Journal of Animal Science

Thrift, F., A.;Whiteman, J., V.

doi: 10.2527/jas1969.294521xpmid: N/A

Summary One-hundred-twenty purchased Western ewes (predominately Rambouillets) and 120 raised Dorset x Western ewes were compared on the basis of the growth performance of their lambs when both ewe breed groups were bred to the same rams and managed for fall-lambing. The lamb growth variables studied were birth weight (BW), rate of gain from birth to 70 days (RGB70), 70-day weight (70DW), rate of gain from 70 days to market (RG70M) and market age (MA). Each variable was analyzed separately for the two ewe breed groups by least squares procedure. The results of the least squares analyses revealed that for each variable separately, the mean values changed from year to year for the data from the two ewe breed groups. However, within each year, the mean values were quite similar for the data from both breed groups. This was also evident for the age of dam, type of birth and rearing (type of birth for BW) and sex of lamb mean values. These results indicate that the least squares constants were similar for the data from the two breed groups, since the overall means for each of the variables were quite similar. The overall means for BW, RGB 70, 70DW, RG70M and MA were 4.10, 4.06 kg.; 0.281, 0.28.2 kg.; 23.9, 23.8 kg.; 0.24S, 0.250 kg. and 156.4, 155.5 days for the lambs from the Western and Dorset crossbred ewes, respectively. For each of the variables, the difference between the overall means for the data from the two breed groups was not significant. It appears that neither ewe breed group has any advantage over the other relative to the growth rate of their lambs when the ewes are bred to the same rams. This content is only available as a PDF. Author notes 2 Present address: Department of Animal Science, University of Kentucky, Lexington. 3 Department of Animal Science in cooperation with the A.H.R.D., A.R.S., U.S.D.A. Copyright 1969 by American Society of Animal Science American Society of Animal Science

Krehbiel, E., V.;Carter, R., C.;Bovard, K., P.;Gaines, J., A.;Priode, B., M.

doi: 10.2527/jas1969.294528xpmid: N/A

Summary The data for this study consisted of breeding and calving records of 1,504 purebred Angus matings of 395 cows and 48 service sires, and 1,606 purebred Shorthorn matings of 435 cows and 49 service sires, during 13 calf crops produced from 1950 through 1962. The ages of the breeding animals ranged from 2 through 12 yr. for the cows and 2 through 11 yr. for the service sires. Seven breeding lines were developed within each breed to compare breeding systems, i.e., four inbred lines, two single trait selection and one outbred line were established. Inbreeding of individual matings ranged to 40 percent in the Angus herd and to 50% in the Shorthorn herd, also average per line ranged to 19.9 in the Angus and 30.0 in the Shorthorn herd. Each mating was scored by a “0” if it did not produce a calf or a “1” if a calf was born. Factors having a highly significant effect upon fertility were: in the Angus herd breeding system, inbred lines within breeding system, year of calving, age of service sire; and in the Shorthorn herd inbred lines within breeding system, year of calving and age of cow. Other important factors were selection lines within breeding system and age of cow in the Angus herd; also breeding system, selection lines within breeding system and age of service sire in the Shorthorn herd. The fertility means of all inbred lines was not significantly different from all non-inbred lines. None of the partial linear regressions of fertility on inbreeding of mating, cow and service sire were significant. The weighted linear regressions on years were negative for all lines. This content is only available as a PDF. Author notes 3 Present address: A.H.R.D., A.R.S., U.S.D.A., Lincoln, Nebraska. 4 Department of Animal Science, Blacksburg, Virginia. 5 Beef Cattle Research Station, Front Royal, Virginia. Copyright 1969 by American Society of Animal Science American Society of Animal Science

Hohenboken, W., D.;Brinks, J., S.

