THE FEEDING OF DAIRY COWS ON PASTURE.

Otago Witness, Issue 3277, 3 January 1917, Page 8

THE FEEDING OF DAIRY COWS ON PASTURE.

There is a wide diversity of opinion, in the Old Land at any rate, among dairyfarmers as to the advantages or otherwise of supplying some extra food during the milking season. Some hold that the supply of grass in the spring and summer months on fairish pasture is sufficient to ensure a full yield of milk of good quality, without causing any undue strain on the constitution of the animal, and that the addition of concentrated foods adds to the cost of producing milk without giving a corresponding increase in the yield. Of course, this refers to the ordinary grazing season, as we know full well that when the supply and feeding value of the grass falls off as the season advances additional foodstuffs are necessary to keep up the milk supply, as well as the condition of the animal. Others hold the opinion that a small addition to the ordinary paddock feed is of benefit to the milking cow throughout the season. It is held by the latter dairymen that the pasturage alone, however good it may be, is insufficient to meet the full requirements of heavy milkers or newly-calved cows. It is claimed also that the giving of some concentrated fodder other than that which the cow can find in the paddocks counteracts to some extent the fall in the fat-content of the milk, which usually follows the turning out of the cows to pasture, as well as permitting the pastures to carry more stock, thus gaining certain benefits derived from manure residues as a result of extra feeding. The Mark Lane Express cites the report of a series of experiments undertaken by the West of Scotland Agricultural College in order to test the relative advantages of the different methods referred to above. The report is written by Professor Berry, F.O.C The object of the experiment was primarily to determine what would be the effect on the milk yield of giving a small daily allowance of concentrated food to cows on pasture during the summer months. . . . Both lots of cows were treated exactly alike, except that the cows in one lot received 21b of concentrated foods daily in the first month, and 41b in the second and third months of the experiment. One-half of the allowance was given in the byre at the morning milking. The cows were run on pasture clay and night with the rest of the herd. The experiment commenced in the summer of 1912, "and was continued in the two following summers. ... It

was carried out at 15 centres with a total number of 224 cows. The average effect on the milk yield of supplying the additional food to cows on pasture was to produce an increase per cow of a little under one gallon of milk a week for the first month, a little less than one and a-quarter gallons a week for the second month, and nearly two gallons a week for the third month of the experiment. The average total increase obtained during the three months amounted to between 8 and 9 per cent, of the milk-production for that period. Of this amount about 2 per cent, was obtained in the first month, 3 per cent, in the second month, and 4 per cent, in the third month of the experiment. The heavier-milking cows, seemed, on the> whole, to be more responsive to the extra feeding, though the evidence is not very clear when the results at individual centres are fully considered.

The fall in the milk yield due to the advance in lactation and gestation was slower in the case of the cows receiving the extra food, ■ and in consequence the period of lactation of the cows in question was lengthened to an appreciable extent compared with that of the cows receiving pasturage only. The difference in the rate of fall of the milk yield in the two lots of cows accounted for the increases obtained. The progressive return in milk yield produced by the concentrated foods in the latter part of the grazing season indicates clearly a falling off in the supply and nutritive value of the pasturage, or, in other words, a deterioration of its capacity for fcion. The increases, moreover, 'were achieved when most of the cows were well advanced in their period of lactation. Further, with the approach of autumn, the advent of colder nights and lower day temperature, and likewise the increasing demands of srestation also contributed to the result. Whether the additional food supplied was adequate for the best results is not proven in the present experiment. Nor doe,-; it follow that other added foodstuffs will give the same return (equal narts of decorticated cotton cake and Sova lienn cake were used in this instance). The time and extent, of the feeding may be open to modification in accordance with the requirements of local conditions.