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Mineral Composition of Colostral Milk1
MINERAL
COMPOSITION
OF COLOSTRAL
MILK 1
o. F. GARRETT2 AND 0. R. OVERMAN Illinois Agricultural Experiment Station, Urbana, Illinois
Th e u n i q u e i m p o r t a n c e of c o l o s t r u m in the diet of t h e n e w - b o r n calf has m a d e a s t u d y of its c o m p o s i t i o n of especial i n t e r e s t to s e v e r a l i n v e s t i g a t o r s . F u r t h e r i n t e r e s t has been s t i m u l a t e d by th e u su al legal definition of m a r k e t m i l k w h i c h p r e v e n t s t h e sale of m i l k w i t h i n 5 d a y s a f t e r p a r t u r i t i o n . I t has l o n g been k n o w n t h a t c o l o s t r u m is h i g h in to t al solids, e x t r e m e l y h i g h in t o t a l p r o t e i n a n d c o n t a i n s s o m e w h a t m o r e t o t a l ash, fat, a n d c h l o r i n e a n d somew h a t less lactose t h a n n o r m a l milk. I t has also been k n o w n f o r some t i m e t h a t the g r e a t increase in t o t a l p r o t e i n is due p r i m a r i l y to an increase in lactoglobulin. T h e w o r k of C r o w t h e r a n d R a i s t r i c k (1), W e l l s a n d Osborne (2) a n d W o o d m a n a n d H a m m o n d (3) is of especial i n t e r e s t in this connection. O v e r m a n a n d S a n m a n n (4), in 1926 s u m m a r i z e d the results on the COrnTABLE 1 Summarized results obtained by 25 investigators on cows' colostrum
Total solids
Ash
Fat
Total protein
Lactose
Specific gravity
%
%
%
%
%
First Milking No. of Analyses ............ Maximum ........................... Minimum ............................... Average .................................
66 38.40 13.72 24.55
58 2.31 0.68 1.33
73 9.55 0.15 3.89
54 27.35 4.80 16.76
53 4.62 0.00 2.50
59 1.0830 1.0318 1.0604
Second Milking No. of Analyses ............ Maximum ........................... Minimum .............................. Average .................................
45 31.11 11.83 18.00
40 1.37 0.60 0.97
44 9.00 0.50 3.84
42 19.47 5.01 9.33
16 4.70 2.37 3.52
1.0701 1.0299 1.0437
Third Milking No. of Analyses ............ Maximum ........................... Minimum ............................ Average .................................
17 27.62 12.89 16.75
16 1.25 0.67 0.96
15 5.18 0.56 3.1I
17 17.90 4.85 7.06
12 4.44 2.74 3.85
13 1.0710 1.0301 1.0376
Fourth Milking No. of Analyses ............ Maximum ........................... Minimum .............................. Average .................................
13 26.11 12.93 15.21
9 1.24 0.77 0.88
11 6.06 1.70 3.82
12 6.52 4.27 6.16
9 4.80 3.62 4.23
9 1.0625 1.0300 1.0372
38
Received for publication May 31, 1939. 1 The data used in this paper are taken from a thesis presented to the faculty of the graduate school of the University of Illinois by O. F. Garrett in partial fulfillment of the requirements for the Degree of Doctor of Philosophy. 2 Present address, New Jersey Agricultural Experiment Station, New Brunswick, New Jersey. 13
14
o.F.
GARRETT A N D O. R. OVERMAN
position of colostrum as obtained by 25 different investigators. A part of the data presented in table 1 of their article is shown here in table 1. Eugling (5) in 1875 seems to have been the first to report analytical data showing the ash content of colostrum during its change to normal milk. The more recent work of Engel and Schlag (6), in 1924, and Overman and Sanmann (4), in 1926, is more comprehensive, however, and a summary of their data dealing with ash content is presented in table 2. TABLE Changes (Data
from
Engel
in ash content
and Schlag
(6)
2 of colostrum
and Overman Overman
Time after parturition
A t o n c e ........................ 3 h o u r s ..................
