Comparison of meat and carcass quality in organically reared and conventionally reared pasture-fed lambs

Abstract

The 'Organic' product label guarantees a production process that avoids the use of synthetic fertilisers, pesticides and hormones and minimises recourse to pharmaceuticals or veterinary drugs; however, the product's quality remains an issue that needs to be addressed in response to consumer demand. Consequently, this study was conducted to compare the sensory and nutritional qualities of meat and carcasses from pasture-fed lambs reared organically (O) or conventionally (C). Mean lamb growth profile was kept similar between the two treatments to avoid confounding effects with lamb age or weight at slaughter. The experiment was conducted over 3 years (2005 to 2007) with 12 O and 12 C lambs each year. The O and C treatments differed in the level of on-pasture mineral N fertilisation inducing a higher proportion of white clover in the organic pasture than the conventional pasture. Lambs were slaughtered when they attained a fat class of 2 to 3, and carcass and meat quality were evaluated. Lambs were slaughtered at an average weight and age of 35.3 kg and 156 days in the O treatment, respectively, and 35.2 kg and 155 days in the C treatment, respectively. Sensory evaluation indicated that loin chops from the O treatment had a higher level of abnormal fat odour compared with the C treatment. Carcasses from the O treatment had a softer subcutaneous fat one among 3 years (2007) compared to the C treatment. These results are probably due to a higher proportion of white clover in the diet. Organically reared lambs did offer the slight advantage of muscle fatty acid containing a higher level of stearic acid, which may have positive effects in the prevention of cardiovascular disease in humans. This may be the result of a higher rumen bio-hydrogenation of C18:3n-3 due to differences in the botanical composition between the O and the C pasture. Production system had no effect on the colour characteristics of the meat and subcutaneous fat, except lightness of subcutaneous dorsal fat, which was slightly higher in the O lambs. There were no differences between O and C lambs in terms of colour stability and lipid oxidation of the meat during the 6-day refrigerated storage under gas-permeable film.

Effect of the Type of Pasture on the Meat Characteristics of Chilote Lambs

“…The fatty acid levels obtained with naturalized pasture were similar those obtained with different pasture types by Aurousseau, 2004 [29], Lourenço, 2007 [18], and Prache, 2011 [20], with the exception of palmitic acid, which presented higher values with both pasture types. Likewise, Aurousseau, 2007 [7] found markedly lower values for all the fatty acids analyzed in meat of animals fed on natural pasture.…”

“…Although there are different feeding systems (concentrates, pasture or mixed), pasture-based feeding has acquired importance because resulting meat products are viewed by consumers as more natural, healthier, less contaminated and more respectful to animal welfare [16] [17]. Because of this perception, there have been several studies [18]- [20] to determine if the type of pasture and pasture composition affects the quality of ovine meat. To date, there is little information about Chilote lamb meat quality.…”

Influence of breed and feeding on the main quality characteristics of sheep carcass and meat: A review

“…Research on carcass quality is generally conducted under optimal productive conditions and there has been relatively little research conducted under less favorable conditions (Fraser et al, 1996;Prache et al, 2011), because of which it is necessary to consider systems in which productive conditions are more restricted, such as grazing in areas with naturalized or natural grasslands. Ramírez-Retamal et al (2013) compared the main characteristics of the carcasses of Chilote lambs feed on naturalized pasture or natural rangeland and did not find differences resulting from the grassland types used by small-scale producers in Chiloe Island, Chile.…”

Qualités des viandes : influences des caractéristiques des animaux et de leurs conditions d'élevage

“…Deux études sur la viande ovine illustrent cette difficulté. La première, basée sur la comparaison de côtelettes issues d'élevages AB ou conventionnels achetées dans le commerce, concluait que la viande AB présentait des qualités sensorielles et nutritionnelles supérieures (Angood et al 2008 (Prache et al 2011). Dans cette étude, la viande d'agneaux de bergerie présentait une qualité nutritionnelle supérieure en AB, la qualité sensorielle étant similaire pour les deux modes de production.…”

“…De manière générale, l'élevage AB, en promouvant le pâturage, contribue à améliorer la valeur santé de la viande via la nature des AG déposés (Aurousseau et al 2004). De plus, les prairies AB sont souvent plus riches en légumineuses, ce qui est favorable à la teneur de la viande en AGPI n-3 (Lourenço et al 2007), mais risque d'augmenter les défauts de flaveur (Prache et al 2011, Devincenzi et al 2014. Comme les légumineuses sont essentielles pour l'autonomie alimentaire des élevages, les recherches s'orientent vers la mise au point de pratiques d'élevage permettant de limiter l'occurrence de ces défauts.…”