EFFECTS OF YEARLING WEIGHT SELECTION IN SHORTHORN BEEF CATTLE ON AGE-OF-DAM ADJUSTMENT FACTORS

1990 ◽  
Vol 70 (3) ◽  
pp. 963-965
Author(s):  
J. C. OLTHOFF ◽  
G. H. CROW ◽  
G. W. RAHNEFELD
Keyword(s):  
Birth Weight ◽  
Beef Cattle ◽  
Key Words ◽  
Selection Line ◽  
Weaning Weight ◽  
Performance Change ◽  
Adjustment Factors ◽  
Over Time

Lines within a breed which differ in their level of performance may require different age-of-dam adjustment factors in the same way that different breeds do. Age-of-dam adjustments calculated from a control and a yearling weight selection line indicated lower values in the selected line for calf birth weight, weaning weight and yearling weight for 2- and 4-yr-old dams. Trends for adjustment factors in each line over time were generally not significant but tended to diverge. Age-of-dam adjustment factors within a breed may need to be reevaluated at intervals as levels of performance change. Key words: Beef cattle, age of dam adjustment, selection, yearling weight

SEX OF CALF AND AGE OF DAM ADJUSTMENTS FOR SOME PERFORMANCE TRAITS IN TWO POPULATIONS OF BEEF CATTLE

1982 ◽  
Vol 62 (3) ◽  
pp. 699-708 ◽  
Author(s):  
A. K. SHARMA ◽  
L. WILLMS ◽  
R. T. HARDIN ◽  
R. T. BERG
Keyword(s):  
Birth Weight ◽  
Beef Cattle ◽  
Least Squares ◽  
Key Words ◽  
Weaning Weight ◽  
Adjustment Factors ◽  
Main Effects ◽  
Two Populations ◽  
Age And Sex ◽  
Methods Of Application

Sex of calf and age of dam effects on birth weight, preweaning ADG, 180-day weaning weight; and age of dam effects on yearling weight, postweaning ADG in males, and 18-mo weight in females were studied in a Hereford and a beef Synthetic population. The effects of breed, sex of calf, age of dam and year were significant on preweaning traits. The superior milking ability of Synthetic cows over Herefords was more pronounced for male than female calves. Additive and multiplicative adjustment factors were calculated from the least squares analyses. Additive adjustments for age of dam and multiplicative adjustments for sex of calf were found most suitable for preweaning traits. Three methods of application of adjustment factors were studied. Multiplicative sex of calf adjustment followed by additive age of dam adjustment was found to be most effective as indicated by the reductions in mean squares for main effects and interactions. Additive and multiplicative age of dam factors are presented for yearling weight in males and 18-mo weight in females. Use of additive factors is recommended. Extending weaning weight age of dam adjustments for postweaning traits was not found suitable in this study. Key words: Beef cattle, age and sex, adjustment factors

scholarly journals INFLUENCE OF CALF GENETIC TYPE ON PREWEANING TRAITS UNDER COMMERCIAL BEEF CATTLE CONDITIONS

1982 ◽  
Vol 62 (1) ◽  
pp. 287-290
Author(s):  
D. K. AARON ◽  
F. A. THRIFT
Keyword(s):  
Birth Weight ◽  
Beef Cattle ◽  
Key Words ◽  
Genetic Type ◽  
Weaning Weight ◽  
Genetic Types ◽  
Weight Data

Birth and weaning weight data were evaluated on 1/2 Simmental (SH, SA), 1/2 Maine-Anjou (MH, MA), 3/4 Simmental (S.SH, S.SA) and 3/4 Maine-Anjou (M.MH, M.MA) calves. For birth weight, 1/2 Simmental calves were lighter (P < 0.01) than 1/2 Maine-Anjou calves, and calves from Hereford cows were heavier (P < 0.01) than calves from Angus cows. Also, S.SH calves were heavier (P < 0.01) than S.SA calves. For weaning weight, 3/4 Simmental calves were heavier (P < 0.01) than 3/4 Maine-Anjou calves, and 1/2 Simmental and Maine-Anjou calves were lighter (P < 0.01) than 3/4 Simmental and Maine-Anjou calves. Key words: Calf genetic types, grading-up, beef cattle

BREED AVERAGES AND AGE OF DAM ADJUSTMENT FACTORS FOR BIRTH WEIGHT OF BEEF CATTLE

1983 ◽  
Vol 63 (1) ◽  
pp. 7-15
Author(s):  
A. K. W. TONG
Keyword(s):  
Birth Weight ◽  
Beef Cattle ◽  
Key Words ◽  
Interaction Effects ◽  
Adjustment Factors ◽  
Data Files ◽  
Main Effects ◽  
Sire Breed

