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s.
Afr.
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Agric. Sci.
oil,
9, 461-466
Printed in the Repu'6\ of S/ffr. by The Government Printer, Pretoria ,
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INFLUENCE OF HIGH LEVELS OF VITAMIN A IN COMBINATION WITH BEEF TALLOW ON EGG YOLK COLOUR (Met opsomming in Afrikaans) (Avec resume en francais)
--+-J. P. HAYES, Agricultural Research Institute of the Transvaal Region, Pretoria
ABSTRACT
In an attempt to study the effect of high levels of vitamin A, viz. 12,000, 24,000 and 36,000 IU per lb of feed on egg yolk colour, it was found that the colour of the egg yolks was significantly depressed by 24,000 and 36,000 IU of vitamin A. However, when the ration contained 3 per cent ... beef tallow, the vitamin A, even at the highest level, had no effect on the colour of the egg yolks.
INTRODUCTION
According to Sunde (1962), vitamin A when fed at high concentrations to laying hens, tended to decrease the deposition of pigments in the egg yolks. This worker added graded levels of synthetic vitamin A to a basic ration which contained approximately 6,000 international units (IU) per pound (lb) of feed derived from natural sources. At 11,360 IU of synthetic vitamin A per lb of feed, the colour of the egg yolks was materially depressed. On the highest level of vitamin A (56,800 IU per Ib) egg yolks were produced with less than half the pigment content of that produced on the basic ration. Similar results were obtained by Duel, Hrubetz, Mattson, Morehouse & Richardson (1943) and Farr, Cregor & Couch (1962). Whereas it seems that beef tallow has a pigment-enhancing effect (Mackay, Mountney & Naber, 1962) an experiment was conducted at the Pretoria University Experimental Farm to determine the effect of high levels of vitamin A, in combination with beef tallow, on egg yolk pigmentation.
PROCEDURE
New Hampshire hens of the local laying strain, in their first year of production, were used in this experiment. The hens were individually maintained in indoor laying cages with automatic water supply and separate feeders available. Feed and water were at all times supplied ad lib. , Prior to the initiation of the experiment the birds were maintained for four weeks on a commercial type oflaying mash (Table 1) practically devoid of any carotenoid pigments. The birds were then considered sufficiently depleted to commence testing the experimental rations. Received 26 October 1965
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INFLUENCE OF HIGH LEVELS VITAMIN A WITH TALL(iW ON YOLK COU;mR
The treatments, each treatment was applied to a g,'oup of 24 brtds, consisted of graded levels of vitamin A, viz. 12,000, 24,000 and 36,(,\)0 IU Pj.:r Ib of a ration containing either 3 per cent beef tallow of a commercial ~rade ·~r 3 per cent glucose. (The glucose served as a substitute for beef tallow to k~ep;:ne energy content of the rations on more or less the same level). The compositi(lI~· of the experimental ration, which contained 1,200 IU vitamin A per Ib derived Mim the natural source, betacarotene, is given in Table 1. \ TABLE I.-Composition, in percentage, of the laying rations TABEL 1.-Persentasie samestelling van die /e-rantsoene Pre-experimental carotenoid-free ration/ Karotenoidevry uitputtingsrantsoen
Ingredients/Bestanddele
Ground white maize/ Wit mieliemeel. ............ Ground yellow maize/Geelmieliemeel . ........... Wheaten bran/ Koringsemels . ................... Ground oats/ Gemaalde hawer . .................. Pollard ...................................... Fishmeal/ Vismeel . ............................ Ground nut oil cake meal/Grondbone-oliekoekmeel Sunflower oil cake meal/Sonneblom-oliekoekmeel .. Lucerne meal (high quality, sun-cured)/Lusernmeel (hoe graad, songedroog) Fermavite* ................................... Ground limestone/Kalkklippoeier . ............... Bone meal/ Beenmeel . .......................... Salt/Sout ....... .............................. Powdered glucose or Beeftallow/Glukose of Beesvet
% 59·0
-
I
Basic experimental ration/Basiese eksperimentele rantsoen
