DIFFERENCES BETWEEN SIRE GROUPS IN BODY MEASUREMENTS AND BODY WEIGHT CHANGES OF LACTATING COWS

1983 ◽  
Vol 63 (1) ◽  
pp. 27-37
Author(s):  
C. Y. LIN ◽  
T. R. BATRA ◽  
A. J. McALLISTER ◽  
A. J. LEE ◽  
J. P. F. DARISSE ◽  
...  

Body weights and measurements of 694 first, 519 second and 329 third lactation cows in five Research Branch herds of the National Cooperative Dairy Cattle Breeding Project of Agriculture Canada were studied. The A line cows were daughters of U.S., Canadian and Finnish Ayrshire proven bulls, Brown Swiss and Norwegian Red proven bulls and young Research Branch Ayshire bulls and Research Branch Ayrshire cows. Highly selected U.S. and Canadian Holstein proven bulls and young Research Branch bulls mated to Research Branch Holstein cows produced the H-line cows. The model for analysis contained fixed effects for station, year of birth, line, sire group within line and sire within sire group within line as classification variables and age at calving as a covariable. Sire group, line, station and sire had significant effects on all weights studied. However, most effects were not significant for weight changes. Daughters of Brown Swiss and Norwegian Red sires were nearly as heavy as the daughters of Holstein bulls. On average, cows lost about 20 kg of weight from calving to 56 days postpartum of first lactation. The older first calvers were found to lose more weight from calving to 56 days of first lactation and gain less weight from 56 days postpartum onward than the younger first calvers. The effects of station, line and age at calving were significant for most body measurements. Sire group effects were significant for 13 out of 24 measurements. Significant differences between sire groups existed in stature (withers height) at all lactations and ages. In contrast, body length (shoulder to hook) did not differ significantly between sire groups from 112 days of first lactation onward. Key words: Body weight changes, body measurements, dairy cattle

1983 ◽  
Vol 63 (2) ◽  
pp. 269-278 ◽  
Author(s):  
T. R. BATRA ◽  
A. J. McALLISTER ◽  
A. J. LEE ◽  
J. P. CHESNAIS ◽  
J. P. F. DARISSE ◽  
...  

Ages at first heat and first conception, age and weight at first calving, number of services per conception, and incidence of difficult calving and retained placenta were obtained from 853 heifers of the National Cooperative Dairy Cattle Breeding project of the Research Branch of Agriculture Canada. Among these, 483 heifers were from Agriculture Canada Research Branch Holstein cows and by Research Branch, Canadian and U.S. Holstein sires (H line). The other heifers were from Research Branch Ayrshire cows and by Research Branch, Canadian, U.S. and Finnish Ayrshire as well as Brown Swiss and Norwegian Red sires (A line). The data were analyzed by least squares analysis of variance using a model containing fixed effects of station, year of birth, season of birth, line, sire groups within line, and sires within sire group within line. The effects of station and line were significant for most of the heifer reproduction traits studied while the effect of year of birth was only significant for age at first conception and weight at first calving. H line heifers on the average showed first heat 27 days earlier, were 11 days younger at first conception, were 13 days younger at first calving, were 33 kg heavier at first calving, had 30% more difficult calving and 9% fewer retained placenta than the A line heifers. Differences among the sire groups within the H line were small and nonsignificant while within the A line they were significant for age at first heat and weight at first calving. Key words: Heifer reproduction traits, dairy cattle


1986 ◽  
Vol 66 (1) ◽  
pp. 53-65 ◽  
Author(s):  
T. R. BATRA ◽  
A. J. LEE ◽  
A. J. McALLISTER

The relationships between reproduction traits, body weight and milk yield were investigated using data from 1611 heifers and 733 cows from two lines of the National Cooperative Dairy Cattle Breeding Project. The data were analyzed separately for heifers and cows within lines using a mixed linear model containing fixed effects for station, year of birth, season of birth and random effect of sires. Heritability estimates and genetic correlations were estimated by a paternal half-sib analysis. Heritability estimates for heifer and cow reproduction traits ranged between 0 and 26% while those of body weights at calving and 112 d postpartum and milk yield ranged from 24 to 43%. Heifers with difficult calving had a higher incidence of retained placenta than those with normal calving. Phenotypic correlations between heifer reproduction traits and milk yield during first lactation were small. High milk production in cows was associated with longer calving interval. Phenotypic correlations between heifer's and cow's reproduction traits were small. Difficult calving in heifers impairs reproductive performance after calving resulting in greater number of days from calving to first and last breeding and leading to a longer calving interval. Key words: Reproduction traits, heifers, cows, milk yield, dairy cattle


1982 ◽  
Vol 62 (3) ◽  
pp. 709-716 ◽  
Author(s):  
T. R. BATRA ◽  
A. J. McALLISTER ◽  
A. J. LEE ◽  
G. L. ROY ◽  
J. P. F. DARISSE ◽  
...  

Data on conception rate, gestation length, incidence of calving difficulty and retained placenta were obtained from 269 heifers and 525 cows as mates of the pureline foundation phase sires of the National Cooperative Dairy Cattle Breeding Project. The data were analyzed by least squares separately for heifers and cows using a model containing fixed effects for station, year of calving, season of calving, sex of calf, line, sire groups within line, sires within sire group and line, birth weight of the calf as a covariate and residual. Effect of age at first calving was used as a covariate in the heifer data while the effect of parity was included in the cow data. The effect of station, year of calving, season of calving, line, sire groups within line and sires within sire group and line were significant (P < 0.05) for gestation length of heifers and cows. Other significant (P < 0.05) effects in heifers were age at calving on conception rate, sex and birth weight of the calf on calving difficulty. In addition the effects of sex and birth weight of the calf on gestation length, station and parity on calving difficulty and station and line on retained placenta were significant in cows. Key words: Reproductive performance, dairy cattle


1995 ◽  
Vol 10 (4) ◽  
pp. 147-151 ◽  
Author(s):  
J.W. Rust ◽  
C.C. Sheaffer ◽  
V.R. Eidman ◽  
R.D. Moon ◽  
R.D. Mathison

AbstractA 2-year study compared milk production and profitability for confinement feeding versus rotational grazing. Guernsey and Guernsey x Holstein cows grazed perennial grass pastures from mid-May to October or were fed in confinement. Averaged over both years, confined cows produced 7% more milk; their milk was similar in fat concentration to that of grazing cows. Body weight changes and health of the two groups were similar. Net return per cow averaged $64 higher for rotational grazing than for confinement because of lower costs for feeding, facilities, equipment, and labor. Intensive rotational grazing of pastures is a competitive alternative for dairy cow feeding. However, farmers in the northern U.S. will still require stored feeds from late fall through early spring.


1980 ◽  
Vol 95 (1) ◽  
pp. 39-45
Author(s):  
I. D. McArthur

SummaryA survey of sheep production was undertaken in rangeland areas of western Afghanistan to provide basic information of ewe body-weight changes throughout the year and on production variables, including mortality and lambing performance. Ewes lost up to 31% of body weight between December and March and mortality over the same period was 7%. On the basis of the results of this survey, an experiment was made to test the effect on lambing performance of pre-lambing supplementation of range-based ewes.Supplementation reduced weight losses in ewes, but the feeding treatments did not produce significant results in terms of lamb birth weights or survival to 10 days. However, there were indications that selective feeding of weak ewes can produce economic benefits, given that the costs of supervising such animals are minimal and the price of grain supplements is low relative to the price of meat.


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