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Animal Sciences Commons

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1987

University of Nebraska - Lincoln

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Articles 61 - 68 of 68

Full-Text Articles in Animal Sciences

Effect Of Weight At Castration On Steer Performance In The Feedlot, M. A. Worrell, D. C. Clanton, Chris R. Calkins Jan 1987

Effect Of Weight At Castration On Steer Performance In The Feedlot, M. A. Worrell, D. C. Clanton, Chris R. Calkins

Department of Animal Science: Faculty Publications

One hundred eighty-eight male calves were randomly assigned to one of five treatments at about 6 wk of age to determine the effect of castration at different weights on feedlot performance and carcass characteristics. Calves were castrated at 70, 230. 320 or 410 kg or left intact. All calves received a 36-mg zeranol implant 60 d post-weaning and were re-implanted every 56 d for the duration of the trial (196 d). Animals were slaughtered between 14 and 15 mo of age. Intact males gained faster (P<.05) and were more efficient (P<.05) in converting feed to gain than the castrated males. There were no differences (P>.10) in average daily gain (ADG) or feed efficiency (F/G) for males castrated at …


Morphological Variation, Karyology, And Systematic Relationships Of Heteromys Gaumeri (Rodentia: Heteromyidae), Mark D. Engstrom, Hugh H. Genoways, Priscilla K. Tucker Jan 1987

Morphological Variation, Karyology, And Systematic Relationships Of Heteromys Gaumeri (Rodentia: Heteromyidae), Mark D. Engstrom, Hugh H. Genoways, Priscilla K. Tucker

University of Nebraska State Museum: Mammalogy Papers

Morphological variation was assessed within and among populations of Heteromys gaumeri using univariate and multivariate statistical analyses of external and cranial measurements. Although patterns and amount of nongeographic variation in H. gaumeri were similar to other heteromyines, geographic variation was relatively conservative. Mean values of most characters were statistically homogeneous among localities and spatially unpatterned. Consequently, no association was found between levels of within- and among-sample variation for individual characters (the "Kluge-Kerfoot phenomenon"). Populations of H. gaumeri were chromosomally monomorphic. The lack of morphological and chromosomal variation in H. gaumeri contrasts sharply with patterns in other heteromyines. Heteromys gaumeri is …


Estimation Of Genetic (Co)Variances For Milk Yield In First Three Lactations Using An Animal Model And Restricted Maximum Likelihood, H. Swalve, L. Dale Van Vleck Jan 1987

Estimation Of Genetic (Co)Variances For Milk Yield In First Three Lactations Using An Animal Model And Restricted Maximum Likelihood, H. Swalve, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

Genetic relationships among lactation records are of interest because most selection of bulls is on first lactations. Selection also complicates estimation of genetic parameters. Techniques unbiased by selection should be used. Estimation of genetic and environmental (co)variances was done using restricted maximum likelihood with an expectation-maximization algorithm for an animal model. The algorithm involved solving mixed model equations by direct inversion of coefficient matrix that became feasible by neglecting relationships across herds. From data consisting of first to third lactation milk records of New York Holsteins, two computationally manageable subsets were selected of 15 herds each totaling 3070 and 2900 …


Selection When Traits Have Different Genetic And Phenotypic Variances In Different Environments, L. Dale Van Vleck Jan 1987

Selection When Traits Have Different Genetic And Phenotypic Variances In Different Environments, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

Falconer's concept that performance in environment 2 is a different trait from performance in environment 1 allows calculation of expected response in environment 2 if selection is from environment 1. Response to selection in environment 1 and correlated response in environment 2 depend on heritability and phenotypic variance in environment 1, genetic covariance between performance of identical genotypes in the two environments, and selection intensity. If selection is from performance in environment 2, direct response in environment 2 and correlated response in environment 1 also can be calculated. If selection is from animals in both environments and if selected genotypes …


Relationships Between Rate Of Growth, Catheptic Enzymes And Meat Palatability In Young Bulls, Chris R. Calkins, S. C. Seideman, J. D. Crouse Jan 1987

Relationships Between Rate Of Growth, Catheptic Enzymes And Meat Palatability In Young Bulls, Chris R. Calkins, S. C. Seideman, J. D. Crouse

Department of Animal Science: Faculty Publications

Relationships between rate of growth, endogenous muscle enzymes and meat palatability were investigated in 48 young (13 mo) Angus bulls. After backgrounding for 4 mo, bulls were placed on a high-energy diet for 30 d, at which time they were assigned randomly to one of three feeding treatments: 1) high energy (ad libitum-fed), 2) maintenance energy (restriction-fed to maintain body weight) or 3) sub-maintenance energy (restriction-fed to lose .68 kg/d). Cattle were slaughtered after 30 or 60 d on trial. Cathepsins B and H and β-glucuronidase in the longissimus muscle were quantitated at slaughter. Serum hydroxyproline, longissimus muscle collagen, taste-panel …


1987 Beef Cattle Report, Irvin T. Omtvedt Jan 1987

1987 Beef Cattle Report, Irvin T. Omtvedt

Nebraska Beef Cattle Reports

Eighty grain samples of various moisture levels were collected throughout the 1985 harvest season and analyzed for moisture by either moisture tester, microwave oven, or forced-air oven. The moisture tester was not as accurate as the forced-air oven when moisture level exceeded 19%. Microwave drying was as accurate as forced-air oven drying but was more variable between readings of the same sample.


Effect Of Level Of Protein And Supplemental Choline On Reproductive Performance Of Gilts Fed Sorghum Diets, C. V. Maxwell, R. K. Johnson, W. G. Luce Jan 1987

Effect Of Level Of Protein And Supplemental Choline On Reproductive Performance Of Gilts Fed Sorghum Diets, C. V. Maxwell, R. K. Johnson, W. G. Luce

Department of Animal Science: Faculty Publications

A total of 214 gilts was used (two trials) to determine the effect of protein level and choline supplementation during gestation on weight gain, conception rate and subsequent reproductive performance. The gilts were fed either a 12 or 16% crude protein sorghum-soybean meal diet containing either a high supplemental choline level or no supplemental choline in a 2 x 2 factorial arrangement of treatments Conception rate was not influenced by either protein or choline level. Choline supplementation increased pig weight at 42 d of age (P<.14) and litter weight at 21 (P<.12) and 42 d (P<.1). Gilts fed the 16% protein diet produced larger pigs at 42 d (P<.13) and heavier litters at birth, (P<.l) 21 d (P<.14) and 42 d (P<.05) than gilts fed the 12% protein diet. A larger choline effect on litter size and pig and litter weight was observed for gilts fed the 12% protein diet than for those fed the 16% gestation diet, although the protein-choline interaction was not significant for any traits measured. The incidence of spraddle leg condition was low and was not affected by level of dietary protein or supplemental choline.


The Computer As A Collection Management Tool, Suzanne B. Mclaren, Hugh H. Genoways, Duane A. Schlitter Jan 1987

The Computer As A Collection Management Tool, Suzanne B. Mclaren, Hugh H. Genoways, Duane A. Schlitter

University of Nebraska State Museum: Mammalogy Papers

Since the mid-1960s, discussion of computer use for information retrieval in museum collections has usually focused on research potential. Much attention has been given to the idea of networking and the ability to access data across great distances. However, the potential for collection management usage has also proven to be a legitimate rationale for computerization. Numerous aspects of collection management are discussed for which the computer may be employed. Topics include creating cross-reference files, updating taxonomic and geographic information, pinpointing mismatched specimens, locating lost and uncataloged material, controlling loan procedures, producing accession files for insurance purposes, curating all or part …