%
-
12·0 5·0 5·0 4·5 6·5 4·0
59·0 1·0 5·0 5·0 4·5 6·5 4·0 8'0
1·0 1·1 1·4 0·5
1·0 1·1 1·4 0·5 3·0
-
-
100
100
-
Additional vitamins and minerals per l00lbofdiet/Addisionele vitamienesenmineraleper 100 lbrantsoen Manganese sulphate/Mangaansulfaat (80%) .................... , 20 gm Vitamin Da (20,000 IU/gm)/Vitamien D. (20,000 IE/gm)........... 2 gm Vitamin E/ Vitamien E (25 %). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 gm Vitamin A (20,000 IU/gm)/Vitamien A (20,000 IE/gm)............ 6·5 gm * Dried butyl alcohol fermentation solubles from molasses/Gedroogde butiel-alkohol fermentasieprodukte van melasse
On the 15th, 16th and 17th days after the hens had been placed on the experimental rations, eggs were collected from 15 hens of each treatment. The yolks of each hen's eggs were separated from the albumen, pooled and duplicate assays performed for carotenoid pigments. The mean of the two duplicates was calculated for each hen and the data subjected to an analysis of variance according to Snedecor (1956). Duncan's multiple range test, as described by Snedecor (1956), was used to compare treatment means when significant differences were detected by the analysis of variance. The procedure employed in the determination of the egg yolk pigments was the analytical method described by the 'Association of Official Agricultural Chemists (1960). 462
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1. P. HAYES REsULTS
The results obtained ~n this experiment are summarized in Table 2. From Table 2 it is clear that vita~n A, added at levels of 24,000 and 36,000 IU per lb of the diet containing 3 per cent glucose, significantly depressed egg yolk pigmentation These results are in accord~nce with those obtained by workers previously mentioned. Sunde (1962), for example, found that Vitamin A, added at 11,360 IU per lb decreased egg yolk pigmentation. In the present study the addition of 12,000' IU vitamin A per lb to the ration had no significant effect on yolk colour. The basic ration in this study, however, contained almost 5,000 IU per lb less vitamin A in the form of beta· carotene than the ration used by Sunde (1962).
TABLE 2.-The effect of feeding various levels of vitamin A, either in combination with 3 per cent beef tallow or in combination with 3 per cent glucose, on yolk pigmentation TABEL 2.-Die invloed van verskillende pei/e vitamien A in kombinasie met 3 persent .beesvet of in kombinasie met 3 persent glukose op dooier-pigmentasie
Lot/ Groep
Treatment/Behandeling
Average pigmentation· / Gemiddelde pigmentasie p.g/gm
1 2 3 4 5 6 7
8
Control ration containing 3 % beef tallow/ Kontrole rantsoen bevattende 3% beesvet Same as No. 1+12,000 IV Vito A/lb/Diese/fde as Nr. 1+12,000 IE Vito A/lb Same as No. 1+24,000 IV Vito A/lb/Diese/fde as Nr. 1+24,000 IE Vit A/lb Same as No. 1+36,000 IU Vito A/lb/Diese/fde as Nr. 1+36,000 IE Vito A/lb Control ration, containing 3 % glucose/Kontrole rantsoen bevallende 3% glukose Same as No. 5+12,000 IV Vito A/lb/Diese/fde as Nr. 5+12,000 IE Vito A/lb Same as No. 5+24,000 IV Vito A/lb/Diese/fde as Nr. 5+24,000 IE Vito A/lb Same as No. 5+36,000 IV Vito A/lb/Diese/fde as Nr. 5+36,000 IE Vito A/lb
46.5a
b
46.9a
b
48·3 a 45.2a b 46.6a b 42.6b c 40.1 c 38.8 c
• Micrograms of beta-carotene per gram of sample. Means which have the same exponential letter are not significantly different at the five per cent level of probability according to Duncan's multiple range test/Mikrogram beta-karoteen per gram monster. Gemiddeldes wat diese/fde letter in die bo-skrif het verskil nie betekenisvol van mekaar volgens Duncan se veelvuldige reeks toets nie
It is interesting to note that vitamin A, even at the highest level of 36,000 IU per Ib,had no effect on yolk pigmentation when fed in combination with beef tallow. The beef tallow as such, as shown in Table 2, had no pigment-enhancing effect. This is in contrast to the finding of Mackay, Mountney & Naber (1962). The fact, however, that beef tallow cancelled the pigment-depressing property of vitamin A, is difficult to explain and needs further investigation.
