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Vitamin A and Carotene Content of the Blood Plasma of Dairy Calves from Birth up to Four Months of Age*
V I T A M I N A AND C A R O T E N E C O N T E N T OF T H E B L O O D P L A S M A OF D A I R Y C A L V E S F R O M B I R T H U P TO F O U R M O N T H S OF A G E ~ L. A. M O O R E
A N D i~:. H. BER]:~Y
Dept. of Dairy Husbandry, University o/ Maryland
Compared with the wild state~ the present methods of raising dairy calves have considerably altered the quality and quantity of foods which a calf receives up to four months of age. This change has reduced very materially the vitamin A intake. In the wild state the calf remained with its dam and thus received a considerable quantity of whole milk during this period of development. Under some of our present procedures of hand feeding a maximum of only about ten pounds per day is fed, and then for only a month to six weeks. In the wild state the calf usually was born in the spring of the year when the milk which it received was high in vitamin A. Under present day conditions winter milk contains only one-half to onethird the vitamin A of summer milk (5). F u r t h e r m o r e , when the calf was born in the spring of the year in the wild state, the green grass eaten was high in carotene, whereas field cured hay retains only five to ten per cent of its original carotene content. In order to throw some light on this problem Nelson and co-workers (7) obtained blood samples of beef and dairy calves up to four months of age. The dairy calves were raised by the usual modern methods and the beef calves were permitted to r u n with the dams. Both groups were on winter feed so that the comparison did not exactly simulate average present day methods of raising calves as compared with the wild state. The results showed that the vitamin A content of the blood plasma of the beef calves was considerably higher than for the dairy calves, which was probably due to the larger intake of whole milk. The reduced vitamin A intake of dairy calves m a y account in p a r t for the losses due to pneumonia and scours in this age group. Krauss and coworkers (3) at the Ohio Agricultural E x p e r i m e n t Station reported a decreased incidence of pneumonia in calves which received 15,000 units of vitamin A concentrate daily. Gullickson and F i t c h (2) in an experiment involving 72 calves reported less trouble from digestive disturbances was encountered in young calves that were fed cod liver oil than in calves not receiving the vitamin supplement. Some of the non-supplemented calves died. Phillips (8) reported that the administration of high vitamin A potency shark liver oil and certain members of the B complex eliminated l~cceived for publication lY[ay 14, 1945. * Scientific J o u r n a l Article No. 101. Contribution No. 1972 of the Maryland Agricultural Experiment Station. 821
822
MOORE
AND
BERRY
diarrhea and lowered the mortality resulting from pneumonia. Nelson (7) recommended the feeding of fish liver oil where there was difficulty in raising calves. The vitamin A requirements of calves from birth to four months of age has not been established. Converse and Meigs (1) reported results which indicated a higher vitamin A requirement for this age group than for older calves. In order to obtain further information vitamin A and carotene determinations were made each two weeks on calves up to four months of age raised in the dairy herd of the University of Maryland. The effect of feeding lespedeza hay high in carotene was also studied. EXPERIMENTAL
Blood samples of the Holstein, Ayrshire and Guernsey breeds were drawn every two weeks from calves up to four months of age. Plasma, vitamin A and carotene determinations were made according to an adaptaTABLE
1
Daily feeding scheduZe for dairy calves
A oo oa,
Iwh°l°milk'r st°rY° rtor,lbs l IOraln'lb Y'lbslbs I Ayrshire
1-4 4-7 2nd 3rd 4th
days days week week week 5th w e e k 6th week 7th week 8th-10th llth-14th 15th-16th 17th-24th
.............................. .............................. .............................. .............................. .............................. .............................. .............................. .............................. w e e k s ............... w e e k s ............... w e e k s ............... w e e k s ...............
