Nutrition

The protein requirements for maintenance ensure the development of the renewal process of proteins in the body, as well as the synthesis and degradation process of nitrogenous substances.

The protein requirement for maintenance is on average of 3.25 g PDI / kg G^0,75 or it can be calculated using the relation:

PDI (g) = 100 + 0.5 x LW (kg)

In order to establish the necessary protein for milk production it should be taken into consideration the metabolism of proteins in the rumen, and the amino acids that reach the small intestine. The protein requirements for the milk production dependent on the amount of protein contained in 1 liter of milk and the yield of its use in the milk production.

For the synthesis of one liter of milk it is advisable to provide 48 g PDI (1 kg milk with 31 g protein = 31 / 0.64 = 48 g PDI).

In the eighth month of pregnancy, the computed protein requirements for maintenance will be increased by 135 g PDI / head, while the ninth month with 205 g PDI / head. For cows with high milk productions, the protein supplement can be provided, starting with the seventh month (75 g PDI / head).

For the cows with high milk production, almost half of their protein necessity comes from the protein ingested through food, making lysine and methionine become limiting amino acids for the milk production. As a result, Rulquin H. et al. (1993) have introduced the system of digestible lysine and methionine.