doi: 10.2527/jas1969.294534xpmid: N/A

Summary Weaning weights of 4,722 commercial Angus calves from 1,501 dams and 9 yr. were analyzed to compare the accuracy of environmental correction factors computed from herd data (Method A) as opposed to factors recommended by the beef cattle industry (Method B). In each method weights were adjusted for calf age using a standard birth weight and the calf's own average daily gain. Adjustment for cow age was by multiplicative factors in Method B and by additive least-squares constants in Method A. The magnitude of the correction factors was similar in each case. Sex was corrected multiplicatively in each method. Industry correction terms assumed greater differences between bulls and steers than did factors utilized in Method A. Estimated repeatability of weaning weight, computed as the intraclass correlation among calves of a cow, was O.257±O.O16 and 0.251 ± 0.016 from data corrected by Methods A and B, respectively. The correlation between the two adjusted records of an individual was 0.80. It appeared that more of the initial variability was accounted for in Method A analyses than in those of Method B. Results indicated, however, that under commercial conditions the additional expense of computing correction terms specific for the herd was not justified. Possible reasons for the low magnitude of repeatability were presented and discussed. Included were the inclusion in the model of the cow age x year interaction, non-adjacency of records, a possible breed effect and an effect resulting from behavioral characteristics of Angus cows and calves. This content is only available as a PDF. Copyright 1969 by American Society of Animal Science American Society of Animal Science

Waugh, Gary, A.;Marlowe, Thomas, J.

doi: 10.2527/jas1969.294541xpmid: N/A

Summary The purpose of this study was to estimate the magnitude of several environmental influences on continuous growth and grade of yearling cattle of the Angus and Hereford breeds. There were records on 1,485 Angus bulls, 2,093 Angus heifers, 1,262 Hereford bulls and 1,394 Hereford heifers in the study. The effects of herd, year, age of dam, month of birth, age of animal and pre- and postweaning management practice were independent variables, where lifetime ADG and grade were dependent variables. The data were analyzed by least squares procedures. Not only did herds and years significantly affect growth and grade in all analyses, but age of dam and age of animal were also significant sources of variation on growth in all breed-sex groups and on grade in most groups. Yearling cattle out of young dams had the slowest lifetime growth rate, whereas those out of mature dams (6 to 11 yr. old) had the fastest growth rate. Also, short yearlings (10 to 13 months of age) had the fastest growth rate with growth rate decreasing in each successive age group. In contrast to its effect on ADG of weanling calves, month of birth appeared to have no significant influence on ADG of yearling cattle. Creep feeding as calves significantly increased the lifetime ADG of yearling Hereford cattle, and the kind of postweaning treatment used had a significant effect on ADG of all groups, except Angus bulls, with growth rate being higher for the better fed animals. Even though grade of yearling cattle was significantly affected by some of the independent variables, the effects were in no case large enough to be of practical importance. This content is only available as a PDF. Author notes 1 This paper is part of a thesis submitted by the senior author in partial fulfillment of requirements for the degree of Master of Science. 3 The authors express their sincere appreciation for the data provided by the Beef Cattle Research Station, Front Royal; Virginia Forage Research Station, Middleburg; Virginia Beef Cattle Improvement Association, Blacksburg; and Bland Correctional Farm, Bland, Va. Copyright 1969 by American Society of Animal Science American Society of Animal Science

Stant,, E., G.;Martin, T., G.;Kessler, W., V.

doi: 10.2527/jas1969.294547xpmid: N/A

Summary Forty-eight crossbred barrow pigs were utilized to study potassium content of live animal, carcass, offal, muscle, separable fat and bone of the porcine body at 23, 46, 68 and 91 kg. live weight. Both whole body counting and chemical methods were utilized in estimating potassium contents. As estimated by whole body counting, potassium content of the live pig, carcass and offal increased at a slower rate than did their respective weights. Consequently, total grams potassium increased while grams potassium per kilogram (gm. K/kg.) weight decreased as live weight increased. The data suggested that, at some point early in the life of the pig, the amount of potassium in the skeleton becomes relatively constant. When potassium concentration was expressed as gm. K/kg. fat-free tissue, gm. K/kg. fat-free dry tissue or mg. K/gm. protein, the total variation was greatly reduced. Breed main effect and breed by weight group interaction were virtually eliminated as sources of variance. Effect of weight group was greatly reduced but, in general, remained a significant (P<.05) source of variation. Concentrations of potassium in separable fat and bone were lower than concentration of potassium in muscle on any of the above bases. With increasing weight, a higher proportion of total potassium in the carcass was found in the muscle. Changes in distribution of potassium associated with maturation would tend to explain higher correlations of potassium content with estimates of body composition at higher live weights. The failure of potassium to maintain a constant relationship with other chemical constituents (moisture, ether-extractable constituents and protein) from one type tissue to another and from one weight to another is implicated as a major factor contributing to inaccuracies associated with estimation of body composition from potassium content. This content is only available as a PDF. Author notes 3 Present address: Division of Nuclear Medicine and Biophysics, Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee. 4 Department of Bionucleonics, School of Pharmacy and Pharmacal Sciences. Copyright 1969 by American Society of Animal Science American Society of Animal Science