With
and Holstein-Friesian
cow
8 9 10 9 7 6 4
¼ Free a c c e s s Free a c c e s s
1
1½
0-4t 4-5
Free access Free a c c e s s Free a c c e s s Free access Free a c c e s s Free access Free access
0-4t 4
Free Free Free Free Free Free Free Free Free Free Free
2 3 3]--4 4 4-0*
Guernsey 1 - 4 d a y s .............................. 4 - 7 d a y s .............................. 2 n d w e e k .............................. 3 r d w e e k .............................. 4 t h w e e k .............................. 5 t h w e e k .............................. 6 t h w e e k .............................. 7 t h w e e k .............................. 8 t h w e e k .............................. 9 t h w e e k .............................. 1 0 t h w e e k .............................. llth-14th w e e k s ............... 15th-16th w e e k s ............... 16th-24th w e e k s ............... * Gradually t Gradually
decreased. increased.
With
cow 5 6 7 7 6 6 5 4 3 3
¼ 1
1½ 1½ 2
2½ 3 3½-4 4-0*
access access access access access access access access access access access
823
THE BLOOD PLASMA OF DAIRY CALVES
tion of a previously published method (4). The calves were fed according to the schedule given in table 1. N u m b e r I clover and t i m o t h y h a y was fed as a roughage. Milk f r o m the Holstein herd was fed to all calves d u r i n g the milk feeding period. I n addition, one g r o u p of calves was fed according to the schedule in table 1 for the first 90 days a f t e r which they were placed on a v i t a m i n A deficient ration to s t u d y the rate of depletion as indicated b y blood-plasma analysis. A similar g r o u p of three calves were fed lespedeza h a y in place of clover and timothy hay. The clover a n d timothy h a y contained 15 microTABLE 2 Vitamin A and carote~e content of blood plasma of calves of the various breeds
Age, days
Holstein
I
~_yrshir¢
I
Guernsey
Micrograms vitamin A per 100 ml. plasma 8-21 22-35 36-49 50-63 64-77 78-91 92-105 106-119 120-133
(18) ~ 10.8+0.62 (17) 7.7 ± 0.79
(19)
8.2 ± 0.40
(15) (19) (17) (20) (19) (19)
9.9 + 0.76 10.2+0.58 10.1 +0.73 10,9 +0.57 10.2 +0.63 10.5±0.53
(10) (10) (11) (10) (11) (11) (10) (11) (8)
9.0 ± 7.2 + 8.1 +_ 9.2 +_ 8.9 + 9.9 -+_ 10.3 ± 11.7± 10.8±
1.19 0.52 0.51 0.50 0.79 0.79 0.91 0.94 0.80
(10)
11.0± 1.08
(9) (9) (10) (9) (9) (10) (8)
9.8± 9.7+ 11.1_+ 12.82 13.1+ 14.0+ 13.0±
(10)
9.8± 0.80 1.05 0.51 0.81 0.87 1.11 1.74 0.96
Micrograms carotene per 100 ml. plasma 8-21 22-35 36-49 50-63 64--77 78-91 92-105 106-119 120-133
(20) (19) (20) (16) (19) (20) (21) (20)
(18)
17.7 ± 1.8 23.3 +2.9 34.4_+3.7 52.6+4.4 52.6 +4.5 57.9±4.1 62.8±5.3 68.5 + 5.1
70.5+5.8
(10) (11) (12) (10)
19.6+ 16.5+ 30.8+ 46.5 ±
(12) (12) (12) (9)
45.5± 6.2 52.9_+ 8.0 63.6+ 6.6 81.1+_11.3
(12)
2.0 1.9 3.8 8.1
42.0+_ 5.0
(9) (10) (10) (9) (10) (9)
40.8+ 5.0 35.4+ 4.7 42.9+ 6,4 68.9 +10.6 82.8 + 9.3 80.9.+ 7.1 79.4_+10~2
(i0) ( 9 ) 100.0 + 13.7 (8)
97.6+12.7
Figures in parenthesis indicate number of determinations.
g r a m s of carotene per g r a m of h a y while the lespedeza contained 50 microg r a m s per gram. RESULTS AND DISCUSSION
The results of the analysis of the blood plasma for v i t a m i n A a n d carotene for the calves raised in the herd are shown in table 2. The d a t a h a v e been averaged according to breeds for each two weeks and the s t a n d a r d error ealeulated. The blood plasma values for the Holstein and A y r s h i r e calves are in close agreement. The plasma, carotene and v i t a m i n A values for the Guernsey calves are slightly higher. The higher values m a y be d u e to the f a c t t h a t the Guernsey calves received whole milk f o r a longer p e r i o d of time t h a n the Holstein and A y r s h i r e calves, or the correction f a c t o r applied to the an¢imony trichloride Vitamin A value for the carotene content
824
MOORE AND BERRY
of the blood plasma may be in error. standard
W h i l e b e t a c a r o t e n e w a s u s e d as a
for correction, this procedure
is o p e n t o c r i t i c i s m .
