Livestock Event 2014: Silage quality poorer than the wet season of 2012
While many silage clamps are overflowing with first-cut silage, qualities are looking as poor as those made in the wet year of 2012, when milk yields suffered.
And the key to minimising the impact on herd performance this winter is to stimulate feed intakes, as well as consider crimping cereals, say experts.
Trouw Nutrition’s ruminant manager Adam Clay highlighted that many fields were carrying higher covers because of the mild winter. Early growth was rapid, but the wet weather meant few cows were turned out in early spring and rain also delayed cutting.
See also: More from the Livestock Event 2014
“This led to a much more mature crop in spring, resulting in high volume, lower quality silage.”
Looking at the analysis of more than 1,300 samples, dry matter is 3.9% lower than last year, being a wetter crop, and his biggest concern is the lower amount of structural rather than long fibre.
Analysis shows poorer first cuts
Silage analysis conducted by North West feed company HST Feeds is also showing poorer first cuts.
On average, silage is wetter than at the same stage last season, with an average dry matter of 27.2% versus 32.4% last year, said the firm’s technical manager, Sion Richards.
Both digestibility and metabolisable energy is down. He said these results could have a big impact for dairy farmers in the north-west this autumn and winter.
“Silage containing more fibre and less energy will need to include more starch and sugars, as well as more rumen protein to help aid fibre digestion,” said Dr Richards.
“The lower energy content will mean either less milk is going to be produced, or more feed will be required to produce the same level of milk.”
“Structural fibre is needed to create the rumen mat, which is essential for good rumen function,” explains Dr Clay.
A higher lactic acid level will also add pressure on rumen health and raise the risk of acidosis.
Digestibility is lower, and so is metabolisable energy, which is even 0.2MJ/kg DM lower than the average in the wet season of 2012.
There are some positives, such as the low pH of 3.9 suggesting a good fermentation, which means it should be stable in the clamp at feedout.
The result is a grass silage with an intake potential that is lower than in 2013 and even 2012, which could prove critical this winter, said Dr Clay.
“Especially given that cows will need to eat an extra 4.1kg of freshweight just to maintain their dry matter intake and that the lower energy content means they need to consume a further 0.4kg of dry matter on top of that.”
Dr Clay estimated that milk yield potential is 0.8 litres a head a day lower than the average first cut in 2013, based on a grass silage dry matter intake of 10kg.
The key will be to stimulate feed intakes this coming winter. Roy Eastlake of Biotal suggested that mixed forages, rather than a single forage, can help increase intakes.
Short term
Those farmers still to make their second cut may consider maximising quality by taking it lower and earlier. “Traditionally, first cut was for quality and second cut was for bulk. Effectively we have got piles of cotton wool and we need to balance with better quality forages,” said Mr Eastlake.
With cereal crops approaching harvest, Malcolm Graham, nutritionist with alkalage firm FiveF, said preserved cereals could help balance the poorer grass silage.
“Many dairy farmers are now crimping a dry, mature cereal crop to produce alkagrain. Being an alkali-based preservation, acid loading is reduced,” he added.
The addition of the proprietary pellets in its production boosts the conserved feed’s protein level and allows a greater proportion of cereal to be used in the ration.
“The lower grain prices may tempt more to crimp cereals rather than sell the dried grain,” he said.
SILAGE RESULTS | |||
|---|---|---|---|
2012 | 2013 | 2014 | |
Dry matter (%) | 30.8 | 32.4 | 28.5 |
Crude protein (%) | 13.6 | 14 | 13.7 |
D value | 67.5 | 69 | 66.2 |
ME (MJ/kd DM) | 10.8 | 11 | 10.6 |
pH | 4.1 | 4.0 | 3.9 |
Intake potential (g/kg0.75) | 101 | 105.6 | 94 |
Source: Trouw Nutrition | |||
Long term
Looking ahead to this winter, including molasses can help drive intakes. But Mr Clay said feed management will be key. “Think about pushing feed up and cleaning troughs more often and look after feed mixing.”
Mark Scott of KW Feeds also suggested including a source of rumen fermentable energy, such as molasses, to drive rumen bug activity.
Moist feeds are good at improving palatability and encouraging cows to eat. “Many see them as concentrate replacers, but are as much a forage replacer,” he said.
There are several options including brewer grains, distilling byproducts and specialist mixes like a wheat feed/syrup mix.
“Brewery and distillery byproducts have a nice odour, which helps encourage cows to eat. This could prove valuable with the wetter silages with higher acid loading. Especially given that intake is king in high-yielding cows,” he said.