What is the most profitable way to supplement the rations of milking cows that are being rotationally grazed? There is little consensus among those who graze. Our trial this year was devised to shed some light on this question.
We split our herd into two groups in April. They were similar in age and stage of lactation. Group #1 was fed no supplemental protein or forage (hay or silage) from April 20th through September. Group #1 received 4 lbs ground corn for six weeks in the spring and 14 lbs thereafter. Salt and minerals were offered free choice.
The other group, #3 was fed to produce a higher level of production. They received more grain, from 14 lbs to 30 lbs, as the summer progressed. This grain was a 14% protein mix that included some soybean meal and cottonseed. Free choice hay was offered starting July 20th. It was also our intention to use insecticide to control flies and to bring this group into the barns, as needed, to avoid heat stress, but neither flies nor heat stress were problems this year.
Income over feed cost were remarkable similar for the two groups over the 150 days of the trial (Fig. 4).
Our trial was inconclusive as to whether the lower or higher input method of supplementing lactating dairy cows on pasture was more profitable on a per-cow basis. However, it is important to realize that there is less risk in a system that requires less daily expense to obtain the same net profit.
Too often, as total cash flow increases in higher input systems of farming, producers assume that greater gross production translates into greater profits. This perception leads to greater capital expenditures to maintain the higher input systems. The reality is that higher input systems have lower percent profit margins that are lowered even further by the cost of the capital expenditures.