Journal of Animal Science

Russell,, L.;Cox, D., F.;Larsen,, G.;Bodwell,, K.;Nelson, C., E.

doi: 10.2527/1991.6915pmid: 1825995

Abstract A total of 82 feed manufacturers located within seven midwestern states (Iowa, Nebraska, Minnesota, Illinois, Indiana, Ohio, Michigan) participated in a survey of mold and mycotoxin contamination of corn. Samples were submitted from a composite of the grading samples taken from each incoming load of corn. The survey was initiated in July 1988. During the 12-mo period, moisture content of the corn samples upon receipt at the laboratory ranged from 10.5 to 13.3%. The greatest variation occurred in the springtime. Iowa's corn samples were driest (11.2%), and samples submitted from Ohio were wettest (12.8%). Mold counts averaged 2.63 × 104 per gram during the year. The predominant mold found was Fusarium sp. Samples were checked by black light and averaged 25.4% positive during the period. When assayed for mycotoxins, 19.5% of the samples were positive for at least one of the following: aflatoxin, zearalenone, T2 toxin and deoxynivalenol (vomitoxin). Aflatoxin and T2 toxin made up the majority of these samples containing toxin. The highest incidence of mycotoxin-contaminated corn (48%) occurred in samples submitted in July of 1988. Over the 12-mo period, the highest mycotoxin contamination occurred in Iowa, Illinois and Michigan. When samples were subjected to 90% relative humidity and 32°C, an average of 3.9 d was required for mold growth to appear. After incubation, 24.7% of the samples contained one of the four toxins. The data indicate that mold and mycotoxin contamination of mixed samples of corn is widespread, even in the midwestern corn belt of the U.S. This content is only available as a PDF. Author notes 2 The authors wish to thank A. Rolow, Kemin Industries, Inc., for helpful suggestions. We wish to thank Jan Mudderman and Ann Van Zee for preparation of the manuscript and the 82 feed mills participating in the Survey. 3 Feed Specialties, Inc., 1877 NE. 58th Avenue, Des Moines, IA 50313. 4 Dept. of Stat., Iowa State Univ., Ames 50011 5 Kemin Industries, Inc., P. O. Box 70, Des Moines. IA 50301 Copyright 1991 by American Society of Animal Science

Notter, D., R.;McClaugherty, F., S.

doi: 10.2527/1991.69113xpmid: 2005006

Abstract Performance of 1/2-Suffolk, 1/2-Rambouillet (Western) and 1/2-Suffolk, 1/4-Ram-bouillet, 1/4-Finnsheep (1/4-Finn) ewes was compared in three different lamb production systems over 3 yr. System 1 (56 ewes) involved late fall lambing over 84 d. System 2 (51 ewes) involved January and February lambing for 60 d. System 3 (47 ewes) involved March and April lambing for 45 d. Pregnancy rates for yearling ewes were lower in System 1 in yr 1 (50.7% vs 87.4% for Systems 2 and 3) but differed little among systems for older ewes or in remaining years. Average pregnancy rates for 2-yr-old and older ewes were 89.5, 94.0 and 85.7% for Systems 1, 2 and 3, respectively. When the pregnancy rate was adjusted to a 45-d lambing season, means for older ewes were 78.6, 89.5 and 85.7% for System 1, 2 and 3, respectively. Ewe breeds did not differ in their pregnancy rates. Prolificacy (lambs bom per ewe lambing) was higher for 1/4-Finn ewes (1.83 ± .06 vs 1.55 ± .07) and was higher in System 3 (1.86 ± .06) than in Systems 1 (1.60 ± .07) or 2 (1.63 ± .05). Body weight at breeding in postyearling ewes was less in System 3 (64.3 kg) than in Systems 1 or 2 (average of 73.1 kg). Breeds did not differ in weight at 1 or 2 yr of age, but Western ewes were 2.1 ± 1.1 kg heavier as 3-yr-olds.(ABSTRACT TRUNCATED AT 250 WORDS) This content is only available as a PDF. Author notes 2 Dept. of Anim. Sci. Copyright 1991 by American Society of Animal Science

Notter, D., R.;Kelly, R., F.;McClaugherty, F., S.

