Early grass silage tests show promising quality

Initial results from the analysis of over 1,000 first cut grass silage samples by Trouw Nutrition GB point to better feed quality than the 2014 crop, with potential on a par with the quality seen in 2013.

“These results will come as good news for dairy farmers facing a difficult season and volatile milk prices, comments Trouw Nutrition GB ruminant manager Adam Clay. “They improve prospects for the coming winter.”

 Mr Clay attributes the change to favourable weather conditions. “The better grass crops can be traced back to last winter, where the colder temperatures meant winter growth rates were lower.  Sporadic hard frosts through March and even April also prevented early grass covers from getting too heavy.  This means grass had a fresh start in the spring, covers were not excessive at harvest and there was less old material in the sward.”

The initial analyses show marginally drier first cuts than in 2014, with an average dry matter of 30.2% (29%), although there is a considerable range. 

“Typically, lower grass covers deliver silages with a lower NDF content and higher digestibility,” Mr Clay continues. “This is certainly true this year with NDF dropping from 48.3% in 2014 to 46.8%.  This directly affects digestibility and therefore ME, which has increased from 10.7MJ/kgDM in 2014 to 10.9MJ/kgDM this year.  Based on a daily dry matter intake of 10kg grass silage, this improvement in ME means cows can produce 0.4litre/head/day more from grass silage.

“The really encouraging news is that so far this year 47% of silages have analysed out at over 11ME compared to just 21% last year.  Only 23% of the forages are less than 10.5ME compared to 54% last year.  This suggests more farmers will have better quality feed.”

Protein content has improved from 13.7% to 14.2%, sugars are slightly higher at 3.5% and the average pH is 3.9.  Mr Clay suggests these factors indicate that clamp stability should be good, reducing the risk of wastage and making more feed available over the winter.

“In addition to a better average nutritional analysis, intake potential has also increased from 96 to 99.  This means cows will be more enthusiastic about eating larger quantities of silage which will be good for diet formulation.”

However, Mr Clay warns that the reduced NDF and higher sugar scores will affect acid loading on the rumen. “It will be important for herd managers and their nutritionists to take steps to optimise rumen health,” he adds.

 

               

 

 

 

 

First Cut Grass Silage Analysis 2015

                                               

 

 

1st Cut 2013

1st Cut 2014

1st Cut 2015

Min

Max

Dry Matter

%

32.4

29

30.2

16.4

54.8

Crude Protein

%

14

13.7

14.2

7

22.1

D Value

%

69

66.9

68.3

58.1

75.8

ME

MJ/kg

11

10.7

10.9

9.3

12.1

pH

 

4

3.9

3.9

3.5

4.8

NH3N

%

2.6

3

2.5

0.4

10.1

Sugar

%

2.8

3.3

3.5

0.2

9.4

Ash

%

8.4

8

8.8

5.6

11.3

NDF

%

46.8

48.3

46.8

39.3

63.9

ADF

%

30

31.6

29.1

21.3

39.5

AD Lignin

g/kg

36.7

32.5

42.8

10.9

76.6

VFA

g/kg

16.2

14.2

16.3

0.1

66.8

Lactic Acid

g/kg

61.4

66.1

62.8

6.3

130

Intake Potential

g/kg0.75

105.6

96

99.2

70.9

135.8

PAL

meq/kg

739.3

770.3

727.8

423.6

1097.7

 

 

Source: Trouw Nutrition GB