Use this URL to cite or link to this record in EThOS: https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.797340
Title: Enhancing the eating quality of concentrate fed lambs
Author: Hamo, Reyzan
ISNI:       0000 0004 8503 5113
Awarding Body: Harper Adams University
Current Institution: Harper Adams University
Date of Award: 2019
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Abstract:
Two studies were carried out to investigate the effect of dietary concentrate carbohydrate and fat source, and vitamin E level on animal performance, carcass composition and meat quality of concentrate fed lambs. In the first study, forty Suffolk cross Texel ewe lambs were blocked by live weight (LW) into four treatments (ten lambs/treatment): Grazed grass (G), barley based concentrate (B), dried grass based concentrate (DG) and sugar beet based concentrate (SB). The three concentrate diets were formulated to provide a similar level of crude protein, ether extract and an effective rumen degradable protein/fermentable metabolisable energy ratio > 10.0 g/MJ. Diets DG and SB provided a similar water soluble carbohydrate content, but different proportions of neutral detergent fibre, whereas, in diet B the energy was supplied mainly as starch. Diet B contained Megalac© (rich in saturated fatty acids), whereas diets DG and SB contained linseed oil (high in C18:3n-3). Diet B was formulated to contain 60 mg vitamin E (α-tocopherol-acetate)/kg DM, and diets DG and SB to contain 250 mg vitamin E (α-tocopherol-acetate)/kg DM. Lamb performance on diet G was lower than that of those fed the concentrate diets. Concentrate carbohydrate source, fat source and vitamin E concentration did not affect animal performance, carcass composition or carcass measurements. Lambs fed diets DG or SB had a similar muscle C18:3n-3, C20:5n-3, cis-9, trans-11 CLA, n-6:n-3, C18:2n-6: C18:3n-3 and vitamin E content to those finished on grass. Lambs fed on either the grass orconcentrate diets had similar lipid stability and sensory evaluation characteristics. In the second study, forty Suffolk cross Texel wether lambs were blocked and allocated by live weight to one of four treatments: Grazed grass (FG) or one of three iso-energetic and iso-nitrogenous diets, based on barley that contained Megalac© with 250 mg vitamin E (α-tocopherol-acetate)/kg DM (BML), or linseed oil at two levels of vitamin E 250 (BLL) and 500 (BLH) mg/kg DM. Lambs fed the concentrate diets had a higher live weight gain than those finished on grass. Concentrate fat source and vitamin E level did not affect lamb performance, although lambs finished on BLH tended to have a lower feed conversion ratio compared to those fed diet BLL. Compared to lambs fed BML, the C18:3n-3, C20:5n-3 and C22:6n-3 content of longissimus dorsi muscle from lambs fed diets BLL or BLH were increased, although, cis-9, trans-11 CLA was low compared to lambs fed diet FG or those diet DG (experiment 1). Muscle derived from lambs finished on BML or BLH had an enhanced shelf life (colour and lipid stability) compared to those fed BLL or FG. Neither grass nor concentrate diets affected the sensory attributes of lambs as perceived by consumers. Overall, the meat quality of concentrate fed lambs can be improved by inclusion of linseed oil with supra-nutritional vitamin E.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.797340  DOI: Not available
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