Engel and Schlag
1.01
~
.....................
0.91
12
"
.....................
0.89
18
"
.....................
6
24 30 36 42 48 54 60 66 72 78 84 90 96 102 108 114 120 126 132 138 144 150
'~ c, ~' ~c ~' c~ ~' ~c c~ " ,c ,c " '~ ~' ~~ cc " cc ,.c ~~ "
156
~c
..................... .....................
162
~c
.....................
168
~ ~
.....................
...................
................... ..................... ..................... ..................... ..................... ..................... ..................... ..................... ..................... ..................... ..................... .....................
0.86 0.83 0.84
0.84
0.83
......................
...................... ..................... .....................
0.85
..................... ..................... ...................... ......................
0.84
and Sanmann and
Sanmann
Holstein 3rd lactation
1.02 0.91 0.97 0.93 0.86 0.84 0.82 0.81 0.82 0.80 0.80 0.79 0.79 0.77 0.77 0.80 0.78 0.79 0.76 0.76 0.85 0.82 0.78 0.79 0.80 0.76 0.77 0.78 0.75 0.76
(4))
Ayrshire 14th lactation
15th lactation
Left half 1.02
Right half 1.06
Left half 0.82
Right half 0.76
1.02
1.02
0.92
0.76
1.01 1.01 0.91 0.91 0.85 0.85 0.81 0.81 0.83 0.83 0.81 0.81 0.8O 0.80
0.92 0.87 0.84 0.82 0.79 0.77 0.77 0.78 0.80 0.80 0.78 0.77 O.78 0.78
0.94 0.91 0.90 0.85 0.77 0.78 0.85 0.79 0.78 0.76 0.76 0.75 0.76 0.74
0.90 0.90 0.94 0.94 0.79 0.79 0.88 0.88 0.77 0.77 0.73 0.73 0.76 0.76
0.76
0.76
0.78
0.76
65g
05~
The data of Overman and Sanmann is of especial interest with reference to the data presented in this paper which were also obtained on colostrum from a Holstein and an Ayrshire. The Ayrshire used by Overman and Sanmann, however, was quite an old cow while the one used in these studies was a first-calf heifer.
MINERAL. COMPOSITION OF COLOSTRAL MILK
15
Engel and Schlag (6) reported that the percentage of P205, CaO, MgO and NaC1 vary somewhat during the colostral period. IIollcn (7) found that the ash of colostrum differed considerably from that of normal milk. His data indicated that calcium and potassium had increased and the sodium decreased by the sixth day while the phosphorus had not reached a normal level. In the study reported in this paper the milks from a purebred IIolstein and a purebred Ayrshire were used. Both animals were first-calf heifers. In collecting the eolostrum samples all the milk from two quarters on the same side of the udder was taken. After thoroughly mixing, the milk was analyzed for total solids, total ash, total protein, fat, lactose and chlorides and samples were taken for the mineral element analysis. The latter were dried in large porcelain crucibles and slowly ashed in an electric furnace at a t e m p e r a t u r e w h i c h n e v e r e x c e e d e d 650 ° C. R e c o v e r y t e s t s o f a d d e d m i n e r a l e l e m e n t s i n d i c a t e d t h a t v e r y l i t t l e o r n o loss of e l e m e n t s o c c u r r e d d u r i n g the ashing process. T h e g r o s s c o m p o s i t i o n of t h e m i l k s of t h e t w o cows a r e p r e s e n t e d i n t a b l e TABLE 3 Gross
Time after calving
Specific gravity
composition
of
Total solids per
cent
colostrum
Ash per
cent
Protein per
cent
Fat per
cent
Lactose I per
cent
Holstein A t parturition ............... 6 hours .............................. 12 " .............................. 18 ,t .............................. 24 " .............................. 30
36 44 52 60 68 76 84 11
"
..............................
