Patterns of Growth and Development in Cattle

This publication contains the proceedings of a seminar held in Ghent, Belgium on October 11th-13th 1977, under the auspices of the Commission of the European Communities, as part of the EEC programme of co-ordination of research on beef production. The seminar was initiated by the scientific working group on 'Carcass and Meat Quality' and attracted the interest of the working groups on 'Genetics and Selection' and on 'Nutrition and Management'. Consequently it developed into a multi-disciplinary programme, organised under the responsibility of the working group on Carcass and Meat Quality. This group comprised Ir. H. de Boer (Chairman), Netherlands; Prof. R. Boccard, France; Dr D.E. Hood, Ireland; Dr R.W. Pomeroy, UK; Dr A. Romita, Italy; Professor Dr L. Sch~n, Fed. Rep. of Germany; Mr P. L'Hermite, CEC; and Dr J.C. Tayler, UK (adviser to the CEC). In view of the broad scope of the subject, a special plan­ ning meeting was organised, involvi.ng experts from the different disciplines involved. The additional participants were: Dr B. Bech Andersen, Denmarkj Dr A.J.H. van Es, Netherlands; Prof. Dr J. Martin, Belgium; Dr. St.C.S. Taylor, UK. The multidisciplinary scope of this ~eminar follows a series of seminars in 1975-76 on more specific aspects of beef production research in the individual fields involved. It seems logical that further seminars should integrate the approaches by different disciplin~s in order to achieve a balanced programme of research on the very complex topic of beef production.

Section 1 : Patterns of Growth and Development of Bone, Muscle and Fatty Tissue.- Historical and general review of growth and development.- Bovine compositional interrelationships.- Dressing percentage in relation to weight, sex and breed.- Development with age of the anatomical composition of the carcass of bulls.- Biochemistry of muscle in relation to growth.- Development of connective tissue and its characteristics.- Sources of variation in muscle weight distribution.- Variation and impact of muscle thickness.- Bone growth and development with particular reference to breed differences in carcass shape and lean to bone ratio.- A note on conformation and meat characteristics in beef carcasses.- Meat amino acid composition of calves and steers slaughtered between 200 kg and 500 kg live weight.- Myorheological, chemical and colour characteristics of meat in water buffalo and bovine calves slaughtered at 20, 28 and 36 weeks.- Assessment of changes in myofibre size in muscle.- Partition and distribution of fatty tissues.- Factors affecting the fatty acid composition of depot fats of cattle and other ruminants.- The development of adipose tissue in cattle.- The development of fat cells in different anatomical positions in carcasses of young bulls, heifers and cow-heifers.- Fatty acid composition of fat in water buffalo calves and bovine calves slaughtered at 20–28 and 36 weeks of age.- Effect of Finnish landrace and Galway breeds on carcass composition, fat distribution and fatty acid composition of different fat depots in lambs.- Discussion.- Section 2: Growth and Nutritional Efficiency and the Effects of Genotype, Sex, Hormones and their Interactions.- Biological models of quantifying growth and efficiency.- Some neuroendocrine aspects of growth.- Anabolic agents in beef production: their action as growth promoters.- Nutritional efficiency of protein and fat deposition.- Feed efficiency and genotype-nutrition interactions in growing animals, particularly in cattle for beef production.- Effect of energy level on growth and efficiency.- Influence of nutrition on the growth pattern of fattening bulls of two different breeds (Friesian and Simmental).- Influence of nutrition on body composition and carcass quality of fattening bulls of different breeds (German Friesian and Simmental).- Nitrogen utilisation of young fattening bulls kept on two different energy levels.- Genetic variations in growth and body composition of male cattle.- Effect of breed and interaction with nutrition.- Effect of siregroup within breeds on growth and efficiency and interaction with nutrition.- Efficiency of lean meat production by dairy steers.- Multibreed comparisons of body weight and food intake in cattle.- Influence of age, nutrient intake and body type on weight gain and body composition in young fattening bulls of the breeds German Schwarzbunte and German Fleckvieh.- Carcass composition of different breeds.- Growth rates and carcass composition of water buffalo calves and bovine calves slaughtered at 20, 28 and 36 weeks.- Discussion.- Section 3: Possibilities for the Improvement of Beef Production in Relation to the Customer’s Requirements.- Possibilities for fulfilling trade and consumer requirements for meat quality in present and future beef production systems.- Targets for beef production in relation to market and consumer requirements.- Eating quality of buffalo and bovine calves slaughtered at 20-28 and 36 weeks of age.- Discussion.- Section 4: Methods of Quantifying Growth and Development.- Methods of quantifying growth and development: general review.- A survey of allometric analysis.- Growth curves: their nature, uses and estimation.- Nutritional models of growth.- Quantifying breed difference in shape.- An approach to the comparison of growth curves of Dutch Friesian, British Friesian and Holstein Friesian cows.- The relationship between growth curve parameters and carcass composition.- Discussion.- Section 5: Summary and Needs for Future Research.- Recapitulation and Outline for the Future.- General discussion.- Final considerations.- Closing remarks.- List of participants.