Effects of dietary lipid type on muscle fatty acid composition, carcass leanness, and meat toughness in lambs

Enhancing lamb growth and meat quality: analysis of kazakh fat-tailed and crossbred in central Kazakhstan's sharply continental climate

The article presents the results of scientific research on the production of lamb in the conditions of the Akmola region. The experiment was conducted on purebred Kazakh short-tailed rough-haired and cross-bred sheep obtained from industrial crossing of Kazakh short-tailed rough-haired queens with sheep- producers of the hampshire breed. Further, the article presents the results of feeding and fattening, as well as the morphological composition of the carcass of sheep of the Kazakh coarse-haired sheep breed of different ages. The object of the study for feeding and fattening were three groups of experimental sheep of the above-mentioned breed, where compound feed was included in the diet of the I experimental group in the form of top dressing, in the II experimental group, grain waste was also used for top dressing, and the control group was kept in the feed without top dressing. Based on the study of the feeding of experimental sheep, it was found that the absolute increase during the feeding period in experimental sheep who received fertilization in the form of compound feed is higher than in their peers, respectively, by 0.2 and 1.49 kg. In terms of morphological and varietal composition, in particular, the number of cuts of grade 1, there was also an advantage of experimental sheep that received fertilization in the form of compound feed compared to their peers, respectively, by 2.3-8.3%. In general, the results of a study on the growth, development and slaughter qualities of experimental sheep, i.e. purebred Kazakh short-tailed rough-haired and crossbred, obtained from crossing with sheep producers of the precocious breed "hampshire" showed that from the moment of birth to 2 and 4 months. For example, crossbred sheep were slightly superior to purebred peers in terms of the studied indicators. In particular, the results of feeding sheep of the Kazakh coarse-haired broad-tailed breed from 4 to 6 months, depending on the top dressing.

Insights into the influence of diet and genetics on feed efficiency and meat production in sheep

Feed costs and carcass yields affect the profitability and sustainability of sheep production. Therefore, it is crucial to select animals with a higher feed efficiency and high-quality meat production. This study focuses on the impact of dietary and genetic factors on production traits such as feed efficiency, carcass quality, and meat quality. Diets promote optimal sheep growth and development and provide sufficient protein can lead to higher-quality meat. However, establishing an optimized production system requires careful consideration and balance of dietary parameters. This includes ensuring adequate protein intake and feeding diets with higher intestinal absorption rates to enhance nutrient absorption in the gut. The study identifies specific genes, such as Callipyge, Calpastatin, and Myostatin, and the presence of causal mutations in these genes, as factors influencing animal growth rates, feed efficiency, and meat fatty acid profiles. Additionally, variants of other reported genes, including PIGY, UCP1, MEF2B, TNNC2, FABP4, SCD, FASN, ADCY8, ME1, CA1, GLIS1, IL1RAPL1, SOX5, SOX6, and IGF1, show potential as markers for sheep selection. A meta-analysis of reported heritability estimates reveals that residual feed intake (0.27 ± 0.07), hot carcass weight (0.26 ± 0.05), dressing percentage (0.23 ± 0.05), and intramuscular fat content (0.45 ± 0.04) are moderately to highly heritable traits. This suggests that these traits are less influenced by environmental factors and could be improved through genetic selection. Additionally, positive genetic correlations exist between body weight and hot carcass weight (0.91 ± 0.06), dressing percentage (0.35 ± 0.15), and shear force (0.27 ± 0.24), indicating that selecting for higher body weight could lead to favorable changes in carcass quality, and meat quality.

Corncob biochar supplementation improves nutrient digestibility, fattening performance and carcass characteristics of fattening sheep

BACKGROUND

Corncob is a cheap source for biochar in developing countries. No studies reported on use of biochar as sheep fattening supplement.

OBJECTIVES

The goal of this study is to determine the effect of corncob biochar supplementation on growth performance and carcass characteristics of sheep.

METHODS

Twenty-four Horro yearling rams (18.6 ± 0.938 kg live weight) were randomly distributed to four groups, control (300 g/day concentrate + local hay ad libitum), BC1.5 (control +1.5 g/day biochar), BC3 (control +3 g/day biochar) and BC4.5 (control +4.5/day biochar). The experimental concentrate consisted of 200 g/day wheat bran and 100 g/day Noug cake. The study consisted of a growth trial of 111 days followed by a digestibility trial of 10 days. Carcass characteristics for all rams were recorded at the end of the trial.

