Feeding Concentrates to Milking Cows

New Zealand Journal of Agriculture, Volume 99, Issue 2, 15 August 1959, Page 153

Feeding Concentrates to Milking Cows

By

G. R. MOSS,

/ - . „ Instructor in Agriculture, Department of Agriculture, New Plymouth

CONSIDERABLE quantities of dairy concentrates are sold in New Zealand each year. Their place as a supplementary ration to pasture and crop is limited by their cost in relation to the returns obtained from the sale of milk and butterfat. This and such practical aspects as the type of concentrates to feed and how to buy them are discussed in this article. 'T'HE term “concentrate” is used when -®- referring to a foodstuff low in fibre but high in digestible nutrients. Most dairy concentrates are seeds or seed products such as bran and linseed meal. Other types of concentrates include molasses, buttermilk powder, and lucerne meal. The feeding of concentrates can be economic only when they are cheaper than alternative foodstuffs, where there are not enough foodstuffs available to meet the requirements of the animal, or where the foodstuffs available are lacking in quality. With the dependence on pasture' and crop in New Zealand and the seasonal type of farming so interlocked with pasture growth, there is often a time when a crop failure or an unpredicted crisis makes the feeding of a dairy concentrate a possible solution to a difficult situation. When Concentrate Feeding May Pay Concentrate feeding is most likely to pay when returns from the sale of milk are relatively high, as with town milk supply. Even for town milk, concentrate feeding should be used with discretion owing to the extra costs. Concentrates sell at between £2O and £4O a ton*, or even more for dehydrated lucerne meal and other

high - protein rations. Because of these high costs it is essential to obtain the maxi-

mum returns possible if a profit is to be made. Concentrate feeding is most likely to give the best return when: © The level of feeding without the concentrate ration is low. © The cows are still producing at a reasonably high level. @ The cows are potentially high producers.

There are two methods of feeding concentrates on New Zealand dairy farms. The more common method can be referred to as “crisis feeding”, that is, feeding for a short period during a feed shortage. The second method is to feed concentrates continuously throughout the milking season. Crisis Feeding Feed crises are most likely to occur during the first few weeks after calving or during a dry summer or severe winter. Previous training in meal feeding is helpful when a sudden switch to a concentrate is made during such a

crisis. If cows have not been accustomed to this type of feeding and refuse the ration, a substantial drop in milk production will occur. Calving normally takes place six to eight weeks before the spring flush of pasture growth. If the autumn is dry and unfavourable for growing autumnsaved pasture, it may be advisable to feed an alternative supplement until feed requirements can be met adequately from the pasture. Work at the Department of Agriculture’s Ruakura Animal Research

Station with identical twins has shown that concentrates fed after calving when the cows were not able to get their full requirements from the pasture gave a payable return. Concentrates were fed for eight weeks after calving. During the period of feeding the increase in milk and butterfat did not pay for the concentrates fed, but when returns were calculated on the basis of increased production over the whole lactation there was a substantial profit under town milk and factory supply conditions. These trials were repeated where ample feed was available from pasture

after calving. Concentrates did not then give a payable return for butterfat produc-

. . ’ tion, but there was a small profit with town milk supply. The results of these trials indicate a substantial carryover effect. Under conditions of feed shortage meal used early in lactation is more likely to give a greater return than when used later, not only because the response after good feeding will be obtained longer, but because the degree of response is likely to be greater. Carryover Effect The feeding of concentrates to only the higher producing cows in a herd

