Weight Estimation

2.3 WEIGHT ESTIMATION

When Is Weight Estimation Important?

When calculating a dose of medication: Doses are often based on the animal's weight.

When selling an animal: In some places, animals are sold by weight.

To monitor weight gain: An owner may want to monitor an animal's weight gain or loss.

Methods of Weighing Animals Using a Scale: This method is most accurate if the scale is good.

Using a Tape Measure: This method requires only a tape measure and can be used almost anywhere. Once the animal is measured, then one of two methods can be used:

 a table is used to look up the weight of the animal, or  a calculation is made based on the measurements.

Weight Estimation of Cattle - Method One

To estimate the weight of cattle, wrap a flexible measuring tape (that measures in centimeters) around the thorax (i.e. chest) of the animal. This measurement is called the circumference, or “girth.” Use the table on the following page for the corresponding weight.

Table for Estimating Weight in Cattle

Weight Estimation of Cattle - Method Two Wrap a flexible tape measure (that measures in inches) around the thorax of the animal to measure the "circumference" or “girth” of the animal. Wrap the tape around the animal just behind the front legs.

Measure the "length" of the animal from the point of the shoulder to the most posterior point of the hip.

Calculation: (girth x girth x length) / 10,840 = Weight (in kilograms).

Conversion (to pounds): weight in kilograms X 2.2 = weight (in pounds).

For example, a cow has the following measurements Girth = 140 cm Length = 124 cm Calculation: (140 x 140 x 124) / 10840 = 224 kilograms Conversion: 224 x 2.2 = 492 pounds Weight Estimation of Pigs

To estimate a pig's weight: Measure the "length" and "girth" of the pig. Then refer to the table below.

Measure the "length” from between the pig's ears to the base of its tail.

length Measure the girth by wrapping a measuring tape around the pig's thorax just behind the front legs.

girth Calculation: girth (cm) x girth (cm) = weight (in kilograms)

120. g Weight table for pigs On the horizontal row at the top of the table, find the closest number representing the "length" and put a finger of your right hand on that number. On the vertical column to the left of the table, find the closest number representing the "girth", and put a finger of your left hand on that number. Slide your right index finger down the table and your left finger horizontally across the table until your two fingers meet. The number on which your fingers meet is the estimated weight of the pig in kilograms.

Length (cm)

Kilograms Weight Estimation of Horses Measure the diameter of the horse by placing a measuring tape around its "girth" (i.e. its chest or thorax) just behind the front leg. Use the table to find the corresponding weight.

Weight Table For Horses

Weight Estimation of Goats And Sheep Measure the girth of the goat or sheep by placing a measuring tape around the animal's thorax just behind the front leg. Use the table to find the corresponding weight.

Weight table for goats and sheep.

Note: In thin goats and sheep, this table tends to overestimate the weight.