RESULTS

Dry matter intake, crude protein intake, dry matter digestibility and acid detergent fibre digestibility of BC1.5 were significantly higher than the control. Corncob biochar supplementation significantly improved daily weight gain and feed conversion ratio of the rams. Supplementation sheep with corncob biochar improved significantly dressing percentage, hindquarters weight, forequarters weight, ribs weight, brisket weigh and rib eye muscle area. There was a significant effect of the dietary treatment on weight of internal organs; however, they were all within the normal range of sheep.

CONCLUSIONS

Corncob biochar supplementation would be recommended at a level of 1.5 g/day to improve growth performance and carcass characteristics of sheep.

Enrichment of Dairy-Type Lamb Diet with Microencapsulated Omega-3 Fish Oil: Effects on Growth, Carcass Quality and Meat Fatty Acids

The hypothesis that adding omega-3 oil to feedlot pellets will improve the meat's favourable n-3 PUFA composition was tested in this experiment. Therefore, we evaluated the productive traits and modification of the composition of n-3 PUFA of Longissimus lumborum (LL) muscle in growing lambs supplemented with microencapsulated omega-3 oil (MEOIL) in pelleted total mixed rations (TMR). Thirty six one month old Valle del Belice male lambs (14.04 ± 0.1 kg) were randomly distributed to one of the three dietary treatments (n = 12 lambs each) and provided the supplemented diets up to 14 weeks of age: 1. control (CON) pelleted TMR without omega-3 oil supplementation; 2. omega-3 oil fortified pelleted TMR at 1% (MEOIL1) supplementation; and 3- Omega-3 oil fortified pelleted TMR at 3% (MEOIL3) supplementation. Supplementing MEOIL at both levels in diet positively impacted (p < 0.05) body weight (BW) and feed efficiency. At the end of feeding period, most carcass quality traits did not vary significantly (p > 0.05) among groups, with the exception of carcass dressing and loin yield at both levels of MEOIL. The color and physical traits of LL muscle were affected by MEOIL supplementation (p < 0.05), with no significant change in chemical characteristics. Fatty acids composition of meat in term of linolenic, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were significantly (p < 0.05) influenced by both levels of MEOIL. It was concluded that the tested microencapsulated omega-3 oil preparation may be included at 1% in lamb diet for increasing unsaturated fatty acids in meat without any detrimental effects on lamb productivity.

Introducing Mediterranean Lupins in Lamb Diets: Effects on Carcass Composition, Meat Quality, and Intramuscular Fatty Acid Profile

The objective of this preliminary study was to evaluate the effects of partial replacement of soybean meal by lupins on lambs’ diets, on the carcass traits, meat characteristics, and meat fatty acid profile. Two trials were conducted: In trial 1, the soybean meal (control; C) was partially replaced by Lupinus albus or Lupinus luteus (50 g/kg; LA5 and LL5, respectively); in trial 2, lambs were fed four diets with graded levels of Lupinus luteus (0, 100, 150 and 200 g/kg; C, LL10, LL15, LL20, respectively). At the end of the feeding trials, animals were slaughtered to evaluate carcass characteristics and meat composition, including fatty acids. Carcass composition in tissues was not affected (p > 0.05) by diet in both trials. Additionally, no significant (p < 0.05) differences were observed in meat quality attributes between diets in trials 1 and 2. Overall, the Longissimus muscle’s fatty acid content was not affected by diet (p > 0.05) in both trials. Carcass and meat quality was overall comparable between lambs fed with soybean meal and lupins, indicating the latter as a potential alternative protein source. However, the lack of significant differences could also be attributed to the small sample size.

