ESTIMATION OF GENETIC TRENDS FOR CANADIAN STATION-TESTED BEEF BULLS

1988 ◽  
Vol 68 (1) ◽  
pp. 49-56 ◽  
Author(s):  
E. P. de ROSE ◽  
J. W. WILTON

Data collected from Canadian central test stations were used to obtain estimates of genetic progress for test station average daily gain (ADG-T), height at hooks (HH), ultrasonically measured backfat thickness midway between the 11th and 12th ribs (FAT) and scrotal circumference (SC). Where possible, records for preweaning average daily gain (ADG-W) from the Federal-Provincial Herd Record of Performance program were obtained for tested bulls. Estimated breeding values were regressed on year of birth to obtain estimates of genetic trend for each trait, for the six principal breeds enrolled in the testing program: Aberdeen Angus (AA), Charolais (CH), Hereford (HE), Limousin (LM), Shorthorn (SH) and Simmental (SM). Estimated trends were generally significant with the exception of those for the LM breed, and the trait of SC. For FAT, trends were generally positive for the exotic breeds, and negative for the British breeds. Significant positive trends were observed for HH, ADG-W and ADG-T for most breeds. Examples of estimated genetic trends, for the HE breed, were 0.0022 kg d−1 yr−1, 0.0023 kg d−1 yr−1, 0.090 cm yr−1 (NS), − 0.029 mm yr−1, and 0.009 cm yr−1 (NS), respectively, for ADG-W, ADG-T, HH, FAT and SC (NS = not significant). Most estimated trends were low, in the order of 0.1 to 0.5% of population mean per year. Key words: Genetic trend, central test stations, beef bulls

1996 ◽  
Vol 76 (1) ◽  
pp. 1-5 ◽  
Author(s):  
J. M. Stookey ◽  
L. A. Goonewardene

Data from two record of performance test stations (ROP) were used to compare selected traits of polled and horned bulls. The University of Saskatchewan (SASK) ROP test station provided data on 578 Charolais (CH) and 375 Hereford (HE) bulls from 1985 to 1992, while the Alberta (ALTA) Hereford ROP station provided data on 1485 HE bulls from 1985 to 1993. Polled and horned CH bulls from SASK showed similar (P > 0.05) on-test average daily gain (ADG), while polled HE bulls from SASK showed significantly higher (P < 0.03) ADG than their horned counterparts (1.41 ± 0.01 and 1.36 ± 0.02, respectively). Polled CH bulls were 11.4% fatter than horned bulls at the end of the test (P < 0.01). No significant differences in ADG, weight per day of age (WPDA) or scrotal circumference (SC) were observed between polled and homed HE bulls in ALTA. These results show no disadvantage for polled bulls compared to horned for ADG, WPDA, adjusted SC and adjusted yearling weight. From a welfare perspective, it may be advantageous to use polled bulls to circumvent the need for dehorning. Key words: Polled horned bulls ADG test station


2021 ◽  
Vol 42 (4) ◽  
pp. 2523-2538
Author(s):  
Sindy Liliana Caivio-Nasner ◽  
◽  
Albeiro López-Herrera ◽  
Luis Gabriel González-Herrera ◽  
Juan Carlos Rincón Flórez ◽  
...  

The Colombian creole cattle breed Blanco Orejinegro (BON) is an important zoogenetic resource, but there is little knowledge about the genetic parameters and trends of its reproductive traits. Therefore, the aim of this study was to estimate parameters for the reproductive traits calving interval (CI), age at first calving (AFC), gestation duration (GD) and genetic trends for CI in the BON breed. Genealogy information from 7,799 animals was used, and employing the MTDFREML program, the components of the variance, heritability (h2), repeatability (rep), and estimated breeding values (EBV) for CI (n=3308), AFC (n=729), and GD (n=306) were estimated, in addition to the inbreeding coefficient (F) of the population. Genetic trends were established through linear regression using R software. Finally, the animals were classified as inbred (F > 0) and noninbred (F=0), and the effect of inbreeding on reproductive performance was established through a generalized linear model using the R program. An average F value of 4.41%±0.06 was observed. The h2 for CI was 0.11±0.03 with a rep of 0.15±0.04; for AFC, h2 was 0.00±0.05; and for GD, h2 was 0.00±0.08. The genetic trend for CI was -0.01 days/year. Finally, for CI, inbreeding depression was evident; this trait increased when inbreeding increased. These results indicate an important environmental influence on reproductive traits. The heritability estimate for CI suggests that little genetic progress could be achieved through selection. The evidence of inbreeding depression raises the need to control inbreeding to conserve this genetic resource.


