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E B Burnside

Publications and source records attributed to E B Burnside.

29 records · Page 2Linked to original sources
PubMed1987

Impact of selection on components of variance and heritabilities of Canadian Holstein conformation traits.

Sire and error variance components and heritabilities were estimated for 26 conformation traits using linear type classifications of 175,693 daughters of 6681 Holstein sires in 21,869 herd-round-classifier subclasses. Estimates from first classifications during first lactations were contrasted with estimates from the same 175,693 females' most recent classification, which included reclassifications. Only cows that have their final classification raised a full category receive an official reclassification record; thus, heritability estimates from data that include these reclassification records may be biased. A total of 9420 (5.4%) of the first lactation, first classifications were replaced by reclassifications for the second analysis, which is current practice for official sire evaluations for Holsteins in Canada. Records, expressed as Snell's scores, were preadjusted for age within parity and stage of lactation at classification. Sire and error components of variance were estimated by Henderson's new method. When reclassifications replaced first classifications in the analysis, estimates of sire and error variances increased 7.2 and 11.1% respectively, as compared with the first lactation, first classification estimates. Heritabilities ranged from .07 for rear heel to .38 for stature and decreased by an average of 2.5% when first lactation, first classifications were replaced by reclassifications. Results indicate that the inclusion of reclassifications tends to bias heritabilities downward.

Animals↗
PubMed1987

Impact of somatotropin and other biochemical products on sire summaries and cow indexes.

This paper outlines the potential impact of bovine somatotropin on dairy cattle improvement programs and pinpoints research needs. Recording of manufacturer, dosage, and date of start and finish of somatotropin administration is recommended in order to allow analysis of data for cow and sire ranking. Alternatives, such as restriction of somatotropin administration to certain lactations or parts of the cow's lactation are discussed. Cooperator herds or nucleus breeding schemes as alternatives to the random sampling of AI bulls may become more practical if somatotropin is widely used in the future.

Animal Husbandry↗
PubMed1986

Relationships between conformation and calving interval in Holstein cows.

Type information collected by the Holstein Association of Canada from 1976 to 1983 was matched with calving interval records from the Record of Performance program of Agriculture Canada. Type traits considered were final class, major scorecard breakdown traits (general appearance, dairy character, capacity, rump, feet and legs, mammary system, fore udder, rear udder), and eight descriptive traits (stature, size, style, dairyness, chest floor, loin strength, thurl width, pin setting). The edited data consisted of 22,791 records on first calf heifers by 2548 sires in 9272 herd-round of classification groups. Sire evaluations for both type and calving interval were available for 3312 sires. Heritability of calving interval was estimated to be .04. Heritability estimates of type traits ranged from .06 for style to .33 for size. Phenotypic correlations between the type traits and calving interval were essentially zero. The highest favorable genetic correlations with calving interval were for chest floor (-.42), rear udder (-.37), capacity (-.34), and highest antagonistic correlations were for dairyness (.43) and dairy character (.38). Direct selection for improved calving interval was estimated to be more efficient than indirect selection on any of the type traits considered.

Animals↗
PubMed1985

Genetic parameters of bovine serum immunoglobulins.

Radial immunodiffusion techniques were used to determine serum concentrations of immunoglobulins G1, G2, M, and A in 1,293 daughters of 282 Holstein-Friesian sires from 31 herds in southwestern Ontario, Canada. Mean serum immunoglobulin concentrations (mg/100 ml) were 2,163, 2,409, 531, and 107 for immunoglobulins G1, G2, M, and A, respectively. Herd effects were significant for all four immunoglobulin isotypes. Age of cow effects were significant for immunoglobulins G1 and G2 only. Both immunoglobulins G1 and G2 increased with age, but the rate of increase of G2 was twice that of G1. Stage of lactation had a significant effect on G2 and M. Immunoglobulin G2 was highest in the first 200 d post-calving and immunoglobulin M was highest late in lactation and during the dry period. Paternal half-sib heritabilities for immunoglobulins G1, G2, M, and A were .10, .10, .09, and .14, respectively. Genetic correlations among the four immunoglobulin isotypes ranged from .49 to 1.02. Genetic correlations between immunoglobulin G2 and 305-d milk and fat yields were .36 and .13 and between immunoglobulin A and 305-d milk and fat yields were .37 and .63. Genetic correlations between immunoglobulin M and milk and fat production were negative (-.83 and -.34). Phenotypic correlations between immunoglobulin isotypes were low except for the correlation between immunoglobulins G1 and G2, which was .36.

