FACTORS INFLUENCING WEANING WEIGHTS OF RANGE BEEF AND DAIRY-BEEF CALVES

1980 ◽  
Vol 60 (3) ◽  
pp. 727-742 ◽  
Author(s):  
SARAH BUTSON ◽  
R.T. BERG ◽  
R.T. HARDIN

June and September measurements of lactation were made using 206 (1976) and 242 (1977) cows ranging from 2 to 10 yr of age from the University of Alberta beef herd representing four beef and dairy-beef breeds and lines. Influences on calf weaning weight investigated were age and breed of dam, sex of calf, and the continuous variables of calf age, calf birth weight, cow winter weight loss, cow post-calving average daily gain, milk yields and constituent yields of butterfat, protein and lactose. Milk and constituent yields had similar relationships to calf weaning weight (r = approximately 0.6). Stepwise regressions involving age and breed of dam accounted for 48 and 45% of the variance in weaning weight. When age and breed of dam were ignored, milk or constituent yields accounted for approximately 40% of weaning weight variance. After removing main effects, milk variables explained from 6.2 to 10.4% of the total variance. A unit increase of 1 kg in average daily milk yield was associated with 7.7 kg increase in weaning weight. Birth weight of calf and cow weight change during lactation had minor effects on calf weaning weight. No significant source of variation in weaning weight was explained by cow winter weight loss. As a significant proportion of the variation in weaning weight is accounted for by milk and constituent yields, selection for increased lactation performance and the introduction of dairy breeds into the breeding program of a beef herd can effect meaningful increases in calf weaning weights.

1971 ◽  
Vol 51 (3) ◽  
pp. 561-577 ◽  
Author(s):  
H. B. JEFFERY ◽  
R. T. BERG ◽  
R. T. HARDIN

Two years data involving 176 and 201 cows from the University of Alberta beef breeding herd were used to study the influences on calf preweaning performance of: breed, age, weight, summer and winter weight changes and milk yield of dam; breed of sire; and birth weight, weaning age and sex of calf. All independent variables combined explained 73 and 70% of total variance in average daily gain (ADG) to weaning and 81 and 70% of total variance in weaning weight, respectively, for 1966 and 1967. Of all variables considered, milk yield had the greatest influence on preweaning performance, explaining about 60% of the variation in ADG to weaning and 40 to 50% of the variation in weaning weight. A 1-kg increase in daily milk yield resulted in an 11- to 14-kg increase in weaning weight. Breed of dam explained about 23% of total variance in ADG to weaning, most of which was accounted for by breed differences in milk yield. Breed-of-sire differences accounted for 5.7 and 1.4% of variance in ADG of progeny for 1966 and 1967 data, respectively. Male calves exceeded female calves in birth weight by 2 kg, in ADG to weaning by 0.03 kg, and in weaning weight by 8 to 9 kilograms. Birth weight was positively associated with calf growth rate. A 1-kg increase in birth weight resulted in 1.74- and 1.59-kg increases in weaning weight for 1966 and 1967, respectively. A 10-kg increase in post-calving weight of cow, independent of milk yield and cow age, resulted in approximately a 0.7-kg increase in weaning weight of calf. Average daily gain to weaning was influenced slightly more by cow age than by post-calving weight of cow. However, about 80% of the variation in ADG explained by either cow age or post-calving weight of cow was accounted for by differences in milk yield associated with either variable.


2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 304-304
Author(s):  
Matthew D Garcia ◽  
Madelyn Kunzler ◽  
Kim Chapman

Abstract This study evaluated changes in performance of bulls enrolled in the Utah Beef Improvement Association’s (UBIA) annual performance tests conducted in accordance with central bull test standards established by the Beef Improvement Federation. Breeds with over 500 bulls enrolled over the period of 2004 to 2018 were included in the evaluation. The breeds with greater than 500 animals evaluated included the Angus, Red Angus, Hereford and Simmental Breeds. Traits evaluated included birth weight, initial weight, a 205-day adjusted weaning weight, final test weight, average daily gain, adjusted yearling weight, and weight per day of age. The mixed model procedure of SAS and interval regression analyses were utilized to evaluate the yearly rate of change for each breed and to determine if that rate of change was significantly different (P < 0.05) between the evaluated breeds. When evaluating all breeds represented across years, significant differences (P < 0.05) were observed for rate of change when evaluating birth weight and 205-day adjusted weaning weight. However, no differences were observed between breeds with more than 500 animals represented. Significant differences (P < 0.05) for rate of change were observed when comparing the top four represented breeds, for average daily gain, initial test weight, final test weight, adjusted yearling weight and weight per day of age. Specifically, a declining trend was noted for all breeds when evaluation all significant traits. When evaluating the previously described traits, the Angus breed was significantly different in its rate of decline when compared to the Red Angus and Hereford breeds. The lone increasing trend was observed in the Hereford breed which had a positive increasing trend for initial test weight which was significantly different (P < 0.05) from both the Angus and Red Angus breeds but not significantly different from the Simmental breed.


