MILK YIELD OF COWS DEPENDING ON A LINE ON LINEAR BELONGING AND METHOD OF MAINTENANCE
Authors: Voitenko S. L. , Zheliznyak I. M. 
Published: May 2019

Modern market conditions require high quality products, that is why before the producers of animal husbandry, the issue is not only to constantly increase the productivity of animals but also to pay attention to the quality of products. Considering the need to increase milk production as one of the main types of livestock products, the most energy-saving technology should be chosen, which will provide comfortable conditions for keeping animals and displaying their genetic potential, especially for milk production. Taking into account that the purpose of other researches was to determine the influence of the linear dependence of Ukrainian Black-and-White breed cows and the method of keeping them on display of their milk productivity.
The researches were carried out on cows of Ukrainian Black-and-White milk breed of such lines as Bella 1667366, Eleveishn 1491007, Marshal 2290977, Starback 352790 and Chif 1427381. Two different technologies of keeping cows in the lactation period were investigated: industrial technology with unassociated keeping of cows at "Gogolevo" Ltd. and traditional technology with crying attachment in "Shyshatska" LLC, which are part of LLC "Agrofirma im. Dovzhenka" in Poltava region. The hopes of cows for the first and third lactations were determined by the standard techniques in cattle breeding. The analysis included the materials of the electronic database of the economy on the indicators of dairy productivity of cows in the format of the SUMS "ORSEC" as of 2018. Materials of scientific researches were worked out using the methods of variation statistics and software package of STATISTICA-10.
The researches have determined that in the case of a loose housing way of keeping ("Gogolevo" Ltd. ) cows – the firstborns of the five studied lines had hopes at the level of 7493–7913 kg. The highest dairy performance was characterized by firstborns of the line of Eleveishn – 7913 kg of milk which is higher than the average figures for the studied lines by 253 kg. Daughters of the Starbak line for the first lactation at loose housing way of keeping had low productivity – 7493 kg of milk that on 167 kg of milk less then the average values of the studied lines. In this case, in each studied line, especially Eleveishn, Marshall and Starbak, which cows were kept by loose housing during lactation, there is an opportunity to improve the dairy productivity by selection methods, as evidenced by the coefficients of variability of milk yield testify to (Сv = 15,8 ... 23,9%).
Keeping of cows on the leash (LLC "Shyshatska") milk yield of the firstborns varied at the level of 6328 kg of milk (the line Bella) to 7059 kg of milk (Marchal's line). The difference between the yields of cows of the most productive line and the low productivity in this herd was 731 kg, and between the most high-yielding and low-yielding lines compared with the averages to milk yield of the studied lines, respectively, 355 kg and 376 kg of milk. It is proved that keeping of cows on the leash there is an opportunity to increase the milk productivity of the firstborns by selection methods, the confirmation of which is the coefficient of variability of the sign (Сv = 15,3 ... 21,3%).
Comparing productivity of daughters of the studied lines, it should be noted reliable advantage on milk yield the firstborns which were at loose housing way of keeping in comparison with cows of similar lines, but which were kept during the lactation period on the leash. The difference between cows of the line of Bella was 1190 kg of milk (P < 0,05), line of Eleveishn – 1207 kg (P < 0,001), the line of Marshal – 767 kg (P < 0,001), the line of Starbak – 1007 kg (P < 0,001) and the line of Chif – 611 kg (P < 0,001). The difference between average milk yield of the firstborn cows of the studied lines in two herds was 956 kg of milk (P < 0,001), indicating production efficiency of milk for use of modern progressive technology.
The analysis of the milk yield of cows of the studied lines in the herds of the two farms has also led to the conclusion that a significant increase of milk yield of cows from the first to the third lactation. It is established that cows with the third lactation at loose housing way of keeping produced from 8575 kg to 10276 kg of milk depending on the line. At the same time, the cows of the line Eleveishn 1491007, having the highest tastes – 10276 kg of milk, surpassed another cows from of this herd of other lines, which were kept at loose housing, on 891 kg of milk. Cows of Starbak line 352790, although they increased their milk yield from the first lactation to the third one, but they showed the lowest milk yield, yielding 1701 kg of milk to the daughters of the line of Eleveishn and 810 kg – the average values for the studied lines of herds of "Gogolevo" Ltd.
In herd with keeping of cows on the leash (LLC "Shyshatska") daughters of the line of Marchal had the highest milk yield – 8128 kg of milk, and low ones – the line of Bella, respectively, 7092 kg. And though cows of this herd increased milk yield from first to the third lactation, all of them significantly conceded to cows of similar lines of "Gogolevo" Ltd. which were kept at loose housing during lactation.
We also investigated that the cows of the Bella line, which were kept at loose housing, exceeded the cows of the same line that were kept on the leech, by the number of milk for the third lactation by 2617 kg (P < 0,05), the Eleveishn line – by 2547 kg (P < 0,001), Marshall – by 872 kg, Starbak – by 956 kg (P < 0,05) and Chif – by 1903 kg of milk (P < 0,001). The difference between the average milk yield of cows of the studied lines in two herds was 1779 kg of milk (P < 0,01) for advantages of cows, which were kept at loose housing.
The possibility of selecting cows by the results of the third lactation was in direct dependence with the size of milk yield, that is the higher the yield, the lower the coefficient of variability of the indicator and consequently the effectiveness of selection.