Oxidative Status of Marchigiana Beef Enriched in n-3 Fatty Acids and Vitamin E, Treated With a Blend of Oregano and Rosemary Essential Oils

The aim of this study was to evaluate the effects of basal dietary supplementation with linseed and linseed plus vitamin E in Marchigiana young bulls on the instrumental color, oxidative stability, and fatty acid composition of beef steaks with and without treatment with a blend of essential oils (oregano and rosemary) after storage times of 0, 3, 6, and 9 days. The fatty acid composition was evaluated in meat after 0 and 9 days of storage. No variation in the fatty acid composition of each type of meat was observed after storage. The use of dietary linseed and vitamin E, compared with linseed alone, significantly improved the oxidative stability, lightness (L*), and redness (a*) of the meat. A higher degree of oxidation was observed in meat samples from animals in the group fed linseed (L) followed by the control group (C) and the group fed linseed and vitamin E (LE). Moreover, the essential oils treatment (O) exerts a significant effect on beef oxidative stability of the group LE more than groups C and L during storage. The fatty acid composition of the meat was also affected by the diet: levels of healthful fatty acids (PUFA, n-3 PUFA, and CLA) were higher in meat from the groups that received linseed than the control group. Our results suggest that dietary vitamin E and treatment with essential oils are effective approaches to preserving the stability of beef cattle receiving a diet enriched in unsaturated fatty acids for up to 9 days of storage.

Breed and Nutrition Effects on Meat Quality and Retail Color after Lamb Pre-Slaughter Stress

The main objective of this research was to investigate the interactions between breed, nutrition and pre-slaughter stress, and the potential impacts on the meat quality and retail color/shelf life of lamb meat. Forty-eight Merino and second cross (Merino × Border Leicester) × Poll Dorset lambs were allocated to 2 dietary treatments: low energy diet (LE; 7.8 MJ ME/kg and 12% CP) vs. high energy (HE; 11.8 MJ ME/kg and 12% CP). Samples of longissimus lumborum (LL), and rectus femoris (RF) were taken 15 min post-slaughter for glycogen and lactate determination. pH and temperature of muscle samples were recorded at 0.5, 1.5, 3, 4.5, 6, and 24 h post-mortem. Muscle LL samples from the same side were collected at 24 h post slaughter for tenderness, cooking loss and retail color assessment. For retail color stability, the selected portion of muscle LL was sliced to create a fresh surface, placed on a tray and over wrapped. Color measurements were made fresh (after a 30 min bloom at 4°C, d 1) and then on d 3 and 6 of display, using a Hunter lab spectrophotometer XE Plus. Second-cross lambs on HE had the highest muscle glycogen at slaughter for both LL and RF. For the RF, the pHu values were elevated in Merinos on both LE and HE diets and 2X on the LE diet. Only for 2X lamb was the HE diet sufficient to reduce the pHu. HE diet reduced blood lactate in 2X lambs and elevated in Merinos. Merinos produced tougher meat at 6 d post-slaughter, which was also reflected by higher cooking losses. Both breeds of lambs on the LE diet had longer color shelf-life (higher R630/580) than the lambs on the HE diets.

Replacing sunflower oil by rumen-protected fish oil has only minor effects on the physico-chemical and sensory quality of Angus beef and beef patties

In the present study, the effects of feeding 450 g/day of rumen-protected fish oil (FO) compared to sunflower oil (SO) to Angus heifers (60 g/kg total intake) were quantified. Animal performance was not affected whereas the physico-chemical meat quality, assessed in three muscles, was slightly affected by diet. The oxidative shelf life of the perirenal fat declined with FO compared to SO. Despite the formerly shown increased n-3 fatty acid proportions of meat due to FO supplementation, a trained sensory panel identified an only slightly more intense fishy flavour in grilled steaks and beef patties from the FO compared to the SO group. In FO compared to SO patties, flavour intensity was more pronounced. The perception of off-flavours was negligible and differences between muscles were larger than between diets. In conclusion, supplementing ruminants with FO containing nutritionally beneficial n-3 fatty acids results in few side-effects on meat quality, restricted to quite faint off-flavours and a shorter fat shelf life.