1988 ◽  
Vol 68 (3) ◽  
pp. 965-967 ◽  
Author(s):  
K. R. KOOTS ◽  
R. D. H. COHEN ◽  
H. H. NICHOLSON

Trends were determined for the performance traits of beef bulls of five breeds tested at the Saskatoon ROP bull Test Station between 1965 and 1986. Means were calculated for each year for each breed with respect to start-of-test weight, end-of-test weight, average daily gain-on-test, and adjusted 200-day weight. A significant (P < 0.05) year-of-test effect was found for each of the four traits studied for Angus; for start-of-test, end-of-test and 200-d weight for Hereford and Shorthorn; for start-of-test and end-of-test weight for Simmental; and for only start-of-test weight for Charolais. These data suggest that bulls in all five breeds were significantly heavier each year when entering the test and that all except Charolais were heavier each year when completing the test but that only the Angus breed gained weight on test at a significantly faster rate each year. Key words: Record of performance, bull, beef


1998 ◽  
Vol 78 (2) ◽  
pp. 229-232 ◽  
Author(s):  
L. A. Goonewardene ◽  
P. A. Day ◽  
N. Patrick ◽  
H. D. Scheer ◽  
D. Patrick ◽  
...  

Birth weights of Boer (BO) sired kids were 9% higher than Alpine (AL) sired kids. Weaning, 160 d weight and preweaning average daily gain (ADG) were similar for the AL × AL, AL × SA and BO × AL. Breed of dam was significant (P < 0.02) for birth, weaning, 100-d weight, and preweaning ADG. Similar dressing percentage (DP) and ribeye muscle area (REA) were observed among AL × AL, AL × SP, and BO × SP crosses. Key words: Crossbreeding, Boer, Alpine, growth, carcass, ultrasound


1982 ◽  
Vol 62 (3) ◽  
pp. 665-670 ◽  
Author(s):  
D. C. JEFFRIES ◽  
R. G. PETERSON

Genetic parameters were estimated for 2403 purebred Yorkshire pigs over a 2-yr period, representing 21 sires. The traits studied included average daily gain, age adjusted to 90 kg, ultrasonic measurements of backfat at the mid-back and loin positions, total and adjusted total ultrasonic backfat and corresponding carcass backfat measurements. Least squares analyses were used to estimate and adjust for the effects of sex, year-season and sex by year-season interaction. Heritabilities and genetic correlations were calculated for all traits using both half- and full-sib estimates. Adjusted age and adjusted total ultrasonic backfat measurements were found to have the highest heritabilities of the live traits in this study. Estimates of heritability for adjusted age and adjusted total ultrasonic backfat were 0.24 ± 0.10 and 0.26 ± 0.10 based on half-sib and 0.56 ± 0.07 and 0.41 ± 0.06 from full-sib analyses. The genetic correlation between these two traits was −0.07 ± 0.28 based on the half-sib method. The total phenotypic correlation was −0.01 ± 0.02. Key words: Swine, ultrasonic backfat, heritabilities, genetic correlations


1993 ◽  
Vol 73 (4) ◽  
pp. 967-970 ◽  
Author(s):  
D. R. ZoBell ◽  
L. A. Goonewardene ◽  
K. Ziegler

Studies were undertaken to evaluate bloodless castration (B) based on growth and carcass traits. During the first 28 d, bloodless and surgical (S) castrates showed a 51–53% and 68–73% reduction in average daily gain, respectively, compared with intact bulls (I) (P < 0.05) in two trials. Bulls grew faster than steers overall. Carcass traits and grade were similar for B, S and I (P > 0.05). Key words: Bloodless, surgical, castration, growth, carcass traits


1993 ◽  
Vol 73 (2) ◽  
pp. 287-293
Author(s):  
S. L. Boyles ◽  
L. J. Johnson ◽  
W. D. Slanger ◽  
B. J. Kreft ◽  
J. D. Kirsch

