Quality and fatty acid profile of the milk of indigenous goats subjected to different local diets in Tunisian arid lands

The study tested the hypothesis that certain pastoral forages and olive by‐products, available in arid areas, may positively influence fatty acid composition and physicochemical properties of goat's milk. Thirty indigenous goats (body weight = 25.2 kg; age = 4.1 years) were allocated to three groups. During 60 days, the goats received ad libitum either dried olive leaves + Stipa tenacissima (group OL), khortane grass hay (group Ko) or oat hay (control diet, group OH). Milk samples were collected and analysed for total solids, fat, protein, lactose and ash content and fatty acid profile. Average milk yield did not statistically differ among groups. Milk total solids from OL group were higher in comparison with Ko and C groups (15.3, 14.7 and 14.5%, respectively; p < 0.05). Fat content was also higher for the OL group as compared to the other groups (5.44 vs. 5.01 and 4.66%, respectively, for Ko and OH). No significant differences were observed for the milk content of lactose, protein and ash. The percentage of saturated fatty acids of total milk fat was higher in OL and Ko groups compared to the C group (p < 0.001); the milk whereof was characterized by the highest percentage of monounsaturated (p < 0.01) and total unsaturated fatty acids. Milk fat of Ko and C groups showed significantly higher proportions of rumenic (CLA cis‐9 trans‐11) and vaccenic acids (C18:1 trans‐11) compared to OL milk. The feeding system based on Stipa tenacissima and dried olive leaves resulted in the milk lowest proportion of trans‐fatty acids and the highest proportion of polyunsaturated ω3‐fatty acids (p < 0.05).     

Physical and nutritional properties of buffalo meat finished on hay or maize silage‐based diets

The current study examines the effect of different finishing diets (hay‐ vs. maize‐silage on meal ration) on carcass quality, physical, chemical and sensory properties, and fatty acid profiles of buffalo meat. Twenty male Italian Mediterranean buffaloes (246 ± 9.00 kg live weight) were distributed at random into two groups at the beginning of the finishing period (368 ± 20 days). The buffaloes were offered two finishing diets: a maize silage (MS) or an alfalfa hay (AH) diet. No significant differences were found between dietary treatments for live and carcass weight. Meat chemical composition was influenced by dietary treatment. A higher fat content was detected in meat from animals finished with MS than AH (P < 0.05). Overall, the data indicated differences between the fatty acid profiles of meat as a consequence of different feeding systems. The higher fat deposition in the MS group resulted in meat with a less favorable fatty acid profile (i.e. a lower polyunsaturated/saturated fatty acid ratio and α‐linolenic fatty acid content) in relation to human health compared with meat from animals fed the AH diet.     

Effects of dietary oleuropein supplementation on growth performance,serum lipid concentrations and lipid oxidation of Japanese quails

An in vivo experiment was conducted to compare the effects of dietary supplementation with oleuropein and/or α‐tocopheryl acetate on growth performance, serum lipid concentrations and lipid oxidation of Japanese quail meat during refrigerated storage. Performance and slaughtering parameters were not affected by dietary treatments. The diets supplemented with oleuropein at the levels of 150 or 200 mg/kg were more effective in delaying lipid oxidation in breast and thigh meats compared with the control diet. The dietary inclusion of neither vitamin E nor oleuropein at different levels did not significantly affect the fatty acid compositions of the breast meat compared with the control diet. The diets supplemented with oleuropein at the levels of 150 or 200 mg/kg had significantly the highest polyunsaturated fatty acid and omega‐3 fatty acid contents in thigh meat compared with the vitamin E diet. The ratio of omega‐6 fatty acids to omega‐3 FAs in thigh meat of quails fed diet supplemented with vitamin E at the level of 200 mg/kg was equivalent to those of quails fed the diets supplemented with oleuropein at the levels of 100 and 150 mg/kg . The results showed that the dietary oleuropein supplementation at 150 mg/kg level may be used in quail diets enriched with the polyunsaturated fatty acids of vitamin E as a natural antioxidant.     

