Wednesday, April 26, 2017
Alternative vegetable protein sources for broilers.
Alternative vegetable protein sources for broilers. Soybean meal and dried distiller’s grains with solubles (DDGS) remain the primary source of protein for broilers. Soybean meal is the No. 1 source of protein for broilers worldwide, but its use is supplemented by locally available secondary sources such as DDGS ,rapeseed meal and sunflower meal . There are minor, local sources of protein that can offer the benefits of volume and low prices. When such opportunity arises, broiler producers are enticed to use these alternative, protein-rich ingredients, but results are often disappointing. The main reason is not as much quality, but rather lack of understanding of the limitations posed by each ingredient. These limitations arise from the concentration, which can be quite variable, of certain anti-nutritional factors that cause an almost toxic effect in the bird’s metabolism. Knowing these factors and their concentration can lead to very successful feed formulations using alternative protein sources and to very profitable production outcome. 1) Palm kernel meal The rapid growth of palm oil production in Asia, Australia, South America and Africa has led to tremendous quantities of palm kernel meal being available for all types of livestock. Not a protein-rich ingredient (less than 18 percent crude protein), palm kernel meal remains an interesting ingredient because it can contribute to significant cost savings. It is poor in lysine and methionine, with average digestibility values, but it contains sufficient energy to constitute a good part of the total dietary protein fraction. It is also relatively high in crude fiber (up to 20 percent). In many aspects, palm kernel meal can be compared to corn gluten feed. It is speculated that any adverse effects of palm kernel meal observed in broilers is due to its grittiness and overall physical quality aspects and not due to its nutrient profile. As such, high quality palm kernel meal can be used relatively freely, within constrains imposed by its limited nutrient profile, in broiler diets. 2) Cottonseed meal A by-product of the extraction of oil from cotton seeds, this protein source is not often available for broiler feed due to competition from ruminant feeds — something that increases its price. Cottonseed meal contains about 40 percent crude protein, of moderate digestibility, whereas the major anti-nutritional factor is gossypol. Broilers can withstand much higher levels of gossypol compared with layers, but the usually high fiber concentration (15 percent) in cottonseed meal will pose an upper limit in formulation. In regards to gossypol, it is possible to reduce the negative effects by neutralizing it through the addition of certain iron salts. Low- or no-gossypol cultivars are also available yielding meals that are tolerated well by broilers. A gradual introduction into feed formulas is recommended. 3) Corn gluten meal There is nothing really wrong with corn gluten meal, which is a by-product of the starch extraction process from corn kernels. It contains about 60 pecent crude protein, with digestibility values being comparable to that of corn. It also contains the majority of pigments from the kernel, and it leads to heavy pigmentation of the broiler skin — which can be a desirable or undesirable carcass trait according to market circumstances. continue