Paternal Half-sisters Research Articles

Response within Herd to Sire Selection

Effective sire selection should result in predictable differences among progeny groups within herds. National data from cows with lactations in 1979 gave within-herd regressions for Holstein yield on Predicted Difference of sire of 1.00 for milk and 1.01 for fat. First-lactation data gave regressions of 1.20 for milk and 1.13 for fat. Holstein herds were stratified into 10 classes by average milk yield of herd. Within-herd regressions of first-lactation yield on Predicted Difference of sire ranged from .71 for the lowest yield class to 1.49 for the highest yield class. Yield response to Predicted Differences of sires was related positively to herd yield, which suggests that sire selection for increased yield gives a greater return for herds with high yield than for herds with low yield. These results were supported by data from other breeds. Phenotypic variation within herds increased with herd yield, but coefficient of variation decreased. Heritabilities for yield from paternal half-sisters increased markedly across six classes of increasing herd yield for Holsteins.

Components of Genetic Variation for Descriptive Type Traits of Holsteins1,2

Data consisted of first available classification scores for 12 descriptive type traits on 298,875 registered Holstein cows and their dams. Traits were final score, stature, head, front end, back, rump, hind legs, feet, fore udder, rear udder, udder support, and teats.Covariances among cow-dam pairs, full-sisters, paternal half-sisters, and maternal half-sisters were used to estimate four components of genetic variation for the 12 type traits. Genetic components of variance produced by additive direct, dominance direct, additive maternal, and covariance between additive direct and additive maternal effects were estimated.Heritabilities from sire components of variance ranged from .39 for final score to .06 for hind legs with all traits except final score and stature less than .25.Dominance effects ranged from 2 to 6 times as great as additive variation whereas additive maternal effects were similar to additive direct effects. Effects due to additive direct by additive maternal covariance effects were small but consistently negative.

Heritabilities and Correlations of Lactation Yields and Fertility for Holsteins

First lactations from a total of 5802 cows in the North Carolina Institutional Breeding project from 1950 to 1980 were used. Heritabilities from paternal half-sisters were .05 for days open, .05 for age at first calving, .27 for lactation milk yield, and .29 for fat yield. Corresponding estimates from regressions of cow on dam were .13 for days open, .06 for age at first calving, .35 for milk yield, and .33 for fat yield. Genetic correlations between yields and days open from various methods of estimation and editings of the data were all antagonistic and ranged from .35 to .60. Genetic correlations of yield and age at first calving were favorable, ranging from −.10 to −.36. Heritabilities for days open and genetic antagonism between days open and yield were greater for cows calving prior to the hot summer months than for cows calving in the fall. Heritabilities and variance of sires increased for days open and yield traits from the 195O's to 1980. For records from 1970 to 1980, heritability from paternal half-sisters of days open was .12. Genetic increase of 1000kg milk would result in 5 to 10 additional days open.

Climatological and Genetic Effects on Milk Composition and Yield

Objectives were to quantify variations in milk from genetic and climatic effects in a subtropical climate. Monthly test day samples of milk from 1959 to 1977 from the Florida Agricultural Experiment Station were characterized for 17 variables and subjected to least squares analysis of variance. Maximum temperature, minimum temperature, minimum relative humidity, and solar radiation as a set accounted for significant portions of variability in all traits, from 1.2 to 14.5% with Holsteins and .5 to 18.1% with Jerseys. Yields were affected more by climate with Holsteins, whereas percentages were more affected with Jerseys. Heritabilities from variances of paternal half sisters for a mean of 10 monthly measurements ranged from .10 to .23 for Holsteins and .23 to .27 for Jerseys for yields, and .27 to .90 for Holsteins and .18 to .59 for Jerseys for percentages. Genetic correlations between yields ranged from .07 to .96 for Holsteins and .69 to .98 for Jerseys. Genetic correlation between milk yield and chloride percent was .51, – .82 between milk yield and feulgen-deoxyribonucleic acid reflectance percent (an inverse measure of somatic cell count), and –.88 between chloride percent and reflectance percent with Holsteins. Ratios of solids-not-fat and protein to fat were correlated positively with yields and negatively with percentages. Phenotypic correlations of reflectance percent with yields were positive and low, consistent in sign but variable in magnitude with percentages. Selection for milk yield should cause correlated increases in other yield traits and decreases in percentages.

