30 Calf Performance and Sex Ratios in Second Generation Reciprocal Nellore-angus Crosses

2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 14-15
Author(s):  
Dana Mickey ◽  
James Sanders ◽  
David G Riley ◽  
Andy D Herring

Abstract The objectives of this study were to analyze calf weight and sex distribution differences in reciprocal F2 Nellore-Angus calves (n = 559) born 2010–2015 and calves out of these F2 females through 4 yr age (n = 469) born 2012–2018. The F2 animals were produced by 4 F1 parent type combinations from Nellore-sired (NA) vs. Angus-sired (AN) sires and dams. Weight traits were analyzed using mixed models, and sex distribution was analyzed through PROC GLIMMIX in SAS. Sire type and dam type affected birth weight (P < 0.05) but not weaning weight of the F2 calves. However, the interaction between sire type and dam type accounted for weaning weight differences (P = 0.038). Birth weight averaged 3.5 kg heavier from NA vs. AN sires, and 2.4 kg heavier from NA vs. AN dams. Weaning weight displayed a different pattern than observed in birth weight with the heaviest calves being NAAN (224.5 ± 3.7 kg) and lightest being ANAN (215.9 ± 3.9 kg). Sire type accounted for important variation (P = 0.036) in the calf sex distribution at birth among F2 calves. Percentage males at birth exceeded the expected ratio for NA-sired calves (66.6%, n = 168) but not for AN-sired calves (49.9%, n = 105). The sire and dam type main effects in the F2 females did not influence weight traits or sex distribution in their calves (from predominantly Angus sires). However, the interaction of sire type x dam type x sex showed a trend in birth weight (P = 0.080) and importance for weaning weight (P = 0.010) where only from ANNA and NANA dams were males heavier than females. These results suggest that some of the calf weight reciprocal differences typically observed among F1 Bos indicus-Bos taurus crosses can persist in later generations.

1973 ◽  
Vol 13 (61) ◽  
pp. 117 ◽  
Author(s):  
JE Frisch

The mortality rates, weight changes and associated effects of a. draught in 1969 were observed in a herd of Shorthorn x Hereford (SH), Brahman x SH (BX) and Africander x SH (AX) crossbred cows and small herds of purebred Brahman and Africander cows at 'Belmont', Queensland. About half of the cows calved over a two month period from mid-October 1969. All the cows were weighed in February 1968, February and October 1969 and in January 1970 and the data from the crossbreds analysed by the method of least squares. The weights and weight changes of both the calving and non-calving groups followed a similar pattern though the weight changes of the non-calving group were of greater magnitude. The weights showed that the three crossbreds reached the same mature weight but at different rates. The SH cows reached mature weight least rapidly, had the highest mean weight loss during the drought and had the lowest mean gains after the season broke. Weight changes both during and after the drought were however dependent on lactational status in February 1969. The mean weight loss of cows that weaned a calf in 1969 (wet) was similar for all breeds. However, the mean loss of the dry SH cows was significantly greater than that of the dry BX and AX cows. Previously wet cows exhibited compensatory gains after calving but the gain of the wet SH cows was the lowest of the crossbred means. The mean birth weight of the SH calves was reduced below the long term mean by about 4 kg but birthweights of BX and AX calves were similar to those in other years. During the drought the purebred Brahmans lost the least and the purebred Africanders lost the most weight of all breeds. However, the nature of the data precludes any strict comparisons from being drawn. Mortality rates of breeding cows were recorded from 1960 to 1969. Rates were generally highest for the SH, particularly in the drought years of 1965 and 1969. Some reasons are advanced which may explain the differences in performance of the breed types.


