Tegza I. M.

A.Baitursynov Kostanay State University, Kasakhstan

Reproductive functions of Holstein cattle in conditions of LLP «Sadchicovskoe»

A very important moment for the correct reproduction of the herd is economically reasonable duration of the cycle of cows between calve that is the period of time from one calving to another. The desired length of calve cycle is 365 – 395 days. It depends on the duration of pregnancy of a cow and the service period, on the one hand, and duration of lactation and dead period from the other hand.

Pregnancy is the time period from the fruitful insemination of cows to her calving. If we consider that duration of the pregnancy value is constant and averages 280 – 285 days, the more influence on calving cycle provides the service period that is the period from the calving cows to its fruitful insemination. The duration of the service period influences the choice of the optimal period for insemination of cows after calving. When establishing the terms of insemination of cows after calving take into account the nutritional status of the animals, their level of productivity as well as the specific conditions of farming (feeding, management, the direction of the breeding season and others)

High level of reproduction is achieved by the first calving at an earlier age (23 – 24 months), shorter intervals between calves and larger number of pregnant animals. However, the animals must not be overfed; otherwise they become too fat, that adversely affects reproduction and their health status.

When moving animals in new climatic conditions, first of all these consequences are affected on productivity and reproductive functions, so the study asses of the productivity and reproductive abilities of animals is one of the main indicators of the fitness of the organism to new environmental conditions.

In this regard, the purpose of our work was to study the reproductive abilities of cows of Holstein breed in LLP “Sadchikovskoe”. The object of research was the herd of cows of local and German selection. Reducing of the reproductive ability is observed among the newly imported cattle from abroad, in particular Holstein cows and German selection (Table 1).

Table 1. Reproductive ability of cows Holstein breed difference selection

Index	Of the local selection		Of the German selection
	M±m, kg	Cv, %	M±m, kg	Cv, %
Age of the 1^st calve, days	27.4±0.142	3.6	27.6±0.14	3.64
The duration of service period, days	52.22±1.13	15.3	43+2.74	45.2
The duration of dead period, days	57.4+1.36	16.8	55.3+1.63	20.9
Calve period	343.88+0.01	5.890	329.8±4.08*	8.75
Coefficient of reproductive ability	1.09±0.01	6.71	1.08±0.0139	8.85
Live weight of animal yield, kg	31.2±0.48	10.89	37.14±0.367***	6.98

Note: -P<0.05; ***-P,0.01

We found that the age of cows of German at first calving was only 0.2 month more than the local ones, that is the values were differed little from each other and the difference was not true.

The coefficient of the reproductive ability is of German was 1.08 and is lower than the local animals for 0.01.

The live weight of calves at birth is the important breeding character. According to the researches it was established, that the offspring of German cows had superiority almost 6 kg of this difference is accurate (P<0.001).

It should be noted that in the studied indices the two groups of cows were uniform.

The determine the reproductive ability of cows it is necessary to analyze additional indicators such as the length of service and dead, and also calving periods.

We noted in general the optimal duration of the service period and dead period for both groups of animals but nevertheless cows of the local selection exceeded their German counterparts according to the service period for 9 days but the duration of the dead period for 2 days. However, the calving period of German cows on average was 14 days shorter than their peers (P<0.05)

Meanwhile, if by the duration of the calving period, animals in both groups were similar, the duration of the dead and especially the service period sets high variability, as evidenced by the coefficient of variability characteristics.

Thus, cows of the local and German breeding have high individual variation and it should be considered when selecting the cows in the herd (Cv – 15.3…45.2%).

Generally, based on the analysis of the obtained results, we can say that the process of adaptation of German Holstein in the conditions of Kostanai passes satisfactorily.

List of literature:

1. Reproductive qualities of mares’ meat breeds and their crosses/ V. Kosilov// Milk and meat animal husbandry. – 2008, №8, p. 11 – 12.

2. O. Mityashova, A. Oborin // the animal husbandry of Russia. – 2008, №9, p. 45 – 46.