North Dakota Agricultural College

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1 THE EFFECT OF NUTRITION UPON WOOL PIGMENTATION 1 MERLE R. LIGHT, EARLE W. KLOSTERMAN, M. L. BUCHANAN and D. W. BOLIN 2 North Dakota Agricultural College HE occurrence of banded wool has been reported by several investi- T gators. Boyd (1930) reported the occurrence of color'banding in the fleeces of five different sheep. She observed several different types of banding and noted that sheep which produced banded fleeces always began life as colored lambs. Boyd postulated that since banding took place with regularity over the whole fleece, it must in some way be related to a definite physiological condition of the body as a whole, although she thought it to be primarily genetic in origin. Nichols (1927) reported on the occurrence of dark fibers in the Suffolk fleece; he theorized that there are thresholds of irritation for inhibiting factors of pigment production which he thought could be affected by temperature. A rather common occurrence in some breeds of sheep (for example Hampshires and Suffolks) is the birth of lambs which have very darkly pigmented wool when born and later grow normal white wool. Cross sections of such wool on the flesh side, point of change,' and outer tips are shown in figure 2, G, H, and I. Since it is known that the vitamin A levels of new-born lambs are very low, (Weir, et al., 1949), and because vitamin D, which is also a fat soluble vitamin, is probably low, it is possible that either of these vitamins may be responsible for the dark pigmentation. More recently, Glazener, et al., (1946) demonstrated that diets deficient in vitamin D caused an abnormal blackening of the feathers of New Hampshire chicks. Glazener and Briggs (1948) studied the effects of a vitamin D deficiency on five different breeds of chicks. They showed that there is a breed difference in the abnormal blackening of feathers during a period of vitamin D deficiency. Lillie and Bird (1949) confirmed the work of Glazener and Briggs (1948) showing a difference between breeds and possibly between strains of the same breed. Previous work with lambs at this station showed that several vitamin A depleted lambs of Hampshire origin produced abnormal amounts of melanin during the latter stages of deficiency. These lambs had been fed a carotene deficient ration and were confined in a shed out of direct contact with sunlight. The fleece of number 176 was found to be distinctly banded when sheared (figure 1, A). The fleece in this 1 Publication approved by the Director of the North Dakota Agricultural Experiraent Station. 2The authors gratefully acknowledge Wyeth, Incorporated, Philadelphia, Pennsylvania, for furnishing the vitamin A for these studies. Thanks are also given to Dr. Glen C. Holm, Veterinarian, N.D.A.C. for the photography.

2 600 LIGHT, KLOSTERMAN~ BUCHANAN AND BOLIN Figure I. case was white on the outer portion and black on the flesh side. I t was noted in individual fibers that some which were normally black turned white and vice versa. Figure 1, E shows the change from white to

3 EFFECT OF ~-"N-UTRITION ON WOOL PIGMENTATION 601 black. Figure 1, F shows the change from black to white. Cross sections of wool tufts on either end and at the point of change are shown in figure 1, B, C, and D. Experimental Procedure Avitaminosis A was suspected to be the causative factor involved in the wool pigmentation reversal in ewe number 176. In March, 1950, ewe 176 was given a ration containing sun-cured alfalfa hay to determine whether a change from black to white could be produced. This change did occur as shown on figure 2, J, and the outer fleece shown in figure 2, K and L. Nine lambs of mixed origin, plus ewe 176, were placed on a carotene deficient ration in June of The ration consisted of water, wheat straw, beet pulp, soybean oil meal, and a mineral mixture consisting of trace mineralized salt plus bone meal. They were confined in the same shed used in the first experiment and were kept out of direct contact with sunlight, although sunlight was admitted through an open door and through several open windows. The genetic makeup of the expermiental lambs was as follows. Five were purebred Hampshires, two were white Columbia-type lambs that were sired by a black ram and two were sired by a Delaine-Merino ram and were out of Rambouillet ewes. The fleeces of the lambs were inspected at the start of the experiment and all fleeces were considered normal for their respective breed types. Blood sera samples were analyzed for vitamin A at varying intervals to determine the extent of avitaminosis A. Gross deficiency symptoms and any fleece changes were noted periodically. Each lamb was individually treated with either water soluble vitamin A injected intravenously or a vitamin A and D supplement administered by stomach tube after pigmentation changes were noted in the wool fibers of several of the Iambs. Discussion and Results Analyses of blood sera indicated that the lambs were becoming vitamin A deficient by January of 1951 and in several cases, gross * deficiency symptoms were noted. Examination of two rams which were in the group revealed that atrophy of testicular tissue was taking place. Blood sera vitamin A levels were noted to fluctuate throughout the

4 602 LIGHT, KLOSTERMAN, BUCHANAN AND BOLIN Figure 2. period of deficiency (table 1). Most levels, however, remained near 30 I. U. per 100 ml. which Eveleth and co-workers (1949) considered a deficient level.

