DDT in Milk and Tissues of Dairy Cows Fed DDT-Dusted Alfalfa Hay

DDT in Milk and Tissues of Dairy Cows Fed DDT-Dusted Alfalfa Hay CLYDE BIDDULPH, G. Q. BATEMAN, M. J. BRYSON, J. R. HARRIS, D. A. GREENWOOD, WAYNE BINNS, M. L. MINER, L. E. HARRIS, and L. L. MADSEN

Downloaded by AUBURN UNIV on December 26, 2017 | http://pubs.acs.org Publication Date: January 1, 1950 | doi: 10.1021/ba-1950-0001.ch044

Utah Agricultural Experiment Station, Logan, Utah

Untreated alfalfa hay and hay dusted with technical DDT were fed to 16 Holstein cows during 2 years DDT appeared in the milk within 4 days after the feeding of DDT-treated hay and the amount gradually increased until a fairly constant level was reached. More DDT was found in milk and tissues of cows that consumed hay treated with higher levels of DDT. DDT persisted in the milk for 4 months and dis appeared approximately 6.5 months after feeding of DDT-treated hay was discontinued.

Γ revious studies have shown that D D T appears in the milk and body fat of dogs (18), in the milk of rats and goats (11), in the tissues, especially fatty tissues, of rats (5, 6) and rabbits (4), i n the milk and tissues of dairy cows (1, 10), and i n the tissues (2) and milk (7) of sheep following the ingestion of D D T or of feeds containing D D T residues. D D T persists i n the milk of cows for relatively long periods of time after they have been sprayed with D D T for the control of flies (3). Inasmuch as these studies established the accumulation of D D T i n the fatty tissues and its appearance i n the milk following the ingestion of relatively large doses of D D T , the question arose as to whether the milk of dairy cows consuming alfalfa hay with low D D T residues contained sufficient D D T to be hazardous to animals and humans consum ing the milk. The problem assumed greater importance because of the practice i n this and other areas of dusting forage alfalfa with D D T for the control of alfalfa weevil and other insects and the feeding of such alfalfa hay to dairy cows. This paper reports data obtained following feeding of D D T - d u s t e d alfalfa hay to H o l stein dairy cows. M i l k , blood, and tissues were analyzed for their D D T content during two different years of feeding of the D D T - d u s t e d hay.

Materials and Methods Alfalfa hay was obtained from a 44-acre unirrigated field at Petersboro, Cache County) U t a h . Thefieldwas divided into sixteen 1-acre plots with intervening untreated buffer strips of sufficient width (150 feet) to prevent drift of the D D T dust from one plot to another at the time of application. A block of four 1-acre plots received the following treatments during the summer of 1947 : no D D T , 1 pound, 2.pounds, and 4 pounds of tech nical D D T per acre, and no D D T , 0.5 pound, 1 pound, and 2 pounds of technical D D T per acre during the summer of 1948. These treatments were repeated on the remaining three blocks of plots, so that a total of four 1-acre plots received each treatment. T h e treatments within each block were assigned at random. The D D T dust i n a pyrophyllite carrier was applied with a power duster when a sub237

AGRICULTURAL CONTROL CHEMICALS Advances in Chemistry; American Chemical Society: Washington, DC, 1950.