"
.............................
"
..............................
" "
..............................
'' c~
..............................
.............................. ..............................
'~ .............................. days .................................
1.0537 1.0345 1.0316 1.0308 1.0297 1.0304 1.0304 1.0302 1.0297 1.0301 1.0298 1.0314 1.0317 1.0302
27.42 27.47 15.63 14.56 13.98 13.41 13.54 13.52 ]3.35 14.22 14.17 13.82 ]4.70 12.78
1.37 :1.07 0.89 0.87 0.87 0.87 0.86 0.85 0.86 0.84 0.84 0.85 0.81 0.75
~3.97 9.34 4.77 4.25 3.99 4.09 3.85 3.57 3.66 3.70 3.79 3.86 3.58 2.92
8.45 13.02 5.68 5.26 4.88 3.88 4.08 4.25 4.14 5.02 5.19 4.68 6.79 4.33
3.63 4.04 4,29 4.18 4,24 4.57 4.75 4.85 4.69 4.66 4.35 4,43 3.52 4.78
1.16 1.03 0.91 0.83 0.79 0.87 0.91 0.86 0.82 0.82 0.85 0.75
14.70 11.36 7.00 4.44
5.40 4.85 8.46 4.90 4.43 2.31 3.92 3.14 3.23 4.25 4.00 3.73
4.12 3.91 3.95 4.67
Ayrshire A t parturition ............... 6 hours .............................. 12 " ............................. 18 '~ ............................. 24 " ............................... 32 ~' .............................. 40 ,c .............................. 48 , t .............................. 56 " ............................... 64 ' ' .............................. 72 " .............................. I 0 days .................................
1.0594 1.0457 1.0389 1.0342 1.0343 1.0346 1.0345 1.0322 1.0332 1.0321 1.0324 1.0361
25.38 21.15 20.32 14.84 ]3.70 11.65 13.81 12.22 12.52 12.98 12.87 13.56
4.09 4.17 4.06 3.73 3.83 3.86 3.17
4.38 4.81 4.16 4.74 4.08 4.16 5.91
O. F. GARRETT AND O. R. OVERMAN
16 3.
The lactose was obtained by difference
F a t ) ). At parturition
(Total solids--(Ash
+ Protein+
the specific gravity, total solids, total ash, total protein
and fat are high. These initial values are followed by a fairly steady decline during the colostral period. I t is i n t e r e s t i n g t o n o t e t h e h i g h f a t c o n t e n t i n t h e m i l k s o f t h e t w o cows r e s p e c t i v e l y a t 6 a n d 12 h o u r s a f t e r p a r t u r i t i o n . T h e l a c t o s e c o n t e n t of t h e s e m i l k s is c o r r e s p o n d i n g l y
low but shows, a fairly
steady increase as the other milk components decrease. The percentages of calcium, magnesium, potassium, sodium, phosphorus a n d c h l o r i n e a r e s h o w n i n t a b l e 4. C a l c i u m w a s d e t e r m i n e d b y p e r m a n g a n o metric titration of the precipitated oxalate, magnesium by thiosulfate titration after precipitation with 8-hydroxyquinoline and bromination of the precipitate, potassium by permanganometric t i t r a t i o n of t h e p r e c i p i t a t e d potassium sodium cobaltinitrite, sodium by uranyl zinc acetate precipitation a f t e r r e m o v a l of o r t h o p h o s p h a t e w i t h s o l i d z i n c c a r b o n a t e , p h o s p h o r u s b y a l k a l i t i t r a t i o n of t h e p r e c i p i t a t e d a m m o n i u m p h o s p h o m o l y b d a t e a n d c h l o rine by a modified Volhard titration. TABLE 4 Mineral
Time after calving
Calcium I per cent
[
composition
of colostrum
Magnesium
Potassium
Sodium
Phosphorus
Chlorine
per cent
per cent
per vent
per cent
per vent
0.074 0.061 0.051 0.048 0.050 0.050 0.048 0.049 0.054 0.074 0.052 0.065 0.053 0.036
0.235 0.178 0.146 0.143 0.137 0.134 0.131 0.127 0.125 0.135 0.125 0.176 0.131 0.113
0.118 0.118 0.101 0.098 0.]02 0.101 0.103 0.098 0.103 0.105 0.103 0.099 0.099
0.079 0.050 0.072 0.068 0.065 0.052 0.053 0.058 0.054 0.052 0.056 0.047
0.192 0.123 0.142 0.130 0.129 0.132 0.150 0.137 0.120 0.124 0.125 0.110
0.122 0.117 0.121
ttolstein A t parturition .... 6 hours ..................... 12 " ..................... 18 c, .................... 24 '~ "..................... 30 ,c ..................... 36 ~' ..................... 44 ~~ ..................... 52 " ..................... 60 ~ ..................... 68 ,c ..................... 76 " ..................... 84 '~ ..................... 11 days ........................
