Hematological indices and the rate of growth depending on duration of embryonic growth of pigs obtained by commercial cross-breeding

Abstract

The studies were performed in pigs obtained by commercial cross-breeding under conditions of pig-breeding complex of Agricultural Open Joint-Stock Company Agrokombinat Kalyta. 115 crossbred breeding sows (Big White x Landras) – of similar age and development – were selected for the study; they were mated with purebred Big White boars. Three groups by five animals were selected from these breeding sows by pregnancy duration. The first one (control group, the pregnancy duration was the farm average) – 112-116 days; the second one (study group, reduced pregnancy duration) – 103-111 days; the third one (study group, extended pregnancy duration) – 117-120 days. The authors studied the growth duration and hematological parameters of these breeding sows’ offsprings after ablactation until the end of fattening. The piglets were ablactated at the age of 26 days. The young stock were fed with dry feed stuff according to the conventional technology. The feed level for the pigs of all groups was the same. The pigs were weighted upon birth at 1, 2, 4, 6 months, and the relative weight gain and actual growth rate of the pigs were determined by Shmalgauzen and Brody formula. Hematological tests were performed at the age of 2, 4 and 6 months in four animals from each group (two gilts and two boars). Blood for tests was collected from auricular veins before feeding. Red blood cell count and hemoglobin concentration were measured by hemascope, total protein, albumin and globulins were measured refractometrically. It has been established that the piglets obtained from the breeding sows with reduced pregnancy duration had the lowest body weight at birth, and the piglets obtained from the extended pregnancy had the highest body weight. From the age of two months, the young stock with the reduced embryonic growth duration were superior to the age-mates with the average and extended pregnancy in terms of body weight. The animals with reduced embryonic growth duration had higher relative weight gain and the actual growth rate factor, which characterizes their high growth intensity. The pigs obtained at commercial cross-breeding with different embryonic development duration had different blood composition. Thus, the piglets with reduced and average embryonic growth duration, had higher red blood cells count, hemoglobin and total protein content. Higher hematological indicators in pigs with reduced embryonic period coincide with the period of their higher growth energy which indicates the interrelation between the intensity of the animals’ growth and the red blood cell count, hemoglobin and total protein in blood. Therefore, the embryonic development period reduction positively affects the growth energy, that is associated with improved hematological indicators, which is advisable to consider in pigs selection program.