However, it
TABLE 3
Vitamiu A i~ micrograms per i00 ml. of blood plasma of calves fed a mixture of clover and timothy or lespedeza hay Clover and timothy 468 Age
469
Vitamin A
Age
470
Vitamin A
Vitamin A
Age i
41 52 70 83
7.5 7.4 7.7 10.4
39 54 68 81
9.6 7.2 5.7 7.5
25 39 54 68
19.7 13.2 10.4 12.9
97
5.7
95
6.3
81
10.2
112 126
2.4 0.6
110 124
2.4 0.3
95 110 126
4.5 7.2 7.8
Age
473
472
471 Vitamin A
Age
Vitamin A
Age
Vitamin A
25 39 54 68 81
9.0 6.0 6.6 4.8 7.5
26 41 55 68 82
6.3 6.0 6.3 12.3 9.0
16 23 38 52 65
9.0 5.4 5.4 12.9 14.1
95
3.0
97
12.6
79
10.5
ll0 124
4.8 5.1
111 124
5.4 5.1
94 108 129
11.7 7.8 3.0
Lespedeza 463
464
466
Age
Vitamin A
Age
Vitamin A
Age
Vitamin ±
36 50 57 76
10.5 12.3 21.6 27.3
32 39 49 55
12.6 15.9 21.9 26.7
34 60 71 84
13.4 12.3 23.4 22.5
107 120
16.2 10.5
64 77
31.2 27.8
98 112
10.2 3.6
128
13.5
91 105 120
21.0 5.1 6.6
126
8.1
* P l a c e d on carotene-free ration at 90 d a y s o f age.
seems quite unlikely that the vitamin A values for the Guernsey calves for this age group are lower than for the Holstein and Ayrshire calves.
THE BLOOD PLASMA OF DAIRY CALVES
825
I t should be pointed out and emphasized that the vitamin A values are in the deficient range when compared to those obtained f r o m calves four months to one year of age in data reported from this laboratory (6). While it should be noted that there are individual variations in calves kept on the same carotene intake, such low values as noted in this group of calves would lead to some expression of deficiency symptoms in older calves d u r i n g the winter months (6). Values of 15 micrograms of vitamin A per 100 ml. of plasma or above should be maintained to prevent deficiency symptoms in older calves. The data obtained with the two groups of calves fed lespedeza and clover and timothy hays are shown in table 3. Where clover and timothy hay was fed low-plasma vitamin A values similar to those as shown in table 2 resulted. When the calves were placed on a carotene free ration at 90 days of age, the vitamin A values dropped sharply. Where lespedeza was fed in place of the clover and timothy hay, the plasma vitamin A values were markedly higher. These higher values presumably were due to the higher carotene intake from the lespedeza hay. When the three calves were placed on the carotene free ration at 90 days of age, the vitamin A content of the blood plasma decreased at a slower rate and not to the extent as noted for the calves fed clover and timothy. This would indicate a much greater storage of vitamin A in the liver for the calves fed lespedeza hay. F r o m the practical feeding standpoint where limited amounts of whole milk are fed these data indicate that some vitamin A supplementation might be beneficial for calves for the first four to six weeks of age, especially where some difficulties are encountered in raising calves. W h e r e the roughage is of poor quality some supplementation to three months of age is indicated. These data, also, indicate that lespedeza hay because of its high carotene content should prove to be a good hay for calves. Some f u r t h e r attention should be given to the use of high carotene roughages f o r young calves which would obviate the feeding of vitamin A supplements, except for the first 30 days. J
SUMMARY
1. The vitamin A content of the blood plasma of calves of the Holstein, Ayrshire and Guernsey breeds from birth up to four months of age varies from 7.2 to 14 micrograms per 100 ml. 2. These values are in the deficient range when compared with those for vitamin k deficient calves at one year of age. 3. Some vitamin A supplementation is indicated where difficulty in raising calves is encountered. 4. The feeding of high-carotene lespedeza hay produced higher plasma vitamin A values in young calves than No. 1 mixed clover and timothy hay.
