ASSOCIATION ArSAI~S 1457

chinattmn, University of Arkansas, Fayet te- ville.

Fur ther studies on effect of' level of protein and energy supplementation of cows on pasture on milk yield and composition; and certain blood and rumen constituents. J. T. Huber and R. L. Boman, Virginia Agricul- tural Experiment Station, Blacksburg.

Radio telemetry systems for observations of

in-pasture animal activities. G. E. Paar "~:" and G. H. Rollins, Auburn University, Au- burn, Alabama.

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A B S T R A C T O F P A P E R S P R E S E N T E D A T T H E E A S T E R N D I V I S I O N A L M E E T I N G O F T H E A M E R I C A N D A I R Y

S C I E N C E A S S O C I A T I O N , C O R N E L L U N I V E R S I T Y , I T H A C A , N E W Y O R K , J U L Y 1964

New method for the extraction of milk phos- pholipids. A. H. DUTHIE ¢~ AND STUART PAT- TOX, Pennsylvania State University, Univer- si ty Park.

On the hypothesis that the Mojonnier method does not quanti tat ively extract milk phospholipids, a new procedure was developed. The whole milk sample was compounded with silicic acid, placed in a glass chromatographic colunm, and the phospholipid fraction eluted with 20% (V/V) formic acid in ethyl ether. To determine extraction efficiency of the new procedure, phospholipid recovery from I0-ml aliquots of milk were compared for each method-- the new, the Mojonnier, and the modified Mojonnier (1.5% NaC1 added to the milk sample pr ior to a Mojonnier extract ion) . Lipid phosphorus analysis and thin-layer chromatography were used for the comparison. Five tr ials verified that the modified Mojon- nier method and the new silieic acid column chromatographic method recovered 10.2 and 12.2 mean per cent, respectively, more l ipid phosphorus than the conventional Mojonnier procedure. When aliquot samples from the phospholipid extracts recovered by the three methods were compared by thin-layer chroma- tography, visual observation showed minor differences in the l ipid patterns.

Altering the fatty acid composition of milk. R. G. JENSE~, The Universi ty of Connecticut, Storrs.

Several methods for al ter ing the f a t t y acid composition of milk are available, if it be- comes necessary. Emphasis has been placed on increasing the polyunsatura ted f a t t y acid content. The methods are: (a) substi tut ion of polyunsaturated oils for nfilk fat , (b) ad- dition of polyunsaturated oils to whole milk or milk products, (e) processing of milk f a t ; interesterifieation, winterization, (d) reduc- tion of biohydrogenation in the rumen, (e) feeding. Methods (a) and (b) would be the

Author presenting paper.

most efficient and economical. Method (c) cannot compete economically at present, but is being investigated. Method (d) appears promising and is also being studied. Wi th (e) it is possible to change milk fa t to a largely unsaturated fa t by feeding safflower oil, but the polyunsatura ted acid content is not in- creased significantly and production is dras- t ically reduced (J. Dai~ T Sci., 47: 37. 1964).

Connecticut milk flavor improvement pro- gram. E. O. ~NDERSOX, Department of Agri- culture and Natural Resources, Har t ford , Con- necticut.

The objective of the program established in 1962 is to foster increased consumption of Class I milk by preserving the flavor of milk as it is drawn from the cow and protect ing i t from the development of off flavors until it reaches the consumer. Most of the work has been in three areas : (a) conduction of workshops on odor discrimination for 171 gaugers and samplers ( tank t ruck drivers) and 163 milk plant personnel. About 13% of the gaugers and samplers and 15% of the milk p lant personnel had l i t t le or no odor dis- crimination. (b) The flavor of 1,339 samples of milk purchased at retai l stores was determ- ined. Eight per cent of the milk purchased was unsat isfactory in flavor. (c) Spot service is given with milk inspectors and fleldmen from cooperatives to solve flavor problems on the farm and in the milk plant. Af te r feed flavor, oxidized flavor is most frequently en- countered in raw milk. The farmer has infer- marion at hand to control or minimize all flavors except spontaneously oxidized milk. Two odd flavors have been encountered; a black walnut flavor from unwilted grass silage and an almond flavor from wild cherry leaves which the cows ate during a recent drought.

