Sample preparation and storage effects on fatty acid profile of rabbit Longissimus thoracis et lumborum muscle

[EN] Twenty-five Pannon White male rabbits reared and fed in similar conditions were slaughtered at 11 weeks of age. The longissimus thoracis et lumborum muscles (LTL; right and left) were removed at 24 h post-mortem and allocated to four sampling/storage treatments: the left side of LTL muscle was divided in half perpendicularly, with the posterior portion being analysed within one day (fresh), and the anterior portion vacuum packaged and stored for 1 mo at 20°C (whole-frozen); the right LTL side was ground with half of the product vacuum packaged and frozen for 1 mo at 20°C (ground-frozen), whereas the other half was freeze-dried, vacuum packaged, and stored for 1 mo at 4°C (freeze-dried refrigerated). Treatments impacted percentages of total saturated (P<0.01), monounsaturated (P<0.05), and polyunsaturated fatty acids (P<0.001), whole-frozen treatment affecting the most the fatty acids profile of the meat. Method of preparation and storage of meat samples before performing fatty acid analysis had an impact on the percentage of specific fatty acids, which could render the precision of study-to-study comparisons less reliable.Dalle Zotte, A.; Pranzo, G.; Tenti, S.; Szendr?, Z.; Szabó, A. (2022). Sample preparation and storage effects on fatty acid profile of rabbit Longissimus thoracis et lumborum muscle. World Rabbit Science. 30(3):187-193. https://doi.org/10.4995/wrs.2022.1716018719330

Effect of dietary supplementation with full-fat silkworm (Bombyx mori L.) chrysalis meal on growth performance and meat quality of Rhode Island Red × Fayoumi crossbred chickens

The objective was to study the effect of the partial substitution of soybean meal and oil with full-fat silkworm (Bombyx mori L.) meal (SWM) in the diet of growing chickens, on their growth and meat quality traits. A total of 195 1-day-old chicks of both sexes were allocated to 15 littered floor pens and assigned to three dietary treatments (5 replicates/treatments) until 8 weeks of age: a commercial diet (Control) and other two diets with an inclusion of either 25% (SWM25) or 50% (SWM50) SWM. At 8 weeks of age, two males/replicates were slaughtered and carcases dissected to compute yields. Pectoralis major muscle was subjected to pH and L*a*b* colour values, proximate composition and fatty acid profile analysis. All chickens showed satisfactory growth performance throughout the trial, with the best growth being observed in the SWM25 group. Carcase traits remained unaffected by the dietary treatment, but SWM25 chickens had a higher breast yield (p < .05) than the Control group. The pH of SWM50 breasts was higher than Control (p < .01). Dietary treatments affected meat protein content, differing between SWM25 and SWM50 (22.2 versus 23.3%, respectively; p < .05). SWM dietary inclusion increased n-3 PUFA and lowered the n-6 PUFA proportions in a level-dependent manner. Consequently, n-6/n-3 ratio diminished, thus improved, with the dietary SWM inclusion. Results showed that it is possible to partly substitute soybean meal/oil with SWM in the diet of chickens, ensuring satisfactory performance and carcase traits, and providing meat with a healthier n-6/n-3 ratio.Highlights Silkworm (Bombyx mori) chrysalis is a possible sustainable feed ingredient for growing chickens, alternative to conventional soybean. The dietary inclusion of silkworm full-fat meal in chicken diets provided satisfactory growth performance, carcase and meat quality traits. The dietary inclusion of full-fat silkworm meal in chicken diets enriched meat lipids with omega-3 fatty acids

Comparison of two feeding finishing treatments on production and quality of organic beef