doi: 10.2527/1991.69122xpmid: 2005017

Abstract Lamb growth, survival and carcass characteristics were compared for progeny of either 1/2-Suffolk, 1/2-Rambouillet (Western) ewes or 1/2-Suffolk, 1/4-Rambouillet, 1/4-Finnsheep (1/4-Finn) ewes produced over 3 yr in three different management systems. System 1 lambs were born in late fall and fed to slaughter on a concentrate diet. System 2 lambs were born in January and February and grazed pure stands of alfalfa or ladino clover after weaning. System 3 lambs were born in March and April and remained with their dams on native bluegrass-white clover pasture throughout the grazing season. Lambs were slaughtered as males reached 55 kg and as females reached 50 kg. One-half of the males in System 1 were left intact; all males in Systems 2 and 3 were castrated. Lamb survival did not differ among systems. Lambs from yearling 1/4-Finn ewes had higher survival rates than lambs from yearling Western ewes, but at older ewe ages, progeny of the ewe groups did not differ in survival. Lambs in System 1 grew fastest (mean lifetime gains of 310 ± 4 g/d) and were youngest at slaughter (156 ± 3 d), and lambs in System 3 were oldest at slaughter (234 ± 2 d). System 2 lambs differed considerably among years in growth rate and slaughter age (mean slaughter ages of 191, 230 and 193 d across years), primarily in response to differences in rainfall. Lifetime gains and slaughter ages of lambs did not differ between ewe breeds. Ram lambs grew 15% faster than wethers and were leaner. Differences among systems in carcass traits were small. System 1 lambs tended to be fattest and System 2 lambs leanest. Progeny of 1/4-Finn ewes had higher subjective scores for carcass fatness (e.g., feathering, flank fatness) and conformation but did not differ from progeny of Western ewes in objective measures of fatness (e.g., backfat, yield grade). This content is only available as a PDF. Author notes 2 Dept. of Anim. Sci. 3 Dept. of Food. Sci. Copyright 1991 by American Society of Animal Science

Rhodes, M., T.;Davis, D., L.;Stevenson, J., S.

doi: 10.2527/1991.69134xpmid: 2005028

Abstract Gilts (n = 267) were allotted to flushing (1.55 kg/d additional grain sorghum), altrenogest (15 mg · gilt−1 · d−1) and control treatments in a 2 × 2 factorial arrangement. Altrenogest was fed for 14 d. Flushing began on d 9 of the altrenogest treatment and continued until first observed estrus; 209 gilts (78%) were detected in estrus. The interval from the last day of altrenogest feeding to estrus was shorter (P < .05) with the altrenogest + flushing treatment (6.6 ± .2 d) than with flushing alone (7.6 + .3 d). Ovulation rates (no. of corpora lutea) were higher (P < .05) in all flushed gilts (14.5 ± .4 vs 13.4 ± .4), whether or not they received altrenogest. Flushing also increased the total number of pigs farrowed (.9 pigs/litter; P = .06) and total litter weight (1.43 kg/litter; P = .01), independent of altrenogest treatment. Number of pigs born alive and weight of live pigs were higher for gilts treated with altrenogest + flushing and inseminated at their pubertal estrus than for gilts in all other treatment combinations. In contrast, gilts receiving only altrenogest had greater live litter weight and more live pigs born when inseminated at a postpubertal estrus than when inseminated at pubertal estrus. We conclude that flushing increased litter size and litter weight, particularly for gilts that were inseminated at their pubertal estrus. Increased litter size resulted from increased ovulation rates, which, in nonflushed gilts, limited litter size at first farrowing. This content is only available as a PDF. Author notes 3 Present address: Dept. of Anim. Sei., Univ. of Missouri, Columbia 65211. 5 Dept. of Anim. Sci. and Ind. Copyright 1991 by American Society of Animal Science

Neal, S., M.;Irvin, K., M.