Heritability of Teat Shape and Teat End Shape in Cattle

Lojda L., M. Stavikova, J. Polai!ek.: Heritability of Teat Shape and Teat End Shape in Cattle. Acta vet. Bmo, 51, 1982: 59-67. Heritability of teat shape and teat end shape was studied in Bohemian Pied cows. Teat shape was evaluated by visual inspection and on the basis of indices 11 and II pro­ posed in this study. The coefficients of heritability of the two indices computed from the regression of daughter on dam in 185 dam-daughter pairs were 0.380 ± 0.08 and 0.354 ± 0.08, respectively. The coefficient of heritability of teat end shape com­ puted from the dam-daughter regression was 0.414 ± 0.17, but the coefficient of her i­ tability of this characteristic computed by means of the intraclass correlation coefficient in groups of paternal half sisters sired by 30 bulls was only 0.085. Fourteen pairs. of dizygotic twins were included in the study to investigate their concordance with regard to teat shape and teat end shape. Half of the pairs of twins both had all 4 teats of equal shape; 3, 2 and 1 equally shaped teats were found in 3, 1 and 1 pairs, res­ pectively, and two pairs were completely discordant. The concordance of twins with regard to teat end shape was also considerable: 78.5 per cent of the pairs both had 4, 3 or at least 2 teats with equally shaped ends and only 2 pairs were completely discor­ dant. Where the dams of the twins were available for comparison, their teat and teat end shapes agreed with those of one of their daughters at least. Cattle, heritability, teat shape, teat end shape, mastitis.

Genetic Aspects of Lactation Curves

Parameters of lactation curves were defined by a gamma-type function for 113,705 lactations from the California Dairy Herd Improvement Association. Heritabilities and genetic correlations were estimated from a mixed-model analysis of paternal half sisters for first, second, third, and later lactations. Daily milk production on day 6 postpartum was estimated from production at first test-day to reduce the percentage of atypical lactations to less than 1% instead of an expectation of 30% without estimating production for day 6. The natural logarithm of the gamma-type function was ln(Yt) = ln(a) + b ln(t) - ct, where Yt was daily milk production in the tth week and ln(a), b, and c were coefficients. Persistency (c−(b+1)), week of peak yield (b/c), peak yield (a(b/c)be-b), and coefficient of determination were estimated from coefficients for each lactation. Heritabilities in first lactation were: ln(a) .10±.01, b .06±.01,c .14±.02, persistency .02±.01, week of peak yield .02±.01, peak yield .23±.02, and determination .03±.01. Heritabilities for later lactations were similar. Cows in first lactation had lower ln(a), lower peak yield, lower c, greater persistency, and took longer to reach peak yield than did cows in later lactations. Genetic and phenotypic correlations indicated that selection for increased peak yield would be associated with increased ln (a), b, and c without changing persistency or week peak yield.

Variation of Traits of a Mating Appraisal Program

Data from Mating Appraisal for Profit of Midwest Breeders Cooperative were analyzed for a model with evaluator, herd, parity, sire, linear days milked, quadratic days milked, interaction of evaluator by parity, and residual. Parity affected all traits except basic form and legs. Evaluators interacted with parity, and sires affected all traits. All traits except front were affected by quadratic days milked and all traits by linear days milked. Heritabilities from paternal half sisters were basic form .96, scale .55, front .34, body .42, back .13, legs .14, feet .16, rump .13, rear udder .13, fore udder .14, center support .14, and teats .19. The heritability of basic form may be inflated by sire identification prior to scoring. Traits in close physical proximity showed genetic correlations in excess of .50; those not in close proximity showed smaller or negative correlations. Correlations with basic form showed that thicker cows score superior for correlated traits. Subcodes were used for seven of the traits in the program. Heritabilities for subcodes generally were small, ranging from .00 to .15 with most less than .10. Changes in conformation can result from selection, but selection on specific faults (subcodes) will not yield changes quickly.

Computing Algorithms for Sire Evaluation with All Lactation Records and Natural Service Sires

Models for sire evaluation by best linear unbiased prediction procedures which consider all lactation records, an environmental correlation among paternal half-sisters in the same herd, herd-year-season effects, genetic groups, and sires within groups are described. The computing algorithms are outlined briefly. Attention is drawn to a mimeographed publication of 46 pages (12) which describes in detail the computing algorithms for a model including an interaction between sire and herd (the environmental correlation) and a model which does not include the environmental correlation.