The study compared growth and slaughter performance and meat quality of organic beef cattle finished with or without pasture grazing. One group of 10 Limousin heifers was finished under confined conditions and fed ad libitum a total mixed ration based on maize silage, hay and cereals grains. A second group of 10 Limousin heifers rotationally grazed two contiguous pasture plots of 1.5 ha each with a daily supplementation of a concentrate mix based on cereal grains and roasted soybeans. Heifers were slaughtered at commercial finishing and meat quality traits were assessed on Longissimus thoracis muscle. The grazing group, due to a lower average daily gain (0.74 vs 0.95 kg/day; P<0.05), required a prolonged finishing period (172 vs 155 days; P<0.05) than the confined animals. Meat samples from grazing cattle were less tender (shear force: 3.92 vs 3.24 kg/cm2; P<0.05) and showed a lower lightness (L*: 33.0 vs 35.8; P<0.001) and a higher redness (15.4 vs 13.7; P<0.01) and yellowness (15.6 vs 14.6; P<0.05). Fatty acid composition of the intramuscular fat was significantly affected by the finishing system. Grazing heifers had a higher content of polyunsaturated fatty acids (4.06 vs 3.66 % of total fatty acids; P<0.05), conjugated linoleic acids (0.16 vs 0.10 % of total fatty acids; P<0.01) and ω-3 (0.44 vs 0.30 % of total fatty acids; P<0.001) than confined animals. The detrimental effects of pasture grazing on growth performance and on some important meat quality traits explain the limited adoption of this finishing system in organic beef production

Research Note: Effect of chicken genotype and white striping–wooden breast condition on breast meat proximate composition and amino acid profile

The present experiment compared the proximate composition, the amino acid content, and profile of the breast meat of a commercial broiler hybrid (Hybrid-Normal) vs. a broiler hybrid affected by the simultaneous presence of white striping (WS) and wooden breast (WB) myopathies (Hybrid-WSWB) vs. the Italian purebred Polverara chicken (Polverara). To this purpose, a total of n = 30 breast meat cuts from male chickens/group were subjected to meat quality evaluations. Chickens were slaughtered at their commercial age. The meat of the Polverara breed showed the highest protein (P < 0.0001) and the lowest lipids (P < 0.0001) contents, whereas that of the Hybrid-WSWB broiler chickens had the lowest protein and ash (P < 0.0001) contents and the highest (P < 0.0001) amount of fat. Meat of Hybrid-Normal chickens displayed intermediate values. Polverara meat was the richest in most amino acids (g/100 g meat), whereas Hybrid-WSWB one had the lowest content (P < 0.0001). Taurine was not detected in the meat of the Polverara chicken. The meat of Hybrid-Normal chickens was the richest in valine and taurine amino acids (P < 0.0001). Results on the amino acids proportions (% of total amino acids) highlighted that lysine, arginine, leucine, glutamic acid, aspartic acid, alanine, and serine were the most representative essential and nonessential amino acids, respectively, in all 3 meat-types chickens. The study confirmed that WS and WB myopathies negatively affect the meat proximate composition and the amino acid content. The meat of the Polverara breed displayed a remarkable meat quality including a high protein content of very good quality. This may represent a tool to promote its meat among consumers and help the survival of this endangered breed. Furthermore, research efforts should be conducted to understand why taurine was absent in the breast meat of Polverara chicken

Effect of unsaturated fatty acid supplementation on performance and milk fatty acid profile in dairy cows fed a high fibre diet.