doi: 10.2527/1991.69141xpmid: 2005034

Abstract Data from 254 crossfostered pigs and 753 noncrossfostered pigs of Duroc and Landrace first-parity litters were used to assess the phenotypic effects of crossfostering on baby pigs. Differences between crossfostered and noncrossfostered pigs in the recipient litter were analyzed. Phenotypic correlations were calculated for selected individual pig traits (n = 1007, combined foster and nonfoster data). Birth weight was correlated positively with improved birth vigor (r = .40; P < .01), survival to 21 d (r = .34; P < .01) and weight at 21 d (r = .37; P < .01). Improved birth vigor was correlated positively with pig survival to 21 d (r = .70; P < .01) and to weaning (r = .66; P < .01). These correlations indicate that baby pig size and strength are related and that these two characteristics influence survival and performance. Pigs that were not crossfostered (adjusted for birth vigor) had a 4.8% (P < .10) higher rate of survival to 21 d and a 6.8% (P < .05) higher rate of survival to weaning (42 d). However, crossfostered pigs had greater birth vigor (P < .01). Unadjusted for vigor, crossfostered pigs had an 11.3% (P < .01) higher rate of survival to 21 d and an 8.6% (P < .05) higher rate of survival to weaning than noncrossfostered pigs. These results indicate that when average-strength pigs were crossfostered, livability was reduced. However, crossfostered pigs that were stronger than average had greater livability than pigs that were not crossfostered.(ABSTRACT TRUNCATED AT 250 WORDS) This content is only available as a PDF. Author notes 2 Present address: Dept. of Anim. M., Agric. Tech. Inst., The Ohio State Univ., Wooster 44691. 3 Dept. of Anim. Sci., The ohio State univ., Columbus 43210. Copyright 1991 by American Society of Animal Science

Siemens, A., L.;Lipsey, R., J.;Martin, W., M.;Siemens, M., G.;Hedrick, H., B.

doi: 10.2527/1991.69147xpmid: 2005037

Abstract Liquid scintillation detection of potassium-40 was used to estimate pork carcass composition of 124 boars, barrows and gilts. Pigs were fed to five live weights (23, 45, 68, 91 and 114 kg) and 40K emissions were determined on live pigs in a whole body counter (WBC) equipped with a two-pi liquid scintillation detector. Then, pigs were slaughtered conventionally and the right side of each carcass was weighed, 40K emissions of this carcass side was determined in the WBC and total grams of potassium were calculated. The right side of each carcass was ground, sampled and analyzed for fat, protein, moisture and potassium. Fat, protein, moisture and overall potassium percentage means were 23.9 ± 7.2, 16.5 ± .94, 57.0 ± 6.5 and .25 ± .02, respectively. Whole body counter carcass potassium was highly correlated (P < .01) to chemically determined carcass potassium (r = .70). Percentage of fat, protein and moisture prediction equations were formed by stepwise regression using the linear, quadratic and interactive effects of live animal and carcass side weight. Whole body counter live animal and carcass potassium and sex were utilized as independent variables. Carcass weight and 40K determined potassium of the carcass explained more of the variation in carcass composition than did live animal weight and 40K determined potassium of the live animal. This content is only available as a PDF. Author notes 1 Journal paper no. 10986 of the Missouri Agric. Exp. Sta. This research was supported in part by Merck & Co. The authors express appreciation to Monsauto Agriculture Company, Anim. Sci. Div. for use of carcasses for validation 2 Dept. of Food Sci. and Nutr. 3 Dept. of Anim. Sci. 4 Present address: Dekalb Feeds, Mechanicsville, IA 52306. Copyright 1991 by American Society of Animal Science

McLaren, D., G.;Novakofski,, J.;Parrett, D., F.;Lo, L., L.;Singh, S., D.;Neumann, K., R.;McKeith, F., K.

doi: 10.2527/1991.69154xpmid: 2005038

Abstract Use of real-time ultrasonography in meat animal improvement programs has increased largely as a result of the perceived accuracy of such instruments in measuring longissimus muscle area (LMA) and fat depth (BF). The objective of this study was to examine operator effects for ultrasonic determination of BF and LMA in market-weight cattle, sheep and pigs. The day prior to slaughter, five persons scanned 45 pigs, 32 sheep and 18 cattle at the last rib using an A-mode Ithaco Model 731AM101 body composition meter (ABF) and a Johnson and Johnson Ultrasound 210DX B-mode scanner fitted with a 3.0 MHz probe. All operators measured their own B-mode recordings (OBF, OLMA); an independent, experienced technician also obtained measurements from all recordings (TBF, TLMA). Species × machine × operator interaction effects were detected (P < .001) for ultrasonic BF. Within-species analyses also revealed that the machine × operator interaction was important (P < .001) for all species. Analyses of ABF, OBF, TBF, OLMA and TLMA detected species × operator interactions (P < .001) for all traits except TLMA (P > .20). Assuming a random model with animal, operator and residual effects, variance components were estimated by maximum likelihood for each species. Repeatabilities, calculated as the intraclass correlation among animals for BF and LMA scanned and interpreted by different operators, were .13, .21 and .51 (OBF) and .28, .15 and .29 (OLMA) for cattle, sheep and pigs, respectively, indicating the importance of operator effects. Repeatabilities of TBF were .90, .42 and .68 and of TLMA were .19, .55 and .65 for cattle, sheep and pigs, respectively, indicating the importance of image interpretation in determining operator effects associated with use of the 210DX B-mode scanner. Technical training standards must, therefore, be established for operators of such equipment. This content is only available as a PDF. Author notes 2 Dept. of Anim. Sci. Copyright 1991 by American Society of Animal Science