1976 ◽  
Vol 16 (80) ◽  
pp. 325 ◽  
Author(s):  
IP Gregory ◽  
EM Roberts ◽  
JW James

Several methods of correcting lamb weaning weight for age were compared. Lambs were weighed at birth, at 90 � 1 day of age, when the oldest and when the youngest lamb was 90 days and when the average age of lambs was 90 days. Weights were adjusted to 90 days by the methods of regression, regression pooled within sire groups, average daily gain with and without a standard birth weight and weight per day of age. All the correction methods examined gave similar results and there was no significant difference between methods. The correlations between the actual 90-day weight and the adjusted weights ranged from 0.922 to 0.960 and were highest when the weights taken when the average age of lambs was 90 days were used as the basis for adjustment. All adjusted weights were significantly biased as estimates of actual 90-day weight, but the bias was least for weights when average age was 90 days.


1979 ◽  
Vol 59 (3) ◽  
pp. 635-637
Author(s):  
S. D. M. JONES ◽  
M. A. PRICE ◽  
R. T. BERG

The effect of winter weight loss in Hereford cows on calf birth weight and performance to weaning was examined over a period of 4 yr. The average winter weight loss of cows (60 ± 36.2 kg mean ± SD) over the period of this study had a significant effect (P < 0.001) on calf birth weight, but no significant (P > 0.05) effect on the pre-weaning daily gain, or weaning weight of their calves.


1977 ◽  
Vol 57 (4) ◽  
pp. 697-703 ◽  
Author(s):  
E. E. SWIERSTRA ◽  
G. W. RAHNEFELD ◽  
R. L. CLIPLEF ◽  
J. H. STRAIN

Age and weight at first observed estrus (puberty) were studied in 471 crossbred heifers produced by inseminating Angus, Hereford, and Shorthorn cows with semen from Charolais, Limousin, and Simmental bulls. Heifers were kept in drylots after weaning and gained an average of 0.68 kg/day. Visual observations and vasectomized bulls fitted with marking harnesses were used for estrous detection. At puberty, the median and mean ages were 336 and 342 days, and the median and mean weights 296 and 305 kg. At puberty, Charolais- and Simmental-sired heifers were about 22 days younger (median age; P < 0.01) than Limousin-sired heifers (324 and 326 vs. 347 days, respectively). Charolais-sired heifers were significantly heavier (median weight) than Limousin- and Simmental-sired heifers (306 vs. 294 and 292 kg, respectively). Heifers from Angus and Hereford dams were about 22 days older (P < 0.01) at puberty than heifers from Shorthorn dams (median 347 and 346 vs. 324 days). Heifers with high preweaning growth rates attained puberty at an earlier age (r = −0.24; P < 0.01). Day of birth within the year had a significant effect on age and weight at puberty; i.e., heifers born early in the calving season were older and heavier at puberty. Weight at puberty was associated with weaning weight (r = 0.61; P < 0.01), birth weight (r = 0.41; P < 0.01), and preweaning average daily gain (r = 0.54; P < 0.01). Calves that were heavy at birth tended to be heavy at weaning, and heavy weaning weights, in turn, were associated with heavy weights at puberty. By 15 mo of age, 99% of all heifers were cycling.


1976 ◽  
Vol 56 (4) ◽  
pp. 791-801
Author(s):  
I. GARNETT ◽  
G. W. RAHNEFELD

Female reproductive performance and pre-weaning survival and growth were examined in a population of swine over 11 generations of selection for post-weaning average daily gain (ADG). Three separate breeding groups were used: (1) a Lacombe (L) line selected each generation for ADG, (2) a Yorkshire control (Y) line, and (3) a crossbred Lacombe × Yorkshire group (LY) generated each generation from the L and Y lines. Breeding group differences were evident for litter size, perinatal mortality, pre-weaning mortality, gestation length, birth weight, pre-weaning average daily gain (PreADG) and weaning weight. Selection did not affect number born, number born alive, number weaned or birth weight. When the values for the L line were expressed as a deviation from the control, pre-weaning mortality showed an increase. The increase appeared to be due to a decrease in the control rather than an increase in the L line. Gestation length showed a negative response to selection. As in the case of pre-weaning mortality, the response appeared to be a reflection of the instability of the control line. Genetic gains in PreADG of 0.004 kg/day/generation were realized in both the L line and LY group. Correspondingly, responses of 0.18 and 0.19 kg/generation were realized for weaning weight in the L line and LY group.