A subset of birth weight records consisting of 191 535 calves, from 7021 herd-years with fewer than 50% estimated weights, tested during 1971 through 1980 was selected from the data files of the Federal-Provincial Record of Performance program for beef cattle to estimate breed averages and age of dam adjustment factors. The main effects included herd-years, breed of sire, breed of dam, sex of calf and age of dam. The interaction effects for breed of sire by sex of calf on birth weight were significant (P < 0.01) and the estimated differences for 22 breeds of sire expressed as deviations from the Hereford breed ranged from − 4.05 to 6.27 kg for male calves and from − 3.70 to 6.20 kg for female calves. The effects of breed of dam, sex of calf, age of dam and all the two-way interactions were significant at P < 0.01, while the three-way interaction was significant at P < 0.05. Additive age of dam adjustment factors within sex of calf were derived for 12 breeds of dam. The general age of dam effects averaged over breed of sire and breed of dam, expressed as deviations from the mature dams, were − 2.69, − 1.27, − 0.41, 0 kg for male calves, and − 2.64, − 1.26, − 0.50, 0 kg for female calves from 2-, 3-, 4-, and 5 + yr-old dams. Key words: Birth weight, breed averages, age of dam adjustment factors

Adjusting scrotal circumference of yearling beef bulls in five composites

1996 ◽  
Vol 76 (2) ◽  
pp. 189-191 ◽  
Author(s):  
D. D. Kress ◽  
K. C. Davis ◽  
M. W. Tess
Keyword(s):  
Birth Weight ◽  
Low Birth Weight ◽  
Beef Cattle ◽  
Key Words ◽  
Fixed Effects ◽  
Linear Quadratic ◽  
Scrotal Circumference ◽  
Adjustment Factors ◽  
Significant Regression ◽  
Linear Regressions

Records from five composite strains of beef cattle were used to estimate age of dam and age of bull adjustment factors for scrotal circumference of yearling bulls. Data were obtained from Beefbooster Cattle Alberta Ltd., Calgary, AB. There were 5244 scrotal circumference records on yearling bulls born from 1987 to 1992. M1, M2, and M4 were maternal composites selected primarily for weaning weight, M3 was a terminal composite selected primarily for low birth weight, and TX was a terminal composite selected primarily for feedlot gain. The prominent foundation breeds were Angus for M1, Hereford for M2, various small breeds for M3, Limousin and Gelbvieh for M4, and Charolais for TX. Statistical analyses were performed for each composite separately according to the model that included the fixed effects of herd, year, age of dam and linear (quadratic was not significant) regression on age of bull at measurement. Average age at measurement was 340, 333, 361, 358, and 375 d for M1, M2, M3, M4, and TX, respectively, and range in age was about 100 d for most composites. Age of dam was significant for all composites except M4. Linear regressions on age of bull were 0.0376, 0.0379, 0.0308, 0.0410, and 0.0349 cm d−1 for M1, M2, M3, M4, and TX, respectively. Scrotal circumference of composite bulls should be adjusted additively for age of dam and linearly for age of bull. These adjustments tended to be smaller for age of dam and larger for age of bull than those reported for straighbred or purebred bulls. Key words: Beef cattle, composites, scrotal circumference, adjustment factors

scholarly journals Factors affecting growth traits of beef cattle breeds raised inSlovakia

2011 ◽  
Vol 50 (No. 1) ◽  
pp. 14-21 ◽  
Author(s):  
E. Krupa ◽  
M. Oravcová ◽  
P. Polák ◽  
J. Huba ◽  
Z. Krupová
Keyword(s):  
Birth Weight ◽  
Beef Cattle ◽  
Least Squares ◽  
Linear Model ◽  
Growth Traits ◽  
General Linear Model ◽  
Weaning Weight ◽  
Factors Affecting ◽  
Sex Effect ◽  
Beef Cattle Breeds

Growth traits of purebred calves of six beef breeds (Aberdeen Angus &ndash; AA, Blonde d&rsquo;Aquitaine &ndash; BA, Charolais &ndash; CH,Hereford &ndash; HE, Limousine &ndash; LI and Beef Simmental &ndash; BS) born from 1998 to 2002 were analysed. Traits under study were birth weight (BW), weight at 120 days (W120), weight at 210 days &ndash; weaning weight (WW), weight at 365 days &ndash; yearling weight (YW) and average daily gains from birth to 120 days (ADG1), from birth to 210 days (ADG2), from birth to 365 days (ADG3), from 120 to 210 days (ADG4). General linear model with class effects of breed, dam&rsquo;s age at calving, sex, herd-year-season (HYS) and covariation of age at weighing was used for analyses. All effects significantly affected both weight and gain traits except for dam&rsquo;s age that was significant for BW, W120, YW and ADG3, and age at weighing that was significant for W120, WW, YW, ADG2, ADG3, ADG4. Estimated least squares means of growth traits were compared using Scheffe&rsquo;s multiple-range tests. Highest BW (40.57&nbsp;kg) and W120 (172.43 kg) were found for BA calves. BS calves had highest WW (260.30 kg), YW (424.07 kg), ADG1 (1&nbsp;154&nbsp;g), ADG2 (1 053 g), ADG3 (1 054 g) and ADG4 (1 098 g). Highest BW, YW, ADG3 and ADG4 were found for males-singles. Males-twins had highest W120, WW, ADG1 and ADG2. Calves descending from 5&ndash;7 years old dams had highest BW, W120, WW, ADG1, ADG2 and ADG4. The proportion of variability of growth traits explained by HYS effect (42.96&ndash;71.69%) was high, whereas proportions of variability explained by SEX effect (2.03&ndash;5.77%), age of dam (1.02&ndash;2.24%) and breed (1.05&ndash;2.21%) were low. Residuals accounted for 23.71 up to 53.79% of total variance. &nbsp;