Relationships between the contents of vaccenic acid, CLA and n − 3 fatty acids of goat milk and the muscle of their suckling kids

The relationship between goat milk fatty acid composition, especially trans-11 C18:1 (vaccenic acid, VA), conjugated linoleic acid (CLA) and n − 3 fatty acids, and that of the meat from their suckling kids was investigated by feeding the dams a diet supplemented with whole cottonseed (COT) or extruded linseed (LIN). Fifteen Sarda goats, fed 1.2 kg/day per head of concentrate and hay ad libitum, were divided into two groups and supplemented during weeks 4 and 5 post-partum with 32 g/day per head of fat from LIN and COT, which have high C18:3 and C18:2 content, respectively. Fifteen kids were fed exclusively by suckling maternal milk until slaughtering (at 9–10 kg of body weight and approximately 6 weeks of age). Twenty-four hour after slaughter, the longissimus dorsi (LD) muscle was removed from each carcass. Fatty acid profiles of milk and LD were significantly affected by diets. Compared to COT, feeding LIN changed the milk fatty acid profiles by decreasing the proportion of C16:0 and increasing the contents of VA, C18:3 n − 3 (linolenic acid) and total CLA, including cis-9, trans-11-, trans-11, cis-13-, trans-11, trans-13- and trans, trans isomers. The concentrations of VA, cis-9, trans-11 C18:2 (rumenic acid, RA) and linolenic acid in milk and those in kid muscle were strongly correlated. The fatty acid profile of meat from suckling kids was effectively modified by manipulating the diet of the dams.     

Influences of dietary regimens on microbial content in gastrointestinal tracts of meat goats

This experiment was conducted to evaluate the effects of dietary treatments on microbial loads and pH of gastrointestinal tract contents in meat goats, as well as the concentration of volatile fatty acid (VFA) in the rumen. Crossbred (Boer x Spanish) goats (n = 36; BW = 17.7 kg) were assigned randomly to one of three experimental diets (n = 12/diet or 3 pens/treatment) for 90 days:alfalfa (Medicago sativa) hay alone (AH-diet); 18% CP concentrate alone (C-diet); or, a combined diet (AHC-diet), consisting of the AH-diet for the first 45 days, followed by 45 days of the C-diet. After evisceration, pH values of rumen liquor and colon digesta were immediately measured from each animal, as well as aseptically collected rumen liquor and rectal samples to determine the microbial loads. Collected rumen liquor was also prepared for volatile fatty acid (VFA) contents. Feeding meat goats with alfalfa hay alone had higher (P < 0.05) rumen (7.17) and colon (7.10) pH compared with those fed either the concentrate alone or combined-diet. Although the acetate content was high in the AH-fed group (66.3 mM) compared to the AHC-diet group (34.6 mM), no significant differences were found in the total VFA contents in rumen liquor among the goats fed three different dietary regimens. Total plate counts were not significantly different among goats fed the experimental diets in the rumen or rectal samples. Escherichia coli counts in the rectal samples were lower (P < 0.05) in the AH-diet group (6.43 log₁₀ CFU/g) compared with the C-diet (8.21 log₁₀ CFU/g) or AHC-diet (8.40 log₁₀ CFU/g) groups. However, no significant differences were found in the E. coli counts of rumen samples from goats fed the experimental diets. The mean (± SEM) rumen E. coli counts were 1.38, 1.65, and 2.51 ± 0.560 log₁₀ CFU/g in the AH-, C-, and AHC-diet groups, respectively. The results indicate that feeding hay alone may decrease the fecal shedding of E. coli in meat goats with increasing the rumen and colon pH.     

Influence of dietary condensed tannins from sericea lespedeza on bacterial loads in gastrointestinal tracts of meat goats

