The impact of using slow-release urea instead of fast-release urea in feed on the milk production of Awassi sheep and some blood traits

Abstract

UR study was Conducted in the sheep field of the (Kosar) company in the Kalk area / mosul/iraq to determine the effect of adding slow-release urea to the concentrated feed gradually instead of fast-release urea in an attempt to improve the efficiency of feed utilization and improve rumen conditions and reflect that on milk production of Awassi sheep using 24 heads of newly born ewes aged between 3 and 4 years distributed to four treatments fed on a concentrated feed close in its energy and protein content and different in its urea content, which was gradually replaced with slow-release urea (Minogen) where the 1 st treatment took (1.5% urea only) and the 2nd treatment (1% urea and 0.6% slowrelease urea) and the 3 rd treatment (0.5% urea and 1.2% slow-release urea) and the 4 th (1.8% slowrelease urea only). The study lasted four months, from the birth of the ewes until the end of the milking season (their dryness), with a completely randomized design (Completely Randomized Design). The average total weight gain for ewes was (8.37, 9.72, 6.74 and 5.67 kg), and through the results it was observed that there is a positive effect of adding Minogen to Awassi ewe feed in average daily milk production and total as the 4 th treatment excelled significantly (P≤ 0.05) on the rest of the treatments as average production reached (202.92, 286.40, 207.13 and 320.69 g/day) and total reached (1623.33, 2291.17, 1657.00 and 565.50 g/ewe), respectively, and fat and protein ratios also excelled in the 4th treatment significantly (P≤0.05) on the rest of the treatments as fat ratios reached (3.463, 3.366, 3.866 and .326%) and protein (4.763, 4.714, 4.769 and 4.928%), respectively, The milk lactose ratio did not record any significant differences, reaching (4.637, 4.525, 4.559 and 4.540%), while the total solid matter ratio decreased significantly (P ≤0.01) in the 2nd and 3rd treatments compared to the 1st and 4th treatments, reaching (10.415, 10.043, 9.986 & 10.096%). As for the effect of slow-release urea on blood traits, no significant difference was observed in the concentration of total blood protein and albumin, but the concentration of blood urea was significantly increased (P≤ 0.05) for the 4th treatment compared to the other treatments, reaching (34.44, 38.72, 43.27 and 6.26 mg/100ml blood), and plasma cholesterol concentration increased significantly (P≤ 0.05) with increasing levels of slow-release urea in the 3rd treatment compared to other treatments as the concentration reached (68.16, 71.72, 80.22 and 2.60 mg/100ml blood), while the concentration of triglycerides in the blood decreased significantly (P≤0.05) with increasing levels of slow-release urea for the three treatments (2 nd , 3 rd and 4 th ) compared to the 1 st containing fast-release urea as it reached (67.22, 57.38, 59.55 and 9.86 mg/100ml blood), as for blood enzymes ALT and AST there was a significant increase (P≤ 0.05) in the 3 rd treatment in ALT enzyme concentration followed by the 4th treatment compared to the 1st and 2nd as the concentration reached (...