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- Pigs (4)
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Articles 1 - 16 of 16
Full-Text Articles in Animal Sciences
Effect Of Uni Lateral Hysterectomy And Ovari Ectomy On Puberty, Uterine Size And Embryo Development In Swine, Ying-Tsorn Huang, R. K. Johnson, G. R. Eckhardt
Effect Of Uni Lateral Hysterectomy And Ovari Ectomy On Puberty, Uterine Size And Embryo Development In Swine, Ying-Tsorn Huang, R. K. Johnson, G. R. Eckhardt
Department of Animal Science: Faculty Publications
Eighty crossbred gilts were assigned randomly to treatments: 1) removal of an ovary and ipsilateral uterine horn (UHO) at 130 d of age and removal of the remaining ovary and uterine horn 12 d post-puberty; 2) UHO at 130 d of age, mated and reproductive tracts recovered when slaughtered at 30 d of gestation; 3) UHO 12 d post-puberty, mated and slaughtered at 30 d of gestation and 4) unoperated controls that were mated and slaughtered at 30 d of gestation. Age of puberty was not affected by treatments. Gilts in treatment 1 had a mean ovulation rate at the …
Growth Performance For Four Breeds Of Swine: Crossbred Females And Purebred And Crossbred Boars, D. G. Mclaren, D. S. Buchanan, R. K. Johnson
Growth Performance For Four Breeds Of Swine: Crossbred Females And Purebred And Crossbred Boars, D. G. Mclaren, D. S. Buchanan, R. K. Johnson
Department of Animal Science: Faculty Publications
Purebred and two-breed cross (F1) boars were mated to F1 females to produce all possible three- and four-breed cross pigs involving the Duroc, Yorkshire, Landrace and Spotted breeds. Individual post-weaning average daily gain (ADG), age at 100 kg (AGE) and probed backfat thickness at 100 kg (BE) data were collected on 3,456 pigs. A total of 213 pens with an average of 15.58 pigs per pen was evaluated for post-weaning feed-to-gain ratio (F/G) and average daily feed consumption (ADF). Genotype x environment interactions, specifically breed x year-season farrowed and breed X parity (for ADG), were found to …
Individual Heterosis And Breed Effects For Postweaning Performance And Carcass Traits In Four Breeds Of Swine, D. G. Mclaren, D. S. Buchanan, R. K. Johnson
Individual Heterosis And Breed Effects For Postweaning Performance And Carcass Traits In Four Breeds Of Swine, D. G. Mclaren, D. S. Buchanan, R. K. Johnson
Department of Animal Science: Faculty Publications
Individual heterosis and direct and maternal breed effects for postweaning average daily gain (ADG), off-test age (AGE) and probed backfat thickness (BF) were estimated from data on 1,664 pigs produced in a complete diallel mating system involving the Duroc, Yorkshire, Landrace and Spotted breeds. The same genetic parameters were estimated for various carcass traits by analyses of data collected on 269 barrow carcasses. Significant breed x environment (i.e., year-season farrowed, parity and sex) interactions were found for ADG, AGE and BF. Specific heterosis estimates for ADG and AGE were all highly significant and reasonably consistent among crosses. Overall heterosis for …
Genetic Parameters For First Lactation Milk Yields At Three Levels Of Herd Production, J. C. De Veer, L. Dale Van Vleck
Genetic Parameters For First Lactation Milk Yields At Three Levels Of Herd Production, J. C. De Veer, L. Dale Van Vleck
Department of Animal Science: Faculty Publications
A multivariate linear model was used to estimate sire variance and covariance components and residual variance components for first lactation milk yield and logarithms of yield at three herd production levels using Restricted Maximum Likelihood with the Expectation- Maximization algorithm. Data for four separate analyses were 305-d, mature equivalent first lactation milk records from cows sired artificially in the northeastern United States that freshened in 1970, 1971, 1976, and 1984. Respective numbers of records for each year were 42,618, 40,207, 33,581, and 34,196. Corresponding numbers of sires were 298, 289, 305, and 313. Herd production level was defined by mean …
Aspects Of Selection For Performance In Several Environments With Heterogeneous Variances, D. J. Garrick, L. Dale Van Vleck
Aspects Of Selection For Performance In Several Environments With Heterogeneous Variances, D. J. Garrick, L. Dale Van Vleck
Department of Animal Science: Faculty Publications
Dairy cattle evaluation schemes routinely assume homogeneous variance with respect to environment. Increasing evidence suggests the presence of systematic changes in variance components associated with mean level of performance. Best linear unbiased prediction procedures that account for heterogeneity are reviewed. The consequences of incorrectly assuming homogeneity for evaluation are demonstrated for a progeny test and an artificial breeding program that screens dams of sires from heterogeneous populations. Selection assuming homogeneity can be very efficient when heritability, and therefore accuracy of selection, is greatest in the more variable environment. Conversely, appreciable reduction in response results when heritability is greater in the …
Effect Of Protein And Energy Intake By Primiparous Sows During Lactation On Sow And Litter Performance And Sow Serum Thyroxine And Urea Concentrations, J. H. Brendemuhl, A. J. Lewis, E. R. Peo, Jr.