This research assessed the potential use of a low input forage containing a high amount of condensed tannins (CT) to reduce foodborne pathogens prior to slaughter of meat goats. In a completely randomized design, twenty Kiko × Spanish intact male kids (BW = 19.2 ± 0.74 kg) were fed ground sericea lespedeza [SL; Lespedeza cuneata (Dum-Cours) G. Don; 2 pens], a high-CT legume, or bermudagrass hay [BG; Cynodon dactyon (L.) Pers.; 2 pens], at 75% of daily intake with a corn-based supplement (25% of intake) for 14 weeks (n = 10 goats/treatment). At the end of the feeding trial, the animals were slaughtered using standard procedures. Immediately after evisceration, rumen and rectal samples were collected to assess bacterial loads and volatile fatty acids in the rumen. Concentrations of rumen volatile fatty acids were significantly different between dietary treatments. Goats fed SL hay had higher (P < 0.05) contents of butyric (8.66 vs 7.16 mM), isobutyric (1.94 vs 1.44 mM), isovaleric (3.03 vs 2.13 mM), and valeric (1.43 vs 1.07 mM) acids than those fed BG hay; however, the content of acetic acid (78.6 vs 64.4 mM) was higher (P < 0.05) in the BG-fed groups than in SL-fed groups. Escherichia coli (2.33 vs 1.13 log₁₀ CFU/g) counts of rumen contents were higher (P < 0.05) in the SL-fed group compared with the BG-fed group. However, E. coli counts in feces were not different (P > 0.05) between dietary treatments. The high-CT influenced (P < 0.05) total plate counts in the feces; and the total plate counts in feces of SL- and BG-fed goats were 4.95 and 6.57 log₁₀ CFU/g, respectively. The results indicated that high CT in the diet might influence rumen volatile fatty acid composition, but might not reduce the bacterial loads in gastrointestinal tracts of meat goats.     

Effect of a dietary supplementation with linseed oil and selenium to growing rabbits on their productive performances,carcass traits and fresh and cooked meat quality

The present experiment tested a dietary supplementation with linseed oil and selenium to growing rabbits. The basal diet (B) contained 3% sunflower oil, while it was substituted with 3% linseed oil in the experimental feed (S). The selenium (Se) content of the two diets was 0.10 vs. 0.46 mg/kg. Rabbits were fed with B diet from the age of 18 days. One group was fed with the B diet until 11 weeks of age (group B), whereas the experimental groups were fed with S diet for 1, 2, 3 or 4 weeks (groups S1, S2, S3 and S4, respectively), before slaughtering (11 weeks of age). Live performance and carcass traits of rabbits, fatty acid (FA) profile and selenium content of their hind leg (HL) and Longissimus thoracis et lumborum (LTL) meat were considered in this study. In addition, the effect of two different cooking methods on the nutritional value of the enriched HL meat was also assessed. The tested dietary supplementation only minimally affected the live performance and carcass traits of rabbits. The S supplementation significantly reduced the Σ n‐6 FA and increased the Σ n‐3 FA of the HL meat and LTL meat, compared to the B diet (p < 0.001); thus, n‐6/n‐3 ratio was improved (p < 0.001). In addition, HL meat and LTL meat of S fed rabbits were significantly enriched in Se reaching a twofold increase in both meat cuts (p < 0.01). Therefore, the S supplementation improved the functional value of the rabbit meat. The heat treatment affected cooking loss, Se and vitamin E contents as well as the oxidative status of the HL meat (p < 0.001), with the different cooking methods providing different results. In addition, even if the beneficial C20:5 n‐3 and C22:6 n‐3 decreased with cooking, the n‐6/n‐3 ratio remained unaffected.     

Comparative study between sheep and goats on rumenic acid and vaccenic acid in milk fat under the same dietary treatments

A number of studies have shown that the rumenic acid (RA = cis-9 trans-11 C_18:2 CLA) content of milk fat is usually higher in sheep than in goats, due partly to different dietary regimens. An experiment was conducted with 12 lactating dairy ewes and 12 goats with the objective to compare the two animal species (sheep/goats) fed diet with the same forage/concentrate (F/C) ratio, on their milk fatty acids (FA) profile with emphasis on RA and vaccenic acid (VA) production. The experiment was carried out in three consecutive phases, lasted 3 weeks each, immediately after weaning of lambs and kids. In phase I, the ewes and the goats were fed according to their maintenance and lactation requirements, with 14 kg alfalfa hay, 4 kg wheat straw and 12 kg concentrate the 12 ewes (F/C ratio = 60/40), and with 14 kg alfalfa hay, 4 kg straw and 24 kg concentrate the 12 goats (F/C ratio = 43/57). In phase II, 14 kg alfalfa hay, 4 kg straw and 14 kg concentrate were offered daily to each group of sheep and goats, with a F/C ratio = 56/44. In phase III, all ewes and goats were fed individually with 0.8 kg alfalfa hay, 0.2 kg wheat straw and 0.8 kg concentrate daily with a F/C ratio = 56/44. The results showed that the different F/C ratio between sheep and goats diets, in phase I, changed significantly the milk FA profile, with no significant difference in RA and VA milk fat content between sheep and goats in phase I. In phases II (group feeding) and III (individual feeding), where sheep and goats fed with the same amount of food of the same F/C ratio, the sheep milk fat had higher RA and VA content compared to goats. In conclusion, these findings support the hypothesis that there are species differences, as RA and VA production concerns, which needs further investigation.     

