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Crossbreeding in beef cattle for increased efficiency in reponse to environmental conditions


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Crossbreeding in beef cattle for increased efficiency in reponse to environmental conditions

  1. 1. Crossbreeding in beef cattle for increased efficiency in response to environmental conditions A. Theunissen, M.M. Scholtz, M.C. Mokolobate, O. Ntwaeagae & M. Ferreira SASAE Congress 29 October 2017
  2. 2. Introduction • In SA the importance of indigenous breeds that are adapted to the anticipated warmer climate, lower nutritional value of grazing and harsher conditions is on the increase • Most livestock production is restricted to extensive systems • On the other hand, more than 80% of beef slaughtered in the formal sector originate from commercial feedlots
  3. 3. Introduction cont. • Since most producers already face challenges of sustainability extension services will have to review and evaluate current beef production- and breeding strategies • British/European sire lines and indigenous dam lines may become more important to increase production to meet the requirements of the dual production environments • New consideration should be given to cow efficiency that now includes composite breeds and crossbreeding systems
  4. 4. Aims of the study • To validate existing models that better meet efficient production and feedlot requirements • To make recommendations with regards to future breeding and management of beef herds in arid areas • To evaluate the Nguni cattle breed’s weaning performance in a terminal crossbreeding system that conserves the indigenous resource
  5. 5. Materials and methods • The research was done over a four year period in the semi-arid area of the Northern Cape province • Commercial management practices were followed • There was a total of 238 weaning weights (167 Nguni and 81 Angus x Nguni) • Weaning weights were corrected for 205-day weight (WW) and cow weights (CW) were converted to Large Stock Units (LSU)
  6. 6. Materials and methods cont. • In SA, a LSU is defined as the equivalent of an ox with a weight of 450 kg and a weight gain of 500 g/d on grass with a mean digestible energy concentration of 55%. • To maintain this, 75 MJ metabolizable energy is required (Meizner et al., 1983) • In this study kg calf weaned per LSU was used to express cow efficiency
  7. 7. Materials and methods cont. • The specific equation for small framed cows to convert CW to LSU was: Y= 0.2871428571+0.0025542857x -0.0000005714x2 Where Y = LSU and x = CW (Neser 2012; Mokolobate, 2015) • WW and CW traits were analyzed using a generalized linear model procedure of SAS (v9.3: SAS Inc)
  8. 8. Results and discussion Genotype WW CW Kg calf / LSU Difference Nguni 145 365 116 Angus x Nguni 177 355 142 26 (22.4%) Note that the CW of sucking Angus x Nguni calves was 10 kg (2.7%) lighter than the CW of suckling pure Nguni calves, indicating that the crossbred calves may be putting an additional strain on the cow
  9. 9. Conclusions and recommendations • The results indicated that crossbreeding Angus x Nguni can improve beef production by up to 22% (26 kg calf/LSU) • It may be required to slightly decrease the stocking rate of cows • This breeding strategy reduced the environmental impact of beef production and may be advised to farmers in a semi-arid production environment
  10. 10. Thank you for your attention