Are You Feeding Right to Your Dairy Animals?

Assessment of an Existing Dairy Animal Ration – Are You Feeding Right to Your Dairy Animals?

Whether the diet is fed in the form of a TMR or based on more traditional feeding practices involving a mixture of fresh or conserved pasture, supplemented by concentrate mixtures, it will be necessary to evaluate the ration to see whether current milk yield, rate of decline in milk yield and other indices of performance, e.g. body condition and fertility, are in line with expectations. To give a traditional example: consider a HF cow, weighing approximately 600 kg and giving an average yield of 27 kg/day. They are receiving moderate grass silage ad libitum plus 3.0 kg/day hay. A dairy cake (concentrate) is fed in parlour at 0.4 kg/kg milk in excess of 10 kg milk/ day (i.e. 6.8 kg). Using values from different standards, we can estimates DMI so that we can set down the supply of nutrients as follows.

In this calculation, MP from ERDP is assumed to be 0.64. This ration closely matches requirements for ME, which is hardly surprising since that is what it was formulated to do. MP supply is slightly but probably not significantly below requirement. However, this is only the beginning. Three questions arise at once.

‘Are the cows able to sustain milk yield on this ration?’

‘Could they do better?’

‘Could I feed them more cheaply?’

Are the cows able to sustain milk yield on this ration?

The answer to the first question may well be yes. However, if the cows are failing to sustain yield, the problem lies almost certainly with the grass silage. Either the nutritive value has been overestimated, or intake is below expectations, or probably both since silage that is poorer than expected tends to be less palatable.

‘Could they do better?’

The first limitation to milk yield in the short term is usually metabolizable protein. When MP is in plentiful supply, cows may ‘milk off their backs’, draw on body energy reserves to supplement a shortage of ME, and lose body weight. If this continues then the condition may deteriorate to the state where milk yield cannot be sustained and fertility falls. In this example MP supply is marginal so there is a case for increasing supply, most simply by increasing the protein concentration in the dairy cake. If this does achieve a significant increase in yield that justifies the additional feed costs, it then becomes necessary to monitor the cows closely for signs of a relative deficiency of ME, i.e. loss of body condition and reduced fertility.

Could I feed them more cheaply?

This question is very individual and not easy to mention its single answer. Because in India feed quality in terms of energy & protein is a major determinant of feed cost especially concentrate feeds. Margins in the case of concentrate are higher as compare to roughage. People who buy ingredients in volume and make their own feed can easily manipulate feeding and costing in their favor but those farmers who buy readymade concentrate from outside cannot bring low costing and performance in a single account. So, it is normal to include these estimates in any feed plan. The people who sell the concentrate will, in their own interests, have prepared their compound feed according to a least‐cost ration formulation. The most effective use of this information at the farm level comes at the strategic planning stage; the prime question being ‘to what extent can I achieve my output target at least cost throughout the year through best use (and choice) of home‐grown feeds?’