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stantial number of alfalfa weevil (Hypera postica Gyll.) larvae were present on the alfalfa. The number was determined by sweeping each of the plots with a hand net and counting the larvae obtained from each plot. These data will be published elsewhere. The alfalfa used was second crop i n 1947 and first crop i n 1948. I t was cut when the majority of the plots dusted with D D T were judged to be i n the tenth-bloom stage. The alfalfa within each plot was allowed to sun-cure, and was then baled and hauled tothe college barns for storage. Eight cows were chosen from the college experimental herd each year, two cows being assigned to hay from each of the field treatments. M i l k and blood samples were obtained from each cow before the experiment started (January 21, 1948, and November 24, 1948), and these samples were analyzed for D D T . On the day after the cows began eating the control and experimental hays (November 1948), and on the fourth day after (January 1948), milk samples were obtained and analyzed for D D T . Samples were then collected and analyzed at 3-day intervals until the concentration of D D T in the milk had reached a relatively constant level, after which samples were collected at weekly or longer intervals until the experiments were terminated several months later (Tables I and I I and Figures 1 and 2). Feeding of alfalfa hay was discontinued on M a y 13, after 113 days, the first year of the experiment, at which time the cows went to pasture. Sampling and analysis of the milk for D D T continued, however, until September 16. During the second year, the feeding of the alfalfa hay commenced on November 24 and continued until February 13, a period of 81 days. Between this time and the time the cows went to pasture ( M a y ) , they were fed untreated hay from the college fields. Blood and milk samples were collected the second year before, during, and following the period of feeding the treated alfalfa hay. The D D T content of the tissues and milk was determined by the colorimetric method of Schechter et al. (8, 9) as modified by the authors (2). The amount of D D T residue on the hay was determined b y the total chloride method of Umhoefer (12). Cow H u 29 (fed hay treated with 2 pounds of D D T per acre) was slaughtered on M a y 20, 1948, one week after experimental feeding was discontinued. Kidney and mesenteric AGRICULTURAL CONTROL CHEMICALS Advances in Chemistry; American Chemical Society: Washington, DC, 1950.

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BIDDULPH ef al.—DDT IN MILK AND TISSUES OF DAIRY COWS


fat, muscle, and liver were analyzed for D D T content. I n 1949 cows H u 36 (fed hay treated with 1 pound of D D T per acre) and H u 329 (fed untreated hay) were slaughtered at the close of the feeding period and the tissues were analyzed for their D D T content as before. Cow Ε 139 (fed hay treated with 1 pound of D D T per acre) was slaughtered on June 29, 1949, approximately 4 months after the feeding of the D D T - t r e a t e d hay was dis continued, and the tissues were likewise analyzed for their D D T content. In addition to the alfalfa hay, the cows received a grain ration which consisted of a mixture of 8 0 % barley and 2 0 % molasses dried beet pulp, to which were added 2 % steam bone meal and 1% fine hay salt (sodium chloride). This ration was fed at the rate of 0.75 pound of grain per day for each pound of butterfat produced during the previous week. If the butterfat production dropped below 0.8 pound per day, the grain ration was routinely discontinued.

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In order to determine whether there was sufficient D D T in the milk to produce effects in rats, milk from the cows was separated and the cream was incorporated into a synthetic diet which was fed to a group of rats for a period of 4 months. Butter was churned from some of the cream and this was likewise incorporated into a diet and was fed to another group of rats. These data will be published elsewhere.

Results and Discussion The amount of D D T present in the milk of the cows during the winter of 1948 is presented in Table I and Figure 1. N o D D T was present in the milk of any of the cows at the beginning of the experiment. However, within 4 days after the feeding of D D T treated hay was begun, D D T appeared i n the milk. The amount gradually increased until a fairly constant level was reached before the feeding of D D T - t r e a t e d hay was dis continued. Calculation of the average amount of D D T present i n the milk throughout the period of feeding of the D D T - t r e a t e d hay shows that the amount i n the milk was de pendent upon the amount applied to the hay (1 pound of D D T applied, 1.7 p.p.m. in the milk; 2 pounds of D D T applied, 3.3 p.p.m. in the milk; and 4 pounds applied, 7.1 p.p.m. in the milk). One of the control cows (A 133) had a trace of D D T in her milk shortly after the feeding of the alfalfa hay was begun. Inspection of the manger of this cow revealed an opening through which i t was possible for her to obtain a small amount of hay from the adjoining manger, and the attendant observed this cow obtaining such hay (treated with 2 pounds of D D T per acre). After the manger was repaired, the amount of D D T i n the milk of this cow decreased, but a trace of D D T persisted even after the cow freshened sev eral months later (see Table I ) . The other cows, Ε 139 and H u 106, came to the end of their lactation period after 3 to 3.5 months on experiment. After freshening there was still a trace of D D T present i n AGRICULTURAL CONTROL CHEMICALS Advances in Chemistry; American Chemical Society: Washington, DC, 1950.

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Table I.

DDT in Milk of Cows Fed Alfalfa Hay Dusted with DDT (1948) (P.p.m. of D D T ) No D D T A 133 Hu 88 Av.


