Mowing before grazing is a strategy sometimes used to achieve target pasture residuals with the belief that intake is increased and surplus pasture will be converted into milk.
However, neither past nor recent research supports this belief.
Past research
Earlier research compared cows grazing mown pastures versus standing pastures and reported little or no benefit to cow production, and reduced pasture growth rates. However, these studies didn't investigate the longer-term effect of mowing pastures with higher-than-recommended pre-graze pasture covers.
Recent research
DairyNZ researchers joined up with farmers, rural professionals, and university professors, to compare the outcome from grazing mown versus standing pastures at two pre grazing covers: moderate (MOD) — 2900 kilograms of dry matter per hectare (kg DM/ha) and high (HIGH) — 3500kg DM/ha.
The experiment was carried out at Lincoln University Research Dairy Farm from October 2016 to February 2017. There were four treatments (see table above right) and eight farmlets (two farmlets for each treatment), each with a stocking rate of 3.5 cows/ha. To achieve different pre-graze covers, rotation length was eight days longer (29 versus 21 days) in the HIGH compared with the MOD farmlets.
