Abstract:
This study was conducted at the goat improvement project pens (Hillat Kuku) to investigate the effect of gradual replacement of molasses of diet by groundnut hulls on ruminal environment and microbial activity, feedlot performance and carcass characteristics of the Nubian × Saanin male kids.
27 animals were randomly selected and used in the feedlot trial, 6 of them were slaughtered and used for carcass analysis, another 3 fistulated male kids were used in the degradability trial (for the 3 diets) 3 iso-coloric and iso-nitrogenous diet were formulated. The 3 experimental diet differ in the level of molasses and groundnut hulls used (50% and 10%, 40% and 20% and 30% for treatment 1, treatment 2 and treatment 3 respectively.
For the feedlot trails, the kids fed adlibitum on the three experimental diets for 2 weeks adaptation period followed by 8 weeks experimental period. Data on intakes of D.M., M.E. and C.P., body weight gain and F.C.R. were calculated. At the end of the experiment two males’ kids from each diet group were randomly selected and slaughtered to obtain the carcass data such as dressing percentage shrinkage non-carcass percentage as well as the wholesale cuts. For the degradability trials one diet was offered to the three fistulated goats for three days as adaptation period followed by four days experimental periods during which six nylon bags were incubated in the rumen of each goats to be removed after 6, 12, 24, 48, 72 and 96 hours of incubation (one bag at a time from each goat). Samples for the rumen liquor were also taken at the end of each incubation period from the three goats. The rumen pH was recorded and the rest of the samples was kept for
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bacterial and protozoan count. This method was done for three experimental diets respectively. Data such as D.M. loss% bacterial and protozoan count per ml were calculated. All the data obtained were analyzed by one-way analysis of variance.
The feedlot performance was not affected by the dietary treatment however; parameters such as final weight, body gain and intakes tended to increase by the increase of molasses and decrease of groundnut hulls. Food conversion ration values showed the opposite trend. The D.M. intake as percentage of body weight of these male kids ranged between 4.11 and 4.5% with no effect due to diet treatment. The diet treatment has no significant effect on the slaughter and empty body weight, gut fill, dressing percentage, shrinkage and non-carcass component, they showed significance in external offal’s percentage of the non-carcass component where treatment 1 and treatment 2 were similar and the two were significantly higher than treatment 3. The dressing percentage on slaughter weight basis ranged between 38.5 and 43.7% where that on empty body weight ranged between 46.4 and 52.3%.
The different levels of molasses in the diet affected significantly D.M. loss, rumen pH, bacterial and protozoan count. When molasses level decreased the D.M. loss percentage, rumen pH and protozoan count increased and bacterial counts decreased.
When the D.M. loss percentage regressed on time of incubation according the formula:
Y = a + b (1 – exp-ct)
Showed the coefficient of determination and the calculated degradability ranged between 20.6 and 30.2 at 0.02 particles per hour flow rate, 16.74 and 26.27 at 0.05 particles per hour flow rate and 40.56 and
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24.75% at 0.008 particles per hour flow rate with no significant effect due to diet treatment however it tend to decease with the increase of molasses level in the diet and also decrease with the increase of the flow rate.
The result of this study showed that the high groundnut hulls diet increase the dry matter loss and protozoan counts than the higher molasses diet. It also produced body gain and carcass weight similar to that of high molasses diet which was expensive as in term of feed cost per gram of gain. The result also concluded that the potential for meat production of Nubian ×
saanin kids is poor when compared to other types of goat