is often recommended. This may be sound advice if the concentrates are being used in a liberally fed herd, but it must not be forgotten that the profits come from the carryover effects and that these arise not only from increased levels of production but from increased lengths of lactation. In the Ruakura trials some of the largest differences in production were obtained with low producing sets of twins simply because the meal-fed members continued to produce much longer than their unsupplemented mates. An abnormally dry summer, can cause a sudden decline in milk and the premature drying off of the herd. Precautions can be taken to avert such circumstances by the use of cropping or irrigation, but many dairy farmers are prepared to take the risk. When such conditions occur, the feeding of a concentrate ration should be considered, especially if other alternative feedstuffs such as silage and good hay are unavailable or insufficient to check declining production. Many farmers make the mistake of feeding concentrates too late. If concentrates are to be used during a dry summer, they should be fed early before production drops. The dairy farmer must be prepared to feed heavily until pasture growth is adequate. Once concentrate feeding has begun it must be continued until, requirements can be fully met from pasture; otherwise there will be a sudden decline in production. Winter milk production is difficult. The basic ration for winter milk is pasture or conserved pasture. Techniques such as provision of autumnsaved pasture or special-purpose pastures in which species are included for their winter growing ability are available. Winter crops for milk production include chou moellier, swedes, and (more especially in the South Island) green cereals. Winter problems include pasture pugging and adverse conditions for feeding out supplements such as hay and silage. Concentrate feeding at this time of year can make farming easier by reducing the amount of feeding out required and can play a valuable role if a crop or pasture growth fails. In some districts where winters are severe special production allowances are paid for autumn and winter milk. Under winter conditions or any conditions which reduce the level of feeding, the solids-not-fat (S.N.F.) content of the milk may be reduced. If the average S.N.F. percentage of a herd is already low, as it may be in some Friesian herds, a further drop may reduce the level below the legal figure of 8.5 per cent for town milk. Additional feed in the form of a suitable concentrate may help to avoid such a drop and the subsequent penalty. Concentrate feeding may be fully justified on a town milk farm if it can be used to increase production during

the quota-determining period. During this period an extra gallon of milk may mean that for each day during the following season more milk can be sold at the premium town milk price. Provided the farmer is. confident of meeting the following season’s commitments, concentrates fed at this time can increase returns above the immediate benefit from the extra milk produced. When our pasture management techniques become more efficient and field practices such as drainage and irrigation are used more widely the need for concentrate feeding to meet feed crises will be less. Continuous Feeding Continuous concentrate feeding is expensive, but has the advantage that it facilitates feeding out and assists yarding and bailing of the cows. This method has the greatest appeal on farms where test bucket figures are important in the sale of stock, as with pedigree herds. The method normally used is to ration the cows individually, giving the biggest rations to the highest producers. It is common during cold, wet spells, to increase the rations in an endeavour to compensate for loss of grazing time and consequent loss of production. The biggest disadvantage of continuous bail feeding is that it increases the risk of spreading disease among stock. Tuberculosis especially can be passed through a herd using common feed troughs. The feeding of concentrates for milk production is not simply a matter of feeding a cow a definite amount of a ration to obtain an extra gallon of milk. Only a certain percentage of any concentrate feed will be digested and enter the bloodstream. Once in the bloodstream the nutrients can be drawn on for numerous purposes apart from milk production. No amount of extra feeding can increase production past a certain point. The law of diminishing returns applies to the feeding of animals as it does to the application of a fertiliser. The economics of continuous feeding of concentrates is difficult to work out in actual pounds, shillings, and pence. Under normal New Zealand conditions the method is too expensive and is not to be recommended. It is sometimes maintained that the feeding of concentrates over a season has increased production by a payable percentage over a previous season. This may be so, but all factors must be taken into consideration including climatic conditions and changes in management policies. Recent experimental work at the Rowett Research Institute, Aberdeen, failed to show any economic advantages from feeding a concentrate ration to cows well fed on intensively managed pastures. The concentrate fed during the Aberdeen trials was a dried molasses-treated sugar beet pulp.