Busch, D., A.;Dinkel, C., A.;Minyard, J., A.

doi: 10.2527/jas1969.294557xpmid: N/A

Summary Data from 745 grade Hereford steers from 84 sires were used to evaluate slaughter weight, 18 body measurements, 16 subjective scores and five estimates of certain carcass traits in predicting edible portion of beef cattle carcasses. All independent variables were not measured every year so four different groups were studied. Slaughter weight had the highest intra-subclass correlation with edible portion in all groups and controlled from 75 to 88% of the variation in edible portion. Body measurements were of little value in predicting edible portion, as slaughter weight and all measurements controlled from only 2 to 4% more variation in edible portion than slaughter weight alone. Slaughter weight and all estimates controlled 6 and 7% more variation in edible portion than slaughter weight alone. Estimated fat thickness had the largest standard partial regression coefficient of the estimates and in combination with slaughter weight controlled 5 and 4% more variation in edible portion than slaughter weight alone. Slaughter weight and all scores controlled from 2 to 6% more variation in edible portion than slaughter weight alone. Final condition had the largest standard partial regression coefficient of the scores and in combination with slaughter weight controlled 3% more variation in edible portion than slaughter weight alone. Three prediction equations for edible portion were developed using slaughter weight alone and either final condition or estimated fat thickness in combination with slaughter weight. These equations controlled from 76 to 80% of the variation in edible portion. This content is only available as a PDF. Author notes 2 Present address: Am. Int. Charolais Assn., Houston, Texas. Copyright 1969 by American Society of Animal Science American Society of Animal Science

Riley, M., L.;Field, R., A.

doi: 10.2527/jas1969.294567xpmid: N/A

Summary Data were collected on 64 ram and 564 wether and ewe carcasses. Simple carcass measurements were useful in developing equations for estimating percent fat, weight of retail cuts and percent retail cuts. The equation using body wall thickness and fat depth 3.8 cm. from the midline between the 12th and 13th ribs had multiple correlations of 0.72 and 0.87 and standard error of estimates of 2.95 and 3.90 for predicting percent fat in the boneless carcass of ewes and wethers and rams, respectively. Carcass weight, body wall thickness and fat depth 3.8 cm. from the midline between the 12th and 13th ribs had a multiple correlation of 0.84 and a standard error of estimate of 0.34 for estimating kilograms of retail cuts from lamb carcasses. Carcass weight and body wall thickness had a multiple correlation of 0.99 and a standard error of 0.44 for predicting kilograms of retail cuts of ram carcasses. Body wall thickness, kidney weight and fat depth 3.8 cm. from the midline between the 12th and 13th ribs had a multiple correlation of 0.73 and a standard error of 1.47 for estimating percent retail cuts from lamb carcasses. The equations mentioned in this summary indicate that percent fat, percent retail cuts and weight of retail cuts can be estimated without breaking the carcass or by using subjective measurements. This content is only available as a PDF. Copyright 1969 by American Society of Animal Science American Society of Animal Science

Beames, R., M.