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INFLUENCE OF HIGH LEVELS VITAMIN A WITH TALLOW ON YOLK COLOUR
It is fully recognised that a difference exists in tbe energy content of glucose and beef tallow. There was, however, no relationship between the amount of feed consumed and the pigment content of the egg yolks of the hens in the different treatment groups. It may be assumed thus that the intake of carotenoids from the feed were equal between the different groups.
CONCLUSION
Under the conditions this experiment was carried out, it may be concluded that vitamin A, in concentrations exceeding 24,000 IU per lb, significantly decreased egg yolk vigmentation. This effect, however, could not be detected when the rations contamed 3 per cent beef tallow. Even 36,000 IU vitamin A per lb had no influence on the deposition of pigments in the egg yolks. Opsomming DIE INVLOED VAN HOE PElLE VITAMIEN A IN KOMBINASIE MET BEESVET OP DOOIERPIGMENTASIE Drie peile vitamien A, nI12,000, 24,000 en 36,000 internasionale eenhede (IE) per pond (lb) is aJsonderlik en in kombinasie met 3 persent beesvet aan le-henne gevoer. Daar is gevind, deur die hoeveelheid pigment in die eierdooiers te bepaal, dat 24,000 en 36,000 IE per lb voer dooierpigmentasie betekenisvol onderdruk. Indien die rantsoen egter 3 persent beesvet bevat, het se(fs die hoogste vitamien A-peil (36,000 IE per lb) geen invloed uitgeoeJen nie op die hoeveelheid pigmente wat in die .eierdooier neergele word. Die energie-inhoud van die rantsoene is min oj meer konstant gehou deur die insluiting van glukose waar die rantsoen nie beesvet bevat he! nie. Dit het ook geblyk uit die voerverbruik van die henne dat bogenoemde verskynsel nie aan 'l.erskille van pigmentinname gewyt kan word nie. Resume INFLUENCE DE NIVEAUX ELEVES DE VITAMINES A, EN COMBINAISON AVECDELA GRAISSE DE BOEUF, SUR LA COULEURDES JAUNESD'OEUFS Des poules pondeuses ont ete nourries de rations contenant trois niveaux de vitamines A, notamment 12.000, 24.000 et 36.000 unites internationales par livre (454g). Ces rations Jurent donnees, soil separement, soil en combinaison avec trois pour-cent de graisse de boeuf En determinant la quantile de pigment dans Ie jaune des oeuJs, on a pu constater que 24.000 et 36.000 unites internationales de vitamines A par livre de nourriture entravaient de maniere significative la pigmentation du jaune des oeuJs. Si, par contre, les rations contenaient trois pour-cent de graisse de boeuf, meme Ie niveau de vitamines A Ie plus eIeve (36.000 unites internationales par livre) n'a pas eu d'inj/uence sur la quantite de pigment depose dans les jaunes. La teneur en energie des rations Jut tenue plus ou moins constante grace al' addition de glucose aux rations ne contenant pas de la graisse de boeuJ. La consommation de nourriture par les poules a egalement demontre que Ie phenomene decrit ci-dessus ne peut etre attribue ades differences dans l'absorption de pigment.
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J. P. HAYES REFERENCES
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ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS. Official Methods of Analysis, 9th ed., Washington, D.C. DUEL, H. J., HRUBETZ, M., MATTSON, F. H., MOREHOUSE, M. G. & RICHARDSON, A., 1943. Studies on carotenoid metabolism. J. Nutr. 26,673-685. FARR, F. M., CREGOR, C. R. & COUCH, J. R., 1962. Egg yolk pigmentation. Poult. Sci. 41, 1643. MACKAY, E., MOUNTNEY, G. J. & NABER, E. C., 1962. Yolk colour resulting from different levels of paprika extract in the ration. Poult. Sci. 41,1660-1671. SNEDECOR, G. N., 1956. Statistical methods. Ames, Iowa: Iowa State College Press. SUNDE, M. L., 1962. The effect of different levels of vitamin A, beta-apo-8'-carotenal and alfalfa on yolk colour. Poult. Sci. 41, 532-541.
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