What to Feed Under New Zealand conditions a balanced concentrate ration is not required. What is required is a supplementary ration to make up crop and pasture deficiencies. Because of this a simple concentrate ration may be suitable. Before deciding what, concentrate to feed, deficiencies should be fully considered and the type of concentrate most likely to make up a balanced ration should be bought. In a dry summer, for example, if feed available on a farm is reduced to a minimum of pasture and overmature silage and hay, the feeding of a concentrate containing a medium level of protein will give best results. On the other hand if there is a supply of irrigated pasture, lucerne, red clover, or highquality hay or silage, the supplementary concentrates need not be high in protein and a crushed grain or grain by-product would be satisfactory. In winter good autumn-saved pasture may supply all the protein requirements, and a ration at this time needs to be high in energy only. In general, the main requirement in any dairy ration is energy; protein requirements are of secondary importance. Once the deficiencies have been determined a suitably priced ration with a known feed value should be selected. Care should be taken to buy a palatable concentrate with good keeping qualities. Often concentrates refused can be made palatable to stock by the addition of molasses. Are Additional Minerals Necessary? Under normal New Zealand conditions there is rarely any need to feed supplementary minerals to milking cows. The mineral requirements, however, should be fully understood, as the dairy cow, particularly the high yielder, needs adequate supplies of lime, phosphoric acid, and chlorine. Every gallon of milk carries away i oz of lime, J oz of phosphoric acid, and 1/6 oz of chlorine. If the diet contains insufficient quantities of lime and phosphate, the amounts needed for milk production must be drawn from the bone reserves and this, if prolonged, leads to a decline in bodily condition and ultimately to a reduced milk yield. This should present no problem provided the calcium and phosphorus in the soil are kept at a desirable level (by topdressing if necessary) and stock are normally healthy. The local Instructor in Agriculture can be asked to take soil samples for laboratory analysis to check the calcium and phosphorus level of the soil and advise any necessary readjustment of the topdressing programme. There is more than adequate chlorine in pasture to meet the milk

ing cow’s needs. If for some reason the intake of grass is reduced, a small quantity of common salt, say 1 lb to every hundredweight of concentrate, could be added. Soil deficiencies in such minor elements as copper, cobalt, and iodine can affect stock health in New Zealand. However, if a herd is thrifty, the problem of a minor-element deficiency need not be considered. Most of the soils deficient in essential minor elements are well known to local Departmental advisory officers, who can make specific recommendations where necessary. How to Purchase It is not easy to compare feedstuffs, because there are so many factors to be considered such as price, palatability, suitability for long storage, whether material needs treating, and so on. The best measure of the relative productive value of feedstuffs is their energy value and protein level. The energy value of any feedstuff is referred to as the starch equivalent (S.E.). The starch equivalent is the unit used by British countries as a guide to feeding value. Bran, for example, has a starch equivalent value of 40. This means that every 100 lb of bran fed would be equivalent in productive value to 40 lb of starch. Comparative figures for feedstuffs can be obtained by dividing the price per ton by the starch-equivalent figure. For an actual example of bran at £2l per ton and barley at £25 the position would be: Bran costing £2l a ton has a starch equivalent value of 40. 4205. _ . ' . 40 unit Barley costing £25 a ton has a starch equivalent value of 71. 500 s. _ 71 unit At these prices barley is the cheaper food.

TABLE I—UNITS OF ENERGY AND DIGESTIBLE PROTEIN IN 100 LB OF FEEDSTUFFS (TYPICAL FIGURES)

Starch equivalent (energy Digestible value) protein n . lb lb Barley . . . . 71 75 Bran .. .. .. 40 Brewers’ grains (dried ) 48 13 Coconut meal .. 74 15 Copra oil meal .. 75 16 Hay (good) , . . .40 8.5 Hay (average) ..30 ' 4 5 Linseed cake . . 73 25 Maize .... 77 7.5 Molasses . . . .52 10 Oats 6o 7'5 Peas .... .. 70 18 Wheat .. ..71 7.5

The data given in Table 1 show that barley, wheat, and maize, if of good quality, will supply 75 per cent more energy per unit of weight than New Zealand bran. The food value of bran

is no better than that of . good hay. (New Zealand pollard is only slightly better than bran.) The cereals barley, wheat, maize, and oats are low in protein. Copra and peas have a moderately high protein content, linseed cake is a rich source of protein, and all three have a high energy value. The cereals are low in calcium and vitamin D (except yellow maize), but are rich in phosphorus. Bran is perhaps one of the richest sources of phosphorus of the common feeds, but is low in. calcium, vitamin A. and vitamin D.