Environmental Correlations among Paternal Half-Sisters for Type

Official final scores, scorecard, and descriptive type classifications recorded by the Holstein-Friesian Association from January 1, 1967, through June 30, 1974, were used to estimate environmental correlations among paternal sisters. Single records on 330,740 daughters of 2,434 sires were used. Each sire had at least 20 daughters in five or more herds. Final score and the scorecard traits were adjusted for age. Differences among herds were ignored. Correlations were estimated from differences of intraclass correlations among paternal sisters in one herd from those of one daughter in each herd, differences between product-moment correlations among paternal sisters in same and different herds, and the intra-herd correlation among daughters of the same sire. Methods yielded similar correlations ranging from .16 to .18 for final score, .13 to .16 for general appearance, .09 to .14 for dairy character, .11 to .17 for body capacity, and .11 to .13 for mammary system. Most environmental correlations for descriptive traits were less than .10 as stature, head, front end, and feet ranged from .06 to .15, and rear legs and udder support and floor ranged from .02 to .08.

Estudo genético da performance reprodutiva e produtiva de bovinos Pitangueiras (5/8 Red Poll x 3/8 Zebu)

Our data consisted of 500 Pitangueiras females with a total of 1723 lactations distributed over 13 years from 1962 to 1974. The following economic traits were analysed: age at first calving, calving interval, milk and fat production and lenght of lactation period. The variance analysis were made according to the least square method and the heritability estimated through correlations between paternal half-sisters. The mean for age at first calving was 42,87 ± 0,28 months (C.V.=14,31%),for 483 observations. The earliest parturition occurred at age of 23,3 months and the latest at about 76,6 months, showing a great amplitude of variation (53,3 months). The effects of generation and year of parturition had a significant influence on this trait. On relation to calving interval the mean value of the trait was 432.41 ± 2.97 days with a coefficient of variation as 23,73%. The greatest calving interval occurred between 1st and 2nd parturitions and the shortest between the 3rd and 4th parturitions. The repeatibility estimate was 0,01 ±0,07. The mean for milk production at first lactation was 2556,2 ± 33,1 kg (C.V.=27,6%). The maximum production occurred at 5th lactation with an increase of 22,6% from first lactation to productive maturity. Generation, age and year of parturition contributed significantly to the variability of milk production was 0,32 ±0,07. The mean for butterfat production was 117,37 ± 0,84kg (C.V.= 29,33%). The values for butterfat percentage, were 4,15 ± 0,02% with a coefficient of variation as 6,49%. These are completely satisfactory for animals bred in tropics. The repeatability of buttierfat production was 0,31 ± 0,07 . For the studied females about 10,79% of lactations finished before 218 days and 66,59% did not exceeded the 305 days of milking (data for 1st lactation). The mean value of this trait was 281,32 ± 1,39 days (C.V. =20,51%) for 1723 observations. The repeatibility of lactation lenght was 0,15 ± 0,06.

Cytogenetic and Phenotypic Effects of a Chromosomal Rearrangement Involving the Z-chromosome and a Micro-chromosome in the Chicken

Measurements demonstrated that the Z-chromosome was truly metacentric. Forty-six percent of one arm of a female’s Z-chromosome had been translocated to a microchromosome (Z-micro) by irradiation of semen. The break was 23 crossover units distal to the late feathering (K) locus. The barring (B) locus on the non-broken arm assorted almost independently of the Z-micro segment.Semen from eight sons of this Z-micro female was used to inseminate 98 dwarf (dw) broiler-type females. From karyotypes of 147 male and 149 female progeny, we identified 69 males heterozygous and 79 females hemizygous for Z-micro. Body weight of 43 males heterozygous for Z-micro was significantly greater than that of 45 normal Z paternal half-brothers at all ages from 2 to 24 weeks. In contrast, body weight of 57 Z-micro females compared with their 56 normal Z paternal half-sisters was depressed significantly at 2, 4, and 6 weeks but not significantly at 8, 12, 16, and 24 weeks of age. Age at first egg was retarded 8 days and egg production over a 153 day test period was reduced 19.6%, primarily due to a reduction of egg laying sequence from 2.7 to 2.1 days in the Z-micro females.

