Effect of slaughter age on foal carcass traits and meat quality

Meat has played a crucial role in human evolution and is an important component of a healthy and well-balanced diet due to its nutritional richness. Recent studies have shown that horsemeat may be considered as an alternative to other meat (such as beef or pork), and it may have a positive effect on human health from a nutritional point of view. This research was conducted to characterize the carcass measurement, meat quality (chemical composition, colour characteristics and textural traits) and nutritional value (fatty acid and amino acid composition) of foals slaughtered at 8 and 11 months of age (8 and 11 m groups). For this study, a total of 21 foals (10 and 11 animals from the 8 and 11-m groups, respectively) were used. The results obtained showed a positive influence on carcass characteristics with an increase in slaughter age, because 11 m animals had slightly higher values of live (275 v. 247 kg) and carcass weights (148 v. 133 kg), length of leg (72.86 v. 69.85 cm) and carcass (100.41 v. 96.30 cm) and perimeter of leg (97.68 v. 89.22 cm) compared with animals from the 8-m group. Regarding meat quality, only Fe-haeme and cholesterol content in chemical composition and luminosity (L*) in colour parameters showed significant differences. Foals from the 8-m group had the highest content of cholesterol (0.47 v. 0.28 mg/100 g of meat) and luminosity values (39.66 v. 37.88) and the lowest content of ash (1.20% v. 1.40%). In fatty acids content, only five out of 23 fatty acids showed differences between the two groups. However, an interesting change in the fatty acid profile occurred with an increase in the slaughter age. Foals from the 8-m group had the highest values of α-linolenic acid and n-3 fatty acids and the lowest values of linoleic and n-6 fatty acids, which is an interesting fact from a health point of view. Finally, slaughter age had no statistical influence on textural properties or amino acid content. As a main conclusion, animals slaughtered at 8 months of age had higher nutritional quality meat (with higher content of n-3 fatty acids) than meat from foals slaughtered at 11 months of age. The slaughter of animals at 8 months of age also reduced production costs because they ate a smaller amount of commercial fodder.     

Performance and tissue fatty acid profiles in veal calves fed diets supplemented with conjugated linoleic acids

Three groups of six calves each were fed a milk replacer at 0.8 kg and a starter concentrate ad libitum. Calves of the control group received the basal diet supplemented with rapeseed oil at 10 g per kg of feed solids. Calves of treatment groups were fed diets supplemented with a synthetically produced oil containing 62.3% methyl esters of CLA. The CLA-oil was added to milk at expense of rapeseed oil and fed at 5 and 10 g x kg(-1) feed solids for 63 days. Calves were slaughtered at 115 days of age. There was no significant effect of CLA on growth, intake of starter, feed conversion, chemical composition of meat and its oxidative stability. Dietary supplementation with CLA at 10 g x kg(-1) significantly increased CLA content in m. longissimus dorsi (MLD) from 5.6 to 19.3 mg x 100 g(-1), in liver from 13.1 to 68.8 mg x 100 g(-1), and in perirenal fat from 0.37 to 3.17 g x 100 g(-1). Dietary CLA decreased the ratio of cis-9, trans-11 and trans-10, cis-12 isomers of CLA in tissues, concentration of monounsaturated fatty acids in the MLD and fat, as well as the concentration of fatty acids with 20 and 22 carbon atoms. It can be concluded that in veal calves unprotected CLA apparently escaped ruminal hydrogenation, but was preferentially incorporated into depot fat.     

Comparing patterns of human harvest and predation by Eurasian lynx Lynx lynx on European roe deer Capreolus capreolus in a temperate forest

Human harvest is the most important mortality factor for wild ungulates in Europe and can affect several aspects of ungulate biology. There is a growing concern about possible negative side effects of human harvest. To better understand the differences between human and natural mortality, we compared the extent, age and sex structure, nutritional condition, spatial and temporal distribution of human harvest, and natural predation by the Eurasian lynx Lynx lynx on the European roe deer Capreolus capreolus, the most abundant wild ungulate in Europe. Compared to the human harvest, lynx were less likely to kill fawns and yearlings than adults, and among adult deer, lynx were more likely to kill females. The proportion of roe deer with fat-depleted bone marrow was higher among lynx prey than among harvested animals. Average lynx kill rate was estimated to 47.8 roe deer per year, and lynx predation was considerably lower than the human harvest in the same area. While human harvest increased with higher roe deer density, lynx predation was similar across the gradient of roe deer densities. Comparison with other countries indicated that differences between human harvest and natural mortality of ungulates vary considerably in different parts of Europe. Variation in hunting practices and, even more importantly, carnivore predation may have an important role in buffering unwanted side effects of harvest of wild ungulates.     