Protecting milk from fluorescent light. ALEC BRADFIELD, Professor of Dairy Industry , Uni- versi ty of Vermont, Burlington.

In the Boston milk shed oxidized flavor

1458 JOURNAL OF DAIRY SCIENOE

has become the most common defect in milk sold through stores, most of it being developed by exposure to fluorescent lights.

A survey of supermarkets showed that milk in dairy cases is being exposed to fluorescent light of intensity ranging from 20 to 400 ft-c, with a great deal of it in the 300 to 400 range.

Trials were conducted with paper milk car- tons of different types and colored with vari- ous colored inks. Light exposure was 400 ft-c. Light transmission rates were determined on the several cartons used.

Wax-coated cartons gave the least protec- tion from light, not much more than plain glass bottles. Aluminum foil laminated on paper gave complete protection, no oxidized flavor appearing during normal shelf life of the milk. The use of aluminunl foil increases the cost of the cartons by 55%, which is con- sidered prohibitive for milk.

Polyethelene printed in red, blue, black, and green ink was used for cartons. Green showed the lowest light transmission and protected the milk against oxidation longer than the other colors. Milk produced during the winter became oxidized sooner than that produced in summer, with all cartons.

Experiences encountered in automated clean- ing of an ultra high-temperature plate heat exchanger. D. A. EVA~'S( '° ELEANOR L. WEST, AND W . LITSKY, University of Massachusetts, Amherst.

Investigations were undertaken to determine the conditions needed to adequately clean a plate heat exchanger after processing milk at 260F for 0.6 see holding time. Results indicated that cleaning procedures recognized as adequate for plate heat exchangers at HTST conditions on milk did not yield satis- factory cleaning when the heat exchanger was used fc)r processing milk at the elevated tem- perature. After modification of the cleaning process, by doubling the alkali concentration (raised to 1.5% as free caustic), increasing acid concentration by 50%, and circulating the respective cleaning solutions for 30 rain at 195 F, adequate cleaning was obtained using a straight caustic cleaner as determined by swab count and observation of equipment sur- faces. Satisfactory cleaning was not evident, under these conditions, when using either a modified caustic cleaner or a chlorinated alka- line cleaner.

Streptococcus lactis--Pseudomonas fluores- cens interactions: the accelerated coagulation phenomenon. J. A. KOBVaGER ~ AXD DOROTHY J. ORNDORFF, West ¥irginia University, Mor- gantown.

The concurrent growth in milk of S. lactis and P. fluorescens results in coagulation at an unusualily high pI-I (5.3-5.7). Neither organ- ism alone is capable of bringing about this phenomenon. Prel iminary studies showed that

a Seitz filtrate of a milk culture of the pseudo- monad was as active in the association as whole cells. Part ial purification of the filtrate by acetone-ethanol precipitation, ammonium sulfate fractionation, and gel filtration showed it to contain at least two enzymes capable of coagulating milk. This could be demonstrated both by a milk-clotting procedure (Acta Pathol. Mierobiol. Seand., 49: 95. 1960) and by incubation in combination with S. lactis. Coagulation of milk by the most active enzyme fraction was favored by lowering the pH or increasing the calcimn ion concentration at constant pit. Results indicate that limited proteolysis by the pseudomonad and solubili- zation of calcium, due to acid production by S. lactis, are responsible for the phenomenon.

Aging of Streptococci as a function of pit. G. R. COWELL, ~;~ J. A. KOBURGER, AND S. J . WEESE, West Virginia University, Morgan- town.

