RESPONSE OF WEST AFRICAN DWARF GOATS TO DIETS CONTAINING RAW COMPOSITE CASHEW NUTSHELL IN PLACE OF CASSAVA PEELS

Abstract

Cashew (Anacardium occidentale) a multipurpose nut-bearing tropical plant produces huge quantity of shell, regarded as “waste” in Nigeria, after been processed to extract the nut. Despite cashew nutshell being reported to have nutritional potentials for use in ruminant nutrition, yet, its use is grossly inadequate. Hence, the study aimed to investigate the dietary effect of replacing cassava peel withraw composite cashew nut shell (CNS) meal diets on the feed/nutrient intake, fibre fraction, apparent digestibility, ruminal characteristics (volatile fatty acids, rumen pH and temperature) and weight gain of goat-bucks. A Completely Randomized Design (CRD) was employed for the study in which Sixteen (16) growing West African Dwarf (WAD) bucks were raised for 63 days in four dietary groups, where cassava peels were replaced with CNS meal at 0%, 10%, 20%, and 30% replacement level designated as; T1, T2, T3 and T4, respectively. Response criteria evaluated were feed intake, nutrient/anti-nutrient intake, apparent digestibility, mineral balance, weight change, ruminal characteristics and nutrient compositions. All data obtained were analysed using SPSS (2008) version 16 and Duncan Multiple Range Test (DMRT) was used to separate the means. Goats fed T2 (10% CNS) had the best nutrient digestibility values, highest total dry matter intake (402 g/d), highest average daily weight gain (46.37 g/d)and best feed conversion ratio (8.86) compared to goats fed other experimental diets containing CNS meal. The crude fiber of the diet increased with increased replacement of cassava peel, however the fibre fractions does not follow a particular trend. The results also showed that goats fed T4 (30% replacement level) had the highest anti-nutrient intake when compared with their dry matter intake (207.69 g/day). More so, it was observed that the ruminal characteristics of goats fed T2 (10% CNS) had the highest propionic acid (24.97 mmol/100ml), butyric acid (23.9 mmol/100ml), acetic acid (25.8 mmol/100ml) and valeric acid (23.29 mmol/100ml). The ruminal fluid temperature of the goats does not follow a particular trend but the rumen pH declined progressively as CNS meal increases in the diet and ranged from 6.43 (T4) to 6.97 (T1). Goats fed T2 (10% CNS) compared well to goats fed the control diet in terms of performance. However, mortalities were recorded in goats fed diets containing 20% and 30% replacement level of CNS meal. In conclusion, CNS could be beneficial in ruminant nutrition as replacement of cassava peels with raw CNS at 10% replacement level shows no detrimental effect on their general performance. However, higher replacement of cassava peels meal with raw cashew nutshell meal may adversely affect the general performance of West African Dwarf goats. Hence, further studies should be conducted to enhance the nutritive value of CNS for optimum replacement level and for sustained or improved goat production.