" 0.256 0.196 0.154 0.153 0.150 0.151 0.150 0.148 0.154 0.175 0.153 0.176 0.167 0.130
0.037 0.027 0.014 0.012 0.013 0.012 0.012 0.013 0.013 0.014 0.012 0.013 0.012 0.011
0.137 0.128 0.132 0.139 0.145 0.158 0.154 0.136 0.152 0.170 0.151 0.146 0.174 0.153 A rshire
A t parturition ...... 6 hours ..................... 12 " ..................... 18 ~c ..................... 24 ~c ..................... 32 ~c ..................... 40 " ..................... 48 ' ~ ..................... 56 '~ ..................... 64 ~c ..................... 72 c, ..................... 10 days ........................
0.206 0.154 0.142 0.126 0.124 0.133 0.144 0.137 0.126 0.127 0.131 0.120
0.034 0.012 0.019 0.013 0.013 0.013 0.014 0.014 0.012 0.014 0.015 0.011
0.125 0.152 0.140 0.153 0.154 0.178 0.181 0.171 0.149 0.161 0.163 0.152
0.117 0.105 0.091 0.100 0.102 0.094 0.096 0.068
]VIINERAL COMPOSITION OF COLOSTRAIJ 1V~ILK
17
The percentages given in table 4 are for the various elements and not for the oxides of these elements. Calcium, magnesium, sodium, phosphorus and chlorine are all high at parturition and during the early hours of lactation but a rather rapid decline toward a fairly constant level soon sets in as the milk becomes normal. On the other hand, potassium is rather low at parturition but gradually increases toward a fairly constant level as the milk progresses toward normality. REFERENCES (1) CROW~HER, C., AND RA~STRICK, It. Protein composition of milk. Biochem. J , 10: 438. 1916. (2) WELLS, I-I. G., AND OSBORNE, T . B . Anaphylaxis reactions with purified proteins from milk. J. Infect. Dis, 29: 200. 1921. (3) WOODt~AI~,H. E., AND HAMMOND, J. The composition of secretions obtained from the udders of heifers during pregnancy. J. Agr. Sc., 13: 180. 1923. (4) OVERI~AN,O. R., AND SAN~,[ANI~,F . F . Study of the rate of variation in the composition of colostrum of the cow. Le Lait~ 6: 626. ]926. (5) EUGLING, W. Rer. Thatigkeit landw-chem. Vers-Sta. Landes Vorarlberg. page 40. 1875~ 1876. Through " F u n d a m e n t a l s of Dairy Selene%" 2nd. ed, page 20, The associates of L. A. Rogers, Reinhold Pub. Co., New'York, N. Y. (6) ENGEL, I~., AND SC~LAG, H. The colostrum of the cow. Milchwirtsehaft. Forsch., 2: 1. 1924. (7) ttOLLEN, J. Co]ostrum. Deut tierarztl. Wschr. 33" 386. 1925.
