Beef Cattle Life History

Introduction

Life history refers to the full cycle of an animal’s reproductive and productive herd life. There are many more breeding females and young animals destined for beef production than breeding males. Efficient beef production depends upon three component elements, female reproduction, viability and growth of the young and culled female production. In the production system, the breeding male may be regarded as an overhead.

The reproductive life of an animal is determined by age at puberty (or sexual maturity) and stayability. Age at puberty is the time at which the animal acquires the ability to reproduce offspring and stayability refers to the ability of a breeding animal to remain in the breeding herd. The definition of puberty by precise events in both the male and the female (see Annex) allows for the calculation of age at puberty. In cattle this is between 9 and 15 months of age. But age at puberty is of little practical relevance due to the difficulty to accurately determine the date of these events.

The productive life refers to the period of growth of the young and to the period of fattening of slaughter animals and culled cows. Reproductive and productive lifetimes are influenced by a wide range of genetic, environmental, nutritional and management factors.

Synopsis of life history recording events

Table 3.1. Recording requirements
State	Recording requirements 1)
Calf	Conception	Outcome of a breeding, success or failure
		Date of the relevant breeding
	Birth	Date, identification, sex, weight 2)
	Pre-weaning period	Date of weight, measurements 3)
	Weaning	Date, weight, measurements
	Post Weaning period	Date of weight, measurements
	Death/Disposal	Date, reason
Breeding female	Puberty	Date
	First and Subsequent Breeding (s)	Type (AI, natural service, multiple sires)
		Rank of AI
		Sire identification
		Date (AI, mating, mating period)
		Measurements, Weight 1)
	Calving	Date, parity
		Calving ease, Measurements 2), Weight
	Death/Disposal	Date, Reason
Breeding male	Puberty	Date
	Mating/Semen collection	Date, Measurements, Weight,
		Semen characteristics
	Death/Disposal	Date, Reason
Slaughter animal	Finishing	Date (Start/Finish)
		Measurements, Weights
	Slaughter	Date, Carcass, Measurements, Weight; Meat quality measurements

1) The location where each of these events occurs should always be recorded according to the rules given in the section relating to physical location of the animal. Herd identification and slaughter identification are at stake.

2) Weight means live weight or carcass weight.

3) Measurement refers to any body measurement on the live animal or carcass measurement.