Negative influence on dairy productivity of dairy cows was made, first of all, the
periodic change in the use of the slasher, as evidenced by the fact that in the whole
study of the cow of the 1st experimental group, who experienced two changes in the
diet, consistently yielded to the analogues of the 2nd group (one change of diet) for
daily milk yield.
On average, during the two experimental periods, the preference for milk
productivity of animals in the 2nd experimental group was 1.65 liters, or 5.7 % (the
difference in the form of a steady tendency to advantage). This suggests that the impact
on the need for violations of the technological stability (structure) of the diet is more
significant than the effect of the content of the feed mixture of "effective" fiber.
One can also interpret the fact that the fall in the daily milk productivity of cows
of the first group in the second experimental period (after the second change in the
structure of the diet) was more significant, despite the fact that the degree of grinding
of roughage in this group was returned to the level of the equal period, that is, to the
economic the diet.
2. Grinding of roughage and metabolic processes in the organism of cows.
Analysis of the results of biochemical study of serum of experimental cows (Table 6)
indicates the character intensity
of metabolic processes in the organism of high-
yielding dairy cows.
Thus, in all animals, irrespective of the experimental scheme, a relatively low
content of inorganic phosphorus in serum was observed, in combination with low total
protein content. This indicates a significant physiological burden on the organism of
experimental animals. And not surprisingly, because, given the history of the herd and
the relatively short duration of intensive genetic improvement of the herd, it can be
reasonably argued that cow productivity is at the top of their current genetic potential.
However, we can assume that diets need to optimize the content of phosphorus and
protein, which requires more attention to more accurate balancing, especially for the
elements mentioned.
The increased lipid metabolism of the experimental cows in the organisn due to
extremely high milk production is also indicated by the overweight average total
cholesterol content recorded in the cows of both groups throughout the entire study.
Since all test cows were healthy, as evidenced by a regularly monitored health
index, to correct cholesterol in the blood, it is enough to increase feed intake of easily
digestible carbohydrates.
The increased content of blood in experimental cows of alanine aminotransferase
is not more than 2 times not critical for morphofunctional changes in the body, but can
be considered as yet another evidence of increased stress on the body of cows
(especially on the liver) in connection with high milk production.
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