References describing the theories on which the EFG models are based
Emmans, G.C.
A Model of the Growth and Feed Intake of Ad Libitum Fed Animals, Particularly Poultry.
In: Computers in Animal Production. Occasional Publication No 5. – British Society of Animal Production, edited by Hillyer, G.M., Whittemore, C.T. and Gunn, R.G.
Thames Ditton: BSAP, 1981, pp. 103-110
An early discussion of the problems of nutritional modelling and a description of the Edinburgh Growth Model – a forerunner to the EFG Model.
Emmans, G.C.
Computer simulation in poultry nutrition.
In: Proceedings 3rd European Symposium on Poultry Nutrition. pp. 91-103.
World’s Poultry Science Association, UK Branch, 1981, pp. 91-103
Discussion of ideas relating to the development of nutritional models.
Emmans, G.C. and Fisher, C.
Problems in nutritional theory.
In: Nutrient Requirements of Poultry and Nutritional Research, edited by Fisher, C. and Boorman, K.N.
London: Butterworths, 1986, pp. 9-39
A fairly complete statement of the ideas and equations underlying the EFG Broiler Growth Model.
Emmans, G.C.
Growth, body composition and feed intake.
World’s Poultry Science J. 43:208-227, 1987
Formal statements of relationships and equations.
Emmans, G.C.
The genetic variables and efficiency constants.
In: Proceedings International Poultry Breeders Conference.
Ayr, UK, 1987
A discussion of the genetic components of growth models.
Emmans, G.C.
Genetic components of potential and actual growth.
In: Animal Breeding Opportunities.
British Society of Animal Production Occasional Publication No. 12 (1988), pp. 153-181
Similar discussion to previous paper.
Emmans, G.C. and Oldham, J.D.
Modelling of growth and nutrition in different species.
In: Modelling of Livestock Production Systems, edited by Korver, S. and van Arendonk, J.A.M.
Amsterdam: Kluwer Academic Publishers, 1988, pp. 13-21
A wider ranging and more general discussion of modelling issues. Covers farm species in general.
Emmans, G.C.
The growth of turkeys.
In: Recent Advances in Turkey Science, edited by Nixey, C. and Grey, T.C.
London: Butterworths, 1989, pp. 135-166
Equations and parameters for modelling the growth of turkeys using a similar set of ideas to those used for broilers.
Gous, R.M., Emmans, G.C., Broadbent, L.A. and Fisher, C.
Modelling of growth and nutrition in different species.
In: (1990) Nutritional effects on the growth and fatness of broilers.
British Poultry Science 31:495-505
Description of an experiment which tests the underlying ideas concerning the theory of food intake.
Kyriazakis, I. and Emmans, G.C.
The effects of varying protein and energy intakes on the growth and body composition of pigs. 1. The effects of energy intake at constant, high protein intake.
British J. of Nutrition 68:603-613, 199
Description of a pig experiment which explores the effect of diet composition on protein utilisation.
Kyriazakis, I. and Emmans, G.C.
The effects of varying protein and energy intakes on the growth and body composition of pigs. 2. The effects of varying both energy and protein intake.
British J. of Nutrition 68:615-625, 1992
As above.
Emmans, G.C.
Effective energy: a concept of energy utilisation applied across species.
British J. of Nutrition 71:801-821, 1994
A formal description of the energy system used in the EFG Broiler Growth Model.
Kyriazakis, I., Dotas, D., and Emmans, G.C.
The effect of breed on the relationship between feed composition and the efficiency of protein utilization in pigs.
British J. of Nutrition 71:849-859, 1994
Further pig experiments concerned with the effect of diet composition on protein utilisation. Effect of breed.
Emmans, G.C.
Problems in modelling the growth of poultry.
World’s Poultry Science Journal 51:77-89, 1995
An update on the underlying ideas and equations used in the EFG Broiler Growth Model.
Hancock, C.E., Bradford, G.D., Emmans, G.C. and Gous, R.M.
The evaluation of the growth parameters of six strains of commercial broiler chickens.