Fatty acid composition and physicochemical and sensory characteristics of meat from ewe lambs supplemented with zilpaterol hydrochloride and soybean oil

The effects of supplementation of zilpaterol hydrochloride (ZH; 0 or 10 mg/lamb daily) and soybean oil (SBO; 0% or 6%) on carcass traits, body fat deposition, chemical, physicochemical, sensory quality, and fatty acid composition of the longissimus thoracis muscle (LTM) of ewe lambs were studied using a randomised complete design with a 2 × 2 factorial arrangement. After a 32-day feeding period, all ewes were slaughtered and LTM collected. Interactions between ZH × SBO were not observed (P > 0.05) for any of the variables evaluated. Feedlot performance was not modified (P > 0.05) by ZH and SBO supplementation. Biological yield and hot carcass weight were increased by ZH supplementation (P < 0.05). ZH and SBO supplementation did not alter body fat deposition (kidney, pelvic and heart, renal, thickness and intramuscular fat) and the empty bodyweight (P > 0.05). Meanwhile, feeding ZH decreased colour parameters (L*, a*, b* and CHROMA) (P < 0.05), but not others characteristics of LTM (P > 0.05). Sensory panelists observed an increase in appearance (P < 0.001) by ZH supplementation. Additionally, ZH decreased (P < 0.05) the content of C20:5n3 (eicosapentaenoic acid), C22:6n-3 (docosahexaenoic acid) and total omega-3 fatty acids, compared with the zero ZH group. Physicochemicals and sensory characteristics, and fatty acid composition of meat were not modified by SBO (P > 0.05). In conclusion, ZH supplementation to ewe lambs increased biological yield and hot carcass weight, without changes in body fat deposition and decreased eicosapentaenoic acid, docosahexaenoic acid and omega-3 contents and caused a decrease in colour of LTM. However, feeding SBO caused no changes in the carcass or meat quality traits and minimal changes in fatty acid composition of LTM.

The Effect of Extensive Feeding Systems on Growth Rate, Carcass Traits, and Meat Quality of Finishing Lambs

This review aims to summarize the relevant published information about the effects of extensive feeding systems on the carcass and meat quality characteristics of lambs. Lambs finished in a feedlot or with supplementation under extensive systems exhibit faster growth rates, achieve target weights quicker, and produce heavier carcass weights when compared to grazing lambs. However, the literature also shows that finishing lambs on high-quality pasture can produce satisfactory growth rates without compromising carcass and meat quality traits. Lately, the consumer demand for products perceived as "healthy" and that are produced where animal welfare is optimal under systems which do not impact negatively on the environment, has heightened the interest in lamb production under extensive systems. Lambs raised on pasture can meet many of these specifications. Also, lambs fed higher quality green pasture can produce meat with greater amounts of health-claimable omega-3 fatty acids such as eicosapentaenoic acid plus docosahexaenoic acid than feeding systems based on feedlot pellets, grain, or dry pasture/straw. It is apparent that in some previous published research, the number of animals allocated for each treatment, and the lack of replicates, makes it difficult to formulate a correct understanding of the effect of forages on lamb carcass and meat quality. Future research should concentrate on the effect of legume, improved pasture, and specialized forage finishing systems on growth rate, carcass traits, and nutritional value of meat using well-designed experiments with an adequate number of lambs and appropriate paddock replicates per treatment.

Influence of Maternal and Postweaning Linseed Dietary Supplementation on Growth Rate, Lipid Profile, and Meat Quality Traits of Light Sarda Lambs

The effects of dietary extruded linseed (EL) on growth performance, meat quality, and lipid profile of Semimembranosus and Longissimus lumborum muscles of 81 Sarda lambs were studied in a 3 × 3 design: EL content (0%, 10%, and 20%) of maternal dietary concentrate fed from 20 d to parturition to 60 d of lactation and EL content (0%, 10%, 20%) of lamb concentrate fed after weaning for 30 d. The basal diet was composed of alfalfa and meadow hay during pregnancy and alfalfa hay during lactation. At slaughter, carcass and meat quality were evaluated. Sensory quality of Semimembranosus from 0% and 20% EL lambs was assessed. Both maternal and postweaning diets affected growth performance, with higher body weights recorded with the 10% EL concentrate. Carcass and meat quality were not affected by diet. Saturated and monounsaturated FA decreased and n-3 polyunsaturated FA increased with increasing EL content in lamb diet. An increase in vaccenic and rumenic acid was associated with the EL content of the maternal diet. Both diets increased the n-6/n-3 FA ratio. No differences in acceptability were detected by consumers among groups. It is concluded that EL supplementation and early life nutrition can influence performance and FA metabolism in growing lambs.