826
MOORE AND
BERRY
REFERENCES (1) CONVEESE, H. T., AND MEreS, E . B . The Vitamin Requirements for Normal Growth in Young Dairy Cattle. Amer. Soc. Anim. Prod. Proc. 32nd Ann. Rpt., p. 67-72. 1939. (2) GULLICKSON, T. W., AN]) FITCH; J . B . Effect of Adding Cod Liver Oil to the Rations of Dairy Calves. JouR. DAIRY ScI., 27: 331-335. 1944. (3) KRAUSS, W. E., MONROE, C. F., AND HAYDEN, C.C. The Value of Milk F a t Substitute-Skimmilk Combination for Raiging Bull Calves for Veal and Heifer Calves for Replacement. Ohio Agr. Expt. Sta. Spec. Cir. 57. (4) MOORE~ L. A. The Determination of Blood Plasma Carotene in the Bovine Using a Photoelectric Colorimeter. ;[ouR. DAIRY SCI., 22: 501-511. 1939. (5) MOORE, L . A . Vitamin A Activity of Milk Fat. Mich. Agr. Expt. Sta. Quart. Bul., 21: 169-174. 1939. (6) MOORE, L A., BERRY, M. H., AND SYKES, ;[. F. Caroteae Requirements for the Maintenance of a Normal Spinal Fluid Pressure in Dairy Calves. Jour. l~utr., 26: 649-658. 1943. (7) NELSON, H. F., MOORE, L. A., HORWOOD, R. E., AND BRANAMAN, G . A . Mich. Agr. KEpt. Sta. Quart B u l , 27: 27-28. 1944. (8) PHILLIPS, P. H., LUNDQUIST, N. S., AND BOYER, P: D. The Effect of Vitamin A and Certain Members of the B Complex upon Calf Scours. ;[OUR. DAIRY SCI.~ 24" 977-982. 1941.
A N D i~:. H. BER]:~Y
Dept. of Dairy Husbandry, University o/ Maryland
Compared with the wild state~ the present methods of raising dairy calves have considerably altered the quality and quantity of foods which a calf receives up to four months of age. This change has reduced very materially the vitamin A intake. In the wild state the calf remained with its dam and thus received a considerable quantity of whole milk during this period of development. Under some of our present procedures of hand feeding a maximum of only about ten pounds per day is fed, and then for only a month to six weeks. In the wild state the calf usually was born in the spring of the year when the milk which it received was high in vitamin A. Under present day conditions winter milk contains only one-half to onethird the vitamin A of summer milk (5). F u r t h e r m o r e , when the calf was born in the spring of the year in the wild state, the green grass eaten was high in carotene, whereas field cured hay retains only five to ten per cent of its original carotene content. In order to throw some light on this problem Nelson and co-workers (7) obtained blood samples of beef and dairy calves up to four months of age. The dairy calves were raised by the usual modern methods and the beef calves were permitted to r u n with the dams. Both groups were on winter feed so that the comparison did not exactly simulate average present day methods of raising calves as compared with the wild state. The results showed that the vitamin A content of the blood plasma of the beef calves was considerably higher than for the dairy calves, which was probably due to the larger intake of whole milk. The reduced vitamin A intake of dairy calves m a y account in p a r t for the losses due to pneumonia and scours in this age group. Krauss and coworkers (3) at the Ohio Agricultural E x p e r i m e n t Station reported a decreased incidence of pneumonia in calves which received 15,000 units of vitamin A concentrate daily. Gullickson and F i t c h (2) in an experiment involving 72 calves reported less trouble from digestive disturbances was encountered in young calves that were fed cod liver oil than in calves not receiving the vitamin supplement. Some of the non-supplemented calves died. Phillips (8) reported that the administration of high vitamin A potency shark liver oil and certain members of the B complex eliminated l~cceived for publication lY[ay 14, 1945. * Scientific J o u r n a l Article No. 101. Contribution No. 1972 of the Maryland Agricultural Experiment Station. 821