Bayesian analysis of selection for greater weaning weight while maintaining birth weight in beef cattle

2009 ◽  
Vol 87 (10) ◽  
pp. 3089-3096 ◽  
Author(s):  
L. M. Melucci ◽  
A. N. Birchmeier ◽  
E. P. Cappa ◽  
R. J. C. Cantet
Keyword(s):  
Birth Weight ◽  
Beef Cattle ◽  
Bayesian Analysis ◽  
Weaning Weight ◽  
Selection For

A comparison of methods to evaluate beef cow productivity

1993 ◽  
Vol 73 (4) ◽  
pp. 971-975 ◽  
Author(s):  
G. W. Rahnefeld ◽  
Doug Ward ◽  
G. M. Weiss
Keyword(s):  
Beef Cattle ◽  
Key Words ◽  
Comparison Of Methods ◽  
Weaning Weight ◽  
Beef Cow

The following were compared as measures of cow productivity: (A) calf weaning weight per mating opportunity; (B) calf weaning weight per mating opportunity with cow weight at weaning as a covariate; (C) calf weaning weight per mating opportunity per unit of cow weight at weaning; and (D) calf weaning weight per mating opportunity per cow metabolic weight (kg0.75) at weaning. Results indicate that the method described under (C) is best at reducing error followed closely by the method described under (D). The least satisfactory measure of cow productivity was (B). Key words: Beef cattle, cow efficiency, productivity

Genetic trends for weaning weight during development of a multibreed population of beef cattle in two contrasting environments

2000 ◽  
Vol 80 (1) ◽  
pp. 191-193
Author(s):  
J. J. Tosh ◽  
R. A. Kemp
Keyword(s):  
Natural Selection ◽  
Beef Cattle ◽  
Key Words ◽  
Genetic Component ◽  
Weaning Weight ◽  
Common Base ◽  
The Difference ◽  
Selection Differentials ◽  
Genetic Trends

Genetic trends for weaning weight were determined in two herds of multibreed beef cattle that originated from a common base and were subject to mutual breeding policies in separate environments. The herds diverged for the direct though not the maternal genetic component of weaning weight within the 13-yr period examined; in the final year, the difference (P < 0.001) between the herds was almost 3 kg. This could have been partly due to unequal selection differentials and generation intervals. Results suggested the extent of natural selection also differed between the two environments. Key words: Beef cattle, crossbreeding, genetic trends, selection, weaning weight

The effect of castration age, method and implant regime on growth and carcass traits of male beef cattle

1991 ◽  
Vol 71 (2) ◽  
pp. 301-309 ◽  
Author(s):  
R. D. H. Cohen ◽  
B. D. King ◽  
H. H. Nicholson ◽  
E. D. Janzen
Keyword(s):  
Beef Cattle ◽  
Key Words ◽  
Carcass Traits ◽  
Carcass Characteristics ◽  
Carcass Weight ◽  
Feedlot Performance ◽  
Weaning Weight ◽  
Growing Period

In 1984–1985 and 1985–1986 groups of 136 and 127 male calves were used to assess the effects of multiple implants (Ralgro and Steeroid), castration time (early and late) and castration method (surgical and chemical) on growth to weaning and feedlot performance and carcass characteristics. Ralgro increased calf rate of gain to weaning (P < 0.05) and adjusted weaning weight (P < 0.01) but did not affect rate of gain during the feedlot period. Although Ralgro increased (P < 0.001) weight at slaughter, it took longer (P < 0.05) for implanted cattle to reach Canada A1 than unimplanted cattle. Steeroid did not affect rate of gain to weaning but did increase (P < 0.05) adjusted weaning weight. Steeroid increased (P < 0.05) rate of gain relative to unimplanted cattle during the growing period in the feedlot and cattle implanted four times from birth to slaughter gained more (P < 0.05) than cattle implanted twice (birth and weaning). For the entire feedlot period, bulls receiving Steeroid gained faster (P < 0.05) than unimplanted bulls with no difference (P > 0.05) between implant groups (two or four implants). Ralgro implants increased (P < 0.05) carcass weight, rib-eye area and cutability while Steeroid increased (P < 0.05) only carcass weight. However, when rib-eye area was adjusted for carcass weight, the effect of Ralgro was not significant (P > 0.05). Bulls had greater (P < 0.05) shipping weight, carcass weight, rib-eye area, dressing percent and cutability than steers. Age at castration (early or late) had no effect on feedlot performance or carcass traits while method of castration (surgical or chemical) had some effects (P < 0.05) on ADG, liveweight, carcass weight and rib-eye area. Key words: Castration, Ralgro, Steeroid, beef, growth, carcass

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