Advice for balancing winter rations based on latest forage analysis

Latest forage analysis results show first and second cuts are good quality with high levels of energy and protein, but farmers do need to watch out for high acid loads and lower fibre levels.

While this year has been a completely different growing season to last, results from Trouw Nutrition show that second cut and wholecrop are drier than in previous years and crude protein is higher than last year.

Total fermentable protein, total fermentable carbohydrate and metabolisable energy (ME) are high, while neutral detergent fibre and lignin are low.

Nutrient breakdown

Based on the analysis of 3,000 first-cut, 1,300 second-cut and 550 wholecrop samples, results show that quality is high.

“Anecdotally there has been a lot more wholecrop made this year,” says Trouw’s ruminant technical development manager, Liz Homer, and the increased number of samples analysed reflects that.

Therefore knowing how the forage will feed out and its digestive qualities are important. 

Nutrients

Units

First cut

Second cut

Wholecrop

Dry matter

%

32.4

37.5

45.8

Crude protein

% DM

15.4

16.6

8.7

D Value

%

68.9

67.5

66.3

ME

MJ/kg DM

11.0

10.8

10.3

NDF

% DM

46.4

46.3

41.4

Lignin

g/kg DM

27.9

27.9

50.9

Starch

% DM

24.6

Rapidly fermentable carbohydrate (RFC)

g/kg DM

201

193

196

Total fermentable carbohydrate (TFC)

g/kg DM

484

475

405

Rapidly fermentable protein (RFP)

g/kg DM

94

96

50

Total fermentable protein (TFP)

g/kg DM

113

116

56

Acid load

 

52

50

50

Fibre index

 

185

186

174

Glucogenic energy

g/kg DM

137

133

153

Source: Trouw Nutrition

Dr Homer advises considering the following, given the test results:

  • Low fibre levels could reduce butterfat synthesis because 50% of butterfat is synthesised in the udder from acetate, which is produced by fibre digestion in the rumen. Therefore, fibre supplementation is important and may be even more crucial if on a constituents-based milk contract.
  • To balance the high fermentable protein, farmers could consider supplementation with fermentable carbohydrates, but need to beware of acidosis.
  • The acid load is high (52 and 50) and fibre index is moderate, so farmers may need to use rumen buffers because 50 is the target acid load in the whole ration.
  • Starch levels in wholecrop average 24.6% DM, which is another reason to watch out for acidosis and good reason to get wholecrop analysed at an individual level.
  • Beware of the nutrient supply when feeding forage extenders, and if extenders don’t meet cow requirements, find solutions for supplementing rapidly fermentable carbohydrates and protein, glucogenic energy and balancing rumen health.

Forage stocks

While quality looks generally positive, stocks will be short on many farms, so farmers need to ask themselves how they are going to meet nutrient requirements to maintain production, says Dr Homer.

“When I say nutrient requirements, I’m looking a bit beyond ME [metabolisable energy] and MP [metabolisable protein] because we can balance that in the diet, but that’s meaningless if you haven’t got good rumen balance.”

If they haven’t already, Dr Homer stresses farmers must to do a forage budget and decide where priorities lie in terms of chasing litres or constituents and keeping the herd in good condition for turnout, so that they can feed accordingly.

What to watch out for if changing the ration due to low stocks

  • Maintain intakes. Make sure feed is pushed up, neck rails aren’t preventing feeding and keep ration consistent. Sorting could be an issue so one answer could be to add water.
  • Oil levels in by-products. If oil levels in the ration are increased due to more by-products being used, it can have a negative impact on rumen fermentability and milk quality
  • Maize inclusion in compound feeds. Many compounders are looking to maize due to wheat prices. But these are very different crops, so farmers should check with nutritionists and suppliers for specifications of compound feeds.

Managing and supplementing stocks

Adam Clay, head of technical at NWF Agriculture, says he thinks dairy farmers need to focus on three areas now:

1. Alternative forages

  • Consider alternative forages and get them analysed.
  • Ensure alternative forages are supplemented because their nutritional make-up will vary from that of grass silage.
  • Consider alternative forages for future years to reduce the pressure on the milking platform in case of future years like this.
  • Swedes, kale and turnips are options. While, you’re not going to break any records for milk yields on these standing crops, they could be good for dry and growing stock, so might be worth using early next season. Turnips could still be an option for winter.
  • Plantain and chicory might be options for an autumn or spring reseed. They are fairly drought resistant and can fill a summer grazing dip.

2. Increasing feed rates

  • Consider moist feeds and by-products to supplement the ration.
  • Do analysis, get the specification and see how the feed options fit with the needs of the stock.
  • Target feed rates as much as possible – increasing feed rates to a late lactation cow might not give the return. This adds labour but gets the most out of purchased feeds.
  • Manage rumen health when increasing feed rates. Bear in mind the rate of fermentability when increasing the application of concentrates as acidosis will reduce feed conversion efficiency.

3. Costs

  • Speak to nutritionists to predict a response to a changed ration and work out what is needed to offset that extra cost. The herd response needs to be significant enough to make the increased feed cost pay.
  • Feed price increases alone could increase costs on an average dairy farm by 1p/litre. Increased feed usage due to forage stocks could add a further 0.5-1p/litre, bringing the total to 2p/litre extra cost for winter feeding.