Cottonseed Meal in Poultry Diets: A Review

Abstract

The residue of cottonseed oil extraction industry popularly known as cottonseed meal (CSM) is a fairly good source of protein (,,,.* to /0*., g kg ῌ+ ) and metabolizable energy (1.. to ++.33 MJ kg ῌ+ ). The use of CSM in poultry diet is limited due to the presence of gossypol, cyclopropenoid fatty acids (CPFA), high fibre and poor protein quality. The most critical amino acid in CSM is lysine. During the oil extraction from cottonseeds, a portion of free gossypol (FG) binds with the epsilon amino group of lysine, thereby reducing the availability of lysine to the chicken. The concentration of nutrients, FG, CPFA in CSM depends on the variety of cultivars, methods of oil extraction, proportion of kernel to husk, lint and seed coat. The concentration of FG in various varieties of CSM ranges from ,** and /-** mg kg ῌ+ . In glandless variety, the FG concentration is less (῍+-* mg kg ῌ+ ). Gossypol inhibits the activity of pepsin and trypsin in gastro-intestinal tract, thereby reducing the digestibility of protein. The reported toxic e#ects of gossypol are growth depression, lameness, decreased egg size and hatchability. Gossypol and CPFA also deteriorates the internal egg quality by causing yolk mottling and pinkish discoloration of albumen, respectively. The tolerance levels of FG in birds vary widely depending on the age and strain of birds, protein content and quality, duration of feeding, presence of minerals especially the iron content in the diet. The tolerance of FG in chicks varies widely (3* to +*** mg kg ῌ+ diets), however performance of layer chicks could be a#ected even at a lower FG intake of ,.*, mg day ῌ+ bird ῌ+ . Though, growth was not a#ected in broilers at FG concentration in diet below +/* mg kg ῌ+ , feed e$ciency was reduced at lower levels i.e. 0*῎+** mg kg ῌ+ . The depression in egg production in layers fed diets containing more than +** mg kg ῌ+ was mainly due to lowered feed intake. The egg weight and egg quality was not a#ected at FG levels upto ,** mg kg ῌ+ diet. Iron treatment (.:+; Fe:FG) proved to be e#ective in alleviating the negative e#ects on egg quality, but could not alleviate the depression in laying performance. Lysine supplementation to CSM containing diets is also e#ective in counteracting the ill e#ects of FG in chicken, especially chicks and broilers. Other processing methods like solid substrate fermentation, production of glandless cotton seed and use of organic solvents were though e#ective in improving the nutritive value of CSM and reducing the FG content in CSM, these methods are of little practical relevance and uneconomical. Production of glandless variety of cottonseed through genetic modification (Bacillus thuringiensis cotton) is one of the recent trends of reducing the FG content. Some other methods like pelleting, extrusion, cooking and Ca (OH), treatment of CSM could be tried for improving the feeding value of CSM in poultry.

Simultaneous inclusion of sorghum and cottonseed meal or millet in broiler diets: effects on performance and nutrient digestibility

“…Free gossypol in cottonseed meal is known to have an inhibitory action on certain enzymes in bird gastrointestinal tract like pepsinogen, pepsin and trypsin by binding with their free epsilon amino groups of lysine, thus reducing protein digestibility (Sharma et al, 1978). However, in this study free gossypol levels were too low (5 to 13 ppm) to induce any detrimental effect on growth performance (Nagalakshmi et al, 2007); but the effect of free gossypol could not be excluded from the reduction of digestibility with cottonseed meal-based diets. Similarly, lower total tract digestibility of fat and starch and lower AMEn values were obtained with sorghum-based diets consistently with previous reports (Selle et al, 2010;Mahmood et al, 2014) where digestibility coefficients were found inferior in sorghum than in other cereals due to the presence of phytate and phenolic compounds.…”

“…Its presence in sorghum is associated with a poor amino acid digestibility. In cottonseed meal, free gossypol decreases lysine digestibility and inhibits the activity of pepsin and trypsin, thus reducing growth in broilers (Nagalakshmi et al, 2007).…”

Cottonseed oil in diets for growing broilers

“…Although cotton by-products can be good alternatives in broiler diets because of their composition, their use in diets for monogastric animals is still restricted due to the presence of a yellow polyphenolic compound called gossypol (C 30 H 30 O 8 ), produced by glands present in all parts of the cotton tree (roots, leaves, trunk, and mainly in the seeds) (Nagalakshmi et al, 2007). Gossypol has antinutritive properties, as it is responsible for toxic effects in the animal (Santos et al, 2013).…”

“…Gossypol is associated with reduced use of proteins, because in its free form, it binds to proteins or to an amine group free of essential amino acids, especially lysine, reducing the protein biological value (Nagalakshmi et al, 2007). It also has an inhibitory action on the proteolytic enzymes present in the gastrointestinal tract of birds, like pepsin and trypsin, which negatively interferes with the protein digestion, reducing its digestibility (Ryan et al, 1986).…”

Gossypol Promotes the Degeneration of Chicken Ovarian Follicles in Vitro

“…Cottonseeds are used as a protein source in animal feeds, but their use is limited by the presence of gossypol (Nagalakshmi et al, 2007;Gadelha et al, 2014a). Gossypol (2,2-bi(8-formyl-1,6,7-trihydroxy-5-isopropyl-3-methylnaphthalene)) is a phenolic compound produced by the pigment glands in cotton stems, leaves, seeds and flower buds (Rogers et al, 2002;Kenar, 2006;Alexander et al, 2008;Soto-Blanco, 2008).…”