Berndtson, W., E.

doi: 10.2527/1991.69167xpmid: 2005039

Abstract A simple approach was developed for determining the number of replicates needed per treatment group to provide experiments of known power and sensitivity, where power equals the probability that a treatment effect would not go undetected if an effect existed and sensitivity equals the minimal treatment response that will be detectable. This approach, in turn, was used to construct reference tables, applicable across scientific disciplines, from which researchers may read replication requirements directly with ease, speed and reliability. To use the tables, one need only furnish a reliable estimate of the coefficient of variability expected among replicates, which may be obtained from prior observations on similar populations. The tabular data also enable a rapid, reliable assessment of the actual power and sensitivity of completed experiments, such as those contained within the published literature. This content is only available as a PDF. Author notes 2 Dept. of Anim. and Nutr. Sci. Copyright 1991 by American Society of Animal Science

McCarter, M., N.;Buchanan, D., S.;Frahm, R., R.

doi: 10.2527/1991.69177xpmid: 2005040

Abstract Monthly estimates of 24-h milk yield were obtained on 160 spring-calving and 153 fall-calving crossbred cows containing various proportions (0, 1/4 or 1/2) of Brahman breeding, all bred to Limousin sires. Milk production was measured using weigh-suckle-weigh procedures. Interactions between crossbred group and season of calving were not significant. Across seasons, milk production rarely was affected by proportion of Brahman breeding; however, milk yield, averaged over six monthly measurements, was greater (P < .10) for cows out of Hereford dams than for cows out of Angus dams. Averaged over six monthly measurements, estimated 24-h milk yield ranged from 5.3 kg for Hereford × Angus to 6.2 kg for Brahman × Hereford cows. Season of calving affected milk yield during the first and fourth measurement periods. Fall-calving cows produced more (P < .01) milk during the first period whereas spring-calving cows produced more milk during the fourth period. Lactation patterns for the two seasons differed. Spring-calving cows had a more typical lactation curve, whereas the curve for fall-calving cows showed more variability in milk yield throughout lactation. Phenotypic correlations between monthly measurements of 24-h milk yield and calf performance tended to be moderate and positive within the spring group. Correlations for the fall group, although positive, tended to be weaker than those found in the spring group. This content is only available as a PDF. Author notes 3 Present address: Rural Development Center, P. O. Box 1209, Tifton, GA 31793. 4 Present address: Anim. Sci. Dept., Virginia Polytechnic Inst. and State Univ., Blacksburg 24061. Copyright 1991 by American Society of Animal Science

Hohenboken, W., D.;Berggren-Thomas, P., L.;Beal, W., E.;McClure, W., H.

doi: 10.2527/1991.69185xpmid: 1900830

Abstract Production of 18, 12-yr-old Angus cows was summarized as the averaged weaning weight deviations of each cow's calves from their like-aged, like-sexed and similarly managed contemporaries. These cows had spent a large part of their productive lives on pastures dominated by endophyte-infected tall fescue, so differences among them in calf production might have been induced partly by differences in susceptibility to fescue toxicosis. Cows were divided randomly into two groups for a 31-d summer feeding trial. In a crossover design, cows were fed 0 or .9 kg per cow per day of endophyte-infected fescue seed. Various traits were monitored to quantify differences among cows in response to the endophyte-infected fescue seed. Baseline serum prolactin concentration was depressed by fescue seed feeding, but differences among cows in the amount of depression were not related to past calf production. Prolactin release in response to thyrotropin-releasing hormone tended to be depressed by fescue, but the response also was sensitive to factors such as ambient temperature. Serum cholesterol and body weight change did not respond significantly to the fescue challenge. The experiment was not successful in unambiguously differentiating among cows in susceptibility to fescue toxicosis or in relating differential susceptibility to past calf production. This content is only available as a PDF. Author notes 2 Dept. of Anim. Sci. 3 Shenandoah Valley Research Station, Steeles Tavern VA 24476. Copyright 1991 by American Society of Animal Science