Can lucerne deliver for your cows?

Published 9 October 15

Dairy farms suited to growing lucerne should consider it as an option when feeding their dairy cows, according to Dr Stephen Whelan R&D manager at AHDB Dairy.

Dairy farmers around the world are already familiar with feeding their cows lucerne, and now those in the UK are also starting to pay attention to the advantages of the crop. It is drought tolerant, can be harvested multiple times, which helps spread the work load, and does not require nitrogen, saving on inputs. Farmers can also include it instead of grass silage in the cow’s diet, without impacting on animal performance, according to findings of the latest AHDB Dairy-funded research.

AHDB Dairy Research Day, Attleborough

To find out more about including lucerne in the diet of the dairy cow, come along to AHDB Dairy’s Research Day at Hall Farm, Attleborough, Norfolk on Thursday 29 October, and speak with Professor Chris Reynolds.

The work, carried out at Harper Adams University (HAU) and the Scottish Rural University College (SRUC), examined what would happen when lucerne silage replaced grass silage in the diet of dairy cows. The cows received various portions of grass silage, lucerne silage and maize silage, as outlined in Table 1 below, with diets formulated to contain similar levels of energy (12MJ ME/kg DM) and protein (176g CP/kg DM).

Table 1. Ingredient inclusion rate of diets, animal performance and feed costs

 

HAU

SRUC

 

Control

LS1

LS2

LS3

Control

LS1

LS2

LS3

Ingredients (g/kg DM)

 

 

 

 

 

 

 

 

Grass silage

222

111

0

0

574

431

287

144

Lucerne silage

0

111

222

333

0

144

287

431

Maize silage

331

332

332

222

0

0

0

0

Energy concentrate

297

303

308

316

363

373

392

415

Protein concentrate

142

138

129

119

67

43

22

0

 

 

 

 

 

 

 

 

 

Animal performance

 

 

 

 

 

 

 

 

Intake (kg DM/day)

24.5

24.9

24.5

23.4

19.8

21.2

23.4

24.6

Milk yield (kg/day)

42.2

40.7

40.2

40.5

32.0

32.0

32.7

33.2

 

 

 

 

 

 

 

 

 

Feed costs

 

 

 

 

 

 

 

 

£/kg milk

0.11

0.12

0.12

0.11

0.11

0.12

0.14

0.15

£/kg fat and protein

1.53

1.67

1.69

1.51

1.57

1.71

2.00

2.14

 

So how did the animals perform on these diets? The table shows that at HAU, lucerne replaced grass silage in LS1, LS2 and LS3. However, in LS3, maize silage was also reduced. This reduced intake in those cows by 1.2kg DM/day. At SRUC, lucerne replaced grass silage only and intake was increased with higher inclusion rates of lucerne. Despite the differences in intake, lucerne inclusion did not affect milk production.

The similarities in milk production would be partially expected at HAU, given how close the diets were in energy and protein content and the small difference in intake.

However, at SRUC the failure of milk yield to respond to higher intake, reduced the efficiency of milk production and increased the feed costs/kg milk. This may be due to the lower digestibility of the lucerne-based diets at SRUC, which means that as intake went up, the amount of energy and protein available to the cow to produce may have been similar.

For both studies, the results were highly dependent on the quality of the lucerne itself and of the forage it replaced. Where lucerne is included, farmers should carefully reformulate the ration to account for the higher protein content of the forage.

Farmers who are considering growing lucerne next year can find out more information on the establishment of the crop by looking at AHDB’s Growing and Feeding Lucerne.