doi: 10.2527/jas1969.294573xpmid: N/A

Summary Sixty-four, 3-week-old pigs and 128, 4-week-old rats were used to measure the effects on growth and feed efficiency of adding tylosin phosphate and a high level of copper sulfate to diets containing either 6% or 23% soybean meal and 23.5% protein. Each diet was provided without supplement, with copper (250 ppm) as copper sulfate, with tylosin phosphate (110 ppm) and with both copper and antibiotic. The pigs were fed for 6 weeks and the rats for 4 weeks. Tylosin increased feed intake and body weight gain of pigs fed the 6% soybean meal diet only, but with neither diet did tylosin have any effect on efficiency of feed conversion. Copper supplementation improved body weight gain of pigs fed both diets. This improvement was associated with an improvement of feed/gain from 1.93 to 1.83. Feed intake of pigs fed the 6% soybean meal diet was greater than that of those given the 23% soybean meal diet, but the greater feed/gain of the pigs fed the 6% soybean meal diet resulted in body weight gains of a similar magnitude in each group. The addition of tylosin to the diet decreased feed intake and growth rate of rats. The addition of copper improved the efficiency of feed conversion of the female rats but decreased efficiency of conversion of the male rats. Copper supplementation increased final liver copper levels of the pigs from 24 to 122 ppm (P<.05) and of the rats from 16 to 20 ppm (P<.05). This content is only available as a PDF. Author notes 1 The author wishes to thank Mr. J. L. Lamberth for performing the liver biopsies on the pigs. Thanks are also given to Miss P. Pepper for statistical analyses, to members of the Biochemical Branch for chemical analyses and to Mr. R. Phillips and Mr. M. H. Magee for attending to the experimental animals. 2 Animal Research Institute. Present address, Department of Animal Science. The University of British Columbia, Vancouver 168, B. C., Canada. Copyright 1969 by American Society of Animal Science American Society of Animal Science

Ly, M. Velázquez, J.;Preston, T., R.

doi: 10.2527/jas1969.294578xpmid: N/A

Summary Eight intact male pigs were used in a double 4×4 Latin square design to determine the and ME contents of diets containing 75.5% high-test molasses or combinations of 55.5/20, 39.5/36 and 23.5/52% final molasses and crude sugar. The remaining 24.5% of the diet was fish meal, saccharomycers yeast, minerals and vitamins A and D. N-retention and DM digestibility, the latter ranging from 90.6 to 92.2%, were unaffected by dietary variables. DM content of feces was highest (46.9%) with the high-test molasses diet and increased from 25.2% when final molasses with the least amount of added sugar was fed to 40.7% with the highest sugar level. There were no differences between diets in DE, but ME was significantly higher (3.52 mcal./kg. DM) for the high-test molasses diet than for those based on final molasses and sugar (3.35 to 3.46). The content of ME in the diet was positively related to percent fecal DM (P<.05). This content is only available as a PDF. Author notes 1 The authors are indebted to Sra. Ileana Valmaña for assistance in performing the statistical analyses. Copyright 1969 by American Society of Animal Science American Society of Animal Science

Baker, D., H.;Clausing, Warren, W.;Harmon, B., G.;Jensen, A., H.;Becker, D., E.

doi: 10.2527/jas1969.294581xpmid: N/A

Summary Two weight gain assays and one nitrogen retention assay were carried out to evaluate the replacement value of cystine for methionine in the diet of young pigs. An isolated soybean protein diet containing 12.2% protein was supplemented with graded decrements of methionine and graded increments of cystine to provide a total of 0.20% supplementary sulfur-bearing amino acids. Under both group and individual ad libitum feeding conditions, weight gain was as rapid when 56% of the total sulfur amino acid requirement came from cystine, as when all was supplied by methionine. When equally fed in the nitrogen retention assay, the replacement value of cystine for methionine was 66%. Data from all three assays suggested that above a certain level of replacement (56%), cystine imbalances the diet, causing both reduced feed intake and gain. However, at equal levels of feed intake, maximal performance can be achieved on a diet containing at least 66% of the total sulfur amino acids as cystine. This content is only available as a PDF. Author notes 1 Department of Animal Science. Copyright 1969 by American Society of Animal Science American Society of Animal Science