British Poultry Science 36:247-264, 1995
Description of an experiment concerned with the genetic parameters of growth.
Kyriazakis, I. and Emmans, G.C.
The voluntary feed intake of pigs given feeds based on wheat bran, dried citrus pulp and grass meal, in relation to measurements of feed bulk.
British J of Nutrition 73:191-207, 1995
An attempt to tackle the difficult question of diet bulk.
Kyriazakis, I., Emmans, G.C. and Anderson, D.H.
Do breeds of pig differ in the efficiency with which they use a limiting protein supply?
British J. of Nutrition 74:183-195, 1995
A discussion of the utilisation of protein and genetic variation in protein utilisation. Description of an experiment using two very different breeds of pig.
Emmans, G.C.
A method to predict the food intake of domestic animals from birth to maturity as a function of time.
Journal of Theoretical Biology, 186:189-199, 1997
A general model of food or energy intake under non-limiting conditions.
Gous, R.M., Moran, E.T Jr., Stilborn, H.R., Bradford, G.D. and Emmans, G.C.
Evaluation of the Parameters Needed to Describe the Overall Growth, the Chemical Growth, and the Growth of Feathers and Breast Muscles of Broilers.
Poultry Science 78: 812-821, 1999
Description of an experiment concerned with the genetic parameters of growth.
Ferguson, N.S., Arnold, G.A., Lavers, G. and Gous, R.M. (2000)
The response of growing pigs to amino acids as influenced by environmental temperature. 1. Threonine.
Animal Science 70: 287-297
An experiment to corroborate the theory of food intake regulation incorporated into the EFG pig growth model.
Ferguson, N.S., Arnold, G.A., Lavers, G. and Gous, R.M. (2000)
The response of growing pigs to amino acids as influenced by environmental temperature. 2. Lysine.
Animal Science 70: 299-306
As above.
Ferguson, N.S. and Gous, R.M. (2002)
The response of growing pigs to amino acids as influenced by environmental temperature: tryptophan.
Animal Science 74: 103-110
As above.
Johnston, S.A. and Gous, R.M. (2003)
An improved mathematical model of the ovulatory cycle of the laying hen.
British Poultry Science 44: 752-760
First paper in a series to model the potential laying performance of hens, with a view to predicting food intake.
Gous, R.M. and Morris, T.R. (2005)
Nutritional interventions in alleviating the effects of high temperatures in broiler production.
World’s Poultry Science Journal 61: 463-466
Making use of the broiler growth model to demonstrate that there is little benefit in improving the amino acid balance at high temperatures.
Gous, R.M. and Berhe, E.T. (2006)
Modelling populations for purposes of optimisation.
In: Mechanistic Modelling in Pig and Poultry Production, R.M. Gous, T.R. Morris and C. Fisher (Ed’s), pp 76-96
CAB International, Wallingford, U.K.
A discourse on the need for stochasticity when modelling broiler production.
Johnston, S.A. and Gous, R.M. (2006)
Modelling egg production in laying hens.
In: Mechanistic Modelling in Pig and Poultry Production, R.M. Gous, T.R. Morris and C. Fisher (Ed’s), pp 188-208
CAB International, Wallingford, U.K.
Description of a mechanistic model of egg production in a laying flock.
Blanco, O.A. and Gous, R.M. (2006)
Considerations for representing the micro-environmental conditions in simulation models for non-sweating livestock.
In: Mechanistic Modelling in Pig and Poultry Production, R.M. Gous, T.R. Morris and C. Fisher (Ed’s), pp 76-96
CAB International, Wallingford, U.K.
Description of the difficulties involved in determining the effective temperature of broilers.
Nonis, M.K. and Gous, R.M. (2006)
Utilisation of synthetic amino acids by broiler breeder hens.
South African Journal of Animal Science 36: 126-134
First paper in a series that addresses the issue of modelling the effect of nutrition on broiler breeder performance.
Gous, R.M. (2007)
Predicting nutrient responses in poultry: future challenges.
Animal 1: 57-65
Some nutritional issues that need to be addressed in the future.
Johnston, S.A. and Gous, R.M. (2007)
A mechanistic, stochastic, population model of egg production.