5 EFFECT OF NUTRITION ON Vc~TOOL PIGMENTATION 603 Examination of the wool of the lambs in February of 1951 showed that several of the fleeces of Hampshire lambs were beginning to show a noticeable darkening near the skin. This condition was more pronounced by April, Photographs of ewe 176 were made in May, 1951 (figure 2, K and L). These photographs of shoulder and rump areas show the fleece changes that accompanied a vitamin deficiency. Color changes were general over the body area. All sheep were treated with either injectable vitamin A or a vitamin A and D mixture administered orally on June 2, This treatment TABLE 1. BLOOD SERA VITAMIN A LEVELS I. U. of vitamin A per 100ml, Fleece Lamb No Changes l L O indicates no change, + indicates color reversal. was repeated July 3, The amounts used were large enough to bring the sera vitamin A well above deficiency levels. Detailed examination of the fleeces after a period of two months showed that the black wool fibers of one of the Hampshire sheep were changing from black to white. This sheep had been treated with a vitamin A and D mixture. Ewe number 176, which had been treated only with injectable vitamin A, did not respond. Since no response was seen during a three month period when ewe 176 was treated with vitamin A, she was given massive doses (approximately 45,000 I.U.) of vitamin D orally at bi-weekly periods beginning in September, A change from black to white in the pigmentation of wool fibers of ewe 176 was noted in November, Evidentally this was the result of the vitamin D treatment. Sheep used in this experiment, which were of a genetic make-up different from the Hampshire lambs, did not show any visible fleece changes. In fact, their fleeces remained normal in appearance through-

6 604 LIGHT, KLOSTERMAN, BUCHANAN AND BOLIN out the experiment while several of the Hampshires developed weak spots in their wool fibers. This occurred midway through the vitamin deficiency period and resulted in ragged fleeces and a new growth of wool which in most cases contained a heavy concentration of black fibers. This was not observed in every Hampshire lamb, however. There is some reason to question whether vitamin D was the sole factor responsible for the pigmentation reversal noted in some Hampshire lambs during this experiment. Since the reversal was noted during a period when the lambs were known to be vitamin A deficient and no lambs were treated with vitamin D solely, it is possible that a combination of vitamin A and D was necessary for the changes brought about. It seems probable, however, that vitamin D acts in some manner to cause a reversal of pigment production in some Hampshire lambs. Summary I. A reversal of wool pigmentation from white to black and vice versa has occurred in Hampshire sheep fed rations low in vitamins A and D. 2. Vitamin A treatments to depleted sheep of Hampshire origin brought no response in pigmentation pattern. 3. A reversion to original wool pigmentation was noted when vitamin D was administered to lambs previously treated with vitamin A. 4. Sheep of Delaine-Merino X Rambouillet ancestry or Columbiatype sheep that were heterozygous for black showed no pigmentation reversal pattern. 5. There was a difference between Hampshire lambs in their response to rations deficient in vitamins A and D. Literature Cited Boyd, Evlyn Colour-banding in fleeces. Jour. Tex. Insti. 21:T287. Eveleth, D. F., D. W. Bolin and A. I. Goldsby Experimental avitaminosis A in sheep. Bioehem. ]our. 42:xlix. Glazener, E. W, J. P. Matfingly and G. M. Briggs Abnormal blackening of the feathers of New Hampshire chicks as the result of vitamin D deficiency. Poul. Sei. 25:85. Glazener, E. W. and G. M. Briggs Further studies in abnormal blackening of feathers of vitamin D deficient chicks. Poul. Sci. 27:462. Lillie, R. J. and H. R. Bird A breed difference in feather pigmentation of vitamin D deficient chicks. Poul. Sci. 28:140. Nichols,.]'. E On the occurrence of dark fibers in the Suffolk fleece with particular reference to the hirth coat of the lamb. Jour. Tex. Instit. 18:404. Weir, W. C., A. L. Pope, P. M. Phillips and G. Bohstedt The effect of a low carotene winter ration on the blood, milk and liver concentrations of vitamins A and C of ewes and their lambs. JOtTRNAL Or A.','I~rAr, Sc~xc~, 8:381.