Effects of Diets Containing Varying Levels of Cashew Nut Shell on Scrotal Morphometric Characteristics of Growing West African Dwarf

A total of twenty (20) growing West African dwarf bucks were used to evaluate the effect of diets containing graded levels of cashew nut shell on scrotal morphometric characteristics. The goats were fed supplements containing 0% 10%, 15%, and 20% levels of inclusion of cashew nut shell at 100g/goat/day. The goats were also fed bamboo leaves at 200g/goat/day 1 hour before the supplement was fed. The experiment lasted for 50days after an adjustment period of 7days. Scrotal morphometric measurement was taken on weekly basis as well as scrotal weight on the last day of the experiment. There were no significant (p>0.05) differences in the values for initial and final scrotal length as well as initial and final scrotal circumference. They were however significant (p<0.05) differences in the values for the increase in scrotal length and scrotal circumference. The scrotal weight showed significant (p<0.05) difference with T2 (85g) having the highest. It was therefore concluded that animals in T2 (10% level of inclusion of cashew nut shell) had the best scrotal morphometric values. Further experiments using weaner bucks as well as weaner cattle and sheep were recommended.


INTRODUCTION
The future of livestock production will not only rely on maximizing the productive rate of a given animal species but on helping to meet the demand of society for the necessities of life (FAO, 1997).Several factors affect livestock productivity, but the most important environmental factor that determines livestock productivity is feed (Bamikole and Ikhatua, 2007).Adu et al. (1987) had earlier reported that nutrition remains one of the most important factors that determine the profitability of livestock venture.Ruminants do better when energy and protein rich diets are strategically combined for feeding (Adegbola and Asaola, 1986).But the expensive nature of conventional feedstuffs as a result of competition between man and livestock  (Bamikole and Babayemi, 2004) makes this combination difficult.Nutrition is also known to play a role in the reproductive performance of ruminants (Osinowo et al. 1987) scrotal morphometric characteristics of bucks is reported to have an influence on the reproductive performance of goats (Santos and Simplicio, 2000) thus evaluating effect of diets on scrotal morphometric characteristics of bucks is worthwhile.This study was therefore designed to determine the effect of diets containing varying levels of cashew nut shell on scrotal morphometric characteristics of growing West African Dwarf Bucks.

MATERIALS AND METHODS
The experiment was conducted at the Sheep and Goat unit of Teaching and Research farm of the the Department of Animal Production, Kogi State University, Anyigba.Anyigba lies on latitude 7°15ʼ and 7°29Nʼ of the equator and longitude 7°11ʼ and 7°32Eʼ of the Greenwich meridian (Ifatimehin et al., 2009).
A total of twenty (20) growing West African dwarf bucks were obtained from Anyigba and its environs.The goats were housed individually and treated with oxytetracycline hydrochloride, sulphadimidine, procain penicillin and ivomec® to control both endo and ecto parasites and to provide a common health status.The cashew nut shell used for this experiment was collected from cashew kernel processing plant in Kogi State University, Anyigba.The cashew nut shell was pounded and mixed with other ingredient such as rice offal, bambaranut waste, table salt, maize offal, wood ash, fish offal meal and bone meal and then ground to desired texture and mixed thoroughly.The goats were weighed and allotted in a completely randomized design (CRD) into four treatments.Each treatment had five (5) goats.Diets containing cashew nut shell meal at 0% 10%, 15%, and 20% levels of inclusion were formulated (T1, T2, T3, and T4 respectively).Bamboo (Oxytenenthera abyssinica) leaves were harvested from within Kogi State University campus, the leaves were fed to the goats at 200g/goat/day.The supplement was fed at 100g/goat/day.Fresh clean water was given to the goats ad-libitum.The record of forage and supplement consumed were taken every morning.This was achieved by weighing the leftover supplement and forage before feeding them for the day.The experiment lasted for 50 days after an adjustment period of 7 days.
The scrotal morphometric measurements were taken at the beginning of the experiment and on weekly basis thereafter up to the last day of the experiment.The parameters taken were the scrotal circumference, scrotal length and scrotal weight, using a non-stretchable measuring tape and a weighing scale for the scrotal weight.The scrotal circumference was taken by placing the non-stretchable measuring tape round the scrotal sac of the bucks, scrotal length was also taken using the same method but placing the measuring tape vertically on the scrotal sac.Lastly the scrotal weight was determined by cutting off the scrotum of each slaughtered goat and weighing.Samples of experimental diets, cashew nut shell and forage were analyzed for their proximate composition using standard procedure (AOAC, 2000).The experimental design was a completely randomized design (CRD) data collected were subjected to a one-way analysis of variance (ANOVA), significant differences were separated using least significant differences (LSD), with the aid of SPSS (2006) 16.0 version.

RESULTS AND DISCUSSION
The feed intake of experimental animals is presented in Table 3.There were no significant (p>0.05)differences in the daily forage intake.Daily supplement intake and total daily dry matter intake which were both significantly affected (p<0.05),decreased steadily from T1 (94.13) to T4 (24.80) and T1 (196.95) to T4 (134.71)respectively.
The effect of the diets containing graded levels of cashew nut shell on the scrotal morphometric characteristics is presented in Table 4.The values for the initial scrotal circumference (13.50-14.50cm)were not significant (p>0.05).They were lower than (23.3-24.63cm)reported by Pant et al. (2008).The value for initial scrotal length (7.88-8.33cm)were also lower than (16.00-16.61cm)obtained by Campos et al. (2003) and were not significant (p>0.05).The differences in the initial scrotal circumference and initial scrotal length may be due to breed and age of the animal used for the experiments.The final scrotal circumference of 14.00 (T4) -15.10 (T3) obtained in this study were significantly (p<0.05)different and were lower than (26.97-30.45cm)reported by Santos and Simplicio (2000).This discrepancy could be due to the experimental diets fed as well as age and breed of the goats used.The values for the final scrotal length were significant (p<0.05), the values did not follow any definite trend.The increase in scrotal length as well as increase in scrotal circumference were slightly significant (p<0.05),however the values did not follow a definite trend.The values for the scrotal weight differed significantly (p<0.05) with T2 having the highest weight (85g) followed by T1 (70g).

CONCLUSION AND RECOMMENDATIONS
It was concluded that 10% (T2) levels of inclusion of cashew nut shell in supplement diets for goats produced the best scrotal morphometric values.Further research on the scrotal morphometric characteristics should be carried out such that the experiment should last for longer period using weaner goats as well as other species of ruminant animals like cattle and sheep.

CONTRIBUTION OF AUTHORS
OJO designed the experiment drafted the manuscript.POP and OCO collected data on feed intake and Scrotal measurements.OA provided veterinary care and weighing scales during the experiment while NJ processed the feed ingredients.All authors read and approved the final manuscript.

Table 3 : Feed Intake of Experimental Animals (DM)
Treatment means on the same row with different superscripts differ significantly (p<0.05)SEM = Standard error of means