Washed cells of Streptococcus lactis and Streptococcus cremoris were aged up to ten days at 4 C in 0.05 ~ phosphate buffers in the range of pH 4.5-11.5. Decreased glycolytic ac- t ivity of the recovered cells, when assayed in milk, was found to be related to the length of storage and p i t of the suspending buffer. The optimum storage pH for these organisms was 8.5. Within practical limits of pH, cells aged in nfilk exhibited a similar pattern of inactivation. Analyses of the recovered sus- pending buffers indicate that endogenous me- tabolism is an absolute requirement for main- tenance of cellular integrity and maximum viability during storage. When aged cells were recovered from a low pH environment and resuspended at a higher pit , an increase in endogenous metabolism took place and a portion of the glycolytie activity was restored. These results indicate that damage to the cell occurs during extended storage and that the normal repair mechanism associated with vi- ability cannot function.

Multi-unit milk containers. K. S. HALL, Liqui-Box Corporation, Columbus, Ohio.

The use of single-service multi-unit milk containers, consisting of a polyethylene bag in a corrugated box, is a relatively recent de- velopment in the dairy industry. They are widely used for fluid milk, ice cream mix, cream, and concentrated products and are available in sizes ranging from 4 qt to 8 gal. The cost of the 5-gal container is about 36¢. Advantages are: better quality, labor sav- ing, no returns, and space saving. Disadvan- tages are: cost, consumer resistance due to poor drainage and leakers, disintegration, and transmission of certain flavors. Many of the packaging problems have been overcome. A more recent development is the introduction of the 10-qt home dispenser which has the advantages and disadvantages listed above.

ASSOCIATION AFFAIRS 1459

Some additional advantages are convenience snd availability of cold milk to the consumer. The package cost ranges from 17 to 35¢. The use of home dispensers is increasing and may represent an effective method for increasing the sale of milk.

Month-to-month changes in the composition of milk of Holstein cows. N. H. SLACK, ~ K. O. PFAU, AND R. E. MATHER, New Jersey Agri- cultural Experiment Station, Sussex.

Fat, solids-not-fat (SNF), and protein com- ponents were determined by the Babcock, lac- tometer, and formol t i t rat ion methods, re- spectively, in 2,078 monthly one-day-composite milk samples representing 197 complete lacta- tions of 107 animals. Unadjusted means with standard deviations were 4.1, 0.5% for fat, 8.6, 0.4% for SNF, 3.4, 0.4% for protein, and 1,161, 524 lb for milk yield. Multiple covari- anee was used to determine the influences of season, stage of lactation, gestation, and udder health (leucocyte eounts) on the three milk components and milk yield. All but udder health were highly significant sources of vari- ation for all production measures. Seasonally, the components had low percentages in April, July, and August and high percentages in May, June, and winter months. Yields were somewhat the opposite. Stage of lactation effect, adjusted for first test and gestation effects, was negligible for SNF percentage; both fat and protein percentages increased during lactation. First tests were high for all components. After about 120 days of gesta- tion, percentages inereased at an increasing rate. Laetation inereases in SNF percentage were due mostly to gestational influences, whereas increases in fat and protein were more equally attributable to gestation and stage of lactation.

Sire progeny differences in milk composi- tion. S. N. GAUNT ~ AND M. C. GACULA, JR., University of Massachusetts, Amherst.

Lactation records based on monthly testing for percentages of milk fat, protein (Orange G dye), and solids-not-fat (SNF, Golding) were computed on 1,117 daughters with 1,789 records in 34 herds by 204 sires of five breeds. Total solids percentage was computed from the fat and SNF percentages.

Variance component analyses were made on the sire within herd basis and heritabilities computed by the paternal half sib method by breeds and pooled breed data. Heritabilities ~nd their standard errors on the pooled data for the percentages of milk constituents were : milk fat .420 ± .145, protein .364 --+ .144, SNF .897 ± .146, and TS .608 ± .146. The herita- bility estimates for Holsteins on the sire within herd basis were negative, due probably to too few daughters of a sire per herd. Pooled heritabili ty estimates of the other four breeds were: fat .514 ± .154, protein .441 ±

.152, SNF 1.090 --+ .156, and TS .737 ~+ .156. A sire × herd interact ion analysis was made for Holsteins and the sire variance components were positive, but the heritabilities were gen- erally tow, with large standard era'ors.

Sire daughter averages for the components and repeatability values for various numbers of daughters and herds were computed.