Temporal and geographical variation in skeletal fluoride content of roe deer (Capreolus capreolus) from industrialized areas in Germany

In order to study temporal and spatial variation of environmental fluoride levels, we analyzed the mandibular bone fluoride content of 157 roe deer (age range: 1-11 years) from two industrialized regions (Ruhr area: n = 76, sampling period 1955-1998; area W of Cologne: n = 81, sampling period 1983 1998) in the federal state of North Rhine-Westphalia, Germany. Bone fluoride values (dry weight basis) ranged between 150 mg F/kg (2 year-old specimen taken in 1997) and 5724 mg F/kg (10 year-old specimen taken in 1957). In both study areas, a pronounced decline in mandibular bone fluoride concentrations occurred over the respective sampling periods. In consequence, bone fluoride content of animals (both study areas pooled) taken during the period 1990-1998 was significantly (P < 0.00001) lower than that of roe deer from the period 1955 1989, while the two animal groups did not significantly differ in age. These findings are regarded as indicative of a considerable reduction of fluoride deposition into the animals' habitats, due to effective emission control measures. Bone fluoride values for the period 1990-1998 in the roe deer from the Ruhr area significantly (P < 0.005) exceeded those of the individuals from the study area W of Cologne, while the difference in age between the two groups was not significant. In both study areas, a significant (P < 0.00001) positive correlation between age and mandibular bone fluoride content (Ruhr area: rs = 0.601; area W of Cologne: rs = 0.725) was found for animals taken during this period. The present study underscores the suitability of analyzing skeletal fluoride concentrations in wild roe deer in order to monitor the magnitude of environmental contamination by fluoride and thereby to assess the efficiency of measures taken to reduce fluoride emissions from industrial sources.     

Oxidized oils and dietary zinc and α-tocopheryl acetate supplementation: effects on rabbit plasma, liver and meat fatty acid composition and meat Zn, Cu, Fe and Se content

The effects of the addition of heated oils to feeds (3%, w/w) and the dietary supplementation with α-tocopheryl acetate (TA; 100 mg/kg) and Zn (200 mg/kg) on rabbit tissue fatty acid (FA) composition and on the Zn, Cu, Fe and Se content in meat were assessed. Heating unrefined sunflower oil (SO) at 55°C for 245 h increased its content in primary oxidation products and reduced its α-tocopherol content. However, this did not significantly affect tissue FA composition. Heating SO at 140°C for 31 h increased its content in secondary oxidation products and in some FA isomers as c9,t11-CLA and di-trans CLA. This led to increases in di-trans CLA in liver and in t9,c12-18:2 in meat. The c9,t11-CLA was the most incorporated CLA isomer in tissues. The dietary supplementation with α-TA did not affect the FA composition of plasma, liver or meat. The cooking of vacuum-packed rabbit meat at 78°C for 5 min reduced significantly but slightly its polyunsaturated FA content. The dietary supplementation with Zn did not modify the content of Zn, Fe or Se in meat, but it reduced its Cu content. On the other hand, it increased the content of some FAs in meat when SO heated at 140°C for 31 h was added to feeds.     

