Effects of Roughage Quality and Particle Size on Rumen Parameters and Fatty Acid Profiles of Longissimus Dorsi Fat of Lambs Fed Complete Feed

Abstract

The fatty acid composition for the longissimus dorsi (LD) fat of carcass sheep is a crucial factor impacting meat quality. We performed a 90-day feeding trial of 25 Naemi lambs to investigate the effects of roughage sources (alfalfa or wheat straw) of two sizes (regular and 1 cm chopped) when fed with pelleted total mixed ration (TMR) on the growth performance, fermentation patterns, and fatty acid (FA) composition of longissimus dorsi (LD) fat. Lambs were randomly assigned to individual pens with five treatment diets, as follows: C, control group with TMR; T1, TMR and regular alfalfa hay; T2, TMR and alfalfa hay chopped to 1 cm; T3, TMR and regular wheat straw; and T4, TMR and wheat straw chopped to 1 cm. Four lambs were randomly selected from each treatment (20 total) and sacrificed. LD fat of the carcass was extracted and analyzed for FA using a gas chromatography-mass spectrometry. Significantly increased feed intake was found in T1 and T2. The FA composition of LD fat in T2 had higher unsaturated fatty acid (UFA), omega-6 (n6), and omega-3 (n3) FA content. Conjugated linoleic acid (CLA) and α-linoleic acid were highest in lambs fed T1 and T2. Feeding different types of roughage, especially alfalfa hay, either regular or chopped, with total pelleted mixed ration is crucial to improving feed intake and body weight gain, as it positively enhances the rumen microbial fermentation process by controlling rumen pH. The FA profiles of meat from lambs fed TMR with regular or 1 cm particle size alfalfa hay (T1 and T2) are recommended for human consumption as a source of healthy FAs.

Evaluation of Mutton Quality Characteristics of Dongxiang Tribute Sheep Based on Membership Function and Gas Chromatography and Ion Mobility Spectrometry

“…Sheep fat is similar to fat from other ruminants such as cattle. Consistent with our results, the fats in ruminant sediments include mainly saturated and monounsaturated fats, and C16:0, C18:0, and C18:1 c9 account for approximately 80% of the total fatty acids (47). Studies have shown that an increased C18:0 content makes mutton taste heavier (goaty), and the Dongxiang tribute mutton had the lowest C18:0 content (48).…”

Comparative feed management system in sheep fed different physical forms of ration containing Ipomoea aquatica on the performance, rumen characteristics, and chewing activity

“…The ADG was 150 gm and the average FCR was 7.71. It means that particle size did not affect total DMI or organic matter (OM) intake in sheep, as reported by previous researchers [16 , 17] .…”

“…The FCR of the RCF (6.32) and PCF (7.63) lambs was better than that of feedlot lambs (8.61–9.07), as reported by Saldanha et al [20] . Matar et al [16] reported FCRs of 7.12–8.05 using a pelleted TMR.…”

Nutritional Enhancement of Health Beneficial Omega-3 Long-Chain Polyunsaturated Fatty Acids in the Muscle, Liver, Kidney, and Heart of Tattykeel Australian White MARGRA Lambs Fed Pellets Fortified with Omega-3 Oil in a Feedlot System

“…The fatty acid content of meat can be affected by the animal production system [21,22], breed or genotype [23,24], gender [25], age at slaughter [26], liveweight [27], level of fatness [20], type of muscle and feed. In lamb [28], cattle, swine, and poultry [29], it has been suggested that dietary manipulation can be utilized to improve the fatty acid content and nutritional value of meat that more closely meets nutritional guidelines. However, due to extensive rumen microbial biohydrogenation in ruminants, dietary polyunsaturated fatty acids (PUFA) are converted to saturated fatty acids (SFA), absorbed in the small intestine, and deposited in edible tissues (muscles), products (milk), and organs (liver, kidney and heart), thereby causing more health challenges to consumers [30,31].…”