Variation in first-lactation production traits. A. J. LEE * AND C. R. HENDERSON, Cornell Uni- versity, Ithaca, New York.

In the use of selection indices to rank cows on their milk production, differences due to herd and counties are assumed not to exist, or to have been eliminated. Also, the within herd variance of' records is assumed to be con- stant froal herd to herd. First-lactation New York DHIA records since 1957 on 113,549 grade and purebred Holstein cows were clas- sified into 5,813 herds and 50 counties. The traits considered were mature equivalent and herd-mate deviation milk and fat yields. Ex-

-pressing records as herd-mate deviations elimi- nated the large herd and county effects in ma- ture equivalent records. Within herd variances were heterogeneous from herd to herd in all records. The herd to herd heterogeneity of within herd variances increased from mature equivalent records to herd-mate deviation records for fat yield. Expressing records as herd-mate deviations did not change the herd to herd heterogeneity of within herd variances for milk yield.

First-lactation performances and herd life. L. D. VAN VLECK,* Cornell University, Ithaca, New York.

Records of artificially sired cows of five breeds having the opportunity to complete five or more lactations were divided into four groups according to first-lactation deviations from herd-mate average. The average devia- tion for each group in each of four succeeding lactations was greater than for the group which was below it in the first lactation. The fraction of cows having subsequent records was also greater for the groups highest in first-lactation deviations. The pattern was similar for all breeds. The Holstein results showed that more of the high producers (Group 1) in the first lactation had second records than the low producers (Group 4 ) - - 82% vs. 61%. More than twice as many had as least five records--32% vs. 15%. The high producers in the first lactation not only con- tinued to outproduce their lower-producing first-lactation mates but also had a substan- tially longer herd life. These results do not substantiate the claim often made that high producers in the first lactation burn them- selves out and leave the herd at an early age. Actually, these cows appear to stay longer and produce more than their less hard-work- ing first-lactation mates.

1460 JOURNAL OF DAII~Y SCIENCE

Influence of the first lactation on later pro- duction and length of herd life. J. M. WHIWE ~ AND J. R. NICHOLS, Pennsylvania State Uni- versity, University Park.

This study included 16,583 2 × ME 305-day DHIA records of 4,819 daughters of 29 Penn- sylvania A. I. Holstein sires. All first records were begun in 1957-58 at 34 months of age or less. Averages and standard deviations for age at first calving, first lactation milk and fat production, nmnber of lactations com- pleted to date, and age at last reported calv- ing were 27.04 ± 2.45, 12460.00 ± 1918.40, 471.00 ± 68.50, 3.44 ----- 1.30, and 58.82 ± 16.67, respectively.

Firs t records were stratified into nine fat and 11 milk production levels and later records analyzed. I t was found that the higher-pro- ducing heifers remained in the herd longer and produced at a higher rate after the first lactation than heifers with lower first-lacta- tion records.

Within sire-herd-period of first-calving cor- relations between first-lactation milk produc- tion and the number of lactations completed to date and age at last reported calving were 0.216 and 0.254, respectively. Corresponding regression coefficients were 0.0015 lactations and 0.0228 days per 10 lb of milk. For first- lactation fat production, the correlations were 0.234 and 0.270, with regression coefficients of 0.0045 and 0.0670. All correlations and regres- sions were highly significant (P < 0.01).

Specific combining abilities among dairy sires. F. R. ALLAIRE ~:~ AND C. R. HENDERSON, Cornell University, Ithaca, New York.

