Mineral Status in Cattle Fed Rice Straw and Para Grass Combined with Different Levels of Protein Derived from Cassava Foliage

Eight male cattle of the Local Yellow breed with an average live weight of 121 kg and an average age of 18 months were used to evaluate the effects of different levels of sun-dried cassava (Manihot esculenta) foliage supplementation on mineral metabolism in growing cattle fed rice straw and para grass as basal diet. Rice straw ad libitum and para grass (Brachiaria mutica) at 1% DM of BW comprised the basal diet. The study was arranged as a 4×4 double Latin square design, with cassava foliage contributing 0, 0.8, 1.6 or 2.4 g CP/kg BW. The cassava foliage intake was lower than the planned levels. DM consumption was significantly affected by cassava foliage supplementation, with the largest intake observed at the two highest levels of cassava foliage supplementation. Rice straw intake showed the opposite pattern, with lower intake at higher cassava foliage supplementation. No refusals occurred for para grass in any of the treatments. Ca, P, Mg, K, S and Mn intake increased significantly with increasing intake of cassava foliage, but Na intake was not affected by treatment. Faecal excretion of Ca, Mg, S and Mn increased significantly with increasing cassava foliage intake. There were no differences between P, K and Na excretion in faeces. There was a significant diet effect on Mg, S and Mn digestibility. Mg and Mn digestibility increased with increasing cassava foliage supplementation, while S digestibility decreased. Ca, P, K and Na digestibility was not affected by diet. There was a significant effect of treatment on P retention, with the highest value observed for supplementation with 1.6 g CP/kg BW cassava foliage. Ca and Mg showed similar trends, with the highest retention again for supplementation with 1.6 g CP/kg BW cassava foliage. There were weak but significant positive correlations between nitrogen retention and the macro minerals Ca, P and Mg. Furthermore, retention of all these minerals was positively correlated. Mineral losses in urine were not affected by dietary treatment with the exception of P excretion, which was affected by treatment. In conclusion, cassava foliage is a good Ca source which compensates for the low Ca content in rice straw and para grass, but P deficiency appears to be exaggerated in cattle with higher cassava intake. The results suggest that under these conditions growing cattle on a high cassava intake would benefit from P and S supplementation

Feed Intake, Digestibility, and N Retention in Cattle Fed Rice Straw and Para Grass Combined with Different Levels of Protein Derived from Cassava Foliage

Eight male cattle of Local Yellow breed with an average live weight of 121 kg and an average age of 18 months were used to evaluate the effects of different levels of sun-dried cassava foliage supplementation (Manihot esculenta) on intake, digestibility and N retention. Rice straw ad libitum and para grass (Brachiaria mutica) at 1% DM of BW comprised the basal diet. The study was arranged as a 4×4 double Latin square design, with cassava foliage contributing 0, 0.8, 1.6 or 2.4 g CP/kg BW. The cattle selected cassava leaves in preference to petioles. Petiole intake decreased from 64 to 48% of offered petioles when the cassava foliage proportion increased from the lowest to the highest level. The cattle consumed all the leaves at the two lower levels of cassava foliage inclusion and 91% at the highest level. Rice straw intake decreased significantly as the level of cassava foliage increased. Intake of DM, OM, NDF, and ADF increased significantly with increasing intake of cassava foliage. Daily DM intake per 100 kg BW increased from 2.7 to 3.2 kg with increasing cassava foliage intake. No effect on CP digestibility was detected when the level of cassava foliage increased. Digestibility of DM, OM, NDF and ADF was significantly higher in the group fed no cassava foliage than in the other groups. N retention increased from 16 to 28 g/d with the first level of cassava foliage inclusion, but levelled out at the two highest levels. N excretion increased in both faeces and urine as a response to higher intake of cassava foliage. Maximum N retention occurred when 40% of total N intake came from cassava foliage (equivalent to 1.3 g CP/kg BW)

Partial replacements of Stylosanthes scabra forage for lucerne in total mixed ration diet of Saanen goats

The inclusion of Stylosanthes scabra cv. Seca forage in the total mixed ration (TMR) as partial replacement of lucerne (alfalfa) was evaluated for its effects on voluntary feed intake, nutrient digestibility and nitrogen balance in Saanen goats. Three experimental diets were formulated having 0 % Seca (T1), 15 % Seca (T2) and 30 % Seca (T3) as partial replacement of lucerne forage in the TMR diet for goats. Eighteen Saanen goats of about 7 months old were divided into three groups of six animals per group. Each group was randomly assigned to one of the three dietary treatments in a complete randomised design, and the study lasted for a period of 21 days. There was an increase in fibre and mineral content of the diets as Seca inclusion increased, but this resulted in the decrease of crude protein contents and in vitro organic matter digestibility. Animals that were fed 15 % Seca recorded higher voluntary dry matter and nutrient (organic matter and fibres) intake, but the difference was not statistically significant (P>0.05) as compared to the other treatments. Nutrient digestibility as well as nitrogen balance was not significantly different across the three diets. The lack of significant differences in feed intake, nutrient digestibility and nitrogen utilisation following the inclusion of Seca in the TMR suggests that S. scabra forage can partially replace lucerne in the TMR diet of goats.Gauteng Department of Agriculture and Rural Development (GDARD) and National Research Foundation (NRF).http://link.springer.com/journal/112502016-10-31hb201