Reproductive performance and variation in body weight during annual cycles for crossbred beef cows with different genetic potential for milk.

1990 ◽  
Vol 68 (8) ◽  
pp. 2289 ◽  
Author(s):  
M Montaño-Bermudez ◽  
M K Nielsen
2008 ◽  
Vol 51 (4) ◽  
pp. 318-328 ◽  
Author(s):  
R. Pilarczyk ◽  
J. Wójcik

Abstract. The aim of the study was to compare the body weight and the parameters of reproductive performance in beef cows of various breeds following their import to Poland from 1995–1997. The analyses included cows of five beef breeds: Red Angus, Salers, Hereford, Limousin and Simmental. We have compared the body weights and calving intervals during the period from their arrival to Poland in 1995 until 2002, with subsequent calvings included in the analyses. Other aspects included calving difficulty, abortions, stillbirths and twin births. The analysis of the cows’ reproductive performance has revealed that the studied breeds differ in the calving interval. Best results were achieved by Simmental and Limousine cows, while Red Angus cows exhibited the poorest performance. The effect of subsequent calving on the calving interval was also confirmed. We have observed no differences among the mature cows with respect to the body weight and calving ease.


1988 ◽  
Vol 68 (4) ◽  
pp. 1035-1040 ◽  
Author(s):  
M. MAKARECHIAN ◽  
H.-M. KUBISCH ◽  
M. A. PRICE

1233 April/May born calves were weaned either on 30 Sept. (EW) or 31 Oct. (LW) to assess the effects of weaning date on subsequent performance of their dams and female calves. Cows in the EW group lost less weight than those in the LW group in the month of October (0.003 vs. 0.48 kg d−1, P < 0.05). Dam's breed group, year and the interaction between year and age of dam also had significant effects on weight change during October. Cows generally lost weight between weaning and the next calving and the two weaning groups were similar in body weight at calving and reproductive performance. The reproductive performance of the EW and LW female calves were also quite similar. It can be concluded that weaning April/May born calves in September rather than October would not influence the subsequent production of the dams or their female calves, but would probably reduce their maintenance requirements as they enter the cold season in better condition. Key words: Weaning date, beef cows, reproduction, weight changes


2020 ◽  
Vol 41 (6supl2) ◽  
pp. 3299-3310
Author(s):  
Carina Crizel da Vara ◽  
◽  
Magali Floriano da Silveira ◽  
Ricardo Zambarda Vaz ◽  
João Restle ◽  
...  

Cattle farming becomes more intensive when the productive efficiency of the cows is increased, and nutrition is adjusted to the animal biotype. Eighty purebred Charolais and Nellore cows and their crosses between 3 and 7 years of age, were grouped for body weight at calving into Light (332.6 kg), Moderate (385.3 kg) and Heavy (444.6 kg). Cows and their calves were weighed at calving, at 63 days (early weaning) and at 210 days. The estimated milk production of the cows was evaluated by manual milking at 21, 42 and 63 days postpartum. The difference in the weight of the cows at calving was maintained during lactation and at 210 days postpartum. The body size of the cow did not influence milk production. Heavier cows produce heavier calves up to 365 days of age compared to lighter cows. The reproductive performance of the cows is not affected by their weight. The production of kilograms of calf for every 100 kilograms of cow at calving and weaning is higher in Light cows. The production of kilograms of calf adjusted for the pregnancy rate of the cows is higher in Heavy cows. Production efficiency in kilograms of calf per area is lower in Heavy cows.


2009 ◽  
Vol 196 (3) ◽  
pp. 417-430 ◽  
Author(s):  
Kimitake Funakoshi ◽  
Teru Aki Uchida
Keyword(s):  

1994 ◽  
Vol 72 (5) ◽  
pp. 1119-1125 ◽  
Author(s):  
S. M. DeRouen ◽  
D. E. Franke ◽  
D. G. Morrison ◽  
W. E. Wyatt ◽  
D. F. Coombs ◽  
...  