Lactation Records of Jersey Cattle in Pennsylvania: Season of Calving, Phenotypic Trend, Heritability, and Genetic Trend

Lactation records of Jersey cows calving from August, 1961, to November, 1969, in Pennsylvania Dairy Herd Improvement Associations were standardized to 305-day, mature equivalent.Lactation yield increased for cows that calved in late fall and winter compared to those that calved during summer. Cows in first lactation differed little from all cows in month of calving with respect to (1) high frequency of calving (August to November) and (2) high lactation yield (November through March). The phenotypic increase in milk yield for both first-lactation cows and all cows was 36kg per year, an annual increase of .9% of the mature equivalent mean milk yield. Only one-half was genetic, suggesting improvement in management and nutrition. The phenotypic trend for fat yield was 1kg per year with no genetic change. Percentage of fat declined .02% per year.Heritabilities by intraclass correlations among paternal half-sisters from 7,667 first, 6,258second, and 4,799 third lactations were .40, .27, and .23 for deviation of milk from herdmates; .31, .19, and .17 for deviation of fat from herdmates; and .67, .65, and .67 for percentage of fat. The decline of heritabilities of yield traits may be from selection (culling) after first lactation.

Genetic Trends in Milk Production in Florida Dairy Herd Improvement Association Herds

First-lactation records of 4,779 Holstein, Jersey, and Guernsey paternal halfsisters, representing 155 sires and 181 herds for 1958 to 1967, were subjected to a series of least-squares analyses. Average age at freshening was 27.4, 26.4, and 29.5 months for the three breeds. Average production was 4,712kg milk, 3.70% fat, and 173kg fat for Holsteins and average productions for Jerseys and Guernseys were 3,144kg, 4.99%, 156kg, and 3,227kg, 4.57%, and 147kg. Estimates of trends were from weighted regressions of least-squares year constants on years, with and without sire in the mathematical model. Annual genetic trends were for Holsteins: 33kg milk,−.034% fat and−.7kg fat; for Jerseys, 22kg, .008% and 1.3kg; for Guernseys, 92kg, —.048% and 2.8kg. Environmental trends for milk yield were positive for Holsteins (57kg) but negative for Jerseys and Guernseys (10kg and 23kg).

Environmental Correlation Between Paternal Half-Sisters for Milk and Milk Fat Production

Environmental correlations (c2) among paternal half-sisters in the same herd were estimated by four different methods. The data were 55,170 first lactation records in 2,326 herds in eight midwestern states. Both mature-equivalent and deviation records of milk and milk fat were used. The intraclass correlation within herds and sires estimates an environmental correlation due to the variation within herds that affects the paternal half-sisters. Estimates of c2 for sires in artificial insemination were similar to those of sires in natural service (about 0.11). This environmental correlation is large enough to be important in estimating breeding values of sires. A nonlinear function for the regression of one sample of daughters on an independent sample of daughters of the same sire was developed that included c2 and h2 Terms. Hartley's modified Gauss-Newton method was then used to obtain simultaneous solutions for the two parameters.

Ring chromosome D (13).

A girl with a ring chromosome of No. 13 (D group) is alive and active at 10 years of age. Patients with partial deletion of a D chromosome,1-22including those with a ring D chromosome,1,2,4-7,10,13-15,17-19,22present a variety of clinical findings; one infant had many anomalies and was stillborn,2others are less affected. Several of these patients, whose deleted chromosome appears to be No. 13,13,14have unusual patterns of inheritance of haptoglobin, suggesting that a haptoglobin locus might be on this chromosome. Since a comparison of our patient with others could lead to more understanding of the functions of the involved chromosome, her story is presented. Report of a Case This white girl, weighed 1,650 gm (3 lb 10 oz) at term following a normal pregnancy. The primigravida mother was 18 years old; the father was 20. Both parents and a paternal half-sister are apparently normal

Relationship Between Purebred and Crossbred Paternal Half-sisters’ Performance in Chickens

