Fatty acid profiles of muscle, liver, heart and kidney of Australian prime lambs fed different polyunsaturated fatty acids enriched pellets in a feedlot system

Abstract

We investigated the effect of various dietary polyunsaturated fatty acid (PUFA) sources on the fatty acid profiles of muscle, liver, heart and kidney of Australian prime lambs. Seventy-two White Suffolk x Corriedale first-cross lambs weaned at 6 months of age were randomly allocated to the following six treatments: (1) Control: Lucerne hay only; wheat-based pellets infused with 50 ml/kg dry matter (DM) of oil from (2) rice bran (RBO); (3) canola (CO); (4) rumen-protected (RPO), (5) flaxseed (FSO) and (6) safflower (SO) sources in a completely randomized experimental design. Lambs in CO, FSO, SO and RPO treatments achieved contents of eicosapentaenoic acid (EPA, 22:5n-3) plus docosahexaenoic acid (DHA, 22:6n-3) in the longissimus dorsi muscle ranging from 31.1 to 57.1 mg/135 g, over and above the 30 mg per standard serve (135 g) threshold for “source” claim under the Australian guidelines. There was no difference in n-3 LC-PUFA contents in longissimus dorsi muscle of lambs fed dietary oils of plant origin. The highest 18:3n-3 (ALA) contents achieved with FSO diet in the muscle, liver and heart were 45.6, 128.1 and 51.3 mg/100 g, respectively. Liver and kidney contained high contents of n-3 LC-PUFA (ranging from 306.7 to 598.2 mg/100 g and 134.0 to 300.4 mg/100 g, respectively), with all values readily exceeding the ‘good source’ status (60 mg per serve under Australian guidelines). The liver and kidney of PUFA fed lambs can be labelled as ‘good source’ of n-3 LC-PUFA based on EPA and DHA contents stipulated by the Food Standards of Australia and New Zealand guidelines. Therefore, if lamb consumers consider eating the liver and kidney as their dietary protein sources, they can adequately obtain the associated health benefits of n-3 LC-PUFA.

Genetics of Omega-3 Long-Chain Polyunsaturated Fatty Acid Metabolism and Meat Eating Quality in Tattykeel Australian White Lambs

“…Fat content and amount of fatty acids are quantified in mg/100g of meat [79], whereas human nutritionists assess nutrient value of food per 100 g of serve. For food to be categorised or claimed as a source of n-3 LC-PUFA in Australia and New Zealand, its EPA and DHA contents should be greater than 30mg per serve, and declared a good source if it has at least 60mg of EPA and DHA for each standard serve [79][80][81]. In Europe, it is 40mg per 100g [82].…”

Oilseeds in diets of fattening lambs

“…Dry matter (DM), minerals, crude protein (CP) and ether extract (EE) were analyzed according to the AOAC (1995). Neutral detergent fiber (NDF), acid detergent fiber (ADF), and lignin were determined as described by Van Soest et al (1991). To estimate total digestible nutrients in the diet, the percentage of non-fibrous carbohydrates were as calculated by Weiss et al (1992).…”

“…In intensive animal systems production, oilseeds can increase the energy density of diets (PEREIRA et al, 2016;HUMER et al, 2018). They have enough energy to supply the highest nutritional requirement of fattening animals, reduce time to achieve the slaughter weight, and enhance the nutritional quality of lamb meat (OLIVEIRA et al, 2017;GALLO et al, 2019;VAN LE et al, 2019).…”

“…Sheep present dietary limitations inherent to ruminants due to the presence of unsaturated fatty acids in the rumen (FERLAY et al, 2017;FREITAS JR et al, 2019). Oilseed sources are expected to show a different fatty acid profile, inducing different impacts on rumen microbes (JIAN et al, 2016) and animal performance (VAN LE et al, 2019). When whole grains are offered to ruminants, rumen microbes are less affected because fatty acids are released more slowly and depends of rumination (PALMQUIST and MATTOS, 2006), compared to oils.…”

Plasma Metabolites, Productive Performance and Rumen Volatile Fatty Acid Profiles of Northern Australian Bos indicus Steers Supplemented with Desmanthus and Lucerne

“…Lucerne is considered as one of the main perennial legumes in the world with an estimated world cropping area of 30 million ha (mainly located in North America, Europe, and South America), and an extensive use for ruminant livestock feeding systems in temperate Australia [10]. It is globally used due to its high quality crude protein (CP) content ranging between 14 and 24% on a dry matter (DM) basis [11][12][13][14], which induces an increase in animal production. McDonald et al [11] stated that in the Australian southern state of New South Wales, sheep wool and cattle LW increased by 10-20% when lucerne was included in pastures based on subterranean clover or phalaris.…”