Day Ό (Jan. 21) 4 7 11 13 16 19 -22 25 28 31 34 37 40 43 50 57 64 71 78 85 92 99 106 113 120 127 134 141 148 155 162 169 176 183 190 197 204 211 225 232 239 (Sept. 16) a

0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.5 0.0 0.6 0.0 0.4 0.0 0.3 0.0 0.6 0.0 0.9 0.0 1.1 0.0 1.4 0.0 1.2 0.0 1.2 0.0 0.5 0.0 0.5 0.0 0.3 0.0 0.3 0.0 0.4 0.0 0.3 0.0 0.2 0.0 0.2 0.0 0.2 0.0 0.2 0.0 0.4 0.0 0.1 0.0 0.2 0.0 0.2 0.0 Dry 0.0 Dry 0.0 Dry 0.0 Dry 0.0 Dry 0.0 Dry 0.0 Dry 0.0 Fresh 0.0 0.1 0.0 0.1 0.0 0.1 Killed 0.1 0.1 0.1

0.0 0.0 0.0 0.0 0.2 0.3 0.2 0.1 0.3 0.4 0.5 0.7 0.6 0.6 0.2 0.2 0.1 0.1 0.2 0.1 0.1 0.1 0.1 0.1 0.2 0.05 0.1 0.1 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.05 0.05 0.1 0.1 0.1 0.1

1 Lb. D D T per Acre Hu 39 Ε 139 A v . 0.0 1.4 0.3 0.5 2.0 2.2 1.3 0.5 2.5 1.3 0.8 2.6 2.2 1.9 2.3 0.6 2.6 l'.è 2.7 1.6 1.9 1.3 2.6 1.8 0.5 0.5 0.3 0.1 0.2 0.2 0.1 0.2 0.1 0.1 0.2 0.2 0.1 0.05 0.1 0.05 0.05

0.0 0.7 0.4 1.8 1.7 1.5 1.6 1.1 0.8 2.1 2.4 2.7 1.8 2.2 2.2 2.1 1.8 2.9 3.0 3.8 2.6 2.7 Dry Dry Dry Dry Dry Dry Dry Dry Dry Dry Dry Dry Dry Dry Fresh 0.4 0.5 0.3 0.3 0.2

0.0 1.0 0.3 1.1 1.8 1.8 1.4 0.8 1.6 1.7 1.6 2.6 2.0 2.0 2.2 1.3 2.2 2.9 2.3 3.2 2.1 2.3 1.3 2.6 1.8 0.5 0.5 0.3 0.1 0.2 0.2 0.1 0.2 0.1 0.1 0.2 0.2 0.3 0.3 0.2 0.2 0.1

2 Lb. D D T per Acre Hu 29 Hu 106 Av. 0.0 2.2 0.6 0.7 2.6 3.8 1.1 1.1 3.7 3.9 4.9 4.4 3.8 2.4 3.4 3.4 4.5 4.1 5.5 4.9 4.5 4.8 6.3 7.2 Killed

0.0 1.7 0.4 0.6 3.0 2.9 1.0 2.2 3.0 2.2 3.3 3.8 3.6 3.5 2.9 3.3 2.4 3Ϊ6 4.5 3.6 4.5 4.1 4.3 5.4 1.5 1.7 1.1 Dry Dry Dry Dry Dry Dry Dry Fresh 0.4 0.3 0.2 0.2 0.2 0.3

0.0 1.9 0.5 0.6 2.8 3.3 1.0 1.6 3.0 2.9 3.6 4.3 4.0 3.6 2.6 3.3 2.9 4.5 3.8 5.0 4.2 4.5 4.4 5.3 6.3 1.5 1.7 1.1

0.4 0.3 0.2 0.2 0.2 0.3

4 Lb. D D T per Acre Ε 180 Ε 199 Av. 0.0 2.2 1.3 1.6 8.0 8.1 5.4 6.1 8.7 9.0 8.7 12.5 8.1 6.8 9.8 10.0 11.5 9.7 12.5 11.5 11.3 11.9 9.6 12.3 4.2 2.8 1.9 2.0 1.1 1.0 0.8 0.5 0.6 0.5 0.4 0.4 0.3 0.4 0.3 0.3 0.3