British Poultry Science 48: 224-232
Part of a series of papers describing a model that predicts flock laying performance.
Johnston, S.A. and Gous, R.M. (2007)
Modelling the changes in the proportions of the egg components during a laying cycle.
British Poultry Science 48: 347-353
As above.
Johnston, S.A. and Gous, R.M. (2007)
Extent of variation within a laying flock: attainment of sexual maturity, double-yolked and soft-shelled eggs, sequence lengths and consistency of lay.
British Poultry Science 48: 609-616
As above.
Lewis, P.D., Gous, R.M. and Morris, T.R. (2007)
A model to predict sexual maturity in broiler breeders given a single increment in photoperiod.
British Poultry Science 48: 625-634
As above, for broiler breeders.
Nonis, M.A. and Gous, R.M. (2008)
Threonine and lysine requirements for maintenance in chickens.
South African Journal of Animal Science 38:75-82
Addresses the issue of modelling the effect of nutrition on broiler breeder performance.
Gous, R.M. and Nonis, M.K. (2010)
Modelling egg production and nutrient responses in broiler breeder hens.
Journal of Agricultural Science 148: 287-301
The basis on which the broiler breeder simulation model is being developed by EFG Software.
Danisman, R. and Gous, R.M. (2011)
Effect of dietary protein on the allometric relationships between some carcass portions and body protein in three broiler strains.
South African Journal of Animal Science 41: 194-208
Evidence that the allometric relationships between body protein and the different physical components is the same for all genotypes.
Gous, R.M., Emmans, G.C. and Fisher, C. (2012)
The performance of broilers on a feed depends on the feed protein content given previously.
South African Journal of Animal Science 42: 63-73
An important issue when optimising the feeding of broilers. Performance overall is the key; not that within each phase.
Nonis, M.K. and Gous, R.M. (2012)
Broiler breeders utilise body lipid as an energy source.
South African Journal of Animal Science 42: 369-378
Evidence that the lipid content of broiler breeders is labile and can support energy requirements when energy intake is below that required by the bird.
Danisman, R. and Gous, R.M. (2013)
Effect of dietary protein on performance of four broiler strains and on the allometric relationships between carcass portions and body protein.
South African Journal of Animal Science 43: 25-37
Further evidence that the allometric relationships between body protein and the different physical components is the same for all genotypes.
Nonis, M.K. and Gous, R.M. (2013)
Modelling changes in the components of eggs from broiler breeders over time.
British Poultry Science 54: 603-610
Useful information for the broiler breeder simulation model.
Mlaba, P.P, Ciacciariello, M. and Gous, R.M. (2015)
The effect of dietary protein on breast meat yield of broilers reared on different daylengths.
South African Journal of Animal Science 45: 39-48
Evidence that the reduced breast meat yield under 12-h light cannot be overcome by feeding higher dietary protein levels.
Nonis, M. and Gous, R.M. (2015)
Changes in the feather-free body of broiler breeder hens after sexual maturity.
Animal Production Science 56: 1099-1104
Important information when determining the maintenance requirements of broiler breeders
Gous, R.M. (2017)
Predicting food intake in laying hens and its implications for improving economic efficiency.
Proceedings of the 28th Annual Australian Poultry Science Symposium, Sydney, New South Wales, pp 84-92
A summary of the issues to be considered when predicting feed intake in laying hens.
Gous, R.M. and Fisher, C. (2017)
Using models to optimise poultry nutrition.
Applegate, T. (ed.), Achieving sustainable production of poultry meat Volume 2: Breeding and nutrition, Burleigh Dodds Science Publishing , Cambridge, UK (ISBN: 978 1 78676 068 5; www.bdspublishing.com)
Putting the value of simulation models into perspective.
Nonis, M. and Gous, R.M. (2018)
Energy partitioning at low temperatures in broiler breeders.
Animal Production Science 59: 435-440
Important information regarding the energy cost of thermogenesis.
Gous, R.M., Faulkner, A.S. and Swatson, H.K. (2018)
The effect of dietary energy:protein ratio, protein quality and food allocation on the efficiency of utilization of protein by broiler chickens.
