600 Answer questions through 8 about the following graph
Optimum daily weight
and age for heiters
Live Weight
Holstein Fresian
Figure - Optimum live
weight-age relationship
for heifers to calve at 2
Erve
years.
500
400
Jersey
Live Weight (kg)
300
Optimum Average Daily
Growth
200
Holstein Friesian=o. legday
100
Calving
21
Jersey = 0.5kg/day
0
18
Mating
15
Age (months)
Farmers who work with heifers (young female cows that have yet to give birth) need to monitor
(watch) their age and weight very closely. If the cows do not eat enough or eat too much, they
could risk negatively impacting the pregnancy and the health of the cow. How do the farmers
know so much about the health of their heifers? They observe and record the weight every day.
Sometimes they estimate the weight by measuring what is called girth (distance around the
belly of the cow) or wither height (the height from the shoulderſhip to the ground) of the heifer.
The most accurate way is to put them on a scale.
2
1. What age does the Holstein heifer mate at?
calve at?
2. What age does the Jersey heifer mate at?
calve at?
3. What is the optimum weight for a Jersey heifer at 9 months?
4. At what age is the optimum weight of a Jersey heifer 100 kg?
5. What is the independent variable for this graph?
6. What is the dependent variable for this graph?
7. What would the Holstein heifer probably weigh at 27 months?
8. If the Jersey heifer weighed 500 kg, how old would it probably be?