Twenty-six of 52 heifers with an average liveweight of 318 kg were dewormed by intraruminal injection of oxfendazole and placed in drylot on 31 January. The other 26 animals served as controls. All heifers were pastured starting on 14 June and the treatment heifers were dewormed in the same manner as at the start of the experiment (31 January) on 1 July and 31 July. The groups started out with similar total worm eggs per gram of fecal sample, but the dewormed heifers had fewer counts each month thereafter. The drylot average daily gain of the treated heifers was higher (P = 0.01) and less variable (P = 0.12) and by 29 May these animals were heavier by 11.7 kg (P = 0.10). The treated animals did not gain as fast on pasture (P = 0.20), but the gain continued to be less variable (P = 0.09). Age at puberty was not different. Number of open heifers in the treated group was 4 vs. 15% for the control group (P = 0.18). Deworming by intraruminal injection resulted in faster feedlot gains, more uniform gains during both drylot and pasture, reduced parasites and no abscess at injection sites. Key words: Anthelmintics, oxfendazole, cattle, heifers


2013 ◽  
Vol 58 (No. 9) ◽  
pp. 484-490 ◽  
Author(s):  
S. Alves-Pimenta ◽  
B. Colaco ◽  
AM Silvestre ◽  
MM Ginja

The aims of this study were to determine the prevalence and heritability of elbow dysplasia in the Estrela mountain dog breed, to investigate genetic trends over the last 20 years (1990&ndash;2009) and to evaluate the association of individual records with breeding values. The elbows of 351 Estrela mountain dogs were examined using the flexed mediolateral radiographic view and evaluated using the International Elbow Working Group scoring system. Heritability and breeding values were estimated using a linear model. Elbow Dysplasia was found in 16.5% (59/351) of the dogs; males (27%, 34/127) were more affected than females (11%, 24/224) (P &lt; 0.05). The heritability was very low (0.065) and the genetic trend showed a slight positive slope with an improvement in 2004 and 2005. The mean breeding values in elbow dysplasia grades were different but the overlap among grades was very pronounced. The prevalence and heritability of elbow dysplasia in the breed are thus low. Mass selection using individual phenotypes may not be effective. Elbow dysplasia genetic trends are similar to trends for hip dysplasia and passive hip laxity, so the use of selection against hip dysplasia may also result in genetic progress for elbow dysplasia. &nbsp;


1985 ◽  
Vol 65 (4) ◽  
pp. 799-809 ◽  
Author(s):  
M. MAKARECHIAN ◽  
A. FARID ◽  
R. T. BERG

Pregnancy rates and calving dates of beef cows in 27 single-sire breeding herds mated to yearling or 2-yr old bulls were used in this study. The breed groups of bulls were Hereford and Beef Synthetic and cow herds were Hereford, Hereford cross and Beef Synthetic, respectively. A week before the start of the breeding season the bulls were scored for libido, their scrotal circumferences were measured and semen samples were collected. Semen volume, sperm motility and percent normal cells were evaluated. The average bull to cow ratio was 1:20. Pregnancy rate increased as age and body weight of cows increased, but it was independent of the previous calving date. Calving date was not related to body weight or age of cow, but it was influenced by the previous calving date. Each day delay in calving after the first 5 wk of calving season resulted in a 0.7-day delay in the date of calving during the next calving season. The Beef Synthetic-sired herds had higher pregnancy rates (P < 0.05) than the Hereford-sired herds, but the average calving dates of the two groups were similar. Cows mated to 2-yr-old bulls had 5% higher (P = 0.12) pregnancy rate than those mated to yearling bulls. Five of the herds showed low fertility and late calving, probably due to low fertility of the bulls. Yearling weight and feedlot average daily gain were positively (P < 0.05) related to bull fertility. The number of services performed by a bull during a 10 min libido test and total libido score were also found to be useful in assessing bull fertility, but scrotal circumference or semen traits were not related to fertility of bulls when used in single-sire mating at pasture. Key words: Beef cattle, bull fertility, single-sire mating


2000 ◽  
Vol 80 (3) ◽  
pp. 529-531 ◽  
Author(s):  
P. J. Munro ◽  
A. Lirette ◽  
D. M. Anderson ◽  
H. Y. Ju

Two-hundred and nine purebred Yorkshire newly weaned piglets were used to determine the effect of the sweetener Stevia (Stevia rebaudiana) at 83.3, 167 or 334 mg kg−1 diet on feed consumption (FC), average daily gain (ADG) and feed to gain ratio (F/G) compared with treatments with 5% sucrose and no sweetener (control; C). The Stevia-containing diets did not appear to have detrimental effects on the FC and F/G ratios of the piglets when compared with C. The results indicated only a limited potential for Stevia as feed additive for piglets. Key words: Sweetener, palatability, Stevia, weaned pigs


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