Effect of feed restriction and different crude protein sources on the performance, health status and carcass traits of growing rabbits

<p>We evaluate the effect of the crude protein source (CP) in combination with 2 feeding strategies (AL: ad libitum or R: restricted) on the performance, health status and carcass traits of growing-fattening rabbits (between 33 and 75 d of age). Two experimental diets were formulated; the first containing soybean meal (SBM: 70 g/kg) as the main CP source and the second containing white lupin seeds (WLS: 105 g/kg) as the main CP source. A total of 160 weaned Hyplus rabbits (774±10 g live weight) were randomly allocated to the experimental groups, combination of feeding strategy and diet (AL SBM, R SBM, AL WLS and R WLS; 40 rabbits per group with 4 rabbits per cage), for 42 d. The feeding programme was applied as follows: both the AL SBM and AL WLS rabbits were fed ad libitum for the entire fattening period, whereas the R SBM and R WLS rabbits were subjected to feed restriction between 33 and 47 d of age (75% of the ad libitum intake). Afterwards, all restricted rabbits were fed ad libitum until 75 d of age. Regardless of the CP source, the feed restriction reduced the final live weight by 83 g, chilled carcass weight by 65 g, and dressing out percentage by 0.9 percentage points (P&lt;0.05). There was a higher chilled carcass weight (+114 g; P=0.001) and reference carcass weight (+91 g; P=0.001) in rabbits fed with WLS diet than in rabbits fed with SBM diet. No dead or morbid rabbits were observed in restricted rabbits during the restriction period. There was no effect of the diet on the health of rabbits. However when the rabbits of AL SBM and AL WLS group were compared did we observe a lower number of rabbits at sanitary risk in AL WLS group (2 vs. 12 rabbits, P=0.006). In conclusion, the growth performance was not affected by the crude protein source, and no interaction between dietary CP source and feeding regime was observed. Feed restriction regime did not improve sanitary risk index throughout the entire period.</p>

Rate of carcass components gain, carcass characteristics, and muscle longissimus tenderness in lambs fed dietary protein sources with a low quality roughage diet

An experiment was conducted to examine the effects of infrequently fed (twice/week) protein supplements on rate of carcass components gain, carcass traits and tenderness of meat in lambs. Forty-three Dorset Horn×Merino wether lambs (aged 4 months) were assigned by stratified randomization (live weight basis) to five dietary treatments to compare the results with lambs fed very low quality (5.1 MJME/day) roughage diet. Lambs on control diet (BAS; treatment 1) and all other dietary treatment groups were offered ad libitum amounts of a mixed roughage diet (oat hay:lucerne hay) at the ratio of 85:15 throughout the 10-week experimental study. Supplements of barley grain with added urea and sulphate (USB, 226 g DM/day; treatment 2); lupins (LUP, 231 g DM/day; treatment 3); cottonseed meal (CSM, 152 g DM/day; treatment 4); fish meal (FM, 97 g DM/day; treatment 5) were offered at isonitrogenous amounts. Final live weight (FLW) and empty body weight (EBW) were greater (P<0.01) with FM, LUP, USB and CSM when compared with BAS. Rates of gain of carcass components observed during the experimental period resulted in lower carcass fatness (P<0.05) and greater muscle content (P<0.01) with FM; and higher (P<0.05) level of fat and muscle in the carcass with LUP compared to those on BAS diet. Other diets (USB and CSM) had less marked effects, but higher rate of daily fat gain in the carcass with LUP and CSM was indicated by greater carcass fat depth (P<0.05; the total tissue depth of muscle and fat at the twelfth rib, 110 mm from the midline; GR) and content of intramuscular fat (P<0.05), respectively. Energy gained as fat in the carcass was lowest with FM (P<0.05), highest with BAS and intermediate with all other treatments. The increase in carcass leanness and reduction in fatness with FM and USB compared to BAS and other treatments affected neither (P>0.1) meat tenderness (Warner-Bratzler shear force) nor sarcomere length of longissimus thoracis muscle. Feeding small amounts of protein supplements to lambs on very low quality forage diets during dry seasons may be a viable path to improve the carcass weight and leanness in lambs without changing the meat tenderness.