All available 305-2 × -ME lactation records in the New York Dairy Records Processing Laboratory from purebred Holstein cows, hav- ing their sire and maternal grand-sire repre- sented in a group of 200 A.I. sires, were in- vestigated for the importance of specific com- bining abilities among sires. The magnitude of the sire × maternal grand-sire interaction component of variance was used to evaluate the importance of specific combining abilities. These data consisted of 39,160 lactation rec- ords from 17,361 cows. A component of vari- ance analysis was completed on first lactations and mean yields, all expressed as herd-mate deviations. The interaction component of variance estimate for the herd-mate nfilk de- viations was 2.5% and 0.5% of the total vari- ation for the first lactation and mean yield analyses, respectively. Upon restricting the sire × maternal grand-sire subclasses to ten or more cows, the interaction component of variance estimate for the first lactation analy- sis was lower at 1.36% of the total variation and the mean yield estimate was essentially unchanged. Specific combining abilities among sires do not appear to rate important con- sideration in a general breeding program. Evi- dence indicated that some sire and maternal

grand-sire combinations deviated greatly from the expected. The differences observed were those between an index based on a reasonably large nmnber of three-quarter sibs and an index based on one-quarter and one-half sibs simultaneously, when adjusting for numbers in all eases.

Predicting milk output with changing feed input. D. R. WALDO °~ AND L. A. MOORE, Ani- mal Husbandry Research Division, Dairy Cat- tle Research Branch, USDA, ARS, Agricul- rural Research Center, Beltsville, Maryland.

Predicting changes in milk production with a change in feeding level requires a knowledge of the relative eontribution of feed and non- feed factors (other environment and genetics) to milk production. The feed requirement above maintenance per pound of milk proba- bly depends more on the relative use of feed for weight gain and milk yield rather than the level of milk production. The distribution of added feed energy to gain or to milk pro- duction is dependent on the distribution before addition. The feed requirement per pound of milk may give a method for separating the relative contribution of these two factors. The data of Jensen were expressed by C. D. Cas- key, Cooperative Mills, Baltimore, Md., in a personal communication, as milk production = 11,040 (1-.951 x) where x = ewt TDN con- stoned. On a percentage basis, Caskey ex- pressed the above equation as per cent of maxi- mum milk production = 100 (1-.95F). This percentage equation suggests that the change m milk production can be predicted from a com- men equation for animals with different nonfeed potential. This concept has been applied to data on 30 part-lactations (average 49 lb/day) where the feeding level increased for ten, re- mained the same for ten, and decreased for ten. The predicted milk production exceeded the ob- served by 8.2, 8.1, and 12.1 lb per day, respec- tively. The difference between expeeted and observed is attributed to a declining milk yield associated with stage of lactation.

Nutritive value of bremegrass ensiled at varying dry matter levels. G. M. Jo~Es, ~ H. C. DICKEY, W'. H. I-IoovER, AND B. R. POUL~ON, University of Maine, 0rono.

Bromegrass was ensiled at five dry matter levels in conventional and experimental silos. Digestion coefficients were determined with three yearling wether sheep. Voluntary intake studies were conducted on the conventionally ensiled forages using four dairy heifers and three wethers.

The concentrations of lactic acid and the total organic acids decreased as the forage dry matter content, at ensiling time, increased. The volatile fat ty acid data were discordant. The lignin and pH values were higher in the high dry matter silages.

The energy and protein digestion coefficients

ASSOCIATION AFFAIRS 1461

were significantly higher (P ~ 0.01) for the low dry matter silages, and the digestion co- efficients for dry matter were significantly higher at P ~ 0.05 for the same silages. Us- ing Duncan's Multiple Range Test, the means for the energy, protMn, and dry matter diges- tion coefficients o~ the 38% dry nmtter silage were significantly higher than the means for the 69% and the 44.2% DM silages. The nu- tritive value index and the dry matter intake per pound gain were higher for the 38% DM silage than for the 44.2% DM silage.

The pH and lignin values, organic acid con- centrations, and digestion coefficients indi- cated that the silages ranging from 24 to 38% dry matter were highest in nutri t ive value.

Addition of ground limestone to corn silage for dairy cattle. E. M. KESLER,* S. L. SFAHR, AND R. P. JOHNSTON, JR., Pennsylvania State University, University Park.