1988 ◽  
Vol 68 (1) ◽  
pp. 69-81 ◽  
Author(s):  
MOHAMED H. FAHMY ◽  
JACQUES J. DUFOUR

Reproductive performance and body weight were studied on 361 ewes, representing Finnsheep (F), DLS (a population of 1/2 Dorset, 1/4 Leicester, 1/4 Suffolk) and seven combinations ranging from 1/8 to 7/8 Finnsheep breeding. Conception rate in yearlings was 61.5% for DLS compared to 89.0% for F with the crosses being intermediate. Conception rate in older ewes was similar in the different genetic groups (avg. 94%). Ovulation rate and litter size at birth of DLS ewes were 1.72 and 1.44 lambs, which was less than half those of F ewes (3.51 and 2.86 lambs, respectively). Both traits increased progressively with an increase in F breeding in crosses and with advances in age. DLS ewes weaned 1.22 lambs compared to 2.03 lambs for F ewes and 1.84 lambs for 4/8 F ewes. The heaviest litters at weaning (31.7 kg) were raised by 4/8 F ewes, followed by 7/8 F (30.8 kg) while those raised by DLS ewes weighed 23.0 kg and F ewes 29.1 kg. Percentage of ova lost per ewe mated averaged 24% and ranged between 18% (DLS and 1/8 F) and 29% (6/8 F). About 3.6% of lambs were born dead and a further 13.8% died before weaning. Preweaning mortality rate was highest in F (22.9%) and lowest in 3/8 F (9.4%). Average kilograms of lambs weaned per ewe exposed was highest in 4/8 F (27.6 kg) followed by F (26.0 kg), whereas that of DLS was the lowest at 18.1 kg. The 4/8 F cross showed 25% heterosis in kg of lambs weaned per ewe exposed and 52.5% increase over DLS. Significant positive linear regressions were calculated for ovulation rate, litter size and preweaning mortality rate on proportion of Finnsheep breeding in crosses. The relation was quadratic for percent ova lost and lamb mortality at weaning. Yearling DLS females weighted 36 kg compared to 44 kg for F yearlings. However, at 5 yr of age DLS ewes weighed 62 kg, 5 kg heavier than F ewes. The heaviest ewes at all ages were the 4/8 F (45 kg at 1 yr, 65 kg at 5 yr). Key words: Reproduction, DLS sheep, Finnsheep, crossbreeding, heterosis, repeatabilities


2019 ◽  
Vol 196 ◽  
pp. 182-192 ◽  
Author(s):  
V. P. Pogodin ◽  
S. I. Borzov ◽  
M. S. Myakishev ◽  
I. A. Varaksin ◽  
O. V. Zelennikov

Results of cherry salmon juveniles rearing at Reidovo fish farm on Iturup Island during two annual cycles of cultivation are analyzed. Different variants of the breeders selection, feeding, preventive treatment, and release were tested. The breeders were caught in the river mouth and near the fish farm. Mass mortality of young fish in the first and second years was avoided by decreasing of their density and other preventive measures. Minced fish was used as a food for them that is less expensive in compare with a combined fodder. The best diet for the second year of rearing was the minced pink salmon with the daily ration of 2 % of the juveniles body weight; it provided a significant decrease of mortality and enhanced their growth. After 2-year rearing, percentage of females, anadromous males, and dwarf males was 42.1, 36.3, and 21.6 %, respectively. Their weights were similar, though a group of fast-growing males was found among the dwarfs. The mass of ovaries varied from 13 to 46 mg in close dependence on females’ body weight (r = 0.81). Before the release, the ovaries of all females contained oocytes of similar size (varied in 2–4 times) at the final stage of previtellogenesis. Number of the oocytes per transverse section varied from 4.7 to 32.3, on average for 5 cuts and their diameter varied from 164.3 to 279.2 mm and did not correlate with the females body weight. The mass of dwarf males’ testes varied from 14 to 488 mg in dependence on their body weight (r = 0.78). The elder oocytes of females would mature in a year, and majority of dwarf males would reach the maturity in autumn of the current year.


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