Feeds

Litopeneaus vannamei is one of the country’s most significant aquacultured species today. Known worldwide as Pacific whiteleg shrimp, L. vannamei was first cultured in the year 1973 and has continuously increased its production in many parts of the world. This species originated in the Eastern Pacific coast of Sonora, Mexico and other countries such as Central and South America, Tumbes, and Peru.

Effect of replacing maize with β-carotene biofortified cassava grits on physico-chemical attributes of carcass and meat of broilers was investigated in an experiment which lasted 42 days. In a completely randomized design, 210 one-day old Arbor Acre broiler chicks were allotted to seven dietary treatments in triplicates of ten birds per replicate. At both the starter and finisher phases, yellow maize based diet was the control (1). Other six diets were made by replacing 25, 50 and 75% of yellow maize with grits from two different cassava varieties; TMS 01/1371, a β-carotene bio-fortified yellow cassava (2, 3, 4) and TME 419, a conventional white cassava (5, 6, 7), respectively. There was no significant difference (P>0.05) in weight of primal cuts excepting back where birds fed T5 had higher (P<0.05) yield (15.19%) compared with those fed other diets (14.66, 13.65, 14.72, 14.13, 14.38 and 15.01% for birds fed 1, 2, 3, 4, 6 and 7, respectively). Meat pH, water holding capacity and cooking loss were not significantly (P>0.05) affected by the treatment. Meat of birds on 7 had significantly lower (P<0.05) shear force (3.65 kg/cm 3) compared to those on other treatments. Dietary β-carotene cassava grits significantly increased (P<0.05) meat retinol and reduced meat lipid oxidation. However, there was no significant effect (P>0.05) of the replacement on meat proximate composition. Meat colour, tenderness and juiciness differed significantly (P<0.05) among treatments while aroma, flavour and overall acceptability were similar (P>0.05). In conclusion, maize could be replaced with cassava grits from TME 419 and TMS 01/1371 up to 75% without adversely affecting broiler chicken meat yield and quality. Dietary β-carotene bio-fortified cassava up to 75%, improved shelf life and oxidative stability of broilers meat.

Cottonseed meal (CSM) is a by-product of the oil industry, i.e. oil extraction from cotton seeds. CSM is a rich source of protein (30 to 50% in dry matter), characterised by a high concentration of amino acids. However, a relatively low concentration of lysine restricts the quality of protein in CSM. The use of CSM as feed material for poultry nutrition is limited mainly by free gossypol presence, as well as a high variability in nutrient concentration. Gossypol is a polyphenolic compound reducing protein digestibility by inhibition of pepsin and trypsin activity in the intestine and binding iron in the diet. High dietary levels of CSM can negatively affect growth performance and egg production and egg quality. Such dietary treatments as increased iron and lysine dietary supplementation can increase the usefulness of CSM in poultry nutrition by alleviating the toxic effect of gossypol. The results of recent experiments on the use of CSM meal as a feed material for poultry are discussed in this review article. Based on the results presented, cottonseed meal is an acceptable ingredient of poultry diets and could be safely fed at a 10-15% dietary level, partially replacing - in a cost effective way - soybean meal.