Muya M.C., Nherera R.V., Khekana T., Ramapuptla T.
Animal Production Institute, Agricultural Research Council, South Africa; Department of Agriculture, Forestry and Fisheries, Pretoria, South Africa
Muya, M.C., Animal Production Institute, Agricultural Research Council, South Africa; Nherera, R.V., Animal Production Institute, Agricultural Research Council, South Africa; Khekana, T., Department of Agriculture, Forestry and Fisheries, Pretoria, South Africa; Ramapuptla, T., Department of Agriculture, Forestry and Fisheries, Pretoria, South Africa
This study was done to evaluate the effects of restricting Total Mixed Ration (TMR)and supplying Eragrostis curvula and Medicago sativa hay mixture adlib on lactation performance of mid-lactation multiparous Holstein cows. Twenty Holstein cows, averaging 598±73 kg body weight and 100 days in milk were assigned to either a 100% TJ\1R diet (control) or a 75% TMR-restricted diet. Cows on the 75% TMR-restricted diet had adlib access to E. curvula and M. sativa hay mixture (1: 1). The experiment included 2 weeks adaptation period and 4 weeks samphng period. Cows were milked twice daily. Total Dry Matter Intake (DMI), DMI as BW%, daily CP intake and intake of net energy for lactation were higher (p<O.05) for cows on the 100% TMR than for cows on the 75% TMR. Cows in 75% TMR consumed 12.5% less total DM and 14.2% less kg DM as of BW% than cows ni 100% TMR Intake of NDF was not affected (p>0.05) by treatment. Milk yield, milk fat% and yield (kg day-1) did not differ between treatments and averaged 29.2 kg day-1,3.70% and 1.08 kg, respectively. Feed efficiency ranged from 1.22-1.37 and tended to be higher (p<0.10) with 75% TMR diet. Efficiency of nitrogen and phosphorous utilisation was not affected (p>0.05) by treatments. Results suggest that TMR restriction to 75% during mid-lactation does not negatively impact milk production. © Medwell Journals, 2011.