Journal of Animal Science

Miller, J., C.

doi: 10.2527/jas1958.173493xpmid: N/A

Abstract THE industry which this organization represents has enjoyed remarkable growth and development during the past half century. We can be proud of the contributions made to American Agriculture by the membership, individually and collectively, of the American Society of Animal Production during the 49 years of its existence. The American standard of living, and our continuing increase in life expectancy are directly associated with Animal Agriculture and the high protein diet of the American people. The tremendous meat production capacity of our farms and ranches is a tribute to research and education in the broad field of Animal Science. In spite of our accomplishments of the past, the current revolution in American Agriculture creates a real threat to the future of our industry. Can we roll with the punches of Agricultural-Industrial integration? Can we meet the competition of automation and technocracy? In short, can we compete in tomorrow's agriculture? As our past success has been largely due to research and education, so will our future be determined by the same forces. This content is only available as a PDF.

Kottman, Roy, M.

doi: 10.2527/jas1958.173495xpmid: N/A

Abstract The on-rush of scientific discovery with its attendant impact on economic and social change makes it imperative that college curricula be responsive to forces of change. It is equally important that the direction of curriculum change be guided by fact rather than emotion insofar as pertinent data can be assembled. To secure data for the study, we sent three questionnaires to each of the 48 land-grant (white) colleges and state universities. A questionnaire dealing with enrollment went to the Registrar in each institution; one dealing with job opportunities, curriculum trends, qualifications of students entering Animal Husbandry and the source of those students was sent to Heads of Animal Husbandry Departments; still a third schedule of questions was sent to Directors of Resident Instruction requesting data on curriculum changes actually accomplished, on the number of staff members employed at the present time and prior to World War II, and on average beginning salaries for the various major divisions of work represented in most of our colleges and state universities. Response to questionnaires was in all cases cordial, if not always productive of usable data. Certain items on the questionnaires were completed by as many as 3 7 of the 48 land-grant institutions. In other cases, as few as 6 or 7 schools were able to supply data. In most instances, however, there was sufficient response to provide data from a representative sample of schools located in each of the four regions of the United States. This content is only available as a PDF. Author notes 2 Professor of Animal Husbandry and Associate Dean of Agriculture at Iowa State College. 3 The author is pleased to acknowledge the assistance of Heads of Animal Husbandry Departments, Directors of Resident Instruction in Agriculture, and Registrars in the land-grant colleges and state universities from which data were obtained for this study.

Seinwerth, Herman, W.

doi: 10.2527/jas1958.173507xpmid: N/A

Abstract Dr. Herrell De Graff of Cornell University in the September issue of County Agent made an interesting observation: “The industry-agriculture partnership that we hear so much about is nothing new. It's just been intensified to the point where we no longer can say just who is the farm worker!” Dr. De Graft points out that despite sizable increases in population, the number of farm workers has been steadily decreasing. For example, in 1870 out of a total population of 40 million there were 8 million workers on the farms and ranches of the United States—a ratio of 1 to 5. Just 87 years later, in 1957, with an estimated total population of 170 million, there are still only 8 million workers on the farms and ranches—a ratio of about 1 to 22. There is nothing startling or new about these figures. I quote them only to emphasize the dramatic change that has occurred in this specific area which the Land Grant Colleges were designed to serve. I have chosen to reiterate this emphasis because I believe that it has a tremendous impact upon the various phases of the problems this Society is considering at this 1957 annual meeting. This content is only available as a PDF. Author notes 2 Industrial Relations Manager, Swift & Company, Chicago, Illinois.

