11 AUGUST 2016
Following a brief summer and a temperamental spring, analysis of first cut silages for 2016 has returned some variable results. With slow grass growth and poor conditions in spring, late turnout resulted in a delay of first cuts being taken in many instances. In addition to this, the opportunities to get first cuts done were both brief and sporadic. The ‘miracle’ week of hot weather in May allowed many to get an early first cut, but for those whose grass wasn’t ready, conditions were more difficult until further into the season.
The analysis of 1st cut 2016 silages has shown an average Dry Matter (DM) of 31.7 percent (2.8 lower than 2015), with a range of 19.2 - 50.8 percent. The majority of samples fit between 25-35 percent DM.
An average ME of 10.83MJ/kg DM is down by 0.02 compared to 2015, which is in line with the national average for this year, but lower than the 11MJ/kg DM in 2015. This could represent an average yield loss from forage of around 0.5 litres per cow per day. This year, 85 percent of samples had an ME between 10 and 11.5MJ/kg, compared to just 75 percent in 2015; however 2015 had a higher proportion of silages with an ME of 11.5MJ/kg and over.
Lactic acid content is also lower than 2015, (51.9g/kg compared with 40g/kg) which is also reflected in a higher pH, and may be a result of the increased dry matter. This should lead to a reduced level of acid loading in the rumen. The average pH of 4.2 indicates there may be potential issues with clamp stability, heating and wastage.
The presence of trace elements was lower across the board in 2016 compared to 2015, with the exception of potassium which was significantly higher. The Cation-Anion Balance was 24.3% higher this year at 471meq/kg compared to 356meq/kg last year. A high DCAB is no problem for cows in lactation, but in a transition diet a high DCAB value can predispose calving cows to milk fever.
Adequate supplementation of forage with appropriate moist feeds and concentrates to formulate a balanced ration is crucial to cow performance. Ration formulation and mineral nutrition can be advised to suit your system by a member of the ruminant sales team.
Contact Dugdale Nutrition for more information on 01200 420200.