COMPOSITION
OF COLOSTRAL
MILK 1
o. F. GARRETT2 AND 0. R. OVERMAN Illinois Agricultural Experiment Station, Urbana, Illinois
Th e u n i q u e i m p o r t a n c e of c o l o s t r u m in the diet of t h e n e w - b o r n calf has m a d e a s t u d y of its c o m p o s i t i o n of especial i n t e r e s t to s e v e r a l i n v e s t i g a t o r s . F u r t h e r i n t e r e s t has been s t i m u l a t e d by th e u su al legal definition of m a r k e t m i l k w h i c h p r e v e n t s t h e sale of m i l k w i t h i n 5 d a y s a f t e r p a r t u r i t i o n . I t has l o n g been k n o w n t h a t c o l o s t r u m is h i g h in to t al solids, e x t r e m e l y h i g h in t o t a l p r o t e i n a n d c o n t a i n s s o m e w h a t m o r e t o t a l ash, fat, a n d c h l o r i n e a n d somew h a t less lactose t h a n n o r m a l milk. I t has also been k n o w n f o r some t i m e t h a t the g r e a t increase in t o t a l p r o t e i n is due p r i m a r i l y to an increase in lactoglobulin. T h e w o r k of C r o w t h e r a n d R a i s t r i c k (1), W e l l s a n d Osborne (2) a n d W o o d m a n a n d H a m m o n d (3) is of especial i n t e r e s t in this connection. O v e r m a n a n d S a n m a n n (4), in 1926 s u m m a r i z e d the results on the COrnTABLE 1 Summarized results obtained by 25 investigators on cows' colostrum
Total solids
Ash
Fat
Total protein
Lactose
Specific gravity
%
%
%
%
%
First Milking No. of Analyses ............ Maximum ........................... Minimum ............................... Average .................................
66 38.40 13.72 24.55
58 2.31 0.68 1.33
73 9.55 0.15 3.89
54 27.35 4.80 16.76
53 4.62 0.00 2.50
59 1.0830 1.0318 1.0604
Second Milking No. of Analyses ............ Maximum ........................... Minimum .............................. Average .................................
45 31.11 11.83 18.00
40 1.37 0.60 0.97
44 9.00 0.50 3.84
42 19.47 5.01 9.33
16 4.70 2.37 3.52
1.0701 1.0299 1.0437
Third Milking No. of Analyses ............ Maximum ........................... Minimum ............................ Average .................................
17 27.62 12.89 16.75
16 1.25 0.67 0.96
15 5.18 0.56 3.1I
17 17.90 4.85 7.06
12 4.44 2.74 3.85
13 1.0710 1.0301 1.0376
Fourth Milking No. of Analyses ............ Maximum ........................... Minimum .............................. Average .................................
13 26.11 12.93 15.21
9 1.24 0.77 0.88
11 6.06 1.70 3.82
12 6.52 4.27 6.16
9 4.80 3.62 4.23
9 1.0625 1.0300 1.0372
38
Received for publication May 31, 1939. 1 The data used in this paper are taken from a thesis presented to the faculty of the graduate school of the University of Illinois by O. F. Garrett in partial fulfillment of the requirements for the Degree of Doctor of Philosophy. 2 Present address, New Jersey Agricultural Experiment Station, New Brunswick, New Jersey. 13
14
o.F.
GARRETT A N D O. R. OVERMAN
position of colostrum as obtained by 25 different investigators. A part of the data presented in table 1 of their article is shown here in table 1. Eugling (5) in 1875 seems to have been the first to report analytical data showing the ash content of colostrum during its change to normal milk. The more recent work of Engel and Schlag (6), in 1924, and Overman and Sanmann (4), in 1926, is more comprehensive, however, and a summary of their data dealing with ash content is presented in table 2. TABLE Changes (Data
from
Engel
in ash content
and Schlag
(6)
2 of colostrum
and Overman Overman
Time after parturition
A t o n c e ........................ 3 h o u r s ..................
