Journal of Animal Science

Hudson, F., A.;Gaskins, C., T.;Zinn, D., W.

doi: 10.2527/jas1974.394655xpmid: N/A

Summary Trial I. Fifty-one mature white-face ewes were randomly assigned within three dosage levels of cyclophosphamide (CPA); 6.8, 9.0 and 11.4 mg/lb. of body weight, (15, 20 and 25 mg/kg body weight). These ewes were fed a limited allowance, (1.5 lb./day) (0.68 kg/day) of an all-concentrate ration. Least-squares means for days elapsing between dosing and defleecing for the 6.8, 9.0 and 11.4 mg/lb. (15, 20 and 25 mg/kg) groups were 18.7, 15.8 and 14.3 days, respectively, with the 6.8 mg/lb. (15 mg/kg) treatment being significantly different (P< .01) from the other two. The 6.8 mg/lb. (15 mg/kg) group had a minor (P< .05) advantage in regrowth at time of defleecing, but this was not evident when .24 in. (0.6 cm) wool regrowth interval was measured. All treatment groups were characterized by a high feverish state at time of defleecing, which persisted for 7 to 10 days thereafter. Defleecing was easily accomplished over all body areas. This content is only available as a PDF. Author notes 3 Department of Animal Science. Copyright 1974 by American Society of Animal Science. American Society of Animal Science

Dickerson, G., E.;Künzi,, Niklaus;Cundiff, L., V.;Koch, R., M.;Arthaud, V., H.;Gregory, K., E.

doi: 10.2527/jas1974.394659xpmid: N/A

Summary Individual body weights, postweaning feed consumption records and 12th rib carcass backfat measurements were used to predict genetic (sire progeny) differences in efficiency of beef production. Data from years 1961 through 1967 included 222 Hereford heifers and 502 purebred and crossbred Hereford, Angus and Shorthorn steers at Fort Robinson, plus 147 bulls and 122 steers (Angus) at Lincoln, with a total of 99 degrees of freedom anong sire progenies within type of mating and years. Efficiency was defined as value of (essentially) boneless retail cuts, adjusted for marbling score, less feed and time variable costs, from 200 days of age (E1) or from 182-kg live weight (E2) to a 410-kg slaughter weight, or from 200 days to constant age at slaughter (E3). Net efficiency (H) also included expected changes in cow-herd costs from associated increases in cow size and in birth weights (i.e., in calving difficulty and fertility). Accuracy of index (I) selection for E1 was maximum (R = 0.45) when I included 200-day weaning weight (W), postweaning daily gain (G) and backfat (F1); omitting backfat reduced accuracy to R = 0.40 but adding feed intake (N1) did not help; substituting yearling weight (Y) for W and G reduced accuracy by 0.03. Maximum accuracy of selection for E2 was lower (R = 0.31) than for E1; most information (R = 0.29) came from F1 plus G or feed intake (N2), but N2 added little to F1 unless W or Y was substituted for G. Selection for age-constant E3 was more accurate (R = 0.59) than for E1 or E2 and involved little change in carcass composition; yearling weight (Y3) and backfat (F3) gave maximum accuracy (R = 0.59); adding feed intake (N3) did not help; Y3 and N3 were little better than Y3 alone (R = 0.57 vs. 0.56). Accuracy suffered when weaning weight (W) was omitted (R = 0.44 with G alone to 0.47 with G, N3 and F3). When net effects on calf mortality, reproduction and cow size were included in definition of efficiency (H), expected improvement was increased 6 to 7% by adding selection for smaller birth weight (B) to that for heavier yearling weight (IH = Y3 — 3.2 B3) or for yearling weight and backfat (IH = Y3 — 3.2B3 — 2.9F3). Adding selection against B reduced expected increases by 55% in birth weight and by 25% in mature cow size but by only 10% in yearling weight. This content is only available as a PDF. Author notes 2 U.S. Meat Animal Research Center, A.R.S., Clay Center, Nebraska 68933. 3 Animal Breeding Institute, Swiss Federal Institute of Technology, Zurich. Post doctoral support was received from Project 13-3, Beef Carcass Evaluation. 4 Department of Animal Science, University of Nebraska, Lincoln 68503. 5 Authors acknowledge assistance of personnel at the Illinois Agricultural Experiment Station in obtaining carcass data for study. Copyright 1974 by American Society of Animal Science. American Society of Animal Science