THE relative effectiveness of intra-population selection as compared to that of reciprocal recurrent selection in improving cross performance depends on the nature of gene action. Genetic correlations for the same trait between purebred and crossbred progenies having common sires provide quantitative evidence of this (Comstock and Robinson, 1957). Scarcity of such estimates in chickens prompted the present investigation. Analyses and interpretations for two production traits, rate of lay from first egg to 260 days of age and age at first egg, are presented.Data used were from a seven-generation study at this station comparing intrastrain and reciprocal recurrent selection for rate of lay from first egg to 260 days of age. The two reciprocally selected populations were from the Cornell Randombred White Leghorn (CC) and the NC-47 Regional Red Randombred (RR). The breeding populations were produced in two shifts. Each of 20 CC males was mated concurrently with 5 females…

Estimation of Genetic Trends in Dairy Cattle Populations

Usefulness of full sisters and paternal half-sisters to estimate genetic trends was investigated, with 34,380 first lactation Holstein Herd Improvement Registry (HHIR) records reported in 335 herds from 1953 to 1961. Paternal half-sister families comprised one-third and full-sister families one-seventh of the data. All records were analyzed to obtain least-squares constants for year of calving. A weighted regression of these constants on years provided an estimate of the annual trend, genetic plus environmental, (63±11kg for milk and 0.007±0.001 for per cent fat). Full sisters were analyzed to obtain least-squares year constants adjusted for sire and dam effects and corrected for selection. Weighted regression of these constants on years indicated the environmental trend in the population, and comparison with the genetic plus the environmental trend provided an estimate of annual genetic trend (45±16kg for milk and 0.018±0.003 for per cent fat). A second estimate of the annual genetic trend (55±26kg for milk and 0.016±0.005 for per cent fat) was obtained by comparing the over-all trend with one-half the genetic, plus the environmental trend estimated from records of paternal half-sisters adjusted for sire effects.

Transient neonatal diabetes mellitus in half sisters.

THE SYNDROME of transient diabetes mellitus in the newborn has been well documented by Cornblath and Schwartz 1 who collected and summarized 15 case reports. Aside from the fact that recovery is complete after weeks or months, the syndrome meets the diagnostic requirements of true diabetes mellitus: hyperglycemia, glycosuria, and control with exogenous insulin. Ketonuria, however, is not the rule. These neonates are wasted although alert in appearance, and rapidly become dehydrated in spite of adequate food intake and the absence of vomiting and diarrhea. The following cases are reported because of their unique familial relationship, the patients being paternal half sisters with a positive paternal family history of diabetes mellitus. These findings raised the question of possible genetic etiologic factors. Report of Cases Case1.—A white female, was delivered spontaneously at Mississippi Baptist Hospital on July 15, 1966, after 32 weeks' gestation, according to the mother's menstrual history. A

Paternal Half-Sib Correlations Between Pairs in the Same and Different Herds

Correlations were computed between first-lactation milk records expressed as deviations from herd-mate averages of pairs of Holstein paternal half-sibs in the same and in different herds. These were compared to the comparable daughter-dam regressions. After correcting the daughter-dam regression for environmental correlation and change in variance from the dam to the daughter generation, both the daughter-dam and paternal half-sib estimates of heritability were about .34, which suggests that maternal genetic variance is unimportant. This estimate is, however, higher than the .25 found from the paternal half-sib estimate from an analysis for variance components.The comparison of the half-sib correlations where the pair was in the same herd (.168) and in different herds (.086) suggests that the environmental correlation among paternal half-sibs in the same herds is about .08 of the total variance. There was no evidence that this environmental correlation is less for pairs of artificially sired than for naturally sired paternal half-sisters in the same herd.

Associations Between Body Weight Predicted from Heart Girth and Production1,2

Relationships among body weights predicted from heart girth measurements taken the first test day after calving, and age, 90-, and 305-day milk yields, and the corresponding fat percentages were assessed for 3,168 lactations of 1,593 Holstein cows in nine North Carolina Institutional herds.The partial linear regressions of 305-day milk yield on weight independent of age were significant, but they averaged only about 150lb milk for each 100-lb change in weight and accounted for only 1% of the variance in milk yield. Weight was not closely associated with 90-day yield, and it had only a minor influence on the fat percentages.Estimates of the genetic correlation between weight and 305-day milk for the paternal half sister and daughter-dam analyses were positive but small (0.15±.17 and 0.02±.13), whereas those for weight and fat percentage were even nearer zero.Selection indices computed for a range of economic situations and genetic relationships showed that little, if any, benefit can be expected by jointly considering body size when selecting for increased milk yield. Under present economic situations, a slight negative emphasis should be placed against body weight.