Liuzzo, J., A.;Reineke, E., P.;Pearson, A., M.

doi: 10.2527/jas1958.173513xpmid: N/A

Summary A technique was developed for the determination of body volumes of living animals by air displacement. Two experiments were reported in which body volumes were determined at two levels of negative pressure. In the first experiment, specific gravity of 23 adult female guinea pigs, calculated from body volumes determined at a total vacuum of 320 mm. of Hg., were correlated with carcass fat, water, protein and ash. The correlation coefficients were −.70, 0.67, 0.68 and 0.58, respectively. In the second experiment, body volumes of 25 female guinea pigs were determined at a total vacuum of 120 mm. of Hg., employing a constant volume method of manometeric measurement. Correlation coefficients for air specific gravities thus obtained and carcass fat, water, protein and ash were −.82, 0.81, 0.72 and 0.72, respectively. Other factors which influenced the accuracy of the body volume determinations were changes in chamber temperature and humidity. Variations due to the contents of the digestive tract and composition of the viscera did not significantly alter the relationship between air specific gravity and carcass composition. This content is only available as a PDF. Author notes 2 This is a portion of research completed for the Ph.D. thesis by the senior author. 3 Departments of Animal Husbandry, and Physiology and Pharmacology.

Warwick, Bruce, L.;Cartwright, T., C.

doi: 10.2527/jas1958.173521xpmid: N/A

Summary Weaning weights of lambs adjusted by six types of procedures have been compared with the actual weights of 115 lambs at 120 days of age; varying the procedure in each type with respect to time or interval, brought the number of methods compared to 26. The correlation coefficients varied from 0.99 by the use of bracketing weights of one week interval to the lowest of 0.94 by use of regression using one flock weight taken at earlier ages, and by actual weight at nearest weigh day with intervals of three weeks. The results were very similar when the correlations were computed “over-all” to those computed “within sex and type of raising.” All fifty-two correlations were statistically significant, and offer a wide choice of valid methods. This content is only available as a PDF. Author notes 2 Animal Husbandman and Geneticist, McGregor, Texas. 3 Associate Animal Husbandman and Geneticist, McGregor, Texas.

Burris, Martin, J.;Priode, B., M.

doi: 10.2527/jas1958.173527xpmid: N/A

Summary Calving records of Angus, Hereford, and Shorthorn cows at the Beef Cattle Research Station at Front Royal, Virginia, from 1950 to 1956 were analyzed to determine the effect of calving date on subsequent calving performance. Three determinations made from these data include: (1) Percent of cows calving each 20-day period during the calving season which failed to calve the following season, (2) comparison of the previous calving dates of all cows which failed to calve with the previous calving dates of all cows which calved in both years and, (3) the association between calving dates of cows when these calvings occurred in successive calving seasons. The regression of percent of cows failing to calve on previous calving date was 6.1% per 20-day period or 6.1% fewer cows calving for each delay of 20 days in previous calving date. The calving date in the previous year of cows which failed to calve was 9.5 days, 18.2 days, and 15.4 days later than the calving date of contemporary cows in the first year which calved in both seasons in the Angus, Hereford, and Shorthorn herds, respectively. The correlation between successive calving dates was 0.33, 0.38, and 0.46 for the Angus, Hereford, and Shorthorn herds, respectively. These observations indicate that selection for early calving date would result in an increase in calving percentage and an earlier calving date in1 the next year when the breeding season is limited to approximately 90 days. This content is only available as a PDF. Author notes 1 Present address, State Experiment Stations Division, A.R.S., U.S.D.A., Washington 25, D. C. 2 Front Royal, Virginia.

Foote, W., C.;Waldorf, D., P.;Self, H., L.;Casida, L., E.

