Relationship of Residual Feed Intake on specific hematological and biochemical parameters in Rumbouillet sheep

Abstract

Relationships of Residual Feed Intake (RFI) on hematological and biochemical parameters were determined in Rambouillet sheep. After feeding period of 42 days (research period), RFI was calculated in 16 rams and 24 ewes. Lowest negative and highest positive RFI (<0.5 SD below the mean and >0.5 SD above the mean, respectively) rams (n = 8) and ewes (n = 12) were selected. From RFI-categorized sheep, hematological and biochemical parameters were evaluated at day 0, 21, 42 and at day 0, 42 of the feeding period, respectively. Positive RFI ewes (less efficient) tended (p≤0.10) to have more Red Blood Cells (RBC, 106 μL) (9.66 vs. 7.68) and less Mean Corpuscular Hemoglobin (MCH, pg) (9.59 vs. 12.95) thannegative RFI ewes. Positive RFI rams have (p<0.05) more RBC (9.27 vs. 6.67) and white blood cells (WBC, 103 μL) (10.25 vs. 7.77), less Mean Corpuscular Volume (MCV; 30.98 vs. 44.11 fL) and tended (p<0.10) to have lesser MCH (11.50 vs. 16.12) than negative rams. Glucose (mg dL-1) increased (p<0.01) in positive RFI ewes (77.30 vs. 63.57) and rams (80.23 vs. 51.44) in comparison with more efficient ruminants. Data obtained suggest that positive-RFI sheep could be more susceptible to stress compared to more efficient sheep. © Medwell Journals, 2011.