PLASMA-PROTEINS AND HEMATOLOGICAL PARAMETERS IN FATTENING PIGS FED DIFFERENT SOURCES OF DIETARY ZINC

The effect of varying amounts and sources of dietary zinc on some bloo d parameters and the plasma protein ratios of fattening pigs was studi ed. During a 30-day pre-trial period, 42 pigs were depleted of Zn and divided into three groups of 14 animals each. During the 105-day exper imental fattening period two experimental groups (T1-2) were repleted with dietary Zn in the form of inorganic salt (ZnSO4) or metallo-organ ic chelate (zinc methionate, ZnMET), while the control group (C) recei ved no extra Zn. The supplements contained 84.3 and 40.9 mg Zn/kg diet , respectively. The nutritional effects of Zn were evaluated on the ba sis of red blood cell (RBC) count, mean corpuscular volume (MCV), haem oglobin (Hb) concentration, packed cell volume (PCV), white blood cell (WBC) and thrombocyte count, plasma total protein, albumin, and globu lin concentrations, and albumin/globulin (A/G) ratio. During the parak eratosis period (days 28-56) both the basic feed (group C) and the die t enriched with 40.9 mg Zn/kg (as ZnMET) fed to group T-2 pigs resulte d in a lower red blood cell(RBC) count, Hb concentration and PCV than in group T-1 fed a diet containing 84.3 mg Zn/kg (as ZnSO4). Dietary Z n of organic and inorganic origin had no effect on MCV and on the WBC and thrombocyte counts of fattening pigs. At the start of the parakera tosis period (day 28), group C pigs had significantly lower, and by it s end (day 56) significantly higher plasma total protein and globulin concentrations than pigs of group T-1. At the same time, no significan t differences were observed in albumin concentration between group C a nd the two experimental groups. Throughout the trial, feed containing sufficient, and insufficient, quantities of Zn from various sources ha d no influence on blood plasma alpha and beta globulin concentrations. Ln the second part of the experiment (day 56) dietary Zn deficiency r esulted in a significantly higher level of gamma globulin in group C p igs than in pigs given sufficient Zn of inorganic origin. While inorga nic Zn increased some of the blood parameters, namely RBC count, Hb an d possibly PCV, organic Zn seemed to be responsible for raising the pr oportion of plasma globulins.