Does the length of time dried distillers' grain with solubles substitution for soybean meal affect physiological indicators and meat quality in finishing lambs?

This study examined how inclusion of dried distillers' grains with solubles (DDGS) in finishing lamb diets for different periods affects some physiological indicators and meat quality. A total of 40 male lambs were divided into four groups according to feeding regimen during the 120-day finishing period as follows: C120: no DDGS included in diet for 120 days; D120: DDGS included in diet for 120 days; D75: no DDGS included in diet for 45 days + DDGS included in diet for 75 days; D45: no DDGS included in diet for 75 days + DDGS included in diet for 45 days. Dietary inclusion rate of DDGS was 27.5%. Fattening performance and rumen parameters were not affected by treatment. Feeding regimens had no significant effect on meat quality except the instrumental tenderness and juiciness score. DDGS fed lambs had higher level of total trans fatty acids and n-6/n-3 ratio in meat. 10t-C18:1, 11t-C18:1 and 9c,11t conjugated linoleic acid contents of adipose tissue were higher in all the DDGS groups compared with C120 lambs (p < .001). These results suggest that soybean meal can be replaced with corn DDGS in lamb diets for up to 120 days during the finishing period with no adverse effects on some physiological response feedlot performance and meat quality.     

Effect of dietary concentrate content on feed intake,feed efficiency,and meat quality of Holstein steers fattened in a hot environment

The objective of this study was to investigate the effect of feeding high and low concentrate diets on feed intake and feed efficiency, the morphological characteristics of the rumen papillae, and meat quality of Holstein steers fattened under hot climate conditions in Oman. Ten male Holstein calves, of 5 months of age, were selected for the experiment. The animals were fed concentrate and Rhodes grass hay and were divided into two groups of high concentrate (HC, n = 5) and low concentrate diets (LC, n = 5), in which their feed intake, weight gain, and feed efficiency were evaluated across three growing periods. Feed intake and efficiency and average daily gain (ADG) of the HC group were significantly greater than for the LC group and were affected by the diet (p < .01) and the period (p < .001). Across the fattening periods, ADG declined in both groups, with ADG improved by 35% for steers on the HC diet compared to steers on the LC diet. Carcass meat quality was not affected significantly by the dietary concentrate level. In conclusion, our results can be used to make improvements in feed efficiency of Holstein steers under hot climate conditions.     

The potential of ramie as forage for ruminants: Impacts on growth,digestion, ruminal fermentation,carcass characteristics and meat quality of goats

The objective was to evaluate the effects of ramie conserved as forage supplementation on growth, digestion, and meat quality of Liuyang black castrated goats in a 60 days feedlot study. Forty‐eight goats were randomly assigned to each of four treatments: 24% rice straw + 36% ramie residues silage + 40% concentrate; 24% rice straw + 36% raw ramie silage + 40% concentrate; 24% rice straw + 36% ramie residues hay + 40% concentrate; 24% rice straw + 36% raw ramie hay + 40% concentrate. There was an increased tendency for ADG in ramie hay treatment than that of ramie silage treatment (p = 0.067). There was an increase for the apparent digestibility of DM, CP, NDF, and ADF in the ramie hay treatment than that of ramie silage treatment (p ≤ 0.034). An increased tendency was found for C18:1n?9c (% of total fatty acids) in the longissimus dorsi muscle of raw ramie treatment versus ramie residues treatment (p ≤ 0.087). These results indicate that the ramie hay or raw ramie treatment had a tendency for improving the nutrient digestibility and meat quality of goats than that of ramie silage or ramie residues treatment, respectively.     