822
MOORE
AND
BERRY
diarrhea and lowered the mortality resulting from pneumonia. Nelson (7) recommended the feeding of fish liver oil where there was difficulty in raising calves. The vitamin A requirements of calves from birth to four months of age has not been established. Converse and Meigs (1) reported results which indicated a higher vitamin A requirement for this age group than for older calves. In order to obtain further information vitamin A and carotene determinations were made each two weeks on calves up to four months of age raised in the dairy herd of the University of Maryland. The effect of feeding lespedeza hay high in carotene was also studied. EXPERIMENTAL
Blood samples of the Holstein, Ayrshire and Guernsey breeds were drawn every two weeks from calves up to four months of age. Plasma, vitamin A and carotene determinations were made according to an adaptaTABLE
1
Daily feeding scheduZe for dairy calves
A oo oa,
Iwh°l°milk'r st°rY° rtor,lbs l IOraln'lb Y'lbslbs I Ayrshire
1-4 4-7 2nd 3rd 4th
days days week week week 5th w e e k 6th week 7th week 8th-10th llth-14th 15th-16th 17th-24th
.............................. .............................. .............................. .............................. .............................. .............................. .............................. .............................. w e e k s ............... w e e k s ............... w e e k s ............... w e e k s ...............
With
and Holstein-Friesian
cow
8 9 10 9 7 6 4
¼ Free a c c e s s Free a c c e s s
1
1½
0-4t 4-5
Free access Free a c c e s s Free a c c e s s Free access Free a c c e s s Free access Free access
0-4t 4
Free Free Free Free Free Free Free Free Free Free Free
2 3 3]--4 4 4-0*
Guernsey 1 - 4 d a y s .............................. 4 - 7 d a y s .............................. 2 n d w e e k .............................. 3 r d w e e k .............................. 4 t h w e e k .............................. 5 t h w e e k .............................. 6 t h w e e k .............................. 7 t h w e e k .............................. 8 t h w e e k .............................. 9 t h w e e k .............................. 1 0 t h w e e k .............................. llth-14th w e e k s ............... 15th-16th w e e k s ............... 16th-24th w e e k s ............... * Gradually t Gradually
decreased. increased.
With
cow 5 6 7 7 6 6 5 4 3 3
¼ 1
1½ 1½ 2
2½ 3 3½-4 4-0*
access access access access access access access access access access access
823
THE BLOOD PLASMA OF DAIRY CALVES
tion of a previously published method (4). The calves were fed according to the schedule given in table 1. N u m b e r I clover and t i m o t h y h a y was fed as a roughage. Milk f r o m the Holstein herd was fed to all calves d u r i n g the milk feeding period. I n addition, one g r o u p of calves was fed according to the schedule in table 1 for the first 90 days a f t e r which they were placed on a v i t a m i n A deficient ration to s t u d y the rate of depletion as indicated b y blood-plasma analysis. A similar g r o u p of three calves were fed lespedeza h a y in place of clover and timothy hay. The clover a n d timothy h a y contained 15 microTABLE 2 Vitamin A and carote~e content of blood plasma of calves of the various breeds
