ABSTRACT
The study was conducted to evaluate the effect of varying NPK 15;15:15 levels on the forage yield and quality of Brachiaria ruziziensis and performance of Yankasa rams fed different ration of the forage and Concentrate in a total mixed ratioin the Northern Guinea Savanna of Nigeria. The experiment was laid in a randomized complete block design (RCBD) in a 4x3 factorial arrangement comprising of four rates (0,20,40 and 60 kg/ha) of NPK 15:15:15 replicated three times and age of harvest were 10,12 and 14weeks after sowing. The growth components showed that plant height (74.9 cm) and leaf length (33.3 cm) were significantly (P<0.05) higher at 60kg/ha and 40kg/ha, respectively.Number of tillers (23) weremore (P<0.05) at 12 weeks after sowing (WAS). Varying fertilizer levels significantly (P<0.05) affected fresh forage yield with the highest value (15.8t/ha) recorded at 60kg/ha. Age of cutting also had significant (P<0.05) effect on both fresh forage and dry matter yields. The highest fresh weight yield (16.3t/ha) was recorded at 12 weeks after sowing (WAS) where as dry weight (4.3t/ha) was recorded at 14 weeks after sowing (WAS).Proximate compositions ofcrude protein, crude fiber and nitrogen free extract were significantly (P<0.05) affected by the varying levels of fertilizer, whereas Dry matter, crude protein, crude fibre, ether extract, andnitrogen free extract were significantly (P<0.05) affected by age of cutting. The highest DM (94.3%), CP (8.99%) and CF (39.39%) were recorded at 10, 12 and 12 weeks after sowing (WAS), respectively. ether extract (7.88%) and ash (7.67%) were significantly (P<0.05) higher at 12 weeks after sowing. Calcium content of the forage and Calcium (Ca): Phosphorus (P) ratio were significantly (P<0.05) affected as the level of fertilizer application varied with 60kg/ha rate recording the highest percentage (1.62%) and ratio (6.23:1), respectively. Calcium (Ca), Phosphorus (P) and Ca: P ratio were similar (P>0.05) at different cutting intervals. It can be concluded from the result of this study that NPK 15:15:15 compound fertilizer rate 60 kg/ha on Brachiaria ruziziensis gave the better forage yield, Crude protein was higher when harvested at 12 weeks after sowing, mineral composition (Ca and P) was also optimum. Therefore, NPK 15:15:15 rate of 60 kg/ha is recommended for higherBrachiaria ruziziensis forage yield and nutrient composition for smallholder farmers and livestock owners. In the Second experiment a feeding trial which lasted for (12) weeks was carried out to determine feed intake, nutrient digestibility and nitrogen balance of growing Yankasa rams fed different mixture of Brachiaria ruziziensis/concentrate in a total mixed ration. Sixteen healthy Yankasa rams with an average live weight of 21.75kgÂ1kg were randomly allocated to four treatments with four replicates in a Complete Randomized Design (CRD). The treatment diets were ratio of Brachiaria ruziziensis to concentrate: (90:10), (80:20), (70:30) and (60:40)mixtures. Feed intake (57.19kg), Daily feed intake (635.48g/day), Average daily gain (61.11g/day), and feed conversion ratio (10.47) were significantly higher (P<0.05) in animals' fed (60:40) ratio of B.ruzizienss to concentrate mixture and showed a decline across the treatments as the quantity of concentrate inclusion in the mixture decreased. Feed conversion ratio (10.47) was significantly (P<0.05) lower in animals fed (60:40) ratio of B.ruziziensis to concentrate mixture. The DM, OM, CP, CF, EE NFE and ADF digestibility showed significant variation (P<0.05) across the treatments. The Crude protein digestibility (CPD) was significantly (P<0.05) higher (84.25%) in (60:40) ratio B.ruziziensis to concentrate mixture while the least value of 76.12% was recorded in rams fed viii B.ruziziensisto concentrate mixture (90:10) ratio. Nitrogen intake, nitrogen absorbed, nitrogen retained and absorbed as percentage of intake (61.28%, 59.16%, 57.58%, 93.75% and 96.48%) respectively were significantly higher (P<0.05) in animals fed (60:40) ration. Rumen pH (6.80), TVFA (Total volatile fatty acid) (44.87 Mmol/100ml), Rumen Ammonia nitrogen (NH4-N) (16.18 mg/100ml) significantly (P<0.05) differed across the treatments and animals fed (60:40) ratio of B.ruziziensis to concentrate mixture ratio recorded the highest value. It can be concluded from this work that feeding Yankasa rams with 60:40 ratio of B.ruziziensis to concentrate mixture in a total mixed ration improved digestibility, utilization resulted in the highest weight gain (5.5kg) and highest revenue (â‚Â4887.7). Feeding of B.ruziziensis to concentrate at a ratio of 60:40 in a total mixed ration is hereby recommended for smallholder farmers and livestock owners in the Northern Guinea Savanna of Nigeria.
