Feeding value of wild Napier grass (Pennisetum macrourum) for cattle supplemented with protein and/or energy rich supplements

Two experiments were conducted to evaluate the feeding value of Pennisetum macrourum, commonly known as wild Napier grass, as a feed for cattle. Experiment 1 was a nutritive value determination using four crossbred steers and four diets in a 4×4 Latin square design experiment. The four diets were: wild Napier grass + mineral/vitamin mixture (WN), wild Napier grass + 0.5 kg fishmeal + 0.5 kg maize bran + mineral/vitamin mixture (MB+FM), wild Napier grass + 0.5 kg molasses + mineral/vitamin mixture (MO) and wild Napier grass + 0.5 kg fishmeal + 0.5 kg molasses + mineral/vitamin mixture (MO+FM). Wild Napier grass contained 668, 256 and 78 g/kg DM of NDF, ADF and CP, respectively. The DM intake (67.9, 118.9, 96, 132.9 g/kg for animals on WN, MB+FM, MO and MO+FM, respectively) differed (P<0.05) among diets. Metabolizable energy (ME) intake increased (P<0.05) from 17.6 to 32.7 (MJ per day) for steers on diets WN and MO+FM, respectively and N retention was increased (P<0.05) from 7.6 to 51.5 g per day in diets WN and MO+FM, respectively. N absorbed was more efficiently retained (P<0.05) with MO+FM supplements. Experiment 2, used 16 milking cows fed on similar diets to Experiment 1 in a completely randomized experiment. DM intake differed (P<0.05) among diets, except between BM+FM and MO and ranged from 6.3 to 8.7 kg in diets WN and MO+FM, respectively. All cows lost weight, with those on MO diet losing (P<0.05) the most weight. Milk yield differed (P<0.05) among diets ranging from 7.8 to 15.5 kg per cow per day for cows on WN and MO+FM, respectively. Although steers and cows performed better when supplemented with FM, its high cost suggests that feeding of molasses as an inexpensive source of fermentable carbohydrates in the rumen may be recommended as it results in adequate performance.