0.0 2.2 0.7 1.5 5.1 4.4 4.3 2.8 5.2 6.0 6.5 7.3 7.8 4.4 5.0 5.0 7.6 7.3 7.2 9.0 8.3 7.1 6.7 8.0 7.5 3.1 1.6 1.9 1.5 1.3 1.1 0.9 0.9 0.6 0.5 0.6 0.6 0.5 0.2 0.4 0.4

0.0 2.2 1.0 1.5 6.5 6.2 4.8 4.4 6.9 7.5 7.6 9.9 7.8 6.2 5.9 7.4 8.8 9.4 8.4 10.7 9.9 9.2 9.3 8.8 9.9 3.6 2.2 1.9 1.7 1.2 1.0 0.8 0.7 0.6 0.5 0.5 0.5 0.4 0.3 0.3 0.3 0.3

** M a y 13, cows off hay, to pasture.

Table II.

DDT in Milk of Cows Fed Alfalfa Hay Dusted with DDT (1948-49) (P.p.m. of D D T )

Day 0 (Nov. 24) 1 2 6 10 13 16 19 22 25 33 40 47 54 61 69 75 81 (Feb. 13) 82 91 96 103 110 131 145 161 180 209 (June 21)

No D D T Hu 85 Hu329 Av.

0.5 L b . D D T per Acre Av. Ε 181 H u 83

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.1 0.05 0 0 0 0.7 0.8 0.8 0 0 0 0.3 0.8 0.6 0 0 0 0.4 0.5 0.5 0 0 0 0.8 1.0 1.1 0 0 0 0.6 0.6 0.6 0 0 0 0.3 0.4 0.4 0 0 0 0.3 0.4 0.4 0 0 0.6 0.3 0.5 0 0 0 0 0.6 0.6 0.6 0 0 0 0.7 0.6 0.7 0 0 0 0.8 1.3 1.1 0 0 0 1.5 1.4 1.3 0 0 0 1.4 2.2 1.8 0 0 0 1.4 0.9 1.2 Last day that D D T - treated hay was fed 0 0 0 0.5 0.5 0.3 0 0.3 0 0 0 0.2 0.2 0 0 0 0Ϊ2 0.2 0 0 0.1 0 0.1 0.2 0.2 0 0 0 0 0.2 0.2 0.2 0 0 0 0 Dry 0.4 0.4 0 0 0 Dry 0.2 0.2 Killed 0 Dry 0.1 0.1 0 0 0 Dry 0.1 0.1

1 L b . D D T per Acre H u 36 Ε 139° A v .

2 L b . D D T per Acre H u 106 b A 133 « Av

3.1 1.6

0 0 0.2 1.3 1.1 0.6 1.6 1.4 0.8 0.8 1.1 0.4 1.3 2.2 1.9 2.9 2.0

0 0 0.3 1.9 1.0 1.3 2.1 2.1 1.1 1.5 1.7 1.7 1.5 2.0 4.0 3.5 2.5

0 0 0.2 1.6 2.6 1.0 2.6 2.7 1.2 2.1 1.5 1.9 2.9 2.7 3.7 5.6 5.4

0 0 0.3 1.8 1.8 1.2 2.4 2.4 1.2 1.8 1.6 1.8 2.2 2.4 3.9 4.6 4.0

2.3 0.5 0.3 0.1 0.2 0.2 0.2 0.0 0.1 0.1

2.2 0.6 0.6 0.1 0.2 0.3 0.2 0.0 0.1 0.1

2.1 1.4 0.2 0.2 0.5 0.5 0.5 0.2 0.1 0.2

2.8 1.5 0.6 0.9 1.2 1.4 1.2 0.5 Dry Dry

2.4 1.5 0.4 0.6 0.9 1.0 0.9 0.4 0.1 0.2

0 0 0.2 1.1 0.8 0.5 1.6 1.5 0.9 0.4 1.1 0.4 1.3 2.1 1.9 2.6 2.4

0 0 0.1 1.5 1.3 0.7 1.6 1.3 0.7 1.2 1.1 0.4 1.2 2.3

2.0 0.6 0.8 0.1 0.1 0.3 0.4 Killed

Cow received hay dusted with 1 lb. D D T per acre during 1948 (Table I). b Cow received hay dusted with 2 lb. D D T per acre during 1948 (Table I). Cow received hay dusted with no D D T during 1948 (Table I).