Effect Of Protein And Energy Intake By Primiparous Sows During Lactation On Sow And Litter Performance And Sow Serum Thyroxine And Urea Concentrations, J. H. Brendemuhl, A. J. Lewis, E. R. Peo, Jr.
Department of Animal Science: Faculty Publications
The effects of protein and energy intakes by primiparous sows during a 28-day lactation on thyroxine (T4) and urea concentrations in blood serum of sows, and sow and litter performance were examined in two experiments.
Influence Of Picolinic Acid On The Uptake Of Zinc-Amino Acid Complexes By The Everted Rat Gut, D. A. Hill, E. R. Peo, Jr., A. J. Lewis
Influence Of Picolinic Acid On The Uptake Of Zinc-Amino Acid Complexes By The Everted Rat Gut, D. A. Hill, E. R. Peo, Jr., A. J. Lewis
Department of Animal Science: Faculty Publications
Three hundred fifty rats were used in three experiments to: 1) validate the everted gut procedure as an in vitro technique for estimating Zn absorption, 2) determine the effect of increasing ratios of picolinic acid (PA) to Zn on Zn absorption and 3) determine the effect of PA on absorption of Zn and amino acid complexes at pH 6, 7 and 8.
Contemporary Groups For Genetic Evaluations, L. Dale Van Vleck
Contemporary Groups For Genetic Evaluations, L. Dale Van Vleck
Department of Animal Science: Faculty Publications
Contemporary groups are used to remove biases from genetic evaluations due to differential effects such as management associated with the grouping. Numerous groups, however, can result in small numbers of records per subclass with associated loss of effective number of daughters for sire evaluation and increased prediction error variance. Thus, in practice, mean square error, bias squared plus prediction error variance, may be more meaningful than bias alone or prediction error variance. Considering contemporary groups as fixed removes bias due to association between effects corresponding to contemporary groups and sires. If contemporary groups are considered random, then effective number of …
Simultaneous Genetic Evaluation Of Sires And Cows For A Large Population Of Dairy Cattle, R. A. Westell, L. Dale Van Vleck
Simultaneous Genetic Evaluation Of Sires And Cows For A Large Population Of Dairy Cattle, R. A. Westell, L. Dale Van Vleck
Department of Animal Science: Faculty Publications
A strategy for simultaneous sire and cow evaluation of genetic merit was implemented. First lactation records of 1,074,971 Holstein cows in 20,065 herds were included. After inclusion of ancestors, there were 1,741,356 equations: 1,505,938 cow, 229,394 herd year- season, 6000 sire, and 24 genetic group equations. All known genetic relationships among animals were considered. Genetic group coefficients were assigned based on animals that had one or more parents unidentified. Mixed model equations from an animal model were transformed to solve for total additive genetic merit. The coefficient matrix was sparse with .00039% nonzero elements. Equations were blocked by herds. A …
Lack Of Evidence Of Cytoplasmic Inheritance In Milk Production Traits Of Dairy Cattle, P. D. Reed, L. Dale Van Vleck
Lack Of Evidence Of Cytoplasmic Inheritance In Milk Production Traits Of Dairy Cattle, P. D. Reed, L. Dale Van Vleck
Department of Animal Science: Faculty Publications
Heritability estimates, by year of freshening of daughter, were obtained from daughter-dam and granddaughter-granddam regressions using 61,482 triply matched first lactations of artificially sired Holstein cows obtained from the Northeast Dairy Records Processing Laboratory. After adjusting for herd-yearseason effects, residual effects may include additive and other genetic effects of the animal, maternal effects, cytoplasmic effects, and other environmental effects. Analysis of residuals showed that cytoplasmic effects accounted for no variation in milk and fat yield and fat percent. Weighted yearly heritability estimates and standard errors from daughter on dam regressions were .35 + .01 for milk yield, .30 + .01 …
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
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 • 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.
Effect Of Weight At Castration On Steer Performance In The Feedlot, M. A. Worrell, D. C. Clanton, Chris R. Calkins
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 …
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
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
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
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 …
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
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.