Engel and Schlag
1.01
~
.....................
0.91
12
"
.....................
0.89
18
"
.....................
6
24 30 36 42 48 54 60 66 72 78 84 90 96 102 108 114 120 126 132 138 144 150
'~ c, ~' ~c ~' c~ ~' ~c c~ " ,c ,c " '~ ~' ~~ cc " cc ,.c ~~ "
156
~c
..................... .....................
162
~c
.....................
168
~ ~
.....................
...................
................... ..................... ..................... ..................... ..................... ..................... ..................... ..................... ..................... ..................... ..................... .....................
0.86 0.83 0.84
0.84
0.83
......................
...................... ..................... .....................
0.85
..................... ..................... ...................... ......................
0.84
and Sanmann and
Sanmann
Holstein 3rd lactation
1.02 0.91 0.97 0.93 0.86 0.84 0.82 0.81 0.82 0.80 0.80 0.79 0.79 0.77 0.77 0.80 0.78 0.79 0.76 0.76 0.85 0.82 0.78 0.79 0.80 0.76 0.77 0.78 0.75 0.76
(4))
Ayrshire 14th lactation
15th lactation
Left half 1.02
Right half 1.06
Left half 0.82
Right half 0.76
1.02
1.02
0.92
0.76
1.01 1.01 0.91 0.91 0.85 0.85 0.81 0.81 0.83 0.83 0.81 0.81 0.8O 0.80
0.92 0.87 0.84 0.82 0.79 0.77 0.77 0.78 0.80 0.80 0.78 0.77 O.78 0.78
0.94 0.91 0.90 0.85 0.77 0.78 0.85 0.79 0.78 0.76 0.76 0.75 0.76 0.74
0.90 0.90 0.94 0.94 0.79 0.79 0.88 0.88 0.77 0.77 0.73 0.73 0.76 0.76
0.76
0.76
0.78
0.76
65g
05~
The data of Overman and Sanmann is of especial interest with reference to the data presented in this paper which were also obtained on colostrum from a Holstein and an Ayrshire. The Ayrshire used by Overman and Sanmann, however, was quite an old cow while the one used in these studies was a first-calf heifer.
MINERAL. COMPOSITION OF COLOSTRAL MILK
15
Engel and Schlag (6) reported that the percentage of P205, CaO, MgO and NaC1 vary somewhat during the colostral period. IIollcn (7) found that the ash of colostrum differed considerably from that of normal milk. His data indicated that calcium and potassium had increased and the sodium decreased by the sixth day while the phosphorus had not reached a normal level. In the study reported in this paper the milks from a purebred IIolstein and a purebred Ayrshire were used. Both animals were first-calf heifers. In collecting the eolostrum samples all the milk from two quarters on the same side of the udder was taken. After thoroughly mixing, the milk was analyzed for total solids, total ash, total protein, fat, lactose and chlorides and samples were taken for the mineral element analysis. The latter were dried in large porcelain crucibles and slowly ashed in an electric furnace at a t e m p e r a t u r e w h i c h n e v e r e x c e e d e d 650 ° C. R e c o v e r y t e s t s o f a d d e d m i n e r a l e l e m e n t s i n d i c a t e d t h a t v e r y l i t t l e o r n o loss of e l e m e n t s o c c u r r e d d u r i n g the ashing process. T h e g r o s s c o m p o s i t i o n of t h e m i l k s of t h e t w o cows a r e p r e s e n t e d i n t a b l e TABLE 3 Gross
Time after calving
Specific gravity
composition
of
Total solids per
cent
colostrum
Ash per
cent
Protein per
cent
Fat per
cent
Lactose I per
cent
Holstein A t parturition ............... 6 hours .............................. 12 " .............................. 18 ,t .............................. 24 " .............................. 30
36 44 52 60 68 76 84 11
"
..............................
