Physiological reactions and growth performance of lambs supplemented by vitamin A with zinc under summer condictions (with 5 tables) [electronic resource]

Includes references.

Twenty four males of Ossimi lambs averaged 3 months of age and 17.54 :I: 0.95 kg body weight were used during summer to evaluate their growth performance and physiological reactions to supplemental vitamin A, zinc (Zn) and vitamin A with Zn. Animals were randomly divided into 4 equal groups (6 lambs in each). First group served as control while the second group (TI) received oral administration of vitamin A (retinol) at 10.000 IU/head/weekly, and the third group (T2) received 30 mg Zn/kg DM (132.2 mg Zn sulfate/kg DM), and the fourth group (T3) received vitamin A at 10.000 IU/head/weekly with 30 mg Zn /kg DM. Results showed that averages of daily weight gain (DWG) increased (P<0.01) for lambs of Tl, T2 and T3compared with control. Lambs of T3 had higher (P<0.05) averages of final body weight (FBW) than control. Feed conversion (FC) rates were improved (P<0.05) for Tl, T2 and T3 compared to control. Averages of DWG, FBW and FC were improved (P<0.05 and P<0.01) for T3 than those of Tl and T2. Blood Hb, MCR and MCRC increased (P<0.05 and P<0.01) for lambs received Tl and T3 compared to control. Total count of leucocytes increased for T3 lambs compared to control. Tl and T3 lambs showed marked decrease (P<0.05) in neutrophils compared with control. Tl, T2 and T3 exhibited significant (P<0.05) increases in lymphocytes compared with control. Lambs of T1, T2 and T3 exhibited higher (P<0.05) levels of plasma total protein than control, and its concentration in T3 was greater (P<0.05) than Tl and T2. Plasma albumin levels were higher (P<0.05) in all treatments than control while plasma globulin increased (P<0.01) for T2 and T3 lambs compared to control. Plasma vitamin A concentrations were greater (P<O.05) for Tl and T3 than control. Plasma Zn increased (P<0.01) for T2 and T3 lambs comparing to control. Plasma T3 hormone concentrations were greater (P<0.0001) for T3 lambs than those of T1 and T2. No significant changes observed in feed intake, rectal temperature, respiration rate, pulse rate, blood RBC, PCV, MCV, eosinophils, basophils, monocytes %, plasma concentrations of glucose and total lipids for lambs received T1, T2 and T3 compared with control. The results indicated that lambs received supplemental vitamin A with Zn exhibited more favorable signs in their physiolgical reactions than those received each of vitamin A or Zn alone, indicating a synergistic relationship between both nutrients and reflecting superiority of their efficient metabolic activities and growth response under summer conditions.

Summary in Arabic.