2021 ◽  
Vol 26 ◽  
pp. 6-10
Author(s):  
E. M. Awemu ◽  
B. Y. Abubakar ◽  
L. N. Nwakalor

The accumulated and annual levels of inbreeding and their effects on growth traits of lambs were investigated using data collected over 11 years at the National Animal Production Research Institute Zaria. Inbreeding level averaged 1.313% per year, cumulating to 14.45% over the years. Average individuals inbreeding coefficients of offspring from sires used for more than one breeding period was 0.103% across the inbred individuals and 0.004% over all lambs. Regression coefficients of growth traits (everage values per year) on inbreeding levels by year were – 0.185kg ± 1.820g and -0.391kg for birth weight, preweaning average daily gain and weaning weight, respectively. All regression coefficients indicated that birth weight and weaning weight declined by 0.185kg and 0.391kg, respectively while preweaning average daily gain increased by 1.820g. Conscious efforts to reduce inbreeding level and its effects on growth traits will greatly lead to improved productivity


1971 ◽  
Vol 51 (3) ◽  
pp. 551-560 ◽  
Author(s):  
H. B. JEFFERY ◽  
R. T. BERG ◽  
R. T. HARDIN

The joint and separate effects of several cow-calf variables on milk yield were studied with 176 and 201 beef cows from the University of Alberta beef breeding herd for 1966 and 1967, respectively. The dams consisted of Hereford, Aberdeen Angus, Galloway and hybrid breeding. Independent variables considered were: breed, post-calving weight, winter weight loss, summer weight gain and age of dam, and weaning age, sex and birth weight of calf. Total variance of milk yield explained by all variables together was only 40 and 52% for 1966 and 1967, respectively. Breed and age differences of dam accounted for 82 and 87% of explained variance in milk yield respectively for 1966 and 1967. Holding cow age constant, post-calving weight of cow explained 0.0 and 8.5% additional variance in milk yield for 1966 and 1967, respectively. Summer weight gain of cow was negatively associated with milk yield. Winter weight loss of cow had little influence on milk yield. There appeared to be a negative relationship between early parturition and milk yield. The effect of calf sex on milk yield of dam was inconsistent; cows suckling male calves vs. female calves yielded more milk in 1966 but less in 1967. Birth weight of calf had a small positive influence on milk yield of dam. Association between milk yield of dam and preweaning performance of progeny was high. It appeared that the quickest way to improve milk yield in beef cattle would be the introduction of breeds noted for high milk yield and by indirect selection, through selection of dams with progeny that have high average daily gain to weaning.


1976 ◽  
Vol 22 (1) ◽  
pp. 123-125 ◽  
Author(s):  
M. Pasdar ◽  
M. Makarechian ◽  
A. Farid

SummaryAn investigation was made of the association of transferrin types with birth weight, weaning weight and average daily gain from birth to weaning in three breeds of Iranian sheep. Transferrin type was not a significant source of variation in weight.


1976 ◽  
Vol 56 (3) ◽  
pp. 489-496
Author(s):  
J. E. LAWSON ◽  
D. G. KELLER

Hereford calves exceeded cattalo calves (averaging 1/7 bison–6/7 domestic and the product of matings of cattalo bulls of 1/14–3/16 bison to cattalo cows of 1/4–1/2 bison) by 3.8% in birth weight, based on data taken on 654 calves between 1958 and 1964. Hereford (72) and cattalo (164) calves born in 1961–1963 did not differ in average daily gain to weaning or in weaning weight, but Hereford calves exceeded cattalo calves by 15.5 and 4.7% in average daily gain in the feedlot and weight at the end of the 168-day feedlot test. In a comparison of calves born in 1962 and 1963, 32 1/4 Brahman–3/4 Hereford (1/4 Brahman calves were the result of backcrossing Hereford bulls to first-cross Brahman × Hereford cows), 110 cattalo, and 38 Hereford calves did not differ in birth weight; however, 1/4 Brahman calves showed evidence of the superior mothering ability of their dams by surpassing the cattalo by 19.2% and the Herefords by 24.3% in average daily gain to weaning, and excelling them by 17.9 and 14.0% in weaning weight. Hereford calves had 14.1 and 15.9% larger average daily gains in the feedlot and required only 86.6 and 73.2% as much digestible energy (Meal) per kilogram of gain as the cattalo and 1/4 Brahman calves. At the end of the 168-day feedlot test, 1/4 Brahman calves were 7.9% heavier than the cattalo but the 1/4 Brahman and Hereford calves did not differ statistically.


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