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Crossbreeding In Swine: Experimental Results, Rodger K. Johnson
Crossbreeding In Swine: Experimental Results, Rodger K. Johnson
Department of Animal Science: Faculty Publications
A review of recent swine crossbreeding experiments is presented and integrated with earlier work. Variation among experiments in observed heterosis for specific crosses was large for reproduction and sow productivity traits. However, standard errors of estimates were also large. It seems likely that heterosis, expressed in absolute values or in percentage units, is different for specific crosses. It is unclear whether these differences are large enough to warrant the use of unique parameter values for comparisons of alternate mating systems. In addition to average heterosis values, average direct and maternal genetic effects are given.
Genetic And Phenotypic Relationships Between Pubertal And Growth Characteristics Of Gilts, L. K. Hutchens, R. L. Hintz, R. K. Johnson
Genetic And Phenotypic Relationships Between Pubertal And Growth Characteristics Of Gilts, L. K. Hutchens, R. L. Hintz, R. K. Johnson
Department of Animal Science: Faculty Publications
Data on 737 crossbred and purebred gilts were used to obtain heritability estimates for age at puberty (AGEPUB) and weight at puberty (WTPUB) and their genetic and phenotypic correlations with birth weight (BW), weaning weight (WW), postweaning daily gain (ADG), adjusted age at 90.7 kg (AGE) and adjusted backfat at 90.7 kg (BF). The heritability estimates for AGEPUB were low to moderate (.19 and .40, based upon paternal and maternal half-sib estimates, respectively.) The genetic (rg) and phenotypic (rp) correlations between AGEPUB and BW (rg = -.07; rp = -.09), WW (rg = -.25; rp = …
Comparison Of Three-Breed And Backcross Swine For Litter Productivity And Postweaning Performance , E. R. Wilson, R. K. Johnson
Comparison Of Three-Breed And Backcross Swine For Litter Productivity And Postweaning Performance , E. R. Wilson, R. K. Johnson
Department of Animal Science: Faculty Publications
Duroc, Hampshire and Yorkshire boars were mated with crossbred gilts of Duroc-Hampshire, Duroc-Yorkshire and Hampshire-Yorkshire breeding to produce 133 three-breed and 259 backcross litters that were farrowed during four seasons beginning in the fall of 1975. Threebreed cross litters were .31 ± .27, .57 ± .24 and .50 ± .24 pigs larger than backcross litters at birth, 21 and 42 days, respectively, and .6 ± .34, 2.3 ± 1.2 and 5.4 ± 2.4 kg heavier at these ages. The differences in average pig weight and survival percentage were small. Three-breed cross litters gained faster (.024 ± .007 kg/day) and were …
Bone Strength As A Trait For Assesing Mineralization In Swine: A Critical Review Of Techniques Involved, T. D. Crenshaw, E. R. Peo, Jr., A. J. Lewis, B. D. Moser
Bone Strength As A Trait For Assesing Mineralization In Swine: A Critical Review Of Techniques Involved, T. D. Crenshaw, E. R. Peo, Jr., A. J. Lewis, B. D. Moser
Department of Animal Science: Faculty Publications
Lack of standardized test procedures has resulted in considerable variation in reported values for bone strength. Such variation can be attributed in part to the type of instruments used to determine physical properties of bone, procedures used to prepare the bones for testing and equations used to calculate strength. If bone strength is to be used as a major criterion of response in mineral nutrition research, standardization of procedures for measuring and reporting bone strength is essential. Traits that describe the mechanical properties of bone as determined in the commonly used flexure test in which force is applied perpendicularly to …
Effect Of Level Of Dietary Calcium-Phosphorus During Growth And Gestation On Performance, Blood And Bone Parameters Of Swine, R. D. Nimmo, E. R. Peo, Jr., B. D. Moser, A. J. Lewis
Effect Of Level Of Dietary Calcium-Phosphorus During Growth And Gestation On Performance, Blood And Bone Parameters Of Swine, R. D. Nimmo, E. R. Peo, Jr., B. D. Moser, A. J. Lewis
Department of Animal Science: Faculty Publications
One-hundred and ninety-two crossbred weanling gilts (7.25 kg) were assigned to one of two treatments - (A) .65% Ca, .50% P or (B) .975% Ca, .75% P - and fed to an average weight of 92.8 kilograms. Average daily gain (.65 and .67 kg, respectively) and feed/gain were not affected by dietary treatment, but average daily feed intake was lower (P<.05) for gilts on treatment A (1.87 vs 1.95 kg).
Influence Of Age, Sex, And Calcium And Phosphorus Levels On The Mechanical Properties Of Various Bones In Swine, T. D. Crenshaw, E. R. Peo, Jr., A. J. Lewis, B. D. Moser, D. Olson
Influence Of Age, Sex, And Calcium And Phosphorus Levels On The Mechanical Properties Of Various Bones In Swine, T. D. Crenshaw, E. R. Peo, Jr., A. J. Lewis, B. D. Moser, D. Olson
Department of Animal Science: Faculty Publications
Seventy-two 4-week-old pigs were randomly assigned by sex (gilts, barrows, boars) to two dietary treatments and four age periods for determinations of the effects of age, sex and Ca and P levels on the mechanical properties of various bones in swine.