Age Factors↗
PubMed1984

Relationship between external body measurements and calving difficulties in Canadian Holstein-Friesian cattle.

Thirteen body measurements per cow were collected from 1980 to 1981 on 3,193 Canadian Holstein-Friesian cows by 576 sires in 100 herds. These data were analyzed to test effects of herd, age of cow, stage of lactation, and generation group; to predict sire proofs; to estimate heritabilities and genetic and phenotypic correlations among body measures; and to estimate correlations between sire proofs for body measures and sire (maternal grandsire of calf) proofs for calving ease. Herd and age of cow were important sources of variation for all external body measures. Stage of lactation was an important source of variation for heart girth, and for slopes from hip to pin and from thurl to pin. Effects of generation group were not significant for any body measures. Heritabilities were moderate to high (.21 to .45). Genetic correlations among all height characteristics were large and positive (.68 to .99). Daughters that were large with wide pins, long sloping rumps, and little slope from thurl to pin bone seemed to be favored for easy calving.

Age Factors↗
PubMed1983

Variation in serum immunoglobulins in Canadian Holstein-Friesians.

Variation, and relation to pneumonia and mastitis, of four immunoglobulins, G1, G2, M, and A of blood serum measured by radial immunodiffusion, was studied in a sample of 190 Canadian Holstein-Friesian females sired by 22 bulls in artificial insemination. Regression analyses indicated that combined effects of age, stage of lactation, parity, and cow's sire's milk rating accounted for 6, 37, 2, and 3% of the total variation in G1, G2, M, and A. The G2 increased significantly with age, parity, and stage of lactation and decreased slightly with increasing sire milk ratings. Heritabilities by paternal half-sister correlation varied from 0 for G1 and A through .28 to .68 for IgG2 and .08 to .85 for IgM. Immunoglobulin G2 was positively correlated with clinical mastitis (.24) and incidence of enzootic pneumonia (.13) indicating further study of immunoglobulin G2 and its relationship to disease is warranted. No significant correlations existed between other immunoglobulins and mastitis or pneumonia, nor was a cow's production related to immunoglobulin. Selection to alter immunoglobulin content and reduce disease may be feasible and should be examined further.

Age Factors↗
PubMed1982

Evaluation of dairy bulls in Ontario for calving ease of offspring.

The first sire evaluations for calving ease for bulls used in Ontario were published in May, 1981. Evaluations used calving records collected by Ontario Dairy Herd Improvement Association from all supervised herds from May, 1980, to April, 1981. A total of 34,240 records including herd, breed, sire, and cow identification, date of calving, and information about cow size, parity, sex of calf, mortality, and dystocia score were collected. After editing, 28,947 records were available from 1,178 Holstein bulls. Dystocia scores were 1) unobserved or unassisted, 2) easy pull, 3) hard pull, and 4) surgery. Stillbirths represented 5.5% of births coded 1 and 2, 25.1% of births coded hard pull, and 50.7% of surgical births. Analysis of variance showed that cow size, sex of calf, parity, and season (May to September and October to April) affected dystocia scores. Variance components were estimated prior to evaluation by Henderson's new method and resulted in a heritability of .08. Sire evaluation was by best linear unbiased prediction and included the relationship matrix. The prediction model included herd-year-season, dam size-parity-sex, and sire effects. Ninety-one sires had evaluations with a Repeatability of at least 55% and records in at least 20 herd-year-seasons.

Analysis of Variance↗
PubMed1982

Evaluation of Canadian Holstein-Friesian sires on disposal reasons of their daughters.

Data were lactations of 82,971 Canadian Holstein-Friesian cows by 4,778 sires recorded from 1975 to 1978 and included final disposal codes. Progeny were required to have first lactation records and were grouped according to whether they had the opportunity to complete one, two, or three lactations. Henderson's Method I technique was used to estimate sire, herd, and error variances within opportunity group for culling for low production, sickness, and all undesirable causes. Variances were low, and many were negative. Heritabilities ranged from 0 to .13. Best linear unbiased prediction techniques were used to estimate sire proofs for disposal reasons. Sire proofs were not distributed normally. Sire proofs were correlated between opportunity groups within disposal reason. All correlations were positive and ranged from .21 to .82. Correlations were greatest between contiguous opportunity groups and lowest between proofs on early opportunity groups and proofs on cows that were close to maturity, indicating that first opportunity group proofs for disposal are not accurate predictors of longevity. Routine evaluation of sires on disposal reasons is not recommended.

Animals↗