Effects of fermented Yupingfeng on intramuscular fatty acids and ruminal microbiota in Qingyuan black goats

Our previous work has demonstrated that Yupingfeng, a Chinese herb medicine, considered as prebiotic showed beneficial properties in poultry health and disease prevention and regulated intestinal microbiota. The effects of Yupingfeng on fatty acids related to meat flavor and ruminal microbiota are not yet known in Qingyuan black goat. In this study, we supplemented fermented (FYP) and unfermented (UYP) Yupingfeng in different combinations to 90 goats. Compared with the normal control group, FYP and UYP significantly increased the concentration of palmitic acid, octadecanoic acid, and arachidonate acid (related to meat flavor) in the longissimus dorsi muscle (p < .05). In addition, the significant upregulation of peroxisome proliferator-activated receptor gamma (PPARγ) and fatty acid translocase (CD36) was observed in the FYP and UYP groups (p < .05). In addition, Firmicutes and Bacteroidetes were the most abundance in goat rumen. At the genus level, FYP and UYP significantly increased Ruminococcus related to fiber degradation, and Alistipes related to short-chain fatty acids production. In summary, Yupingfeng could improve fatty acids of goat meat, which is probably triggered by the increase of PPARγ and CD36, and microbial activity. Besides, FYP showed more beneficial effects than UYP, with increased flavor fatty acids and beneficial microbes.     

Effect of supplementing Rhodes grass hay (Chloris gayana) with Berchemia discolor or Zizyphus mucronata on the performance of growing goats in Kenya

Twenty growing Small East African goats were used to determine the effects of feeding sun-dried leaves of the browse forages Berchemia discolor and Zizyphus mucronata as supplements to low-quality basal diet, Rhodes grass (Chloris gayana) hay, on voluntary feed intake (VFI), digestibility and growth performance. The grass hay and maize bran were used as a control. The dried leaves were then included at the rates of 15% and 30% of the dry matter intake (DMI). Berchemia discolor had the highest crude protein (CP) content of 195.5 g/kg DM, while Z. mucronata had CP content of 169.5 g/kg DM. The grass hay had the lowest CP content of 50.9 g/kg DM. The browse forages had low fibre content [Neutral detergent fibre (NDF); 257.9-369.5 g/kg DM], while the grass hay had high fibre content (NDF; 713.1 g/kg DM). Goats in the groups supplemented with either of the browse forages had higher total DMI, nitrogen (N) intake and retention and live-weight gains than those in the control diet group. The digestibility of DM and organic matter (OM) was not affected by supplementation, but the CP digestibility increased with supplementation. The use of the browse forages as supplements for goats fed on poor-quality basal diets would enhance the performance of the animals.     

Effect of essential oil supplementation to diet on meat quality,fatty acid composition,performance parameters and intestinal microbiota of Japanese quails

The effect of essential oil (EO) supplementation on carcass characteristics of Japanese quails and interactions between ingredients and intestinal morphology were investigated in this study. A total of 250 quails were fed different diet: D1, basal diet (BD); D2, BD plus palmarosa oil (PO; 100 µg/kg diet); D3, BD plus lemon myrtle oil (LMO; 100 µg/kg diet); D4, BD plus α-Tops (mixture of α-terpineol, cineole and terpinene-4-ol; 100 µg/kg diet); and D5, BD plus cyclodextrin. Overall growth performance was determined at multiple time points during 35 days of experiment. Carcass characteristics (fatty acid, pH and colour), intestinal morphology and the expression levels of meat quality-related genes including the insulin-like growth factor (IGF-1), myogenin and avian uncoupling protein (avUCP) were examined at the end of the trial. Additionally, intestinal microbiome of quails was studied by next-generation sequencing-based culture-independent analysis. Although the inclusion of EOs into the diet had no effect on the growth performance of quails and the microbial profile, the significant changes in pH₂₄ and colour (a*) of the quail's breast muscle (p < .05) in the group receiving PO were observed. Additionally, oleic acid content in the breast muscle was significantly higher in the EOs supplemented groups (p < .01). Quails fed the PO supplemented diet had higher villus and relatively rich in oleic acid. The expression levels of IGF-1 and myogenin genes in quail's muscle were not affected, but the expression of avUCP gene was significantly lower in quails fed with LMO and α-Tops (p < .05). The results demonstrated variable effects of these treatments on intestinal morphology. Taken together, dietary inclusion of EOs is found to be beneficial and hence can be recommended for improving the quality of poultry meat.     

