Various sources such as AFRC (1993), NRC (1996), NRC (2000), Balbuena (2003) affirm that the animal loses weight in the transfer processes. To simplify the information, the values calculated by each author were averaged and it was obtained that each animal loses approximately 170 grams for each Megacalorie expended. We understand that this energy is consumed in the search for water, although it can also be used to select grass, but we will address this issue later. According to AFRC (1993), each animal consumes 0.00062 kcal/kg/linear meter of walking (this increases exponentially when we introduce topographic height into the formula).
The figures are somewhat shocking if we take into account that in Uruguay, in many establishments, the distances that are walked to the water are quite long.
Next, we will carry out the corresponding calculations to determine the energy expenditure of the animals for walking towards the water in the social area. For this we will locate ourselves in the Example Farm, which consists of 172 hectares, occupied by 150 steers of 350 kg on average.
The maximum distance to the social area is 970 meters. The animals attend this sector once a day at noon. In total, the animals walk 1,940 meters per day, but, as they do not stay all the time in the plot further away, we will divide this distance by 2 as an average.
If we assume that the energy expenditure data mentioned above are exaggerated and its value is half that mentioned above: 0.00031 kcal/kg/m
0.00031 x 350kg x 970 mts = 105 kcal / day
Each animal in this establishment consumes approximately 105 kcal per day on average. With this calculation and with the weight loss coefficient mentioned in the previous paragraph, we can approximate how much weight is being lost per animal, data that we will see then:
105 kcal x 365 = 38.325 kcal / year ~ 38,32 Mcal / year.
If 1 Mcal means a decrease in weight of 0.170 grams, by simple calculation we obtain that per year each animal would lose 6.6 kg.
If we multiply this data by the 150 steers from the establishment and multiply it by the price of the kg of meat according to ACG (11/3/2020) of US$1.89 / kg, we will obtain the following value of "annual loss"
6.6kg x 150 steers x $1.89/kg = U$S 1871 / year.