Twin wood-stave silos were filled with alter- nate loads of corn silage in late milk-early dent stage of maturity. High-calcium lime- stone was added to one silo (1% of wet weight) at the blower. The corn averaged 74% moisture; 19.3 and 19.6 tons of DM were placed in control and treated silos, respec- tively, the latter including 1,476 lb of lime- stone. All silage removed during the five- month winter period was weighted. Average pH of control silage was 3.85, that of treated, 4.13. Dry matter averaged 26.5 and 27.0%, respectively. Loss of DM due to seepage and fermentation was 11.9 and 11.8%. Voluntary consumption was measured with 22 cows which averaged 60 lb milk daily. Forage DM to grain ratios of 1:0.7, 1:1.3, and 1:2.0 were employed, with 75% of forage DM supplied by silage. At the three ratios, consumption of control and treated silages averaged 70.5 and 62.1, 55.4 and 46.3, and 44.9 and 42.2 lb, re- spectively. Because forage and grain were fed at fixed ratios, and to appetite, the lower palatabil i ty of treated silage also forced lower intakes of' grain and hay. Digestibility of DM by two cows on each silage did not differ greatly.

reed input and milk output study with high- producing dairy cattle. It. F. JU~AE ~ A~D B. R. PO~L~ON, University of Maine, Orono.

Using ten high-producing Holstein cOWS, a study was conducted to investigate the utili- zation of feed energy and feed protein for milk production. The experimental cows were put on digestion trials as soon as they calved and the feeding and digestion trials were con- tinued until the cow's daily milk production dropped to less than 40 lb. Their milk pro- duction ranged from 40-90 lb of 4% F.C.M. Chromic oxide techniques were used to de- termine the energy and protein utilization of the rations fed to the cows. Studies were made

to determine the maintenance requirement of protein and energy. Calorie and protein re- lations were corrected for the loss and gain in body weight for each digestion trial. Effi- ciency factors were calculated for the relation- ship of feed input and milk output at different levels of milk production. Data will be pre- sented on energy and protein intake-output relationships and various efficiency factors.

New relationships for estimating TDN con- tent of forages from chemical composition. R. S. ADAMS, ~ J. It. MOORE, E. M. KESLER, AND G. Z. STEVENS, Pennsylvania State University, University Park.

An attempt has been made to develop rela- tionships which improve the accuracy of esti- mating the TDN content of forages from their crude protein (CP) and crude fiber (CF) con- tents. Digestion trial data for over 700 for- ages as taken from the world literature were used in this study. The reIationships currently used by the Penn State Forage Testing Serv- ice are: Legumes TDN : 74.43 + 0.35 CP -- 0.73 CF; grasses TDN : 50.41 + 1.04 C P - 0.07 CF; mixed hay-crop and unknowns TDN ---- 65.14 ~- 0.45 CP -- 0.38 CF; annuals other than corn TDN : 90.36 -- 0.29 CP -- 0.86 CF; corn silage TDN---- 77.07-- 0.75 C P - - 0.07 CF. All analyses used in the relationships given should be on a dry matter basis.

Metabolism of arginine by the rumen bac~ terium Peptostreptococcus elsdenii. R. S. HINKSON, JR., ~ A. W. MAItOlqE¥, AiqD B. R. POULTOI% University of Maine, Orono.

A medium containing uniformly labeled C l'- arginine was inoculated with the rumen bac~ terium Peptostreptococcus elsdenii~ Strain B- 85, and incubated at 39 C for 97 hr under anaerobic conditions. The pH of the media ranged from 6.8 to 7.5. At the termination of the incubation period, samples taken from the treatment and control media were analyzed for bacterial and total protein, bacterial mass, volatile fat ty acids (VFA), and amino acids. The CO~ above the media was absorbed for carbon-14 determination. The carbon-14 was detected using a gas flow counter and auto- radiography.

Bacterial mass and total bacterial protein decreased. The VFA values, as determined by the Wiseman-Irvin Column technique, were variable. Only very small amounts of each acid were detected. Acetic acid had consist- ently more C~-aetivity than propionic or buty- ric acids. Carbon-14 was also found in argi- nine, ornithine, alanine, glycine, and CO~. Ammonia was produced. Experimental re- sults indicate that Peptvstreptococcus elsdenii does metabolize arginine. I t appears that this organism contains arginase and contributes to the urease moiety of the rumen as suggested by the ammonia and CO~ production.