Influence of feeding a grass hay diet during the early stage of the fattening period on growth performance,carcass characteristics,and meat production in Japanese Black steers

The present study investigated the influence of feeding a large amount of grass hay to steers from the early to middle fattening period on growth, carcass characteristics, and meat characteristics. Steers were randomly divided into grass hay‐fed (GHF, n = 6) and concentrate‐fed (CF, n = 6) groups. The dressed weight of the GHF steers was lower than that of the CF steers, but the final body weight was not significantly different between the groups. The GHF steers had decreased subcutaneous fat and rib thickness compared with the CF steers. Lipid content, monounsaturated fatty acids, and drip loss in the muscles were lower in the GHF steers than in the CF steers. Furthermore, n‐3 polyunsaturated fatty acids were higher in the GHF steers compared with the CF steers. The GHF steers had lower body weight during the middle fattening stage, which may have occurred as a result of muscle growth suppression caused by increased Myostatin expression; an increase in daily gain during the finishing period may have occurred as a result of muscle growth activation caused by decreased Myostatin expression. Feeding steers a grass hay‐based diet during the early fattening period possibly maintains the quantitative productivity of beef similarly to feeding a concentrate‐based diet.     

Effects of pre-slaughter nutritional condition on intramuscular collagen solubility, pyridinoline cross-links and meat tenderness in aged goats

Effects of preslaughter nutritional condition on intramuscular collagen characteristics were studied, in order to clarify the potential of intensive feeding to aged animals in improving meat tenderness. Ten castrated male goats were assigned into one of two groups: one group was allowed ad libitum access to a concentrate diet (total digestible nutrients 70%, crude protein 15%) and Italian ryegrass hay (ADLIB‐group), and the other group was fed a restricted amount of their diet (concentrate diet 0.5% of bodyweight/day; hay 1.5% of bodyweight/day) to maintain their bodyweight (MAIN‐group). After 3 months of the experimental period, goats were slaughtered and meat samples were obtained immediately. Goats in ADLIB‐group had lower total and insoluble collagen concentrations, higher fat concentrations and collagen solubility than those in MAIN‐group, but soluble collagen concentrations of muscles were similar for both groups. Goats in ADLIB‐group had lower pyridinoline concentrations than those in MAIN‐group, in all muscles, but the differences of pyridinoline concentration between the groups were not statistically significant. Warner‐Bratzler shear force values of Longissimus and Biceps femoris muscles were lower in ADLIB‐group than in MAIN‐group. The increase of meat tenderness by preslaughter intensive feeding seemed to be associated with the increase in intramuscular fat deposition and high collagen solubility, and pyridinoline cross‐link appeared to be one of the factors related to collagen solubility.     

Live weights at slaughter significantly affect the meat quality and flavor components of pork meat

One‐hundred‐twenty crossbred pigs finished at 175–185 days of age were used to investigate the effects of live weights at slaughter on the meat quality, volatile flavor compounds, and sensory attributes of pork meat. Based on the live weights at slaughter, three weight groups (n = 36 per group) were classified as follows: light weight (LW: 100 kg), medium weight (MW: 110 kg), and heavy weight (HW: 120 kg). After slaughter, longissimus dorsi muscle samples were taken and used for the analyses of aforementioned parameters. The HW group had higher fat content and water holding capacity compared to the LW or MW group (p < 0.05). The HW group also showed higher levels for majority of unsaturated fatty acids and total polyunsaturated fatty acids than the LW group (p < 0.05). The slaughter weight significantly affected the amounts of 11 among the 47 flavor compounds identified. Significantly higher amounts of fatty acids oxidation‐derived flavor compounds (aldehydes) were found in the HW group than in the other groups. Noticeably, increasing slaughter weight was associated with higher sensorial scores for flavor, juiciness, and acceptance scores (p < 0.05). Based on the obtained results, 120 kg body weight is recommended as the market weight for this commercial breed without compromising the meat quality.     