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BIDDULPH et α/.—DDT IN MILK AND TISSUES OF DAIRY COWS

the milk of each 4 to 4.5 months later. This would seem to indicate that the D D T is re leased into the blood stream from the storage sites at a slow rate. This is further indi cated b y the presence of traces of D D T i n the milk of a l l the cows that consumed D D T treated hay for more than 4 months after the ingestion of the hay was discontinued. Cows A 133, H u 106, and Ε 139 were all used during the second year's feeding trials. Reference to Table I I shows that at the beginning of the feeding period (November 24, 1948) there was no D D T present i n the milk of any of these. Thus, the D D T had disappeared com pletely from the milk within approximately 6.5 months after the feeding of the D D T treated hay was discontinued. The amount of D D T present i n the milk of the cows during the second winter (194849) is given i n Table I I and Figure 2. Three of the cows used the previous winter (A 133, H u 106, and Ε 139) were used again; the remaining cows were new to this project. T h e results obtained are essentially like those of the previous winter. During the second winter hay treated with 0.5 pound of D D T per acre was substituted for hay treated with 4 pounds. Otherwise the experimental procedure was the same as during the first winter. As before, a greater quantity of D D T was found in the milk of the cows that consumed the hay treated with the higher levels of D D T . Calculation of the average amount of D D T present i n the milk during the feeding period shows a close agreement in the amount of D D T present during the two years, where i t is possible to make such a comparison. For example, the average amount of D D T present in the milk of the cows consuming hay treated with 1 pound of D D T per acre during 1948 was 1.7 p.p.m.; i n 1948-49, 1.3 p.p.m. Following the 2-pound treatment i n 1948, 3.3 p.p.m. of D D T were present i n the milk, whereas i n 1948-49 2.2 p.p.m. of D D T were present. The average amount of D D T pres ent i n the milk of the cows consuming hay treated with 0.5 pound of D D T per acre during the feeding period was 0.7 p.p.m. Considering all the possible sources of variation in the experiments, the agreement in the data from the two years seems fairly good. The amount of D D T residue present on the alfalfa hay fed to the dairy cows during the two years is given i n Table I I I . A greater D D T residue was present on the hay the second year than during the first. A possible explanation of this difference is that during the harvest i n the summer of 1947 the hay was rained on several times after i t was cut and before i t was dry enough to bale, whereas i n the summer of 1948 the hay was not rained on between cutting and baling. Whether this difference in the curing and handling of the hay is the only reason for the difference in D D T residue is not known. The method of application and calibration of the power duster and calculation of the dosage used each year was the same. The details of these procedures will be published elsewhere. Table III.

Average DDT Residue on Alfalfa Hay Fed to Dairy Cows and Average DDT Appearing in Milk during Period of Feeding

1947-48 D D T Treatment, D D T residue, D D T in milk, Lb./Acre p.p.m. p.p.m. None 0 0.05 0.5 .. 1 9.6 1.7 2 12.1 3.3 4 36.0 7.1 DDT-treated hay obtained from adjoining manger. a

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1948-49 D D T residue, D D T in milk, p.p.m. p.p.m. 0 0 9.0 0.7 19.2 1.3 30.0 2.2

The hay used during the first winter was analyzed b y both the colorimetric and total chloride methods (8, 9, 12). The results obtained with the total chloride method were less variable than those obtained with the colorimetric ; consequently, the former method was adopted. I n one third of the samples, the values obtained with the two methods were the same. I n the remaining two thirds of the samples, the values with the colori metric method were approximately 2 0 % below those of the total chloride. However, analysis of the control samples by both methods revealed the absence of D D T i n the u n treated hay, thus indicating that organic compounds containing chlorine were absent in the untreated hay. Analysis of the blood of the cows for D D T before the feeding of D D T - t r e a t e d hay was AGRICULTURAL CONTROL CHEMICALS Advances in Chemistry; American Chemical Society: Washington, DC, 1950.


