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EFFECT OF GRASS OR CONCENTRATE FEEDING

SYSTEMS ON LAMB CARCASS AND MEAT

QUALITY

AUTHORS:

HAIZEA BENGOETXEA

EDURNE ZUDAIRE

JOSU BERGARA

YERAY LANZ

EDER SENDRA

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CONTENTS

1- Introduction

2- Material and methods

3- Results

4- Discussion

5- Conclusions

6- Bibliography

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(1) INTRODUCTION:

- The most important differences are in subcutaneous fat colour, meat flavour and carcase fatness

- Animals with concentrate diet have higher average daily gains

- Meat in a grass system is darker in colour

-The objective was to compare the meat quality when the lambs weight 35 kg

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(2) MATERIAL AND METHODS

- ANIMALS AND DIETS:

- FEED COLLECTION AND ANALISED:

- SLAUGHTER PROCEDURES:

- 32 male Ile-de-France lambs were divided in four equal groups.- A different type of food was given to each group of animals.

- The sampling was done by taking an area of 200cm2 per hectare of grass and making a cut of 3 cm.

- The animals were slaughters when they had had 35 Kg

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- MEAT INSTRUMENTAL QUALITY:

- MEAT SENSORY EVALUATION:

- CARCASS MEASUREMENTS:

- The carcasses were weighed and classified for muscular conformation and for fatness at the time of slaughter and 24 h later

- The right longissimus thoracic et lumborum muscle was excised 24 h post mortem and was determined the Ph

- Samples of longissimus lumborum were vacuum-packed

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- Individual animals were considered as experimental units - STATISTYCAL ANALYSIS:

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(3) RESULTS

DIETS CARACTHERISTICS:

The concentrate hadThe concentrate had:

- 18.2% of crude protein (CP)

- 24.7% neutral detergent fibre (NDF) on a dry matter basis.

CP NDF

Concentrate Diet

18.2% 24.7%

Grass diet 10.1% 59.2%

The grass had:The grass had: - 10.1% CP - 59.2% NDF

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ANIMAL PERFORMANCE:

– Animals of high growth level younger than low growth level animals in the same weight (about 35 kg).

– % of the digestive tract higher in the grass lambs than in the stall lambs.

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CARCASS CARACTHERISTICS:

– Carcasses formed grass lambs

» Had a lower muscular conformation

» Were less fatty than stall lambs.

– Lower proportion of fat

» Fat colour more yellow and they had harder fat than stall lambs.

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– MUSCLE INSTRUMENTAL QUALITY:

- The longissimus muscle ultimate pH higher for the grass lambs compared to the stall lambs

- The colour up to 24 h display was lighter in the stall lambs.

- Higher intramuscular fat content than grass lambs.

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SENSORY EVALUATION:

Meat from stall-fed lambs was more tender and juicy than from grass-fed lambs.

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(4) DISCUSSION:

- CONCENTRATE FEED AND GRASS FEED DIFFERENCES:

- Dry matter:

- Fatness:

- Colour of carcasses:

- The PH:

- Flavour and fatty flavour:

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(5) CONCLUSIONS:

COMPARISON:

– Grass fed vs concentrate fed– When? Slaughtered = body weight

THE GRASS LAMBS:

– lighter carcase – lower subcutaneous fat.

THE STALL LAMBS:

– softer fat – marginally tender to “livery flavour” and “fatty flavour”

notes.