TABLE 2—PROTEIN LEVELS IN COMMON FEEDSTUFFS

High Medium Low Buttermilk (dried) Beans Barley Linseed Brewers’ grains Bran" Skim milk (dried) Coconut meal Maize Meat meal (rarely Copra . Molasses used in dairy Lucerne meal Oats rations due to (good) Wheat unpalatability) Peas Seed offal Sweet lupin

meal Proprietary Dairy Rations Normally, the only information available to the purchaser of a proprietary dairy ration is the price, the list of ingredients (not the percentage of ingredients), and the chemical analysis. Care should be taken when comparing chemical analyses, as these can be misleading as a measure of feeding value. The percentages of carbohydrate and protein in a first-class dairy ration and in dung or old boot leather may be similar. The carbohydrate figure in the chemical analyses gives no indication of digestibility. The protein figure given is a measure of crude protein and this figure is higher than the true protein level and the digestible-protein level. However, as there is no alternative protein figure available, it serves as the only basis for the comparison of protein levels. If it is possible, find out the actual percentage of ingredients in a proprietary ration. Then the total starchequivalent value and the digestibleprotein levels can be calculated. However, as the percentages of the ingredients of most proprietary dairy rations are not available, it is usually impossible to estimate the feeding value. If the ration has not been finely ground or pelleted, an experienced farmer may be able to judge the approximate percentage of the various ingredients and to estimate the feeding value. Because of these facts it is virtually impossible to make a comparison between the food value of two different proprietary rations at different prices. Under the Stock Foods Act dairy concentrate rations must comply with certain standards. There are clauses in the Act for the protection of the purchaser. For example, section 5, clause 1, states: 5. (1) Subject to the provisions of this section, every vendor shall, at the time of the

'■sale by him of any stock-food, or as soon . thereafter as is reasonably practicable, deliver or post to the purchaser an invoice containing the following particulars: (a) The name of the vendor and the name of the place in which the vendor carries on business: (b) The name of the stock-food and the trademark (if any) used in respect thereof: (c) The number of packages (if any) of the stock-food comprised in the sale: (d) The gross weight of each package of stock-food comprised in the sale: (e) Where the stock-food contains more than one ingredient, the name of each of the ingredients: (f) Such particulars of the chemical composition of the stock-food as are specified in the second column of the First Schedule to this Act in relation to the class, as specified in the first column of that Schedule, to which the stock-food belongs. Main Points 0 As concentrate feeding is expensive, a high standard of management is necessary to ensure a profitable return. @ A farmer should consider all aspects before feeding concentrates on a . \ a: fS e scale. This includes the possibility of increasing disease. e 0 Under the New Zealand grassfarming system balanced concentrate rations are not required, but rather supplementary rations to make up crop and pasture deficiencies. A simple concentrate ration is generally sufficient. © In general, the main requirement is energy; protein is rarely important for milk production. © Purchasing should be done mainly on food value, using the starchequivalent system. @ Unfortunately, there is a lamentable lack of information about the feed value of many proprietary dairy rations and their ingredients. The Future In many overseas countries concentrates form a major part of the animal diet, but in New Zealand their role is a very minor one. When dairy farming becomes intensive because of a substantial increase in population, there may well be a swing toward more concentrate feeding, especially on town milk farms close to large cities. References “Concentrate Feeding of Dairy Cattle”, L. R Wallace, “Proceedings of the 1957 Ruakura Farmers’ Conference”, published by the Department of Agriculture. _ Concentrate Feeding in a Dry Summer”, Professor I. L. Campbell, “Massey Agricultural College Dairyfarming Annual 1955”. “Rations for Livestock”, H. E. Woodman, Bulletin No. 48, British Ministry of Agriculture and Fisheries. “Journal of Agricultural Science”, 51 :95 (1958), J. L. Corbett and A. W. Boyne.

• The grain and meal ton Is die short ton of 2,000 lb, not 2,240 lb.