Kotula, A., W.;Lusby, W., R.;Crouse, J., D.;, de Vries, Bert

doi: 10.2527/jas1974.394674xpmid: N/A

Summary Ninety-six market beef forequarters were washed with water chlorinated at 200 ppm, to determine the effects of wash water temperature, pH in the acidic range, and spray pressure on reduction of total aerobic bacteria. Samples were taken before wash, 45 min. and 24 hr. after wash. Reduction in total counts were evident 45 min. and 24 hr. after washing, but the magnitude of the reduction in bacterial numbers was greater after 24 hours. Average log reductions in count for two tests were 1.5191 and 2.3097 when sampled 45 min. after wash and 2.3901 and 3.0716, respectively, when sampled 24 hr. after wash. Reductions in log counts were maximum at pH 6 and 7. Lowering the pH to 4 or 5 with acetic acid decreased the effectiveness of the wash. A high-pressure wash at 24.6 kg/cm2 was more effective than a wash at 4.2 kg/cm2. After 24 hr. the average log reduction for low pressure was 2.1476, and for high pressure, 3.3140. Wash water at 51.7 C yielded an average log reduction of 3.2017 compared to 2.2600 for tap water at 12.8 C. The effects of pH and wash water temperature were overshadowed by the effectiveness of high-pressure washing, wherein the treatment frequently resulted in a reduction of the bacterial numbers to less than two per square centimeter. This content is only available as a PDF. Author notes 2 U.S.D.A., U.S. Meat Animal Research Center, ARS, Clay Center, Nebraska 68933. 3 Consultant, Quad Inc., Chicago, III. 4 Appreciation is expressed for the cooperation of the Liberal Markets, Inc., which supplied facilities; and to Mr. E. James Koch, A.R.S., U.S.D.A., for advice and assistance in analyzing the data. Copyright 1974 by American Society of Animal Science. American Society of Animal Science

Gortsema, S., R.;Jacobs, J., A.;Sasser, R., G.;Gregory, T., L.;Bull, R., C.

doi: 10.2527/jas1974.394680xpmid: N/A

Summary Thirty-nine male crossbred calves (Angus-Hereford) were divided equally into three treatment groups to determine the influence of endogenous testosterone on feedlot performance. Steers, normal bulls and short-scrotum (SS) bulls were fed to approximately 450 kilograms. At the end of the feeding period, average daily gain (ADG), feed efficiency, carcass cutability, plasma testosterone and consumer acceptance were determined. Intact males (normal or SS bulls) gained weight more rapidly (P< .05) and efficiently (P< .05) than steers. Feed efficiency in this study was highly correlated with average daily gain, cold carcass weight per day of age and yield grade. Although quality grade favored the steers (P< .05), all cutability traits significantly (P< .05) favored the intact males. Warner-Bratzler shear values indicated that meat from steers was significantly (P< .05) more tender than that from intact males; however, consumer questionnaires indicated that all treatment groups fell within an acceptable tenderness range. Radioimmunoassay results showed that plasma levels of testosterone in short scrotum bulls were not significantly (P< .05) different from those of normal bulls. This content is only available as a PDF. Author notes 2 Present address: Route 1, Grangeville, Idaho 83530. 3 Department of Animal Industries. Copyright 1974 by American Society of Animal Science. American Society of Animal Science

Rattray, P., V.;Garrett, W., N.;Hinman,, N.;East, N., E.

doi: 10.2527/jas1974.394687xpmid: N/A

Summary The wool-free empty bodies and carcasses of 54 Targhee ewe lambs and 141 mature Targhee ewes were chemically analyzed. Within each age group there were initial slaughter animals, non-pregnant animals fed at maintenance and ad libitum levels of nutrition and pregnant animals. Ad libitum animals were higher in fat and energy, but lower in water, protein and ash concentrations than maintenance and initial slaughter animals. On a fat-free basis maintenance-fed animals were lower in protein and higher in ash concentrations than ad libitum fed animals. Pregnant animals were intermediate. Mature ewes were heavier, higher in fat and energy concentrations and lower in water, protein and ash concentrations than the lambs. On a fat-free basis the mature ewes were higher in ash and lower in protein concentrations than the lambs. Empty body fat % and water % were inversely related in a very precise manner. This relationship was not different between age groups or treatments but was significantly altered when conceptus composition data were included. This content is only available as a PDF. Author notes 1 Present address: Ruakura Animal Research Station, Hamilton, New Zealand. 2 Department of Animal Science. Copyright 1974 by American Society of Animal Science. American Society of Animal Science

Eckert, Thomas, E.;Allee, Gary, L.

doi: 10.2527/jas1974.394694xpmid: 4472186

Summary Three growth trials and two nitrogen retention trials were conducted to determine the limiting amino acids in milo for growing pigs. Lysine supplementation of a basal milo diet resulted in a marked improvement in daily gain, feed efficiency and nitrogen retention. The addition of threonine increased daily gain and improved feed efficiency when added to diets containing supplemental lysine or lysine and methionine. Similarly, nitrogen retention was increased with the addition of threonine to the basal diet supplemented with lysine. Supplementing the basal diet with methionine in presence of lysine gave no beneficial response in two trials and depressed performance in another. The addition of isoleucine in the presence of lysine, threonine and methionine improved daily gains and feed efficiency. No beneficial response was obtained by the addition of non-essential amino acids (glycine and glutamic acid) in the presence of all other amino acids studied. These data confirm that lysine is the first-limiting amino acid in milo protein for the growing pig. The results demonstrate that threonine is the second-limiting amino acid in milo protein for the growing pig and that methionine is not third-limiting. Additionally, these data suggest that isoleucine may be the third-limiting amino acid in milo protein for the growing pig. This content is only available as a PDF. Copyright 1974 by American Society of Animal Science. American Society of Animal Science