"
.............................
"
..............................
" "
..............................
'' c~
..............................
.............................. ..............................
'~ .............................. days .................................
1.0537 1.0345 1.0316 1.0308 1.0297 1.0304 1.0304 1.0302 1.0297 1.0301 1.0298 1.0314 1.0317 1.0302
27.42 27.47 15.63 14.56 13.98 13.41 13.54 13.52 ]3.35 14.22 14.17 13.82 ]4.70 12.78
1.37 :1.07 0.89 0.87 0.87 0.87 0.86 0.85 0.86 0.84 0.84 0.85 0.81 0.75
~3.97 9.34 4.77 4.25 3.99 4.09 3.85 3.57 3.66 3.70 3.79 3.86 3.58 2.92
8.45 13.02 5.68 5.26 4.88 3.88 4.08 4.25 4.14 5.02 5.19 4.68 6.79 4.33
3.63 4.04 4,29 4.18 4,24 4.57 4.75 4.85 4.69 4.66 4.35 4,43 3.52 4.78
1.16 1.03 0.91 0.83 0.79 0.87 0.91 0.86 0.82 0.82 0.85 0.75
14.70 11.36 7.00 4.44
5.40 4.85 8.46 4.90 4.43 2.31 3.92 3.14 3.23 4.25 4.00 3.73
4.12 3.91 3.95 4.67
Ayrshire A t parturition ............... 6 hours .............................. 12 " ............................. 18 '~ ............................. 24 " ............................... 32 ~' .............................. 40 ,c .............................. 48 , t .............................. 56 " ............................... 64 ' ' .............................. 72 " .............................. I 0 days .................................
1.0594 1.0457 1.0389 1.0342 1.0343 1.0346 1.0345 1.0322 1.0332 1.0321 1.0324 1.0361
25.38 21.15 20.32 14.84 ]3.70 11.65 13.81 12.22 12.52 12.98 12.87 13.56
4.09 4.17 4.06 3.73 3.83 3.86 3.17
4.38 4.81 4.16 4.74 4.08 4.16 5.91
O. F. GARRETT AND O. R. OVERMAN
16 3.
The lactose was obtained by difference
F a t ) ). At parturition
(Total solids--(Ash
+ Protein+
the specific gravity, total solids, total ash, total protein
and fat are high. These initial values are followed by a fairly steady decline during the colostral period. I t is i n t e r e s t i n g t o n o t e t h e h i g h f a t c o n t e n t i n t h e m i l k s o f t h e t w o cows r e s p e c t i v e l y a t 6 a n d 12 h o u r s a f t e r p a r t u r i t i o n . T h e l a c t o s e c o n t e n t of t h e s e m i l k s is c o r r e s p o n d i n g l y
low but shows, a fairly
steady increase as the other milk components decrease. The percentages of calcium, magnesium, potassium, sodium, phosphorus a n d c h l o r i n e a r e s h o w n i n t a b l e 4. C a l c i u m w a s d e t e r m i n e d b y p e r m a n g a n o metric titration of the precipitated oxalate, magnesium by thiosulfate titration after precipitation with 8-hydroxyquinoline and bromination of the precipitate, potassium by permanganometric t i t r a t i o n of t h e p r e c i p i t a t e d potassium sodium cobaltinitrite, sodium by uranyl zinc acetate precipitation a f t e r r e m o v a l of o r t h o p h o s p h a t e w i t h s o l i d z i n c c a r b o n a t e , p h o s p h o r u s b y a l k a l i t i t r a t i o n of t h e p r e c i p i t a t e d a m m o n i u m p h o s p h o m o l y b d a t e a n d c h l o rine by a modified Volhard titration. TABLE 4 Mineral
Time after calving
Calcium I per cent
[
composition
of colostrum
Magnesium
Potassium
Sodium
Phosphorus
Chlorine
per cent
per cent
per vent
per cent
per vent
0.074 0.061 0.051 0.048 0.050 0.050 0.048 0.049 0.054 0.074 0.052 0.065 0.053 0.036
0.235 0.178 0.146 0.143 0.137 0.134 0.131 0.127 0.125 0.135 0.125 0.176 0.131 0.113
0.118 0.118 0.101 0.098 0.]02 0.101 0.103 0.098 0.103 0.105 0.103 0.099 0.099
0.079 0.050 0.072 0.068 0.065 0.052 0.053 0.058 0.054 0.052 0.056 0.047
0.192 0.123 0.142 0.130 0.129 0.132 0.150 0.137 0.120 0.124 0.125 0.110
0.122 0.117 0.121
ttolstein A t parturition .... 6 hours ..................... 12 " ..................... 18 c, .................... 24 '~ "..................... 30 ,c ..................... 36 ~' ..................... 44 ~~ ..................... 52 " ..................... 60 ~ ..................... 68 ,c ..................... 76 " ..................... 84 '~ ..................... 11 days ........................