Effects of long‐term microalgae supplementation on muscle microstructure,meat quality and fatty acid composition in growing pigs

We investigated the effects of long‐term microalgae supplementation (7% in a piglet diet and 5% in a fattening diet) on muscle microstructure and meat quality, including fatty acid composition in female Landrace pigs (n = 31). The major effects were muscle‐specific increases in n‐3 and n‐6 polyunsaturated fatty acids (PUFA) concentrations, resulting in increased accumulation of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). Carcass traits and meat quality of longissimus thoracis muscle were not affected by the microalgae diet with the exception of reduced drip loss (p = 0.01) and increased protein proportion (p = 0.04). In addition, the microalgae diet resulted in a shift to a more oxidative myofibre type composition in semitendinosus but not longissimus thoracis muscle. In conclusion, microalgae supplementation offers a unique opportunity to enhance essential n‐3 PUFA contents in pig meat. The results support small but coordinated changes in skeletal muscle phenotypic appearance and functionality.     

Effects of myrtle (Myrtus communis L.) essential oils as dietary antioxidant supplementation on carcass and meat quality of goat meat

Despite the fact that the use of rosemary and thyme residues and essential oils in animal feeding was widely documented, that of myrtle is scarce. To test the hypothesis that myrtle essential oils (MEOs) could improve goats' carcass characteristics and meat quality traits, twenty-one male goats received a ration consisted of 40% oat hay and 60% concentrate. Experimental goat kids received the control diet supplemented with 0, 0.3 and 0.6% of myrtle essential oils (MEOs) for C, Myrt1 and Myrt2 groups respectively. The administration of MEO did not improve the daily DM intake (p > 0.05). Kids of C and Myrt2 groups had higher average daily gain than Myrt1 group (75 versus 55 g). The goats slaughtered at 19.9 kg of weight did not differ (p > 0.05) in carcass weights and carcass yield in terms of commercial dressing percentage (CDP = 41%) and real dressing percentage (RDP = 52%). The administration of MEO increased the meat polyphenol content, being higher in both Myrtle groups (87 versus. 56 μg gallic acid equivalents g^-1 fresh matter, p < 0.05). Myrtle EO administration protected kids’ meat against oxidation (0.48 versus. 0.91 mg MDA/kg of meat for Myrtle and C groups, respectively, at the 9th day of storage; p < 0.05). It could be useful to include MEO as a dietary supplement in goats’ rations since it improves meat's oxidative status without negative effects on FA profile.     

Growth,carcass yield and meat quality attributes of Red Maasai sheep fed wheat straw-based diets

Thirty-two castrated Red Maasai sheep (12.7 kg initial body weight, aged 12–18 months), were used in an 84-day experiment to evaluate diets based on treated straw upon growth performance, carcass yield and meat quality. The animals were blocked by weight into four similar groups and randomly allotted into four dietary treatments, with eight individually fed animals per treatment. The dietary treatments were ad libitum untreated wheat straw (UTS), wheat straw treated with urea and lime (TS), straw and ad libitum hay (UTSH), and TS and ad libitum hay (TSH). In addition, each experimental animal received 220 g/day (on as fed basis) of a concentrate diet. Treatment of straw increased (P < 0.05) dry matter intake (42.3 vs. 33.7 g/kg W ⁷⁵/day), energy intake (4.6 vs. 3.7 MJ ME/d) and the average daily gain (40.7 vs. 23.1 g). Animals on TS produced heavier (P < 0.05) carcasses (6.6 vs. 5.4 kg) with superior conformation than animals on UTS. Percentage cooking loss was higher in carcasses from animals fed TS compared to those from other diets. Except M. longissimus dorsi and M. semitendinosus, tenderness of muscles was not affected by diet but ageing of meat improved (P < 0.001) tenderness. Overall, straw treatment increased carcass yields with limited effects on meat quality attributes.