The influence of unsaturated fatty acid (UFA) supplement on productive performance, physiochemical properties and fatty acid (FA) profile of milk, was investigated in lactating dairy cows fed with high fibre diets. According to a cross-over design, twelve cows were assigned to two experimental settings characterized by different FA profiles. Cows received a high fibre diet (~42% NDF on DM basis) supplemented with soybean based mixtures with these FA compositions: 92.0% of saturated FA (SFA), 2.8% of monounsaturated FA (MUFA) and 5.2% of polyunsaturated FA (PUFA) in the control diet (C-diet); 19.1% of SFA, 20.9% of MUFA and 60.0% of PUFA in the experimental diet (E-diet). The E-diet did not affect dry matter intake nor milk yield. Milk composition and coagulation traits resulted similar between treatments, except for the lactose level, which was lower in the E-diet (5.0 vs 4.8%; P<0.05) and the freezing point (-0.546 vs -0.535 °C; P<0.05). As respects the milk FA profile, the E-diet significantly increased the percentage of UFA because of their greater amount in the ration; however the "transfer" of UFA in milk was limited by the high level of FA biohydrogenation (BH) at the ruminal level. UFA showed low values of carry over in milk (67.5 vs 39.7%; P<0.001) due to the saturation process; on the contrary SFA had a threefold increment (124 vs 323%; P<0.001), mostly due to a peak in the production of stearic acid. In this study, the percentage of CLA in milk (0.50 vs 0.62%; P<0.05) was quite low for both diets, if compared with other studies, and this was probably due to a low vaccenic acid supply at duodenal level

use of rumination and activity data as health status and performance indicators in beef cattle during the early fattening period

Abstract The aim of this study was to measure the level of activity and rumination in young bulls and to assess whether these data can be used as indicators of health status and average daily weight gain (ADG). Two groups of animals (period 1: n = 108 animals; period 2: n = 106 animals) were fitted with sensors to measure daily activity and rumination, were weighed on arrival and at the end of the trial (70 days) and were checked twice daily to verify their health condition. Any clinical signs and therapies were recorded. The dishomogeneity index of rumination (DR), and the daily dishomogeneity indices of activity (DDA) and rumination (DDR), were calculated. Bulls had an ADG of 1.42 ± 0.38 kg/day and showed an average duration of daily rumination of 404 ± 63 min and an average activity of 474 ± 46 bits, respectively. Animals characterised by low ADG had lower values of minimum daily rumination ( P = 0.01) and DDA ( P 0.001), and a greater rumination range ( P = 0.007) and DR ( P = 0.003). Bovine respiratory disease and lameness were detected 31 and five times, respectively; among affected animals, the average daily activity, rumination and DDA were lower ( P 0.05) at 3–6 days before the onset of visible clinical signs, whereas DDR increased compared to the values when individuals were apparently healthy. The use of individual sensors appears promising for the early diagnosis of disease in beef cattle and for improving herd management

Lecithin: a by-product of biodiesel production and a source of choline for dairy cows

The aim of the present study was to compare the effects of soy lecithins (L), a by-product of the biodiesel production process, and choline chloride microencapsulated with hydrogenated vegetable oils (C) on dry matter intake, milk yield, milk quality traits, milk choline and haematological profile of dairy cows. A total of 12 mid-lactating Holstein Friesian cows were assigned to one of two experimental groups and fed according to cross-over design (2 diets x 2 periods). Diets were isoenergetic, isofibrous and isonitrogenous and had the same content of choline. Dry matter intake was not affected by the diet, but L led to lower milk choline (P<0.05) and to a significantly higher milk yield (P<0.05), although the 3.5% fat-corrected milk (FCM) did not change owing to the higher content of fat in the milk of the C-diet group (P<0.01). The remaining milk components were unaffected by the supplements, except for the milk urea, which was lower in the L-diet group (P<0.01), reflecting a more effective use of degradable proteins by the micro-organisms present in the rumen. With regard to the haematological profile, L led to lower urea (P<0.001) and to higher values of glucose (P<0.01) and non-esterified fatty acids (NEFA)/Cholesterol ratio (P< 0.05), but all of the values fell within the physiological range of lactating dairy cows. Results indicated that soy lecithins can be used as an available and cost-effective source of choline in mid-lactating dairy cows

Proposal and validation of new indexes to evaluate maize silage fermentative quality in lab-scale ensiling conditions through the use of a receiver operating characteristic analysis