British Poultry Science 59: 100-109
Describing an important issue regarding the effect of insufficient dietary energy in altering the efficiency of utilisation of dietary protein.
Gous, R. M., Fisher, C., Tůmová, E., Machander, V., Chodová, D., Vlčková, J., Uhlířová, I. and Ketta, M. (2019)
The growth of turkeys. 1. Growth of the body and feathers and the chemical composition of growth.
British Poultry Science 60: 539-547
Critical information when modelling the feed intake of turkeys – how fast can they grow?
Gous, R. M., Fisher, C., Tůmová, E., Machander, V., Chodová, D., Vlčková, J., Uhlířová, I. and Ketta, M. (2019)
The growth of turkeys. 2. Body components and allometric relationships.
British Poultry Science 60: 548-553
More critical information on turkeys – how does their composition change as they grow?
Vargas, L., Sakomura, N.K., Leme, B.B., Antayhua, F.A.P., Reis, M.P. and Gous, R.M. (2020)
A description of the potential growth and body composition of two commercial broiler strains.
British Poultry Science 61: 266-273
An update on the potential growth rate of the Cobb and Ross broiler strains used in Brazil.
Nascimento, M.Q.D., Gous, R.M., Reis, M.D.P., Fernandes, J.B.K and Sakomura, N.K. (2020)
Prediction of maximum scaled feed intake in broiler chickens based on physical properties of bulky feeds.
British Poultry Science 61: 676-683
Critical information required when determining the maximum bulk capacity of broilers.
Vargas, L., Sakomura, N.K., Leme, B.B., Antayhua, F.A.P., Campos, D., Gous, R.M. and Fisher, C. (2020)
A description of the growth and moulting of feathers in commercial broilers.
British Poultry Science 61: 454-464
Comprehensive description of the rates and phases of growth of feathers in broilers.
Nascimento, M.Q., Gous, R.M., Reis, M.P., Viana, G.S., Nogueira, B.R.F. and Sakomura, N.K. (2021)
Gut capacity of broiler breeder hens.
British Poultry Science 62: 710-716
Further information about bulk capacity, this time with broiler breeders.
Azevedo, J.M., Reis, M.P., Gous, R.M., Dorigam, J.C.P. Leme, B.B. and Sakomura, N.K. (2021)
Response of broilers to dietary balanced protein. 1. Feed intake and growth.
Animal Production Science 61(14) 1425-1434
A practical demonstration of the changes that take place in feed intake, growth and composition when broilers are fed a range of dietary protein levels.
Azevedo, J.M., Reis, M.P., Gous, R.M., Dorigam, J.C.P., Lizana, R.R. and Sakomura, N.K. (2021)
Response of broilers to dietary balanced protein. 2. Determining the optimum economic level of protein.
Animal Production Science 61: 1435-1441
An economic analysis of the effect of feeding different levels of dietary protein to broilers. The results conform with our simulation model.
Salisbury, F., Cowieson, A.J. and Gous, R.M. (2021)
Constraints on the modelling of calcium and phosphorus growth of broilers: a systematic review.
World’s Poultry Science Journal 77, 4, 775-795
A review of what is known and not known regarding the modelling of mineral nutrition in broilers.
Reis, M.P., Sakomura, N.K., Azevedo, J.M., Viana, G.S., Dorigam, J.C.P., Fernandes, J.B.K. and Gous, R.M. (2022)
Predicting the extent to which excess lipid is deposited in the physical components of a broiler when dietary protein content is reduced.
Animal Production Science 63(3) 249-255
How fat do the different physical parts of the broiler become when low protein feeds are offered? This influences their allometric relationships with body protein.
Gous, R. M., Fisher, C., Tůmová, E., Machander, V., Chodová (2023)
Dietary energy:protein ratio influences the efficiency of utilisation of dietary protein by growing turkeys.
British Poultry Science 64: 116-121
Evidence with growing turkeys that the efficiency of protein utilisation will suffer if insufficient dietary energy is provided.