Performance, carcass characteristics and chemical composition of beef affected by lupine seed, rapeseed meal and soybean meal

To test the effects of different protein sources and levels on performance, carcass characteristics and beef chemical composition, concentrates with three protein sources [Lupine seed (L), Rapeseed meal (R) and Soybean meal (S)] and two protein levels ['normal protein' (NP) or 'high protein' (HP)] were fed to 36 Simmental calves. Calves initially weighed 276 +/- 3.9 kg and averaged 6 months of age and were randomly allocated to the six treatments. Maize silage was offered ad libitum and supplemented with increasing amounts of concentrates (wheat, maize grain, protein sources, vitamin-mineral mix). Normal protein and HP diets were formulated to contain 12.4% and 14.0% crude protein (CP) dry matter (DM) respectively. At the end of the fattening period of 278 days, the final live weight averaged 683 +/- 14.7 kg. Neither level of protein nor its interaction with protein sources had any effects on most of the traits studied. Feeding the R diet significantly increased final weight, average daily gain (ADG), DM intake and CP intake in relation to the L diet; no differences were observed between the L and S diets for these measures. No differences were observed between the R and S groups in final weight or ADG, but the calves fed the R diet consumed more DM and CP than the calves fed the S diet. Bulls fed R diet had higher carcass weight and dressing percentage than the L groups, and no significant differences were detected between the S and L groups. Chemical composition of the Musculus longissimus dorsi was not significantly affected by source of protein. Also, the major saturated fatty acid (SFA) (C16:0 and C18:0) did not significantly differ among the three treatments. Samples from R group had significantly higher proportions of C16:1 t9, C18:1 c11, C18:2 c9 t11, C18:3 c9, 12, 15 and SigmaC18:1 t fatty acids in relation to L and S groups. Although polyunsaturated fatty acid/SFA ratio was similar for the three dietary groups, n-6/n-3 ratio and Sigman-3 fatty acids content were significantly greater for bulls fed R diet in relation to those fed L and S diets.

Fatty acid composition of minced meat, longissimus muscle and omental fat from Small East African goats finished on different levels of concentrate supplementation

Effects of supplementing Small East African (SEA) goats with concentrate diets on fatty acids composition of minced meat, M. longissimus dorsi (LD) and omental fat were assessed using 23 animals (14.5 months old and 20.1 kg body weight). Goats were subjected to four levels of concentrate supplementation: ad libitum concentrate allowance (T100), 66% (T66), 33% (T33) and 0% (T0) of ad libitum concentrate allowance. All goats were slaughtered after 90 days of experimental period. Minced meat from concentrate-supplemented goats had higher (P<0.05) proportions of unsaturated fatty acids (UFA), monounsaturated fatty acids (MUFA) and desirable fatty acid (DFA) than that of non-supplemented ones (T0). Minced meat from T00 and T66 goats had similar proportions of polyunsaturated fatty acids (PUFA) and n-6 PUFA that were higher (P<0.05) than that of other dietary groups. There was limited variation in fatty acids composition of LD attributable to concentrate supplementation. Trans-vaccenic and linoleic acids were in higher (P<0.05) proportion in omental fat from concentrate-supplemented goats whereas margaric and arachidonic acids were in higher (P<0.05) proportion in omental fat from non-supplemented goats. Overall, LD was associated with PUFA, omental fat with saturated fatty acids (SFA), minced meat with MUFA. It is concluded that finishing SEA goats on concentrate diets will increase the proportion of DFA in meat from them. In addition, the proportion of PUFA in meat from such goats will peak at concentrate supplementation equivalent to 66% of their ad libitum intake. Consumers should avoid high intake of internal fat due to their richness in SFA.