1993 ◽  
Vol 44 (2) ◽  
pp. 179 ◽  
Author(s):  
GP Davis

This paper reviews published estimates of genetic parameters for traits of growth, reproduction and resistance to environmental stresses for Bos indicus and Zebu derived breeds in northern Australia. Most published estimates of heritabilities for growth and reproduction traits were higher for tropically adapted breeds in northern Australia than for Bos taurus breeds in temperate Australia. Weighted mean estimates of heritabilities for the direct component of weaning weight were 39% for the Brahman breed and 30% for Zebu-derived breeds in northern Australia compared with 13% for Bos taurus breeds in temperate areas of Australia. Mean estimates for the maternal component of weaning weight were 5, 24 and 13% respectively. Mean heritabilities for yearling and 550 day weights for Zebu derived breeds in northern Australia (24 and 25%) were similar to those for Bos taurus breeds in temperate areas, though estimates for Brahmans were higher (39 and 39%). Published estimates of heritabilities of later weights (700 and 900 days), which are most relevant to northern Australian production systems, were rare but averaged between 32 and 45% for Zebu-derived breeds and Brahmans. Weighted mean heritability for female calving success was 14% and for realised bull fertility was 5%. Published estimates of heritabilities of scrota1 circumference averaged 31%, and testosterone response to GNRH stimulation was 52%. Heritabilities of resistance to various environmental stresses were all moderate with weighted means between 20 and 34%. Genetic correlations between growth, reproduction and resistance to environmental stresses are also reviewed. There appears to be predictable variation in estimates of parameters between breeds in different environments which is related to level of resistance to environmental stresses, and this is likely to affect the prediction of breeding values for cattle in northern Australia.


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.


1973 ◽  
Vol 13 (61) ◽  
pp. 127 ◽  
Author(s):  
JE Frisch

A study was made over several years of lifetime mortality rates of both purebred Bos taurus and Bos indicus breeds and of several generations of crosses between the breeds. Of 4,678 calves born during the period, 4.7 per cent died at or within one week of birth. A further 2.3 per cent of those remaining died before weaning and a further 1.1 per cent died from weaning to 15 months. Sixteen of 22 calves born as twins were perinatal mortalities. Perinatal losses were highest in purebred Zebus (Africander and Brahman) and in first generation Brahman crossbred (BX) calves. Africander crossbreds (AX) generally had the lowest mortality rates of all crossbreds at each stage of the life cycle. Perinatal mortalities were however high in both F1 AX and F1 BX calves born to primiparous purebred British (Hereford and Shorthorn) heifers. Over all crossbred generations, perinatal mortalities were highest in calves from 3-year-old heifers and decreased with age of dam. More males (4.7 per cent) than females (2.9 per cent) died at or near birth. Mortalities in F1 BX males (10.3 per cent) were the highest of all groups. Relatively high or low birth weight was associated with high perinatal mortalities in the crossbreeds. Losses of stock after weaning were generally higher in the British breed-types than in the Zebu breed-types with the greatest differences in adult mortality rates. Annual mortality rates of breeding cows of each breed were studied over a similar period. 9,537 cow years were involved in the study. Mortality rates of both purebred and crossbred British cows were higher than for purebred and crossbred Zebu cows. One contributing cause was the difference in numbers of cows of each breed that died while calving. In all, 1.4 per cent of British crossbred calvings resulted in the death of the cow compared with 0.6 and 0.3 per cent for comparable AX and BX cows. Losses were negligible in purebred Zebus. Mortality rates in adults generally increased slowly with age and were highest in 8 - 10-year-old cows.


2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 46-47
Author(s):  
Logan Dodd ◽  
David Anderson ◽  
David G Riley ◽  
Barton Johnson ◽  
Andy D Herring

Abstract Number of calves (n = 596) and weaning calf value (n = 574) from natural service, multi-sire breeding groups were evaluated in a crossbred research herd. Sires and dams that were F1 crosses of Angus (A) and Nellore (N) were mated annually during 60 to 90-day breeding seasons to produce spring-born calves in 2009–2015. Numbers of sires used annually varied from 5 to 9; numbers of females exposed per bull ranged from 14 to 22 across years. Bulls were pastured together throughout the year as well as breeding seasons. Sires were identified based on calf DNA genotyping. Calf number, birth date, birth weight, weaning weight, and economic value were determined per bull annually. Calf value was based on weaning weight and reported prices for respective weaning dates. Calf prices were calculated separately for steers and heifers relative to 22.7 kg (50 lb) increments for corresponding weight class and year. Mixed model analyses were conducted that included fixed categorical effects of calf birth year, type of F1 sire (A-sired vs. N-sired), sire nested within type, calf sex, and the interaction of F1 sire type with calf sex. Covariates of Julian birth date and calf weaning age were included for birth weight and weaning weight, respectively. Large differences in calf numbers and performance (P &lt; 0.05) were observed. Weaned calves produced annually per sire ranged from 0 to 48. Average annual calf performance per sire ranged from 28.4 to 50.8 kg for birth weight and 146.5 to 249.0 kg for weaning weight. Annual economic value per sire ranged from $0 to $30,870 when considering half of each calf’s value as attributed to the sire. Commercial producers should consider potential sire variability for calf numbers, birth date distribution, and ratio of female-to-male calves in combination with calf performance for economic assessments.