1462 JOURNAL OF DAIRY SCIENCE

Diurnal bovine temperatures measured by radio telemetry. A. E. D~cY, K. R. SIM- ~[o~s,* W. O. ESSLEI¢, AND C. L. HAUSLER~ Ver- mont Agricultural Experiment Station, Uni- versity of Vermont, Burlington.

F~[ transmitters, sensitive to 0.1 C, were placed in the reticulum, subcutaneously in the left crop region, and lateral to the rectal wall. All transmitters broadcast over frequencies between 180 and 350 KC. The frequencies were manually monitored with a WR3000 Halicrafter receiver.

Recordings were made from each of four lactating cows at 30-min intervals during four consecutive days. All recordings exhib- ited diurnal patterns. The reticular tempera- tures varied from a low of 32.2 C after drink- ing water, to a high of 40.5 C prior to feeding. Usually, 60-90 min were required for the tem- perature to reach the predrinking level. How- ever, the majority of reticular temperatures were between 39 and 40 C. The subcutaneous temperatures varied from 31.9 to 38.4 C and dropped rapidly when the animals were turned out for exercise during outdoor temperatures of approximately 10 C. The rectal temperatures were most constant, but ranged between 34.4 and 39.2 C, reaching a peak during feeding. Rectal temperatures dropped when the animals laid down, but the subcutaneous temperatures rose until they approached or exceeded the rectal temperatures.

Evaluation of polyvinylpyrrolidone (PVP) in the freezing and preservation of bull semen. A . C. MENGE ~ AND J. J. SULblVA~, New Jersey Agricultural Experiment Station, Sussex.

Trial I consisted of a factorial experiment comparing the effects of four levels (0, 3.5, 7.0, and 10.5%) each of polyvinylpyrrolidone (PVP) and glycerol on the freezeability of semen from three bulls. The basic extender (EYC) consisted of 20% egg yolk and 2.9% sodium citrate plus antibiotics. All the levels of PVP resulted in decreased sperm survival in the frozen semen samples as well as in un- frozen semen samples. The two higher levels

of PVP also caused clumping of the egg yolk in the extender. In Trial 2, low levels of PVP (1 and 2%) slightly prolonged the life of sperm extended in sodium citrate solution, but the samples were inferior compared to semen in the EYC extender without PVP. The ad- dition of 1% or more of PVP to semen in EYC extender shortened sperm life consider- ably. I t was obseI~ced in Trial 3 that PVP (1 to 3%) provided sperm with little or no pro- tection against the detrimental effects of a cold- shock treatment. In the final trial semen was diluted and frozen in EYC and heated-whole- milk extenders containing different concentra- tions of PVP and glycerol in a factorial ar- rangement. The PVP was ineffective in replac- ing glycerol, entirely or in part, in its ability to protect sperm cells from the damaging effects of the freezing process.

Uterine distribution of progesterone and its metabolites. W. F. WmI, IA~S, ~ G. D. TVR~Ea, J. LYNCH, AND Z. TEAMA, Department of Dairy Science, University of Maryland, College Park.

Centrifugal fractionation and chromatog- raphy on silica gel have been used to charac- terize the distribution of progesterone and its metabolites in the uterine endometrium and myometrimn. Tentative identification based on thin layer chromatographic Rf values indi- cates the presence of progesterone, 20 fl-ol, and hydroxyprogesterone in both uterine en- dometrium and myometrium. Several cortical steroids have also been tentatively identified. In experiments with progesterone-C -1~ these steroids were all found to be labeled.

In the uterine endometrium and myome- trium the cell nuclei appear to incorporate progesterone and its metabolites to a negligi- ble extent. Particulate incorporation accounts for 20% and the supernatant 80% of the up- take into the cell. The intracellular distribu- tion appears part ial ly dependent on proges- terone concentration in the isolation media. Distribution in the cellular lipoproteins of the supernatant will be discussed in terms of an intracellular transport mechanism.