Page 166 - Calculating Agriculture Cover 20191124 STUDENT - A

14-26 Feeds and Feeding CH 14]

Calculating the amount of feed needed for animals.

There are a number of factors that affect the feeding of animals. Animal feeders, when planning
(budgeting) the requirements of feed for the animals they will be feeding, estimate the pounds of
feed, or tons of feed, or hundred weight (Cwt) of feed that they will need to feed their animals for
market. Their budgeting (planning) is based on their record keeping and history of feeding for pounds
of gain, given the rations that will be prepared. Knowing the feed conversion ratios allows the animal
feeder to estimate the feed they will need.

Example Presume a feeding regimen for 250 pigs and that each pig will gain on average 35
pounds to reach slaughter weight. With a feed conversion of 3.8 : 1, (a) how much
feed will each pig consume to gain 35 pounds? (b) How many pounds of feed will be
required for 250 pigs? (c) How many hundred weight (Cwt) will be planned? (d) How
many tons will be purchased?

Solution

(a) Feed consumed for gain = Pounds to be gained x feed required per pound of gain
= 35 pounds x 3.8 pounds
(a) Feed consumed for gain = 133 lbs per pig

(b) Total pounds required = # of animals fed x Feed consumed per animal
= 250 hd x 133 # / hd
(b) Total pounds required = 33,250 #

(c) Cwt of feed = 33,250 # ÷ 100 # / Cwt
= 33,250 # ÷ 100 # / Cwt
(c) Cwt of feed = 332.50 Cwt

(d) Tons of feed = 33,250 # ÷ 2,000 # / ton
= 33,250 # ÷ 2,000 # / ton
(d) Tons of feed = 16.125 tons

Feeding efficiency — Dairy Cattle and milk production
Dairy cows consume dry hay, silage, pasture and grain
during lactation to produce milk. Feeding efficiency can then be
calculated on each of these elements to their diet, though the
pounds of milk produced is very dependent on their breed. The
measurement can also be made on the pounds of butter fat that
cows produce. Figure 14.11 indicates the ratio of milk to grain.
If a cow is producing 12,000 pounds of milk per year, then its
grain intake will have a ratio of 3 pounds of milk for each pound
of grain fed. Remember, a dairy cow consumes hays, pasture and
water to produce milk. The values in Figure 14.11 are derived
from feeding grain rations (concentrate rations) to a lactating
cow.
Though the traditional individual feeding of lactating cows
in stanchioned barns or milking parlors is still used, the new
methods include challenge feeding lactating cows based on their
individual total milk production and butterfat content, measured
as the cow is being milked. This allows for a more economical
way of feeding individual cows based on their production.
Phase Feeding. Our Agriculture Researchers recommend that the lactation of a cow be divided
into four periods or phases, each requiring a different type of feeding program.
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