Aquaculture Articles on Feed, Nutrition and Water

The ability of nutritionists to formulate feed to provide nutrient levels for optimum economic layer performance is dependent upon understanding the microenvironment in which layers are reared, and upon adjusting feed formulations for those changes in feed intake caused by the environment. The environmental temperature has a tremendous influence on feed consumption, because the layers try to maintain a homeostatic body temperature by adjusting the intake of nutrients to the amount of heat the laying hen dissipates. The dietary requirements for ME and amino acids for layers should be based on specific environmental conditions, maintenance needs and product output. The maintenance energy requirement for layers is very dependent on environmental temperature and body size and has a tremendous effect on total daily feed intake.

Ducks are raised for both meat and eggs throughout Asia, and are an important component of animal agriculture in Indonesia, Philippines, Thailand, Malaysia, Vietnam, Taiwan and China.

Many systems are used for duck production in Asia, and in some of them nutrition inputs are provided through scavenging, a combination of scavenging and/or use of ingredients such as rice bran, snails etc. However, large numbers of ducks are fed on balanced, mixed diets, often in pelleted form. Varieties of ducks used vary greatly from country to country. All of this makes it difficult to define nutrient requirements. In this article an attempt is made to provide information on the feeding of ducks for both meat and eggs. The information is derived from experience, and from a number of literature sources. For meat ducks, most information relates to the Pekin type of meat duck. For laying ducks, the information is believed suitable for small bodyweight laying ducks such as the Indian Runner type.

The use of an optimum quality fullfat soybean meal (FFSBM) in terms of protein solubility and availability is critical at any layer or broiler operation that looks for a maximum operation efficiency and profitability. For this reason, the protein digestibility index of a fullfat soybean meal obtained with the use of an expander (EFFSBM) with 37.3% of crude protein, 91.15% of protein solubility in potassium hydroxide, 0.06 of urease activity and 3.6 mg/gr of trypsin inhibitor was compared to a soybean meal (SBM) with 48 % of CP and a protein solubility index of 85.45%, 0.19 of urease activity and 2.5 mg/gr of trypsin inhibitor, in commercial rations for Ross broilers and both soybean products were obtained from the same source of soybeans. Soybean meal was used in T-1 and the EFFSBM in T-2 being both isocaloric and isonitrogenous. The difference in terms of CP, TSAA, lysine, threonine and tryptophane content between T-1 and T-2 in relation to T-3, then between T-3 and T-4 and finally between T-4 and T-5 was based on the percentage of difference in terms of protein solubility between the EFFSBM and the SBM, this time of 5.7% and equivalent to 0.42% of protein, considering that 7.4% of the total protein was supplied by the EFFSBM after including it at 20 %. The EFFSBM was then incorporated into starting and finishing broiler rations with different levels of protein (22% for T- 1 and T-2, 21.58%, 21.16% and 20.74% for T-3, T-4 and T-5 respectively in the starting period, and 18% for T-1 and T-2, 17.58%, 17.16% and 16.74% for T-3, T-4 and T-5, respectively for the finishing period). At 49 days no statistical difference (p>0.05) was observed among treatments for body weight gain (2617, 2621, 2636, 2631 and 2587) and feed conversion (1.988, 1.938, 1.946, 1.986 and 1.992).

The most important cost factor when producing poultry is feed costs. Feed represents up to 65% of the cost of growing broilers. How that feed is prepared, mixed, and manufactured impacts the nutritional quality and costs of production. When many nutritionists today are asked “what is the importance of feed manufacturing to the nutrition of poultry?” most will recall the importance of pellet quality, and others will recall how certain nutrients could be damaged during processing. However, few of us tend to think of the feedmill as a kind of ‘chemistry lab’ in which heat, time, and reactants are combined to form a final product. Many years ago when we thought about the feedmill, it was just a place to mix cereal grains into a mash feed, but today, with new enzyme technology, developing antibody additives, genetically modified grains, and new processing techniques, the feedmill will become more integral to the feed formulation process. Yesterday, we worried about getting adequate nutrients to the bird, tomorrow we will worry about the entire process. Those who are able to utilize the correct time, temperature, and chemical reactants that result in the most economical feed at economical processing charges will produce lower cost products.