1993 ◽  
Vol 33 (2) ◽  
pp. 119 ◽  
Author(s):  
G Fordyce ◽  
TA James ◽  
RG Holroyd ◽  
NJ Beaman ◽  
RJ Mayer ◽  
...  

The birth weights and weaning weights of Bos indicus cross calves from 4 inter se mated herd groups in a dry tropical environment were studied. The calving season commenced in late October, about 2 weeks before the start of the pasture-growing season. Second and subsequent generations of 1/2 Brahman and 1/2 Sahiwal crosses and first backcross, and later generations of 3/4 Brahman and 3/4 Sahiwal crosses, were represented. The Bos taurus component of the crosses was primarily Beef Shorthorn. In general, Brahman crosses were heavier at birth and grew faster to weaning than Sahiwal crosses (P<0.05), with consequent advantages in weaning weights of 11 and 6 kg in first backcross and late generation crosses, respectively. There was a birth weight advantage (P<0.05) of 1/2 crosses over 3/4 crosses, which was eroded by the time of weaning. Superior growth rates of 3/4 crosses were primarily expressed in years with greater nutritional stress and appeared to be due to better adaptation to environmental stresses by the calf. The only difference between filial generations was the growth rate advantage (P<0.05) of F2 1/2 crosses over F3 1/2 crosses, apparently due to suckling of F1 and F2 dams, respectively. Males exhibited an 8% average advantage (P<0.05) over females for all weight and growth traits in late generation calves. Calves with mature dams were 1.8 kg heavier (P<0.05) at birth. This, along with their higher (P<0.05) preweaning growth rate (19-49 g/day), resulted in calves with mature dams being 4-10 kg heavier (P<0.05) at weaning than calves of young cows. Differences between years in birth weights and preweaning growth rates were <25% (P<0.05). Birth weight was affected by nutrition of the dam in late pregnancy (early calves were generally about 1 kg lighter than late calves), and growth of calves was higher in years when the pasture growing season commenced earlier.


1982 ◽  
Vol 62 (3) ◽  
pp. 699-708 ◽  
Author(s):  
A. K. SHARMA ◽  
L. WILLMS ◽  
R. T. HARDIN ◽  
R. T. BERG

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


1990 ◽  
Vol 68 (4) ◽  
pp. 960-968 ◽  
Author(s):  
C. M. Bailey ◽  
Y. O. Koh ◽  
W. D. Foote ◽  
D. R. Hanks

Abstract Mature dams representing Hereford, Red Poll, F1 Hereford × Red Poll, F<Analysis of the Hereford1 Red Poll × Hereford, F1 Angus × Hereford, F1 Angus × Charolais, F1 Brahman × Hereford and F1 Brahman × Angus breed types were evaluated. All cows were bred to Limousin sires to produce two-way or three-way-cross progeny. Mature Brahman × Hereford dams produced a higher (P < .05) percentage of live calves than Herefords, but dam breed differences in percentage of calves weaned relative to the number of cows exposed for mating were not statistically significant. Progeny of Angus × Charolais and Red Poll dams were outstanding in weaning weight, but Hereford and Brahman-cross calves were below average. Planned comparisons showed that Angus × Charolais calves were heavier (P < .01) at weaning than Hereford (23.0 ± 3.8 kg) or Angus × Hereford (9.6 ± 3.2 kg) progeny. Mature Angus × Hereford mothers weaned heavier calves than did Brahman × Herefords (7.4 ± 3.2 kg, P < .05) or Brahman × Angus (10.9 ± 3.0 kg, P < .01). Analysis of the Hereford-Red Poll diallel showed evidence of maternal heterosis in calf weaning weight (4.0 ± 2.6 kg, P < .05), but there was no difference in the percentage of calves weaned by crossbred vs straightbred dams.(ABSTRACT TRUNCATED AT 250 WORDS)


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