Trends of the genetic connectedness measures among Nelore beef cattle herds

The purpose of this paper is to discuss how producers can evaluate and manage bull fertility within beef cattle herds. This document is AN153, one of a series of the Animal Science Department, UF/IFAS Extension. Original publication date February 2006.

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Crossbreeding Systems in Beef Cattle

EDIS ◽

10.32473/edis-an165-2006 ◽

2006 ◽

Vol 2006 (17) ◽

Author(s):

Gary R. Hansen

Keyword(s):

Beef Cattle ◽

Breeding Strategy ◽

Animal Science ◽

Fact Sheet ◽

Cattle Herds

AN165, a 5-page fact sheet by Gary R. Hansen, explains to beef cattle producers this breeding strategy that leads to increased performance and productivity in beef cattle herds. Published by the UF Department of Animal Science, September 2006.

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Environmental constraints in habitat use by free-ranging beef-cattle in the Natural Park of Gorbeia (Basque Country)

Proceedings of the British Society of Animal Science ◽

10.1017/s1752756200012928 ◽

2003 ◽

Vol 2003 ◽

pp. 133-133

Author(s):

N. Mandaluniz ◽

L. M. Oregui

Keyword(s):

Beef Cattle ◽

Habitat Management ◽

Abiotic Factors ◽

Basque Country ◽

Physical Factors ◽

Mountain Areas ◽

Free Range ◽

Natural Park ◽

Cattle Herds ◽

Free Ranging

Mountain pastures utilisation in the Basque Country by means of a free-range mixed-grazing system has suffered substantial changes during the last decades. Beef cattle production has increased partially favoured by CAP (Common Agricultural Policy) measures, mainly milk-quotas and the extensification premium. The use of mountain areas is constrained by both biotic and abiotic factors in cattle (Senft et al, 1985; Bailey, 1995) which are necessary to be identified in order to improve habitat management of these mountain zones, usually declared as protected areas. The objective of the current work was to study the influence of physical factors on the behaviour of beef-cattle herds managed in a transhumant free-range system.

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Reproductive Systems for North American Beef Cattle Herds

Veterinary Clinics of North America Food Animal Practice ◽

10.1016/j.cvfa.2016.01.001 ◽

2016 ◽

Vol 32 (2) ◽

pp. 249-266 ◽

Cited By ~ 4

Author(s):

Robert L. Larson ◽

Brad J. White

Keyword(s):

Beef Cattle ◽

North American ◽

Reproductive Systems ◽

Cattle Herds

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Estimation of environmental effects on post-weaning gain and yearling weight of beef cattle

Australian Journal of Experimental Agriculture ◽

10.1071/ea9770885 ◽

1977 ◽

Vol 17 (89) ◽

pp. 885 ◽

Cited By ~ 1

Author(s):

WM Straw ◽

LP Jones

Keyword(s):

Beef Cattle ◽

Environmental Effects ◽

Season Of Birth ◽

Weaning Weight ◽

Cattle Herds ◽

Effect Of Age

Records of post-weaning growth for 1134 heifers and 375 bulls from 11 Victorian beef cattle herds were analysed for the effects of sex, age of dam, age of calf, season of birth and herd/year on postweaning gain (PWG) and yearling weight (YLG WT). Age of dam had a significant effect on PWG and YLG WT for each sex, but the effect on heifer PWG was small. Suitable corrections for the effect of age of dam on heifer YLG WT were made using weaning weight adjusted for age of dam effects plus gain from weaning to yearling. Post-weaning management of young bulls and heifers was very different. Averaged over all herd/years, bulls were 37.5 per cent heavier than heifers at yearling age and grew 57.5 per cent faster between the two post-weaning dates, The environmental effects on PWG and YLG WT were therefore different for each sex. The effects of calf age and season were significant for each dependent variable except YLG WT for bulls and PWG for bulls respectively. The interaction between calf age and season was significant for heifers only.

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Survey of beef bulls in Brazil to assess their role as source of infectious agents related to cow infertility

Journal of Veterinary Diagnostic Investigation ◽

10.1177/10406387211050636 ◽

2021 ◽

pp. 104063872110506

Author(s):

Silvia D. Carli ◽

Maria E. Dias ◽

Maria E. R. J. da Silva ◽

Gabriela M. Breyer ◽

Franciele M. Siqueira

Keyword(s):

Beef Cattle ◽

Infectious Agent ◽

Etiologic Agent ◽

Single Infection ◽

Infectious Agents ◽

Etiologic Agents ◽

Fetus Subsp ◽

Cattle Herds ◽

Cattle Farms ◽

Calving Intervals

Poor reproductive performance in beef cattle caused by infectious agents results in major financial losses as a result of reduced pregnancy rates and extended calving intervals. Bulls can be subclinical chronic carriers of bacterial and protozoal agents involved in cow infertility, such as Campylobacter fetus subsp. venerealis, Ureaplasma diversum, Mycoplasma bovigenitalium, Mycoplasma bovis, and Tritrichomonas foetus. Bulls harbor these microorganisms in their preputial crypts and transmit the agents to cows during natural mating. To obtain an overview of the etiologic agents in the preputial mucus of bulls, we aimed to identify, by PCR assay, C. fetus subsp. venerealis, M. bovis, U. diversum, M. bovigenitalium, and T. foetus in Brazilian bulls from farms with high infertility rates. We collected preputial mucus from 210 bulls on 18 beef cattle farms in Brazil between 2019 and 2020. We found at least one of the infectious agents that we were studying in bulls on 16 of the 18 beef cattle farms tested. We detected at least one infectious agent from 159 of 210 (76%) bulls tested, namely C. fetus subsp. venerealis, M. bovis, U. diversum, M. bovigenitalium, and T. foetus in 87 (55%), 84 (53%), 45 (28%), 28 (18%), and 1 (0.6%) animal, respectively. We found 95 bulls (60%) positive for only 1 etiologic agent (single infection) and 64 bulls (40%) carried multiple agents. Our results demonstrate the occurrence of bacterial and protozoal infectious agents that may be related to infertility in Brazilian beef cattle herds.

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