Agriculture

Forage Quality and Dairy Ration Cost

The forage analysis summary from Norwest Labs for 1996 shows that hay quality is down somewhat from last year. Although there is little difference in crude protein content, acid detergent fibre (ADF) values in 1996 are several percentage points higher, reflecting a more mature crop at harvest. ADF levels are negatively correlated to energy levels.
It is interesting to note that although differences are found between 1995 and 1996 hay samples, no differences in silage analyses between these years were noted. It is also interesting to note that ADF levels were lower and CP levels were higher in forage put up as silage rather than hay. This indicates a crop harvested at an earlier stage of maturity - very likely due to a harvest less dependent on weather.
What impact does forage quality have on the cost of dairy rations? The following table shows forage quality can have a major impact on the cost of producing milk - especially at high levels of production.
 
 
50 lbs milk/day
80 lbs milk/day
LQ*
HQ**
LQ
HQ
Hay
28
35
23
25
Barley
20
15
21.5
23
Canola meal
1.5
--
7
4
DDG - corn
--
--
3
3
Tallow
--
--
1
--
Minerals / Vitamins
0.6
0.6
0.65
0.65
% CP (100% DM)
14
15.4
17
17
NEL (mcal/kg) (100% DM)
1.5
1.5
1.65
1.65
% Concentrate
45
32
60
56
$/100 lbs milk
3.67
3.48
3.49
3.12
* LQ = low quality hay (14% CP, 1.19 mcal NEL/kg, DM basis) ** HQ = high quality hay (17% CP, 1.43 mcal NEL/kg, DM basis)
 
Nutrition Update Volume 7 No.4, February 1997