Agriculture Reference
In-Depth Information
output and the cost of feeding; or, in the
case of broiler breeders, because of the high
value of the hatched chick, maximizing the
number of eggs per hen.
marginal revenue for eggs change, it is not
possible to convert these into concentra-
tions in the feed. The models described here
now offer the possibility of being able to de-
scribe the potential reproductive perform-
ance characteristics of laying and broiler
breeder hens, from which it would be pos-
sible to predict food intake, and as a result
the optimization of feeds for laying hens
and broiler breeders is now possible. Pre-
dicting food intake is only possible once the
potential laying performance of each hen
can be predicted, which is in itself depend-
ent on a large number of interacting sys-
tems, all of which can now be simulated,
although not perfectly.
Conclusions
The major limitation in determining the op-
timum economic amino acid and energy
supply for a flock of laying hens and broiler
breeders has been the inability to predict
how much of a given food the flock would
consume. Thus, even though it is possible
to determine the optimum intakes of these
nutrients as their marginal costs and the
References
Attia, Y.A., Burke, W.H., Yamani, K.A. and Jensen, L.S. (1995) Energy allotments and reproductive of
broiler breeders.
2.
Females
.
Poultry Science
74,
261-270.
Bastian, J.W. and Zarrow, M.X. (1955) A new hypothesis for the asynchronous ovulatory cycle of the
domestic hen (
Gallus domesticus
).
Poultry Science
34,
776-788.
Belyavin, C.G., Boorman, K.N. and Volynchook, J. (1987) Egg quality in individual birds. In: Wells, R.G.
and Belyavin, C.G. (eds)
Egg Quality - Current Problems and Recent Advances
. Butterworths,
London, pp.
105-120.
Bennett, C.D. and Leeson, S. (1990) Body composition of the broiler-breeder pullet.
Poultry Science
69,
715-720.
Blair, R., McCowan, M.M. and Bolton, W. (1976) Effect of food regulation during the growing and
laying stage on the productivity of broiler breeders.
British Poultry Science
17,
215-223.
Bowmaker, J.A. and Gous, R.M. (1989) A quantification of reproductive changes and nutrient require-
ments of broiler breeder pullets at sexual maturity.
British Poultry Science
30,
663-675.
Burnham, D., Emmans, G.C. and Gous, R.M. (1992) Isoleucine responses in broiler chickens. Inter-
actions with leucine and valine.
British Poultry Science
33,
71-87.
Coop, R.L. and Kyriazakis, I. (1999) Nutrition-parasite interaction.
Veterinary Parasitology
84,
187-204.
Deming, W.E. (1986)
Out of the Crisis
. MIT Press, Cambridge, Massachusetts, USA.
EFG Software (1995) EFG Software. Available at:
www.efgsoftware.net
(accessed
1
April 2013).
Emmans, G.C. (1981) A model of the growth and feed intake of ad libitum fed animals, particularly
poultry. In: Hillyer, G.M., Whittemore, C.T. and Gunn, R.G. (eds)
Computers in Animal Pro-
duction.
Occasional Publication No.
5.
British Society of Animal Production, Edinburgh, UK,
pp.
103-110.
Emmans, G.C. (1989) The growth of turkeys. In: Nixey, C. and Grey, T.C. (eds)
Recent Advances in
Turkey Science
. Butterworths, London, pp.
135-166.
Emmans, G.C. and Fisher, C. (1986) Problems in nutritional theory. In: Fisher, C. and Boorman, K.N.
(eds)
Nutrient Requirements of Poultry and Nutritional Research
. Butterworths, London, pp.
9-40.
Etches, R.J. (1996)
Reproduction in Poultry
. CAB International, Wallingford, UK.
Etches, R.J. and Schoch, J.P. (1984) A mathematical representation of the ovulatory cycle of the domestic
hen.
British Poultry Science
25,
65-76.
Ferguson, N.S. and Gous, R.M. (1997) The influence of heat production on voluntary food intake in
growing pigs given protein-deficient diets.
Animal Science
64,
365-378.
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.
