetate and butyrate, produced in rumen fermentation probably by an effect on the relative microfloral populations. Theoretically this should make more energy available to the animal. 

An advantage of pelleting is that it may improve both intake and the efficiency of feed utilization, particularly with fibrous ingredients such as wheat milling by-products. A further advantage of pelleting is that it can help to reduce microbial counts in the feed. 

Seefeld MS, Peterson RE. 1984. Digestible energy and efficiency of feed utilization in rats treated with... 

There are problems associated with the use of copra cake in feed. As the amount of cake in the feed increases, its palatabihty decreases. Copra meal tends to be less digestible than fresh coconut meal. Despite a protein content of greater than 20%, the addition of methionine and lysine improves growth and feed utilization. The method of oil extraction does not appear to influence the quality of meal produced. Neither expeller-extracted nor solvent-extracted copra meal, at levels of 10-14% in poultry diets, caused any difference in egg production, mortahty, or efficiency of feed conversion (61). 

Large quantities of feed are produced daily, transported, and stored, and even a minor contamination with pathogens, for example, Salmonella, has the potential to affect many herds (Sauli et al., 2005). To enhance the nutritional value of feed, large-scale producers treat their feed with organic acids or heat, or both. Dietary inclusion of organic acids has been found to positively affect the growth rate and efficiency of feed utilization (Giesting and Easter, 1991 Mroz et al., 2000), whereas heat treatment... 

Even more complex is the structure of monensin, a compound which has been extensively used as an anticoccidial agent for poultry and shown to improve the efficiency of feed utilization in ruminant animals. When submitted to a culture of Sebekia bevihana, monensin was first quantitatively converted by enzymatic reduction of the 8-hydroxy-ketone (which is in equilibrium with its hemiketal tautomeric form) and was regioselectively further hydroxylated at the C-29 methyl group as well as at the nearby ethyl group substituent[94). 

Fig. W-34. Cattle can utilize efficiently large quantities of coarse, humanly inedible roughages, like cornstalks. This shows cows feeding on corn residue which had been harvested by mechanical means. (Courtesy, Iowa State University)...

Under current feeding programs, efficiency of utilization of dietary proteins for animal growthremains suboptimal. For example, in 14-day-old pigs reared by sows and 30-day-old pigs weaned at 21 days of age, 70% and 55% of dietary amino acids are deposited in body proteins, respectively (Wu et al.,... 

The present sffidy lend support to theories about more efficient recycling of N to the foregut in the llama compared to the small ruminants explaining the superior feed utilization on poor quality diets - except that sheep were even more efficient than the llama in reducing N excretion in urine on the low protein diet. 

Oddy, V.H. and R.M. Herd, 2001. Potential mechanisms for variation in efficiency of feed utilization in ruminants. In Feed Efficiency in Beef Cattle Proceedings of the Feed Efficiency Workshop, Armidale, Australia. CRC for Cattle and Beef Quality, C. J. Hawkins Homestead, University of New England 30-34. 

Frisch, J.E. and J.E. Vercoe, 1977. Foodintake, eating rate, weight gains, metaboUc rale and efficiency of feed utilization in Bos taurus and fios indicus crossbred cattle. Anim. Prod. 25,343-358. 

In the removal of the metal ions such as copper, zinc, cobalt, and strontium, the net result of the metal ion removal from the aqueous feed solution into the aqueous strip solution is the transfer of proton ions from the strip solution into the feed solution. Thus, the pH of the feed solution reduces as the metal is removed. This has a significant effect on module utilization efficiency for SLM systems, and an SLM system operating at a low feed pH of about 2 is highly desirable in order to have a module utilization efficiency of 100% (Ho et al., 2001 Ho, 2003). 

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