" 0.256 0.196 0.154 0.153 0.150 0.151 0.150 0.148 0.154 0.175 0.153 0.176 0.167 0.130
0.037 0.027 0.014 0.012 0.013 0.012 0.012 0.013 0.013 0.014 0.012 0.013 0.012 0.011
0.137 0.128 0.132 0.139 0.145 0.158 0.154 0.136 0.152 0.170 0.151 0.146 0.174 0.153 A rshire
A t parturition ...... 6 hours ..................... 12 " ..................... 18 ~c ..................... 24 ~c ..................... 32 ~c ..................... 40 " ..................... 48 ' ~ ..................... 56 '~ ..................... 64 ~c ..................... 72 c, ..................... 10 days ........................
0.206 0.154 0.142 0.126 0.124 0.133 0.144 0.137 0.126 0.127 0.131 0.120
0.034 0.012 0.019 0.013 0.013 0.013 0.014 0.014 0.012 0.014 0.015 0.011
0.125 0.152 0.140 0.153 0.154 0.178 0.181 0.171 0.149 0.161 0.163 0.152
0.117 0.105 0.091 0.100 0.102 0.094 0.096 0.068
]VIINERAL COMPOSITION OF COLOSTRAIJ 1V~ILK
17
The percentages given in table 4 are for the various elements and not for the oxides of these elements. Calcium, magnesium, sodium, phosphorus and chlorine are all high at parturition and during the early hours of lactation but a rather rapid decline toward a fairly constant level soon sets in as the milk becomes normal. On the other hand, potassium is rather low at parturition but gradually increases toward a fairly constant level as the milk progresses toward normality. REFERENCES (1) CROW~HER, C., AND RA~STRICK, It. Protein composition of milk. Biochem. J , 10: 438. 1916. (2) WELLS, I-I. G., AND OSBORNE, T . B . Anaphylaxis reactions with purified proteins from milk. J. Infect. Dis, 29: 200. 1921. (3) WOODt~AI~,H. E., AND HAMMOND, J. The composition of secretions obtained from the udders of heifers during pregnancy. J. Agr. Sc., 13: 180. 1923. (4) OVERI~AN,O. R., AND SAN~,[ANI~,F . F . Study of the rate of variation in the composition of colostrum of the cow. Le Lait~ 6: 626. ]926. (5) EUGLING, W. Rer. Thatigkeit landw-chem. Vers-Sta. Landes Vorarlberg. page 40. 1875~ 1876. Through " F u n d a m e n t a l s of Dairy Selene%" 2nd. ed, page 20, The associates of L. A. Rogers, Reinhold Pub. Co., New'York, N. Y. (6) ENGEL, I~., AND SC~LAG, H. The colostrum of the cow. Milchwirtsehaft. Forsch., 2: 1. 1924. (7) ttOLLEN, J. Co]ostrum. Deut tierarztl. Wschr. 33" 386. 1925.