STOCK FOODS.

Press, Volume LXVIII, Issue 20612, 30 July 1932, Page 8

STOCK FOODS.

THEIR COMPARATIVE VALUE. CHAMBER OF COMMERCE BULLETIN. Bulletin No. 37, issued by the Canterbury Chamber of Commerce, and prepared by Lincoln College, deals with the question of stock foods, ns follows: When stock feeds are abundant, little consideration is given to their relative values. Year after year, however, there is a period of scarcity, and during that time much thought is devoted to the problem of feed supply. The following information is supplied in the hope that it will provide the basis of a better understanding of the problem in the future. Stock feeds are composed of six main ingredients, water, protein, ash, fafc, fibre, and carbohydrates, all of different digestibilities and of different values to the animal. Tables of cliemreal composition alone give insufficient information, to the «tock feeder, but

if it were possible to express chemical composition, digestibility, and energy value in a single figure, comparison would be much easier. Starch Equivalents. These single-figure values, called starch equivalents, are given in a table below. All feeds arc compared with starch, since that is the commonest food, making up as it docs the bulk of wheat, oats, and other grains. "Starch equivalent" is defined as the number of pounds of starch that have the Same fat-producing capacity as 100 pounds of the particular feeding stuff, taking into account the composition, digestibility, and availability of the ingredients. The calculated values agroc closely with those obtained in feeding trials. For the purpose of using feedstuffs a knowledge of starcli equivalent, dry matter, digestible crudo protein, and ' V numbers is required. ''V" numbers are the percentages of total digested energy that the animal can uso for growth purposes. These percentages depend on the proportion of fibre present; when there is no fibre, V equals 100 ajs in milk; when there is considerable fibre. V may be as low as 40 as in straw. The remaining 60 per cent, of the digested energy can be used only for the production of body heat, and in winter such heat energy is a very desirablefeature of the ration This heat-pro-ducing energy is not included in the starch equivalent value, so that feeds with low V numbers are more valuable for maintenance purposes than their starch equivalent indicates. V numbers mark the division between feeds that can be used for growth purposes and those that Can be used for main-tena-nce. Where the V number is greater than 50, the feed is suitable for growth, below 50 for maintenance only. The following table gives the standard value for dry matter and digestible protein contents, as well as starch equivalents and V numbers of the commoner foods:

Limitations of Starch Equivalents for Mixing Rations. It is well known that feeds are not interchangeable pound for pound. It must also be stated quite definitely that they are not interchangeable on equal amounts of starch equivalent. A balanced ration has three essential features. It must supply* the correct amount of bulk—excess and deficiency are both undesirable. It must supply sufficient protein and sufficient starch equivalent. A slight excess of these does no harm. When these three are adjusted to suit the animal, the figures in the column ./'starch equivalent" in Table T. can Ik? used to compare foods on a cash basis. Thus, 301b of straw and 101b of oats each supply 61b of starch equivalent, but have "not the same feedinc value nor asjain can 71b of oats be replaced by 61b of bgrtey, although the starch equivalents of both these two amounts are identical. Used pronerlv linseed has twice the value of oats per ton ; improperlv used it is dangerous. Purchase of Feeds. For tho purpose of purchasing feeds the figures in Table I. are dependable, and it is for this purpose that starch equivalents are most extensively used. Since the figures in the column "starch equivalent" in Table I. all refer to the starch value of 100 pounds of feed, it is obvious that we can make use of these figures to compare prices of different feeds. Thus. 100 pounds of oats with a-starch equivalent of 60 should be half as valuable as 100 pounds of linseed with a starch equivalent of 120. This process of comparison is used in other countries, and the normal practice is to divine the prico per ton by the starch equivalent figure. This gives the value of 1 per cent, of starch equivalent in one ton and is tpoken of as the unit value. Thus oats at £0 per ton has a unit value of 180 over 60 equals :3s. arid linseed at £ls per ton has a unit value of 800 over-120 eouals 2s f}d. Tt should bo remembered that all figures should he corrected to a ton of 22401b before comparisons are made. In the following table different values are taken

from oats and other feeds compared with them—using these unit values:— Table Showing Comparative Values Per Ton of Different Feeds Based on Varying Prices of Oats. Oats At

