Quality Roughage: The challenge with hidden benefits
The continuing squeeze on profit margins of dairy producers warrants a closer look at areas of potential efficiency improvement. One such an area is the roughage content and composition of diets for dairy cows. When nutritionists and dairy producers are asked to identify major factors that limit milk production in their herds, they often indicate roughage quality as the single most important element. Generally the uncertainty about roughage quality refers to substandard or inconsistent nutrient composition.
Typically the roughage component, on a dry matter basis, constitutes 30 to 40% of a total mixed ration (TMR) for high producing cows. The forage portion is not only responsible to maintain rumen health, but contributes significantly to the total energy, protein, fibre and mineral concentration of the diet. The nutrient concentration and digestibility of the roughage component determine the actual quantity of nutrients available for absorption from a substantial portion of the diet. It also has an impact on the ruminal and intestinal flow rates and thus influences voluntary feed intake and milk production potential.
Although the importance of forage quality is appreciated by South African dairymen, more focus and commitment should be placed on the timeous assessment of roughage quality to improve the efficiency of milk production. The perception that poor quality roughages can be ‘corrected’ by a fancy formula and a better quality concentrate is still common, but not entirely true. Even if this was the case, the cost of correcting a 40% error in the diet will be excessive and dilute profitability. The effect of poor quality lucerne on milk production is clearly illustrated in Table 1.
Date published: 2011-05-24
Dr Joubert Nolte