Each year the world's human population is predicted to increase by 70 - 80 million.
Also the increased purchase capacity and changed food habits are leading to higher consumption of animal meat. Fear of mad cow disease alters the entire traffic to chicken, pork and sea animals. Eggs are becoming cheaper comparative to vegetables. Broiler meat is very low compared to red meat. Consumers consider broiler meat healthy and inexpensive, which will only lead to further increases in demand (Ishibashi and Yonemoch, 2002).
To meet the market demands poultry selection has concentrated on growth rate and muscle mass in broiler. In the last 30 years, the production time needed to raise a 1.3 kg chicken has been halved (Dransfield and Sosnick, 1999). To meet requirements and maintain protein deposition in broilers, nutritionist must look at the demands of the rapidly growing broiler and adapt the formulated diets to meet those demands. To do this, the nutritionists has to look at two major issues -- what is the potential growth rate of the selected broiler and what are the broilers nutrient requirements to meet those needs. A rapidly growing broiler needs to be supplied with nutrients in order to meet its requirements for maintenance and for the growth of all other components of the broiler, including feathers (Gous, 1998). A good definition of potential growth is given by Gous, (1998), as the maximum possible growth rate that the genotype can achieve when given perfect nutritional and husbandry conditions.
POULTRY NUTRITION: PROTEINS
Proteins are supplied by grains, brans, Vegetable protein concentrates like soybean meal, groundnut meal, cottonseed, rapeseed, sunflower extraction, corn gluten meal, and animal protein concentrates like fish meal, meat meal, leather meal, silk worm pupae, meat cum bone meal, bone meal, blood meal, skimmed milk powder etc. Recent advances have been made in developing industrial process for economical production of synthetic amino acids. Lysine and methionine have been available economically for sever years, to balance the amino acid profiles of the poultry feeds with available feeding stuff.
Although there may be some variation in the feed intake from morning to afternoon, it is generally believed that the diumal variation of nutrients in plasma is lower in poultry than in pigs (Riis, 1983). This forms the basis of a better utilization of synthetic amino acids in protein synthesis. Secondly, poultry are more sensitive to amino acid imbalance, which has been shown to have an adverse effect on the feed intake. Experiments with chicken have supported the hypothesis that diets formulated to minimize excess of amino acid over the chickÃ¢â‚¬â„¢s known requirement would improve the efficiency of protein and energy utilization (Waldroup et al., 1976). Moreover, in some instances the relative proportion of essential amino acids may be of greater significance than the absolute amounts because of complex relationship between amino acids (Brewer et at., 1978). Therefore, the advances in balancing amino acid composition of diet and physiological basis for a high utilization of added free synthetic amino acids are generally more favorable in poultry than in pigs. This interpretation was confirmed in a recent study with chicken by Sibbald and Wolynetz (1985). The utilization of synthetic lysine was 0.92, which was significantly (p<0.05) higher than that of protein-bound lysine (0.88).
Using 18% protein diets (N 6.25), consisting mainly of conventional ingredients of known amino acid composition, the amino acid requirements as percentages of diet and of dietary protein respectively for broiler chickens between 14 and 28 d of age were found to be: threonine 0.50-0.52% of diet (2.8-2.9% of dietary protein); glycine 0.48-0.50 (2.7-2.8); valine 0.69-0.71 (3.8-3.9); methionine + cystine 0.58 (3.2); iso-leucine <0.48 (<2.7); leucine <1.05 (<5.8); tyrosine + phenylalanine 1.09-1.12 (6.1-6.2); lysine 0.87 (4.8); histidine <0.34 (<1.9); arginine <0.76 (<4.2); tryptophan < 0.14 (< 0.78).
D L METHIONINE
Methionine is often the first or second limiting amino acid in most diets, and so is most representative of amino acids fed as a nutritional supplement
(Buttery and DÃ¢â‚¬â„¢Mello, 1994).
DL-Methionine is an essential amino acid which must be supplied to the body through protein intake.
Methionine is a principle supplier of sulphur which prevents disorders of the hair, skin
and nails; it helps lower cholesterol levels by increasing the liver's production of
lecithin; it reduces liver fat and protects the kidneys; it is a natural chelating agent for
heavy metals, and finally it regulates the formation of ammonia and creates ammonia-
free urine which reduces bladder irritation
DL-Methionine is necessary for the body to make SAMe.
The body combines DL-Methionine with ATP, which in turn produces SAMe.
SAMe is directl active in 40 biochemical processes and involved indirectly in many more.
NEED FOR AN ALTERNATE MECHANISM:
However, of late, demand being high compared to production, scarcity of L Lysine and D L Methionine is taking place. Also prices of L Lysine and D L Methionine are undergoeing lot of fluctuations.
Hence the need for an alternate mechanism is arised.
Methionine Producing microbes will supply more qualified methionine in a sustained manner.
METHIONINE SECRETING DFM
Lactobacillus spp. were the highest secreters of Methionine, followed in that order by
Leuconostoc sp., Corynebacterium sp. and Bacillus sp.
In survey studies on microbial accumulation of S-adenosyl-L-methionine (AdoMet), various yeasts were found to accumulate AdoMet intracellularly to a high concentration when they were grown in medium containing L-methionine. A group of sake yeasts (Saccharomyces sake) exhibited especially high accumulation. Of these yeasts, S. sake Kyokai No. 6 (K-6), which exhibited the highest accumulation, produced 12.6 ÃŽ¼mol (5.03 mg) of AdoMet/ml broth. Almost all AdoMet produced was accumulated in cells, extracellular accumulation of AdoMet being very low. The maximum content of AdoMet of cells was 5.31 ÃŽ¼mol (205 mg)/g dry cells. This was the highest value that had been reported. Methionine adenosyltransferase (EC 188.8.131.52) activity was significantly higher in this yeast compared to those in other yeasts tested. Ultraviolet photomicrographic studies on S. sake K-6 suggested that AdoMet was gradually accumulated in vacuoles with the passage of cultivation time.