| Popis: |
Aim. Study of the effect of lactulose-containing feed additives on the growth and meat productivity of Kazakh white-headed steers. Materials and Methods. The research was carried out on the basis of the A.N. Sobolev’s farm enterprise, Uryupinsky district, Volgograd region. For the experimental work, 30 heads of the Kazakh white-headed steers at the age of 8 months were selected. The animals were divided into three groups. Each group consisted of 10 animals. The steers of the control group received a general economic diet, consisting of pasture forage with the addition of 2.5 kg of concentrated feed; analogues of experimental group I received the feed additive "Laktuvet-1" in addition to the concentrates; experimental group II – feed additive "Kumelact-1". Feed additives were introduced in an amount of 0.5% by mass of the concentrated feed. The diet of experimental young animals were calculated to obtain average daily gain at the level from 950 to 1000 g. The growth of animals was assessed according to the data of monthly individual weighing and determination of live weight, absolute and average daily gain. The slaughter of experimental animals was carried out according to the method of VNIIMS (1984). All the material presented in the article was processed using standard biometric methods (according to the method of Plokhinsky N.A., 1969) using software Microsoft Office package and determination of the Student-Fischer difference probability criterion. Results. As a result of the studies, it was found that the animals of experimental groups I and II began to surpass significantly steers of control group from the age of 11 months. At the age of 15 months, their superiority in live weight was 9.4 kg, or 2.19% (P≥0.95), and 21.3 kg, or 4.97% (P≥0.999), respectively. The advantage of the animals of experimental groups I and II over the steers of control group in terms of the average daily gain was 4.62 (P≥0.99) and 10.98% (P≥0.999), respectively, for the entire period of the experiment. The results of the control slaughter indicate that the steers that received feed additives exceeded the analogous of control group in carcass yield by 0.10 and 0.30%; fat yield – by 0.10 and 0.20%; slaughter yield – by 0.20 and 0.24%, respectively. Conclusion. The use of feed additives "Laktuvet-1" and "Kumelaсt-1 in the diets of experimental young animals contributed to an increase in live weight and an improvement in the slaughter qualities of cattle. The highest effect was found in the group of animals that received the feed additive "Kumelact-1". |
