Effect of Docking and Diet Energy on Carcass Fat Characteristics in Fat-Tailed Baluchian Sheep
Effects of docking on carcass fat characteristics were studied in fat-tailed sheep. Male lambs were randomly divided into 2 groups. One group was docked after birth using rubber rings, and the tails of the other group were left intact (control). After weaning, 20 lambs from each group were divided into 2 subgroups; one subgroup was fed with a normal energy diet (10.25 MJ/kg ME) and the other one with a high-energy diet (11.42 MJ/kg ME) for 84 days. At the end of the fattening period, 28 lambs were slaughtered for determination of warm carcass weight (WCW) and other carcass characteristics. At 24 h postmortem samples of meat, omental fat, and caudal fat were taken from chilled (4 °C) carcasses for the assessment of fatty acid (FA) composition. No significant difference (P > 0.05) was observed in WCW and omental fat between carcasses of docking and control lambs, but lambs on 2 types of energy diets showed a significant difference (P < 0.05). Under these circumstances, docked lambs produced leaner carcasses than intact lambs (P < 0.05). Diet energy had a significant effect on average daily gain and daily feed intake (P < 0.05). Results showed that the predominant FA in body fat was oleic acid and a significant difference was observed for percentage of FA composition between fat in different parts of body (P < 0.05).
Effect of Docking and Diet Energy on Carcass Fat Characteristics in Fat-Tailed Baluchian Sheep
Effects of docking on carcass fat characteristics were studied in fat-tailed sheep. Male lambs were randomly divided into 2 groups. One group was docked after birth using rubber rings, and the tails of the other group were left intact (control). After weaning, 20 lambs from each group were divided into 2 subgroups; one subgroup was fed with a normal energy diet (10.25 MJ/kg ME) and the other one with a high-energy diet (11.42 MJ/kg ME) for 84 days. At the end of the fattening period, 28 lambs were slaughtered for determination of warm carcass weight (WCW) and other carcass characteristics. At 24 h postmortem samples of meat, omental fat, and caudal fat were taken from chilled (4 °C) carcasses for the assessment of fatty acid (FA) composition. No significant difference (P > 0.05) was observed in WCW and omental fat between carcasses of docking and control lambs, but lambs on 2 types of energy diets showed a significant difference (P < 0.05). Under these circumstances, docked lambs produced leaner carcasses than intact lambs (P < 0.05). Diet energy had a significant effect on average daily gain and daily feed intake (P < 0.05). Results showed that the predominant FA in body fat was oleic acid and a significant difference was observed for percentage of FA composition between fat in different parts of body (P < 0.05).
___
- Van Soest, P.J., Robertson, J.B., Lewis, B.A.: Methods for dietary fiber, neutral detergent fiber, and nonstarch polysaccharides in relation to animal nutrition. J. Dairy Sci., 1991; 74: 3583-3597.
- AOAC: Official Methods of Analysis of the Association of Official Analytical Chemists (W. Horwitz, Ed.), 16thedn., Arlington, USA. 1991.
- Folch, J., Less, M., Sloane Stanley, G.H.: A simple method for the isolation and purification of total lipids from animal tissues. J. Biol. Chem., 1957; 226: 497-509.
- SAS.: SAS/STAT User’s Guide (Release 6.03). SAS Inst. Inc., Cary, NC., 1988.
- O’Donovan, P.B., Ghadaki, M.B., Behesti, R.D., Saleh, B.A., Rollinson, D.H.L.: Performance and carcass composition of docked and control fat-tailed Kellakui lambs. Anim. Prod., 1973; 16: 57- 76.
- Fluharty, F.L., McClure, K.E.: Effects of dietary energy intake and protein concentration on performance and visceral organ mass in lambs. J. Anim. Sci., 1997; 75: 604-610.
- Juma, K.H., Karam, H.A., Al-Maali, H.NA., Al-Barazanji, J.: Effect of docking in Awassi sheep. Ind. J. Anim. Sci., 1974; 43: 931- 935.
- Vernon, R.G.: Lipid metabolism in the adipose tissue of ruminant animals. Prog. Lipid Res., 1980; 19: 23-106.
- Barber, M.C., Ward, R.J., Richards, S.E., Salter, A.M., Buttery, P.J. Vernon, R.G., Travers, M.T.: Ovine adipose tissue monounsaturated fat content is correlated to depot-specific expression of the stearoyl-CoA desaturase gene. J. Anim. Sci., 2000; 78: 62-68.
- Sanudo, C., Sierra, I., Olleta, J.L., Martin, L., Campo, M.M., Santolaria, P., Wood, J.D., Nute, J.R.: Influence of weaning on carcass quality, fatty acid composition and meat quality in intensive lamb production systems. Anim. Sci., 1998; 66: 175- 187.
- Enser, M., Hallett, K., Hewitt, B., Fursey, G.A., Wood, J.D.: Fatty acid content and composition of English beef, lamb and pork at retail. Meat Sci., 1996; 42: 443-456.
- Zygoyiannis, D., Stamataris, C., Catsaounis, N.: The melting point, iodine value, fatty acid composition and softness index of carcass fat in three different breeds of suckled lambs in Greece. J. Agr. Sci. Camb., 1985; 104: 361-365.
- L’Estrange, J.L., Hanrahan, J.P.: Some breed effects on the melting point and fatty acid composition of carcass fat in lambs. J. Agr. Sci. Camb., 1980; 95: 73-76.
- Crouse, J.D., Kemp, J.D. Fox, J.D., Ely, D.G., Moody, W.G.: Effect of castration, testosterone and slaughter weight on fatty acid content of ovine adipose tissue. J. Anim. Sci., 1972; 34: 384- 387.
- Vimini, R.J., Field, R.A., Crouse, J.D., Miller, G.J.: Factors affecting melting point of subcutaneous fat from heavy ram and wether lambs. Int. Goat Sheep Res., 1984; 2: 105-113.
- Daniel, Z.C., Richards, S.E., Salter, A.M., Buttery, P.J.: Insulin and dexamethasone regulate stearoyl-CoA desaturase mRNA levels and fatty acid synthesis in ovine adipose tissue explants. J. Anim. Sci., 2004; 82: 231-237.