These values are based on experiments with cattle and sheep, but not with horses and pigs, and the figures are subjeet to the ssnnio limitations as those in the previous table. Thero arc several interesting points in this tabic: — Prom the buyer's point of view tho current buying prices of P°P ulai " feeds, such as oats, oatsheaf chaff, and roots, are in fair agreement with tho prices here listed for these feeds, when oats can be bought for Ms Gd per bushel. They are the highest priced feeds because they arc satisfactory, they can bo used for all classes of stock, and their use is well understood. Feeds that have only a limited use, such as straws, feeds that ar 0/ only oc casionally used or whoso use requires special care —wheat, maize, barley, linseed, pollard, bran —have a current market price below the listed price levels set by oats at 3s Od per bushel. Barley, maize, meat meal, bran, and pollard are at present below tho 2s lid level of oats, and linseed is nearer the Is <>rl level. La en wheat, although used for human consumption, is cheaper to buy at 0s sis a stock food than oats at -s rl _- lasses and linseed cake are high in price, but these have a dietetic value which may in some cases justify their purConsider next tho foods that are bought to feed in the paddock, such as crass and turnips, at say 4d p.r bond per week. A sheep cats a jou 1111, of starch equivalent pel vttj. and at this rate 1 ton ot turnipslasts nine weeks, a ton of swedes httoen weeks, a ton of green oats seventeen, a ton of ordinary pasture ' and a ton of Italian rye twe weeks. On this bus.s turnips are worth 3s Id per ton; swedes us, oats fte rrrnss 7s 3d, and Italian rye 9s 2d I VTot Corner i»n of with those in Table 11. sl \? w ' s u thlt uS value per ton ot those teeds ess than half their value when oaU cost Is fid per bushel. Sheep are fed such feeds for only a tow tho year, and on grass for the rest of ,ho yen,. A c»« WoJ.c'JC " $ as sr&wrtu g* wlioro mils ate 1» 0d pot biuhcl, age pasture is worth los per > ictualiv costs only 2s oct in other'words, er.izing is u » <lo "^® C J! r y tho cheapest method or sheep ft Lt ';. ~ From the grower's poiiu ot also. Table U. is «I*> worthy of study. If the production costs of groen • root crops are 30s per »ere,_ 10 nf turnips 0 ions of swcdeß, o * OXI - * green oats and 3 tons of Italian U.vfc to t"e nere ,„■« : e..u,re«i to pay tor tho crop by grazing sheep at 4d per he, ' nor week A turnip uop of b0 ton s must he vow n" vrihle hilt low I crops of green feed must be debited to° account, other than grazing. YIELDS OF STARCH "KQUIVALENIS I'KH ACIVE. It is informative to set out in tahuIS t?, tof'l°^— Ttopa o. stated yield : TABLK HI- , . . . LIjS weight Vssitmed ot staroh yield equivalent .. „i.r acre. per acie. n V° I'* 1 '* 40 bus. . 960 OatSTieal duff ~. iMUm g* I Wheat •• * 1411 ~ cW - 'Vbus. 1«« J?" I'* 1 '* ■ SO bus. J 0 , ' 7 cwt. 910 c-r 1 :: :: ir 1000 (2 shcfip per acru or 1 cow pel' two acres) Tst>r,i, • ■ 6 totta S * 7 Ttmiios " - 20 tons 1971 £wX :: 15 tons 2451 %V i tons 406 d Mangels •• -- 2016 Potatoes -• 5, tons Hay U tons Italian ry# •• ;) Green oat 3 *• tons

This table can bo misleading if it is assumed that all the above yieldsi are obtainable on any given cIa SS of lam . Yields in the first half of the table are taken from the Year Book, and are average violds in Canterbury. The lower half of tho table may represent yields on good land round the college, but again it is not intended that the yield per acre of one crop is equivalent ito the yield of another crop. _ E vor y farmor must put in his own yield ana cost and then the table is useful. Further it is not suggested that because a crop is profitable that such a crop can be grown to tlie exclusion of others. Table 111 does not admit of generalisations, but there are two points of New Zealand practice that might be reviewed in the light of information derived from it. First, the universal use of oats as a horse feod in New Zealand; in somo other countries mixtures of barley, peas, beans* hay, or whoaten chaff are used almost as exclusively as oats are here, and it is possible that those feeds may cost less to produce than oats do. Next, on the North Island dairy farms grass is almost exclusively used. Whero 80 tons of mangels can be grown per acre it is difficult to imagine a crop that produces starch equivalent at a cheaper rate. Provided, that mangels can be turned into human food by stock as efficiently as grass is, there is a certainty that the net per acre production from mangels must be better even than that from grass, and the reports of occasional farmers that are exploiting this root crop, especially for the winter feeding of pigs, are among the most promising aspects of the pig industry. In the past, adequate consideration has not been given to the yield of starch equivalent per aero and its production cost. If it had, many of our present practices might be modified —as they might still be it' this new point of view is taken. The actual compounding of rations in the light of the information presented here will be dealt with in a later Bulletin. This Bulletin is an introduction to next month's issue, which will deal with the practical compounding of rations in the light oT the information presented above.