Age, days
Holstein
I
~_yrshir¢
I
Guernsey
Micrograms vitamin A per 100 ml. plasma 8-21 22-35 36-49 50-63 64-77 78-91 92-105 106-119 120-133
(18) ~ 10.8+0.62 (17) 7.7 ± 0.79
(19)
8.2 ± 0.40
(15) (19) (17) (20) (19) (19)
9.9 + 0.76 10.2+0.58 10.1 +0.73 10,9 +0.57 10.2 +0.63 10.5±0.53
(10) (10) (11) (10) (11) (11) (10) (11) (8)
9.0 ± 7.2 + 8.1 +_ 9.2 +_ 8.9 + 9.9 -+_ 10.3 ± 11.7± 10.8±
1.19 0.52 0.51 0.50 0.79 0.79 0.91 0.94 0.80
(10)
11.0± 1.08
(9) (9) (10) (9) (9) (10) (8)
9.8± 9.7+ 11.1_+ 12.82 13.1+ 14.0+ 13.0±
(10)
9.8± 0.80 1.05 0.51 0.81 0.87 1.11 1.74 0.96
Micrograms carotene per 100 ml. plasma 8-21 22-35 36-49 50-63 64--77 78-91 92-105 106-119 120-133
(20) (19) (20) (16) (19) (20) (21) (20)
(18)
17.7 ± 1.8 23.3 +2.9 34.4_+3.7 52.6+4.4 52.6 +4.5 57.9±4.1 62.8±5.3 68.5 + 5.1
70.5+5.8
(10) (11) (12) (10)
19.6+ 16.5+ 30.8+ 46.5 ±
(12) (12) (12) (9)
45.5± 6.2 52.9_+ 8.0 63.6+ 6.6 81.1+_11.3
(12)
2.0 1.9 3.8 8.1
42.0+_ 5.0
(9) (10) (10) (9) (10) (9)
40.8+ 5.0 35.4+ 4.7 42.9+ 6,4 68.9 +10.6 82.8 + 9.3 80.9.+ 7.1 79.4_+10~2
(i0) ( 9 ) 100.0 + 13.7 (8)
97.6+12.7
Figures in parenthesis indicate number of determinations.
g r a m s of carotene per g r a m of h a y while the lespedeza contained 50 microg r a m s per gram. RESULTS AND DISCUSSION
The results of the analysis of the blood plasma for v i t a m i n A a n d carotene for the calves raised in the herd are shown in table 2. The d a t a h a v e been averaged according to breeds for each two weeks and the s t a n d a r d error ealeulated. The blood plasma values for the Holstein and A y r s h i r e calves are in close agreement. The plasma, carotene and v i t a m i n A values for the Guernsey calves are slightly higher. The higher values m a y be d u e to the f a c t t h a t the Guernsey calves received whole milk f o r a longer p e r i o d of time t h a n the Holstein and A y r s h i r e calves, or the correction f a c t o r applied to the an¢imony trichloride Vitamin A value for the carotene content
824
MOORE AND BERRY
of the blood plasma may be in error. standard
W h i l e b e t a c a r o t e n e w a s u s e d as a
for correction, this procedure
is o p e n t o c r i t i c i s m .
However, it
TABLE 3
Vitamiu A i~ micrograms per i00 ml. of blood plasma of calves fed a mixture of clover and timothy or lespedeza hay Clover and timothy 468 Age
469
Vitamin A
Age
470
Vitamin A
Vitamin A
Age i
41 52 70 83
7.5 7.4 7.7 10.4
39 54 68 81
9.6 7.2 5.7 7.5
25 39 54 68
19.7 13.2 10.4 12.9
97
5.7
95
6.3
81
10.2
112 126
2.4 0.6
110 124
2.4 0.3
95 110 126
4.5 7.2 7.8
Age
473
472
471 Vitamin A
Age
Vitamin A
Age
Vitamin A
25 39 54 68 81
9.0 6.0 6.6 4.8 7.5
26 41 55 68 82
6.3 6.0 6.3 12.3 9.0
16 23 38 52 65
9.0 5.4 5.4 12.9 14.1
95
3.0
97
12.6
79
10.5
ll0 124
4.8 5.1
111 124
5.4 5.1
94 108 129
11.7 7.8 3.0
Lespedeza 463
464
466
Age
Vitamin A
Age
Vitamin A
Age
Vitamin ±
36 50 57 76
10.5 12.3 21.6 27.3
32 39 49 55
12.6 15.9 21.9 26.7
34 60 71 84
13.4 12.3 23.4 22.5
107 120
16.2 10.5
64 77
31.2 27.8
98 112
10.2 3.6
128
13.5
91 105 120
21.0 5.1 6.6
126
8.1
* P l a c e d on carotene-free ration at 90 d a y s o f age.
seems quite unlikely that the vitamin A values for the Guernsey calves for this age group are lower than for the Holstein and Ayrshire calves.