In the context of dairy cow feeding, it is increasingly important to know the quality of the maize silage used in the ration and therefore, it appears to be crucial optimizing the techniques necessary to assess it. The aim of this study was to evaluate whether some reference indexes, like the Flieg-Zimmer's (FZS), the German agricultural society's (DLG) and Vanbelle's scores, could properly estimate the quality of fermentations of maize silage made in a lab-scale ensiling system, and to calculate and validate new quality indexes suitable for lab-scale fermentations. The experimental dataset was obtained by analysing through near-infrared spectroscopy 522 samples of whole maize crop ensiled immediately after the harvest, using the vacuum-packing technique. The six (I1 \u2013 I6) new indexes were calculated on the basis of chemical and physical parameters as: pH, organic acids, ethanol, etc. All the indexes were tested for normality with the Shapiro\u2013Wilk test. In order to define the accuracy with which the new indexes ranked the maize silage on the basis of its fermentation quality, a receiver operating characteristic (ROC) analysis was performed, using the FZS as gold standard test and dichotomizing the FZS in two levels according to a cut-off (FZS 360 g/kg) dry matter (DM). In the lab-scale silages the new indexes were normally distributed, whereas the reference indexes were not. The new indexes showed values of AUC ranging between 0.76 and 0.89, with the I5 index showing the best combination of sensitivity (0.87) and specificity (0.77) in discriminating between good and poor quality silage. The cut-off of the new indexes ranged between 45.0 and 57.4 points. The lab-scale silages were all excellent, no matter the category of DM. However, while FZS and DLG did not differ among the 3 categories, I1 \u2013 I6 were significantly higher in silages with low DM (P < 0.001). Silages with low DM had the highest concentrations of lactic acid (56.4 g/kg DM, P < 0.001), ammonia (61.4 g/kg DM, P < 0.001) and butyric acid (0.62 g/kg DM, P < 0.001) as well. Data confirmed that the new proposed indexes are promising in describing the fermentation quality of maize silage in lab-scale conditions

Valutazione del profilo aminoacidico corporeo in ombrine (Umbrina cirrosa L.) alimentate con diete a diverso rapporto lipidi/carboidrati

the objective of the study was to determine by HPLC whole body aminoacid compositions of shi drum after a 4 months long period according with two lipid/carbohydrate ratio (EE/NFE):1.0 vs !.5. Total and essential AA amount were found significantly higher in EE/NFE 1.0 fed fish as well as LYS and LEU content resulting in an higher crude protein retention. Results suggest that low dietary EE/NFE ratio increases protein feed efficiency by reduction of catabolic oxidation of almost two essential amino acid

Optimisation of rabbit meat sample preparation for fatty acid profile analysis

In the rabbit meat the fatty acid (FA) profile determination doesn\u2019t follows a standardized method of meat sample preparation and results obtained could differ significantly. The effect of rabbit meat sample preparation was studied. Longissimus dorsi meat of 25 rabbits was dissected 24h post mortem and divided longitudinally into 4 parts each and prepared as follows: whole part analysed 24h post mortem (Whole-Fresh), whole part stored 1 month at -20 \ub0C (Whole-Frozen), ground part stored 1 month at -20 \ub0C (Ground-Frozen) and ground and freeze-dried part stored 1 month at +4 \ub0C (FD-Refrigerated). Quite all FA were affected by the sample preparation system. Total SFA were significantly higher in the Whole-Frozen compared to the Ground\u2013Frozen samples (33.7 vs 32.7 % total FA; P<0.01). Total PUFA were, on the contrary, significantly (P<0.001) lower in the Whole-Frozen compared to the other 3 sample preparation systems (39.8 vs 41.7 vs 41.8 vs 42.0 % total FA, for Whole-Frozen, Ground-Frozen, FD-Refrigerated and Whole-Fresh, respectively), related to a significant reduction of C20:3n-6, C20:4n-6, C22:5n-3 and DHA. The Whole-Frozen sampling resulted the worse method of meat sample preparation whereas any statistical differences were observed between Ground-Frozen and FD-Refrigerated meat preparations