ENERGY AND PROTEIN CONTENT IN THE DIET AND RELATIONSHIP WITH MILK UREA IN SHEEP FROM THE SYNTHETIC POPULATION BULGARIAN DAIRY


Authors: Milena Mihaylova
Keywords: milk urea, sheep, protein

Abstract:
The aim of the study was to investigate the relationship between energy and protein content in the
diet as well as the level of urea in sheep from the Synthetic Bulgarian Dairy population.
The study included 24 sheep of the breed Synthetic population Bulgarian dairy from the herd of the
Agricultural Institute - Stara Zagora in 2017. Monthly controls were performed and samples were taken
for analysis in April, May and June.
Energy intake (feed units per milk - FUM) and crude protein with ration (CP) were - for April - 2.0
FUM and 241.8g CP, for May - 1.9 FUM and 258.6 g CP and for the month of June - 1.72 FUM and 231.3
CP. Sampling was performed during the morning milking of the sheep at 30-day intervals. Milk samples
were tested immediately for urea concentration in the milk. The urea content was determined by the
method described by Angelov, Ibrishimov, Milashki (1999), based on the urease method with the Conway
cup. The statistical processing of the obtained results was performed with the program STATISTICA for
Windows.
The following conclusions can be drawn from the study:
The urea content in milk increases with increasing concentration of crude protein in the ration. In
the presence of higher amount of energy in the ration, more degraded ammonia can be processed into
microbial protein, which leads to more efficient usage of protein than feed. At a FUM / CP ratio in the
ration of 120.9 for the month of April, the level of urea in the milk is 15.6 mg / dl. For the months of May
and June milk urea was - 136.1 and 134.5, and the levels of urea in milk was expectedly close - 21.8 and
21.9 mg / dl.Download article