THE BLOOD PLASMA OF DAIRY CALVES
825
I t should be pointed out and emphasized that the vitamin A values are in the deficient range when compared to those obtained f r o m calves four months to one year of age in data reported from this laboratory (6). While it should be noted that there are individual variations in calves kept on the same carotene intake, such low values as noted in this group of calves would lead to some expression of deficiency symptoms in older calves d u r i n g the winter months (6). Values of 15 micrograms of vitamin A per 100 ml. of plasma or above should be maintained to prevent deficiency symptoms in older calves. The data obtained with the two groups of calves fed lespedeza and clover and timothy hays are shown in table 3. Where clover and timothy hay was fed low-plasma vitamin A values similar to those as shown in table 2 resulted. When the calves were placed on a carotene free ration at 90 days of age, the vitamin A values dropped sharply. Where lespedeza was fed in place of the clover and timothy hay, the plasma vitamin A values were markedly higher. These higher values presumably were due to the higher carotene intake from the lespedeza hay. When the three calves were placed on the carotene free ration at 90 days of age, the vitamin A content of the blood plasma decreased at a slower rate and not to the extent as noted for the calves fed clover and timothy. This would indicate a much greater storage of vitamin A in the liver for the calves fed lespedeza hay. F r o m the practical feeding standpoint where limited amounts of whole milk are fed these data indicate that some vitamin A supplementation might be beneficial for calves for the first four to six weeks of age, especially where some difficulties are encountered in raising calves. W h e r e the roughage is of poor quality some supplementation to three months of age is indicated. These data, also, indicate that lespedeza hay because of its high carotene content should prove to be a good hay for calves. Some f u r t h e r attention should be given to the use of high carotene roughages f o r young calves which would obviate the feeding of vitamin A supplements, except for the first 30 days. J
SUMMARY
1. The vitamin A content of the blood plasma of calves of the Holstein, Ayrshire and Guernsey breeds from birth up to four months of age varies from 7.2 to 14 micrograms per 100 ml. 2. These values are in the deficient range when compared with those for vitamin k deficient calves at one year of age. 3. Some vitamin A supplementation is indicated where difficulty in raising calves is encountered. 4. The feeding of high-carotene lespedeza hay produced higher plasma vitamin A values in young calves than No. 1 mixed clover and timothy hay.
826
MOORE AND
BERRY
REFERENCES (1) CONVEESE, H. T., AND MEreS, E . B . The Vitamin Requirements for Normal Growth in Young Dairy Cattle. Amer. Soc. Anim. Prod. Proc. 32nd Ann. Rpt., p. 67-72. 1939. (2) GULLICKSON, T. W., AN]) FITCH; J . B . Effect of Adding Cod Liver Oil to the Rations of Dairy Calves. JouR. DAIRY ScI., 27: 331-335. 1944. (3) KRAUSS, W. E., MONROE, C. F., AND HAYDEN, C.C. The Value of Milk F a t Substitute-Skimmilk Combination for Raiging Bull Calves for Veal and Heifer Calves for Replacement. Ohio Agr. Expt. Sta. Spec. Cir. 57. (4) MOORE~ L. A. The Determination of Blood Plasma Carotene in the Bovine Using a Photoelectric Colorimeter. ;[ouR. DAIRY SCI., 22: 501-511. 1939. (5) MOORE, L . A . Vitamin A Activity of Milk Fat. Mich. Agr. Expt. Sta. Quart. Bul., 21: 169-174. 1939. (6) MOORE, L A., BERRY, M. H., AND SYKES, ;[. F. Caroteae Requirements for the Maintenance of a Normal Spinal Fluid Pressure in Dairy Calves. Jour. l~utr., 26: 649-658. 1943. (7) NELSON, H. F., MOORE, L. A., HORWOOD, R. E., AND BRANAMAN, G . A . Mich. Agr. KEpt. Sta. Quart B u l , 27: 27-28. 1944. (8) PHILLIPS, P. H., LUNDQUIST, N. S., AND BOYER, P: D. The Effect of Vitamin A and Certain Members of the B Complex upon Calf Scours. ;[OUR. DAIRY SCI.~ 24" 977-982. 1941.