Feed conversion ratios

The effect of en2ymes, recorded in many feed trials, includes increased final weight of the animal, better feed utili2ation, improved feed conversion ratio (ECR), more homogeneous production, reduced mortaUty, and a reduced amount of sticky droppings (in chickens) (87). 

The effect of probiotic use in chicken production has also been studied by several groups. For example, Kralik el al. (2004) have studied the effect of adding probiotics to the drinking water of avian broilers. They reported an increase of live weights of broilers, an improvement in feed conversion ratios and lower population densities of the pathogenic bacteria E. coli and Staphylococcus aureus in the intestinal contents. 

Table I. Weight gain, feed intake, and feed conversion ratio rats fed indicated bread diets 28 days...

Breada,b in diet Weight gain (mean0 SEM) (g) Feed intake (meanc SEM) (g) Feed conversion ratio... 

Earthworm meal has also been shown to be a useful protein source for Japanese quail. Das and Dash (1989) fed 1-week-old male and female Japanese quails on a maize-based diet containing 60g/kg fishmeal or 60g/kg earthworm meal. After 56 days, total weight gain was 96.1 and 98.5 g, feed intake was 533 and 511 g and feed conversion ratio 5.54 and 5.19g/g for the control and earthworm diets, respectively. Egg quality was not influenced by the diets. 

Since keratinase is a versatile protease that digests all kinds of proteins, it is possible that supplementation of the enzyme in feed may improve the feed digestibility. In 2001 keratinase was tested as a feed additive. The first test in young chicks was positive, and reproduced by many more experiments 0.1% of crude keratinase in a regular corn-soy diet improved the body weight gain, the feed conversion ratio (FCR), or feed efficiency in broiler chickens. Numerous experiments included the cage tests of chicks to 3-4 weeks of age (Odetellah et al., 2003), pen trials on a research farm to 6 week market age (Odetellah et al, 2005), and the commercial tests conducted by private com-... 

The addition of 2% and 4% natural zeolite (NZ) to broiler diet was studied in a 42-day experiment. Body weight gain, feed consumption, feed consumption ratio, some carcass characteristics and chemical analysis in the muscular mass of breast and legs were determined. The supplementation of 2% NZ in the broiler diet resulted in an improvement of the feed conversion ratio and an increase of body weight, carcass yield as well as linoleic and a-linolenic acid content, without any adverse effect on the other measured parameters. The addition of 4% natural zeolite resulted in a significantly higher feed conversion ratio. 

The most likely mechanisms, by which organic acids improve feed conversion ratio and animal health, include acidification, either of the feed or of the stomach, and/ or selective inhibition of pathogenic intestinal micro-organisms. They may also be... 

Table 3. Effect of organic adds or their salts on average daily weight gain (ADG) and feed conversion ratio in piglets and fattening pigs...

Formic (or formate), citric and fumaric acids significantly improved (P<0.05) weaning piglet average daily gain and feed conversion ratio in comparison to the non-... 

Microdiets are expensive (up to 300 Kg) and are likely to remain so. Then-production is difficult and the raw ingredients, in many cases, are very expensive. There is a relatively small market which limits the potential for cost reduction through large-scale production. Therefore, it is necessary to optimize the use and yield from such a product. In the ongrowing sector of fish farming, FCR (feed conversion ratio) is one of the most important factors to assess diet utilization. Using microdiet as a full or partial... 

Based on the excellent results of pond trials in 1991, aU US shrimp ponds were stocked with High Health PL in 1992. Total production of the US industry doubled as a direct result of this innovation. Use of High Health shrimp in commercial farms increased production and survival, improved feed conversion ratio (FCR) and narrowed harvest size distribution all of which contributed to increased profitability. In addition to increased production, use of High Health shrimp reduced incidence of shrimp disease. It was predicted that the shrimp farming problems that were solved by use of SPF shrimp in the US industry could be duplicated elsewhere (Wyban et al., 1992). 

Supplementation of 200 ppm essential oil mixture (EOM) that included oregano, clove, and anise oils (no species name or composition given ) in broiler diets was said to sign cantly improve the daily live weight gain and feed conversion ratio (FCR) during a growing period of 5 weeks (Ertas et al., 2006). Similar results were obtained with 400 mg/kg anise oil (composition not known ) (Ciftci et al., 2005). 

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