Many dairy farmers will face a challenge in getting cows to eat enough grass silage this winter, but according to Promar principal consultant Emma Thompson there are several steps which can be taken to address the issue.
The initial analysis of more than 1,400 first cut silages by Trouw Nutrition shows crops are wetter, with higher fibre levels, and together these factors can reduce intake potential.
Promar principal consultant Emma Thompson says: “The lower dry matter means cows will need to eat more of this year’s crop just to achieve the same dry matter intake as last year.
“If cows are expected to eat 12kg DM of silage a day, they will need to consume an additional 5kg fresh weight of this year’s silage on average, compared to last year, to achieve the same DMI. For a 200-cow herd, that is an extra tonne of silage a day.
“While many farms are reporting excellent stocks of first cut, so having the extra silage to feed may not be an issue, the problem is the intake potential of silage is lower, meaning cows may be reluctant to eat as much, let alone more silage.”
Mrs Thompson says the lower dry matter and higher fibre have combined to reduce intake potential by 10 per cent compared to last year.
“Farmers will need to concentrate on encouraging cows to eat more forage and this will come down to two factors.
The first will be giving cows the desire to eat, making feed as attractive and palatable as possible. The second will be to give them the opportunity to eat, which is a function of accessibility and time.”
The starting point must be to ensure all forages yet to be harvested are made as well as possible.
“In a mixed forage system it will be possible to influence the attractiveness of the total forage portion, masking the lower intake potential of first cut. Make sure third cut grass and maize are made as well as possible.
“To improve overall attractiveness, ensure any spoilt silage is discarded and not fed. A small proportion of mouldy or butyric silage can taint the whole feed and cows will reject the diet. Cows have an acute sense of smell and will discard any tainted feed. For this reason it will also be important to keep troughs clean and to regularly remove left-over feed, which can spoil the quality of fresh feed placed on top of it.
“Feeds such as molasses can improve the palatability and overall quality of the mix, which will be essential to avoid sorting.
“With high fibre grass silage, it will be vital to feed sufficient rumen fermentable energy to ensure cows can digest the diet and have good rumen throughput to stimulate appetite.
“But care must be taken to avoid including too much starch and rapidly fermentable energy or you run the risk of acidosis, which will suppress appetite.”
Mrs Thompson says giving cows the maximum opportunity to eat is also vital, and this is mainly a factor of facilities and time.
She says cows need to eat for about five hours a day, typically made up of eight to 12 feeds. Anything which prevents this happening will reduce intakes and yields.