Effect of Dietary Protected Fat and Roughage Level on Growth Performance and Carcass Characteristics of Growing-Finishing Lambs

Abstract

Sixty male Barki lambs (age 8 month, weight 27.5 Kg) in six similar groups were fed diets containing 10 % or 30 % berseem hay with 0, 4 and 8% Ca-Soaps for 70 days. Feed intakes and body weight were weekly recorded. At the end of the experiment, three lambs from each group were slaughtered to study the effect of protected fat and roughage levels on carcass characteristics and mutton quality. Increasing fat level in diet (P>0.05) increased total body weight gain and average daily gain (ADG). The 8% fat level improved feed conversion ratio (DM and DCP to gain ratio) by 6.4% and 14.3%, respectively. Lambs fed low roughage-high fat showed better body weight gain (16.76 kg); average daily gain (240g /day) and feed conversion ratio (4.5 DM intake/gain and 0.61 DCP intake/gain). Roughage level had no significant effect on body weight gain, average daily gain and feed conversion ratio. Dietary fat level or roughage or their interaction had no significant effect on carcass weight and dressing percentage. Feeding rations containing protected fat had no significant effect on physical properties of meat except the increased (P<0.05) tenderness of the eye muscle of sheep fed 8% fat diets. Protected fat supplement (P<0.05) increased weights of omentum fat, intestinal fat, kidneys fat and total body and ether extract of eye muscle and liver but decreased (P<0.05) protein content of eye muscle. Feeding protected fat had no significant effect on fatty acid composition of eye muscle lipids, except the (P<0.05) higher lauric acid (C12:0) of 4% fat group. Neither fat nor roughage level had significant effect on eye muscle area, eye muscle weight and physical composition of the best 9,10 and 11 th ribs (percentages of lean, fat and bone). Results of chemical composition of whole 9, 10 and 11 th ribs showed that feeding protected fat diets (P<0.05) increased DM and ether extract but decreased (P<0.05) CP percentages compared to the control (0% fat). Ash percentage was not significantly changed. Feeding protected fat to growing lambs resulted in higher average daily gain and higher carcass fats, but it did not alter the percentage of unsaturated fatty acids in carcass fat. Roughage level had no significant effect on either the growth performance or carcass characteristics. (The greater intake of digestible energy by the lambs fed calcium soaps of palm oil may account for the higher average daily gains and fatter carcasses).

Mannan oligosaccharides improve the fur quality of raccoon dogs by regulating the gut microbiota

“…They are oligosaccharides produced by the concentration of mannose protein. Since MOS may interact with pathogens and inhibit their colonization of the gut, MOS are anticipated to become a new green feed additive in place of antibiotics ( Bernal-Barragán et al, 2007 ). In studies related to poultry and piglets, it has been proven that dietary MOS can increase serum immunoglobulin levels, indicating that MOS can enhance animal disease resistance ( Rosen, 2007 ).…”