TABLE I. £3 s O c rS _cy a "2 -3 "3 o > Feed Stuff. ("• .11 <= rt " c1 c.] 5 y, x £ Eoots— p.c. p.c. p.c. Mangolds, white .. 11.5 0.7 70 5.8 Mangolds, jellov; and red l.'i.O 0.7 TO C.8 Swedes 11.5 1.1 83 7.3 Turnips 8.C 0.6 77 4.4 Potatoes 21.0 1.1 100 18.0 Artichokes 20.0 1.0 02 17.0 Carrots ia.o 0.3 87 8.S Glass, etc.— Average pasture .. 20.0 2.5 01 11.2 Perennial ryo 25.0 i!« 81 10.6 Italian rye 31.0 2.1 76 13.7 Cocksfoot 27 1.5 7." 9.8 White clover 10.0 '2.8 88 8.8 Red clover 19.0 2.5 86 10.2 Lucerne 24.0 3.2 70 3.1 Green oats 16.0 1.7 83 8.3 Greon barley 10.0 1.8 80 9.6 Rape 15.0 2.0 67 6.9 Hay and Straw*— Oatsheaf chaff 86.0 3.8 05 30.0 Oats and tares 81.0 6.5 67 30.0 Average hay 8t>.o 5.4 67 31.0 Oat straw 86.0 1.0 45 19.0 Wheat straw 86.0 0.1 33 12.0 Barley straw S6.0 0.8 40 20.0 Wheat or oat savings 86.0 l.G 74 26.0 Giains, etc.— Oats 87.0 8.0 93 60.0 Barley 86.0 6.5 98 71.0 Wheat 87.0 10.2 no 72.0 Maizo 87.0 7.1 100 82.0 Peas 86.0 19.4 98 00.(1 Linseed 03.0 10.4 1)9 120.0 Bye-produiitfl— Pollard S6.0 13.4 86 e?.o Bran 86.0 11.2 77 45.0 Brewers' grains .. 24.0 3.7 86 12.7 Malt eulma 88.0 18.5 38.0 Meat meal !>3.0 5.0 100 95.0 Molasses 80.0 1.1 87 51.0 Linseed cake 012.0 2.8 97 75.0 8.3 Skim milk 9.4 3.3 100 Whey G.G O.C 100 C.l

1/C. 2/6. 3/6. per bus. per bus. per bus. Feeds — Oats 196/Mangels (white) S/13/0 19/. Mangels (red and yellow) 9/6 22/Swedes 10/3 24/Turnips 0/10/3 14/6 Potatoes 59/Average pasture 15/6 26/36/ 6 : Italian ryegrass 10/0 45/Red clover 13/2 4/ - 33/3 Rape 9/0 16/22/0 Green oats 28/Oat sheaf chaff 118/Average hay 101/Oat straw . . 02/Wheat straw 10/0 23/39/0 Cavings . 85/Barley (per ton) 106/232-/ Barley (per bus.) c 3/9 5/2 W'heni (per ton) 101/ IBS/236/ - Wheat (per bus.) 2/6 4/5 0/3 Maize (per ton) 113/- . 208/Maizo (per bus.) it/3 5/2 7/2 Peas (per ton) 161/220/ - Peas (per bus.) 2 / 7 4/4 OfLinseed 392/Pollard 212/Bran ' . . (jo / ' 147/Brewer's grains 41/(wet) 17/9 Malt culms (dry; 310/Meat meal 133/Molasses 163/Linseed cake . . 175/-2-4 5/• Skim milk 11/0 19/4 27/Whey s/o 14/3 20/-