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begun both years showed that no D D T was present. After the D D T - t r e a t e d hay had been fed for 113 and 81 days, analysis showed an average of 0.1, 0.1, and 0.2 p.p.m. of D D T in the blood of cows consuming hay treated with 1, 2, and 4 pounds of D D T per acre, re spectively. These trace amounts of D D T i n the blood were found at the same time the D D T concentration was highest in the milk. Three of the cows used were slaughtered at the end of the feeding period, and a fourth was killed 4 months later. The amount of D D T present i n various tissues at these times is presented in Table I V . It is evident that large amounts of D D T are present i n the fatty tissues, whereas there is little present in muscle, liver, or kidney. Apparently its presence i n the fat, and the slow release into the blood stream from these storage sites, account for the persistence of the D D T i n the milk for long periods of time after the feed ing of the D D T - t r e a t e d hay was discontinued. Cow Ε 139 still had 3 p.p.m. of D D T i n her fat 4 months after the feeding of the D D T - t r e a t e d hay was discontinued. It was not possible to obtain a milk sample at this time, for the cow had ceased lactating some time before she was slaughtered. Table IV.

a

DDT in Tissues of Cows at End of Feeding Period

Cow

D D T Added to Hav Consumed, Lb./Acre

No. of Days Fed Hay

Mesenteric fat

Kidney fat

Hu 329 Hu 36 Hu 29 Ε 139°

0 1 2 1

81 81 113 81

0 21.4 89 3

0 19.3 90 3

_ _ _ D D T , P.P.M. Muscle

Liver

Kidney

0 0.4 1.3 0.1

0 0.2 1.1 0

0 0.1 0 '

Slaughtered approximately 4 months after feeding of DDT-treated hay was discontinued.

D a t a showing daily feed consumption and milk and butterfat production of the cows for the two years are given i n Table V . During the period of feeding, there was no evi dence that the cows receiving D D T - t r e a t e d hay were injured i n any way, or that their milk production was affected. Apparently the amount of D D T ingested daily and the release of D D T from the fatty tissues did not provide sufficient D D T in the blood stream to affect feed consumption or milk production. Table V.

Average Daily Feed Consumption and Milk and Butterfat Production of Dairy Cows

D D T Added to Hay, Lb./Acre

Cows

No. of Days Fed

Hay Consumed. Lb.

Grain Consumed, Lb.

Milk Produced, Lb.

Butterfat Produced Lb.

%

1947-48 0 1 2 4

A 133 H u 88 H u 39 Ε 139 H u 29 H u 106 Ε 180 Ε 199

113 113 113 113 113 113 113 113

32.2 33.2 33.4 29.6 32.9 30.9 23.2 36.2

H u 329 H u 85 H u 83 Ε 181 H u 36 Ε 139 H u 106 A 133

81 81 81 81 81 81 81 81

44.8 40.7 40.1 41.0 40.6 45.4 41.2 43.9

4. .9 5, 5 7. .0 0 .6 4. .5 5 .0 5, .8 7, .7

25. .3 31 .7 33 .2 11. .6 20 2 26 .0 26 .4 37 .1

0 .86 1 .04 1, .25 0 .39 0 .87 0 .96 0 .79 1 .37

3.4 3.3 3.7 3.4 4.3 3.7 3.0 3.7

4. .8 4 .6 4. ,1 4, .7 5, .3 7. .3 6, .9 7, .4

25. .2 24 .3 19, .2 22 .5 29. .5 42 .6 36 .6 35 .6

0. .84 0 .81 0 .72 0 .95 0. .96 0 .36 1. .27 1, .22

3.3 3.3 3.8 4.2 3.3 3.2 3.5 3.4

1948-49 0 0.5 1 2

Three cows calved after the feeding of the hay was discontinued (Table I). The preg nancy of the cows was apparently normal and there were no abnormalities i n any of the calves. This indicated that the level of D D T was not sufficiently high to affect the cows or calves during the period of gestation. The results of these experiments show that D D T accumulates in the fatty tissues of cows, and that it is present in the milk i n varying amounts, the amount being dependent AGRICULTURAL CONTROL CHEMICALS Advances in Chemistry; American Chemical Society: Washington, DC, 1950.