Alpha-linolenic acid and its conversion to longer chain n-3 fatty acids: benefits for human health and a role in maintaining tissue n-3 fatty acid levels

There is little doubt regarding the essential nature of alpha-linolenic acid (ALA), yet the capacity of dietary ALA to maintain adequate tissue levels of long chain n-3 fatty acids remains quite controversial. This simple point remains highly debated despite evidence that removal of dietary ALA promotes n-3 fatty acid inadequacy, including that of docosahexaenoic acid (DHA), and that many experiments demonstrate that dietary inclusion of ALA raises n-3 tissue fatty acid content, including DHA. Herein we propose, based upon our previous work and that of others, that ALA is elongated and desaturated in a tissue-dependent manner. One important concept is to recognize that ALA, like many other fatty acids, rapidly undergoes beta-oxidation and that the carbons are conserved and reused for synthesis of other products including cholesterol and fatty acids. This process and the differences between utilization of dietary DHA or liver-derived DHA as compared to ALA have led to the dogma that ALA is not a useful fatty acid for maintaining tissue long chain n-3 fatty acids, including DHA. Herein, we propose that indeed dietary ALA is a crucial dietary source of n-3 fatty acids and its dietary inclusion is critical for maintaining tissue long chain n-3 levels.

Suitability of Norwegian short-tail lambs, Norwegian dairy goats and Cashmere goats for meat production - Carcass, meat, chemical and sensory characteristics

Six female Norwegian lambs (29kg body weight, 8 months old), six castrated Norwegian goats (27kg body weight, 10 months old) and six castrated Cashmere goats (20kg body weight, 8 months old) were used to study the relative potential of Norwegian lambs, Norwegian goats and Cashmere goats for meat production. Animals were fattened on silage and commercial concentrate before slaughter. Lamb meat had 4 % lower (P<0.05) proteins and 13% higher (P<0.05) fat content than goat meats. Moreover, m. longissimus dorsi samples from lambs were less red (a(∗)) (P<0.05) and had lower colour intensity (C) and wider hue angle (H) than that from goats. Meat from lambs and Cashmere goats had higher proportions of saturated fatty acids (SFA) (P<0.001), especially stearic acid and lower ones for total unsaturated fatty acids (TUFA) and monounsaturated fatty acids (MUFA) than the meat from Norwegian goats. Sensory panellists scored lamb meat fattier, juicier and more tender than goat meats. Meat from Cashmere goats scored highest (P<0.05) in whiteness, and lowest (P<0.05) in both colour tone and colour intensity. It is concluded that, since C18:0 was the main contributor of SFA in meat from Norwegian lamb and Cashmere goats, meats from them are nutritionally comparable to that from Norwegian goats. However, the higher proportion of SFA in Norwegian lambs and Cashmere goats may increase hardness of fat and being easily solidified upon cooling, may influence meat palatability.

Bovine muscle n−3 fatty acid content is increased with flaxseed feeding

We examined the ability of n-3 FA in flaxseed-supplemented rations to increase the n-3 FA content of bovine muscle. Two groups of animals were used in each of two separate trials: (i) Hereford steers supplemented (or not) with ground flaxseed (907 g/d) for 71 d, and (ii) Angus steers supplemented (or not) with ground flaxseed (454 g/d for 3 d followed by 907 g/d for 110 d). For the Hereford group, flaxseed-supplemented rations increased 18:3n-3 (4.0-fold), 20:5n-3 (1.4-fold), and 22:5n-3 (1.3-fold) mass as compared with the control, and increased total n-3 mass about 1.7-fold. When these data were expressed as mol%, the increase in 18:3n-3 was 3.3-fold and in 20:5n-3 was 1.3-fold in the phospholipid fraction, and 18:3n-3 was increased 4-fold in the neutral lipid fraction. For the Angus group, flaxseed ingestion increased masses and composition of n-3 FA similarly to that for the Herefords and doubled the total n-3 FA mass. The effect of cooking to a common degree of doneness on FA composition was determined using steaks from a third group of cattle, which were Angus steers. We demonstrated no adverse effects on FA composition by grilling steaks to an internal temperature of 64 degrees C. Because n-3 FA may affect gene expression, we used quantitative real-time reverse transcriptase-polymerase chain reaction to quantify the effect of feeding flaxseed on heart-FA binding protein, peroxisome proliferator activated receptor gamma (PPARgamma) and alpha (PPARalpha) gene expression in the muscle tissue. PPARgamma mRNA level was increased 2.7-fold in the flaxseed-fed Angus steers compared with the control. Thus, we demonstrate a significant increase in n-3 FA levels in bovine muscle from cattle fed rations supplemented with flaxseed and increased expression of genes that regulate lipid metabolism.