doi: 10.2527/jas1958.173534xpmid: N/A

Summary Forty-nine gilts (average live weight 232 lb.) of mixed breeding were divided into five experimental groups. The experimental period began on the 12th day of an estrual cycle with all treatments being timed from that stage. Group I received no injections; groups II, III and IV received progesterone (0.4 mg. per lb. of body weight, subcutaneously) from day one through day 17 of the experiment; group IV also received 20 mg. estradiol and group V 20 mg. estradiol only on day 14. Group II was slaughtered on day 25 of the experiment while all other groups were killed on day 18. The average number of follicles 3 mm. or larger on the ovaries of gilts in the five treatment groups was 19.9, 7.6, 36.8, 9.2, 3.7, respectively. Estradiol suppressed the development and maintenance of follicles beyond the 3 mm. stage. Prolongation of the cycle by progesterone allowed a significantly greater number of follicles to develop. Pituitary glands were tested for gonadotrophic potency using five-day-old, White Leghorn cockerels. Chick testis weights for the five treatment groups were 51, 54, 64, 64 and 60 mg. and comb weights were 96, 86, 134, 140 and 107 mg. Significant differences were found only between comb weights. These differences between comb weights indicate that the action of progesterone in delaying heat and ovulation is to block the release of luteinizer from the pituitary rather than to suppress its production. Withdrawing progesterone led to LH release but a single injection of 20 mg. estradiol in the presence of functional corpora lutea or of the exogenous progesterone did not. Seven of 11 gilts in group II had ovulated at time of slaughter with an average of 14.1 ova. These differed (P<0,05) from the averages of groups land V (11.3 and 11.7). This content is only available as a PDF. Author notes 2 Ralston-Purina Fellow; deceased October 29, 1957.

Cartwright, T., C.;Butler, O., D.;Cover,, Sylvia

doi: 10.2527/jas1958.173540xpmid: N/A

Abstract THE variation in market price of steers is associated with the market value of the carcasses which in turn are valued according to their presumed eating qualities. There is a dearth of reported data concerning the variables affecting eating quality of beef; therefore, breeders have no proven selection criteria for improving the eating quality of beef. To understand more fully the relationship of the eating quality of beef to ration, inheritance and other influences, it is necessary to understand the relationship of these variables to each other. The data reported by Cover et al. (1957) were suitable for giving evidence of some of these inter-relationships. Materials and Methods Available for study were 18 Hereford steers and 20 F1 (Brahman sires × Hereford dams) steers born on the McGregor Station. They were treated similarly until after weaning when equal numbers of each breed or cross were self-fed a high-concentrate and a low-concentrate ration in the feed lot for a period consisting of 14 days adjustment, 140 days test and 13 to 16 days holding after the test before slaughter. This content is only available as a PDF. Author notes 2 Associate Animal Husbandman and Geneticist, Substation 23, McGregor; Head, Department of Animal Husbandry, College Station; and Professor, Department of Home Economics, College Station, respectively.

Dziuk, P., J.

doi: 10.2527/jas1958.173548xpmid: N/A

Summary Techniques for handling, diluting and storing boar semen are described. Several different diluters were compared in their ability to sustain sperm motility under conditions in which semen was diluted at the rate of 1 part of semen to 2 parts of diluter. On this basis the most satisfactory diluter consisted of 3 gm. glucose, 0.15 gin. sodium bicarbonate, 30 ml. egg yolk, and 70 ml. of distilled water plus 100,000 units of penicillin and 100 mg. of streptomycin. Maintenance of motility was superior in samples stored at 7° C. than in those stored at 16° C. This content is only available as a PDF. Author notes 1 The author acknowledges assistance of Neil McCoughlin, Louis James, Pierre Rio, and Gordon Henshaw in the collections of semen and certain analyses. Appreciation is also extended to the Dairy Science Department for permitting the use of the osmometer.

Dziuk, P., J.;Henshaw,, G.

doi: 10.2527/jas1958.173554xpmid: N/A

Summary Sows and gilts, unselected for reproductive performance, were artificially inseminated with fresh, undiluted semen which had been stored at 7° C. in an egg yolk-glucose-sodium bicarbonate diluter for various lengths of time. The conception rates for fresh, undiluted semen, and semen stored for 1, 2 and 3 days were 56% and 55%, 5% and 42%, respectively. Number of fetuses and embryonal mortality was normal in those cases in which fresh and one-day-old semen was used. Early embryonal mortality increased when the semen inseminated had been stored for 3 days. This content is only available as a PDF. Author notes 1 The authors express their appreciation for assistance received from Dr. B. C. Breidenstein, Meats Division; Dr. S. W. Terrill, Swine Division; Dr. H. W. Norton, Station Statistician; R. H. McDade, Swine Herdsman, and his assistants and from graduate students in the Animal Genetics Division in making this investigation possible. 2 Present address: Assistant County Agent, Cadiz, Kentucky.