BIDDULPH ET AL.—DDT IN MILK AND TISSUES OF DAIRY COWS

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upon the quantity of D D T ingested. Furthermore, sufficient residue remains on alfalfa hay after it has been dusted with the amount of D D T recommended to control insects, to cause substantial quantities of D D T to appear i n the milk and fat. Smaller amounts of D D T persist i n the fat and milk for at least 4.5 months after the ingestion of the D D T treated hay has been discontinued. The possible toxicity of such milk and fat to humans would seem to be dependent upon a number of factors, among which are the amount of D D T applied to the forage, the frequency and total length of time during which the treated hay is ingested b y the cow, the amount and frequency of consumption of such milk and fat b y humans, and possibly the age of the humans consuming these products.


Summary Alfalfa hay that had been dusted with varying amounts of technical D D T for insect control and similar untreated hay were harvested and fed to 16 Holstein dairy cows during two years. D D T appeared i n the milk promptly after the cows consumed the D D T - t r e a t e d hay. The concentration gradually increased until maximum amounts of 2.2, 3.8, 7.2, and 12.5 p.p.m. of D D T were obtained i n the milk of cows consuming hay dusted with 0.5, 1, 2, and 4 pounds, respectively, of D D T per acre. The average D D T residue on the hay var ied from 9 to 36 p.p.m., there being a greater residue on the hay for a given treatment the second year than there was the first. D D T persisted i n the milk for 4 months after the feeding of the D D T - t r e a t e d hay was discontinued. I t disappeared approximately 6.5 months after discontinuance of the feeding of treated hay. Four cows had D D T i n their milk at the end of their lactation period, and after calving traces of D D T were still present i n their milk. The blood was analyzed for D D T before the cows were placed on the D D T - t r e a t e d hay and again before the hay was discontinued. N o D D T was found before and a maxi mum of 0.2 p.p.m. at the close of the feeding period. Four cows were slaughtered and the tissues were analyzed for D D T . The analysis showed a maximum of 89 p.p.m. of D D T i n mesenteric fat, 90 p.p.m. i n kidney fat, 1.1 p.p.m. i n the liver, 1.3 p.p.m. in muscle, and 0.1 p.p.m. i n kidney tissues. The greatest amount of D D T was present i n the tissues of cows consuming the hay dusted with the higher levels of D D T .

Literature Cited (1) Allen, Ν. N., Lardy, Η. Α., and Wilson, H . F., J. Dairy Sci., 29, 530 (1946). (2) Harris, J . R., Biddulph, C., Greenwood, D . Α., Harris, L . E., Bryson, M . J . , Binns, W., Miner, M . L., and Madsen, L . L., Arch. Biochem., 21, 370 (1949). (3) Howell, D . E., Cave, H . W., Heller, V. G., and Gross, W. G., Dairy Sci., 30, 717 (1947). (4) Laug, E . P., J. Pharmacol. Exptl. Therap., 86, 332 (1946). (5) Laug, E . P., and Fitzhugh, O. G., Ibid., 87, 18 (1946). (6) Ludewig, S., and Chanutin, Α., Proc. Soc. Exptl. Biol. Med., 62, 20 (1946). (7) Madsen, L. L., unpublished data. (8) Schechter, M . S., Pogorelskin, Μ. Α., and Haller, H . L . , Anal. Chem., 19, 51 (1947). (9) Schechter, M . S., Soloway, S. B., Hayes, R. Α., and Haller, H . L., Ind. Eng. Chem., Anal. Ed., 17, 704 (1945). (10) Shephard, J. B., Moore, L . Α., Carter, R. H . , and Poos, F. W., Dairy Sci., 32, 549 (1949). (11) Telford, H . S., and Guthrie, J . E., Science, 102, 647 (1945). (12) Umhoefer, R. R., Ind. Eng. Chem., Anal. Ed., 15, 383 (1943). (13) Woodward, G., Ofner, R. R., and Montgomery, C. M . , Science, 102, 177 (1945). R E S E A R C H supported in part by a research grant from the Division of Research Grants and Fellowships, N a tional Institutes of Health, U . S. Public Health Service, and published with the approval of the director of the Utah Agricultural Experiment Station.


DDT in Milk and Tissues of Dairy Cows Fed DDT-Dusted Alfalfa Hay

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