Harmon, B., G.;Cornelius, S., G.;Totsch,, J.;Baker, D., H.;Jensen, A., H.

doi: 10.2527/jas1974.394699xpmid: 4414939

Summary Three studies were conducted with 86 litters containing 807 pigs to evaluate two methods of iron dextran administration and the affect of type of floor. Iron dextran was shown to be effective as a hematinic for 28 days whether injected intramuscularly or administered orally within the first 12 hr. of life, prior to closure of the intestine to absorption of large molecules. Pigs farrowed and raised on steel-slatted floors maintained adequate hemoglobin values with no other iron treatment. Pigs managed similarly on steel slats coated with epoxy developed anemia by 14 days. This content is only available as a PDF. Copyright 1974 by American Society of Animal Science. American Society of Animal Science

Atinmo,, T.;Pond, W., G.;Barnes, R., H.

doi: 10.2527/jas1974.394703xpmid: 4413071

Summary The offspring of gilts fed an energy or a protein restricted diet during gestation only were examined for certain blood and tissue characteristics at birth and at slaughter (80 to 90 kg). Protein restriction (PR) during gestation significantly reduced (P< .05) brain and liver weights of the newborn pig. Serum albumin level was also lower at birth but there was no significant difference between treatments in hemoglobin, serum protein and plasma-free fatty acid (FFA) levels at birth or at slaughter. Neither DNA concentration of the whole brain nor the DNA and RNA concentration of the longissimus muscle were affected by treatment. However, RNA concentration of whole brain was significantly reduced (P< .05) in the newborn and young adult progeny of PR gilts. Daily weight gain of PR progeny from 6 weeks to slaughter was significantly lower than the control and the energy-restricted (ER) progeny (P< .05). Carcass length and back fat measurements were also reduced in the young adult progeny of PR gilts. Loin eye area was not affected by treatment. It appears that maternal protein restriction, but not energy restriction to the degree imposed, affects brain and liver weights at birth, RNA content of the brain at birth and slaughter and postnatal growth rate of the offspring. This content is only available as a PDF. Author notes 1 Department of Animal Science. 2 The Graduate School of Nutrition. Copyright 1974 by American Society of Animal Science. American Society of Animal Science

Steele, N., C.;Frobish, L., T.;Keeney,, M.

doi: 10.2527/jas1974.394712xpmid: 4414491

Summary To characterize the development of adipose tissue in genetically obese and lean swine, adipose tissue metabolic activity and cellularity were examined at two stages of growth. In vitro lipogenesis at a constant age (100 days) revealed that fatty acid synthesis on a wet tissue basis was 33% greater for the obese line (DH) and 60% less for the lean line (DL) compared to the unselected control line (DC). When corrected for fat mass, synthesis was 256% greater and 84% less for the DH and DL lines, respectively, as compared to the DC line. In vitro lipogenesis at a constant weight (95 kg) showed the anticipated age dependent decrease of fatty acid synthesis by the DH and DC lines (85 and 77%, respectively). Corrected for adipose tissue depot, fatty acid synthesis was 78 and 15% greater for the DH and DL lines, respectively, as compared to the DC line. Between the sampling periods, adipose depot fatty acid synthesis was estimated to decrease by 22% for the DH line and increase by 56 and 1043% for the DC and DL lines, respectively. This content is only available as a PDF. Author notes 1 Northeastern Region, Nutrition Institute. 2 Department of Dairy Science. Copyright 1974 by American Society of Animal Science. American Society of Animal Science

Shemesh,, Mordechai;Hansel,, William

doi: 10.2527/jas1974.394720xpmid: 4414598

Summary Changes in the peripheral plasma level of testosterone during the bovine estrous cycle were determined by a rapid competitive protein-binding assay and by radioimmunoassay, using a specific antiserum against testosterone following chromatographic purification of the steroid on Sephadex LH-20 columns. Values obtained by the two methods were similar. Testosterone concentrations increased during the 3 days preceding estrus and attained peak values (47 ± 9 pg/ml) 10 to 16 hr. before the onset of estrus. Minor rises were observed on days 3 to 5 and 11 to 14. The levels of testosterone observed during the cycle generally paralleled the plasma levels of estrogen observed in previous studies. This content is only available as a PDF. Author notes 1 Department of Animal Sciences, and Division of Biological Sciences. Copyright 1974 by American Society of Animal Science. American Society of Animal Science