Influence of the mineral additive "Ostoferol" on productive, hematological indicators and morphology of laying hens' eggs

Purpose. Study of the influence of "Ostoferol" mineral additive on the productive, hematological indices and morphology of laying hens' eggs. Materials and Methods. The studies were conducted in the conditions of a poultry farm in the Sverdlovsk region on layers of the Hisex Brown cross, 28-29 weeks of age, in the 1st phase of egg laying. The experiment lasted 60 days. Three groups (control and two experimental) were formed from hens with signs of hypovitaminosis D. The number of poultry in each group was 100 heads. The laying hens received the mineral additive "Ostoferol" with drinking water twice a month for 3 days over 2 months. The rate of introduction of this additive in the 1st experimental group was 100 ml, in the 2nd experimental group – 200 ml per 1000 l of drinking water. The layers of the control group received drinking water without the mineral additive. Live weight was assessed in 10 laying hens from each group at the beginning of the experiment, on days 30 and 60. Mineral metabolism was assessed by the content of vitamin D, calcium and phosphorus in the blood serum of laying hens. Blood was taken in the morning from the axillary vein of 10 hens from each group after 12 hours of fasting. Egg productivity was assessed at the beginning of the experiment, on the 30th and 60th days by gross egg collection from 10 laying hens of each group. Egg weight was measured by individual weighing on electronic scales at the beginning of the experiment, on the 30th and 60th days, shell weight – after removing the yolk and protein. Shell thickness was determined with a micrometer at three points – at the equator, blunt and sharp ends of the egg, calculating its size based on the average indicator. Statistical processing of the digital data obtained in the experiments was carried out using Statistica 10.0 (StatSoft Inc., USA) and Microsoft Excel (Microsoft, USA) programs. Results. The clinical condition of the laying hens of the 1st and 2nd experimental groups, which received the mineral additive "Ostoferol" in the amount of 100 and 200 ml per 1000 l of drinking water, was satisfactory by the end of the experiment: posture disorders and lameness were not recorded, the number of individuals with plumage changes decreased in the 1st experimental group by 6.0%, in the 2nd – by 9.0% (completely disappeared). The survivability of the poultry in the experimental groups was 6.7% higher compared to the control group. The difference in live weight in favor of experimental groups on the 60th day was 3.9 and 5.0%, respectively. In the blood serum of the laying hens of the two experimental groups, compared to the control, the calcium content was higher by 9.1 and 10.2% (P≥0.95); total phosphorus – by 8.1 and 10.0%; vitamin D – by 12.9 and 16.8% (P≥0.95), respectively. For 60 days of the experiment, the average egg production of hens in the experimental groups was significantly higher than in the control by 5.5 (P≥0.99) and 5.9% (P≥0.99), its intensity – by 5.2 (P≥0.99) and 6.7% (P≥0.99), respectively. The superiority of laying hens of the 1st and 2nd experimental groups over the control was, respectively: by average eggshell weight – 2.8 and 3.2%, thickness – 8.3 and 10.8%, the index of elastic deformation of the shell – 18.9 (P≥0.99) and 21.3% (P≥0.99). Conclusion. The expediency of using the mineral additive "Ostoferol" in industrial poultry farming for the purpose of normalizing metabolism, improving productive qualities, and maintaining a high level of poultry survival has been confirmed.