FEEDING EFFECTS

Waipa Post, Volume 38, Issue 2270, 19 February 1929, Page 2

FEEDING EFFECTS

QUALITY AND QUANTITY

Do certain balanced dairy rations give rise to either a lower yield of milk or to milk deficient in solids or fat? Among some dairy farmers the ' opinion appears to be held that they [ do, says an English exchange, although the rations are properly balanced from the point of view of protein and starch equivalent. Experiments have been conducted on a farm in Gloucestershire to ascertain if changes were actually brought about in the quantity of milk in consequence of feeding balanced mixtures of different composition. The conclusion they pointed to was that correctly balanced foods do not seriously affect the yield or composition of milk.

The cattle were high-yielding pedigree British Friesians, this type being considered likely to be more responsive to changes in rations than moderate yielders. They were fed on six different balanced rations at various times and their yield contrasted with that of control cows fed throughout on the same mixture.

The yield from cows fed on a maintenance ration of 201 b, good hay and a production ration fed strictly according to milk yield varied slightly from day to day, but the variation appeared to be a function of the individual, or due to some external condition, and could not be corelated with a change in the rationing. No corelation could be traced between a change of ration and variation of the butter-fat content, and it would appear that 9 per cent, of oil in a ration does not affect the butterfat yield. Great variations did occur in the fat yield of individual cows, but these variations usually occurred in both groups of cows, indicating that they were the result of some factor other than the ration. These are, however, slight indications that a ration with a high content of oil will depress the butter-fat content. It is hoped to study this point in more detail —using balanced rations with an oil content of over 12 per cent. The solids not fat content of milk from cows fed on balanced rations appeared to be much less variable than the fat, and here again the variations occurred with cows on the standard rations as well as those on changing rations, indicating, as with the fat content, that some external factor or factors, were responsible. From the results obtained it appears that, provided the rations are balanced from the point of view of starch equivalent and protein content and the constituents of the ration are such as not to cause digestive trouble, they will not seriously affect the yield or composition.