Tick burden on European roe deer (<Emphasis Type="Italic">Capreolus capreolus</Emphasis>)

In our study we assessed the tick burden on roe deer (Capreolus capreolus L.) in relation to age, physical condition, sex, deer density and season. The main objective was to find predictive parameters for tick burden. In September 2007, May, July, and September 2008, and in May and July 2009 we collected ticks on 142 culled roe deer from nine forest departments in Southern Hesse, Germany. To correlate tick burden and deer density we estimated deer density using line transect sampling that accounts for different detectability in March 2008 and 2009, respectively. We collected more than 8,600 ticks from roe deer heads and necks, 92.6% of which were Ixodes spp., 7.4% Dermacentor spp. Among Ixodes, 3.3% were larvae, 50.5% nymphs, 34.8% females and 11.4% males, with significant seasonal deviation. Total tick infestation was high, with considerable individual variation (from 0 to 270 ticks/deer). Adult tick burden was positively correlated with roe deer body indices (body mass, age, hind foot length). Significantly more nymphs were found on deer from forest departments with high roe deer density indices, indicating a positive correlation with deer abundance. Overall, tick burden was highly variable. Seasonality and large scale spatial characteristics appeared to be the most important factors affecting tick burden on roe deer.     

Effects of whole linseed supplementation and treatment duration on fatty acid profile and endogenous bioactive compounds of beef muscle

Diet supplementation with oilseeds is known to improve the fatty acid profile of meat, but few studies have been carried out to determine the time required for the incorporation of a significant quantity of n-3 polyunsaturated fatty acids (PUFA) into meat from steers. Therefore, the present study aimed to assess the effects of linseed supplementation and feeding duration on the fatty acid profile, cholesterol and bioactive compounds of bovine meat. In total, 54 Friesian steers were randomly allocated during the finishing period into six experimental treatments following a 2×3 factorial design. The six treatments consisted of two diets, the control diet (CO) with no supplemental fat and the linseed diet (LS) containing 10% whole linseed, fed 40, 75 or 120 days before slaughter. At the end of each finishing period, steers from the CO and LS groups were slaughtered. After 8 days of ageing chemical analysis, the fatty acid profile, cholesterol content and bioactive compounds were determined from the longissimus thoracis muscle. Including linseed in the diet increased the content of monounsaturated fatty acids, CLA and n-3 PUFA, and reduced the proportion of saturated fatty acids and n-6 PUFA. The percentage of myristic fatty acid increased with the duration of feeding, regardless of diet and a decrease in PUFA and n-6 PUFA was observed in the CO and LS diets, respectively. Furthermore, meat from steers fed linseed showed an increased percentage of n-3 PUFA, linolenic acid, and EPA from 40 to 75 days of feeding, whereas vaccenic acid, CLA 9c,11t, and total CLA increased from 40 and 75 days but declined at 120 days. Beef from the linseed group had a higher content of bioactive substances such as creatine, carnosine and anserine than beef from the control group. The duration of feeding significantly affected the creatine concentrations, with an increase in the LS group from 40 to 75 days of feeding. Feeding linseed did not modify the cholesterol content, on average and the lowest cholesterol content was found in meat after 75 days of linseed administration. This study demonstrates that a short-term diet manipulation is sufficient to improve the nutritional properties of meat, including n-3 PUFA and bioactive compounds.     

Trace mineral status and liver and blood parameters in sheep without mineral supply compared to local roe deer (Capreolus capreolus) populations

General health, clinical-chemical blood analysis and copper (Cu), zinc (Zn), selenium (Se) and vitamin E concentrations in plasma and liver tissue (wet weight, ww) of two extensive grazing sheep flocks without mineral supply were compared to the status of local roe deer (Capreolus capreolus) populations (liver samples). Both sheep flocks were classified as healthy except for a remarkable variation in body weight and a slight foot rot infection in one flock. Hematology of sheep was normal, and total protein and creatinine as well as activities of creatin kinase, aspartat-amino-transferase, alkaline phosphatase and gamma-glutamyl-transferase in plasma were within reference levels. The mean of glutamate dehydrogenase (13.8 U/l) was slightly elevated in one flock. Mean liver concentrations of Zn (38.9 and 43.5 mg/kg ww) and Cu (111 and 87.5 mg/kg ww) in sheep flocks were higher compared to the respective roe deer populations (27.5 and 36.3 mg Zn/kg ww; 18.3 and 28.6 mg Cu/kg ww). This is supposed to be caused by differences in Cu and Zn metabolism in sheep and roe deer. Selenium deficiency was diagnosed in liver samples of both sheep flocks (0.21 and 0.23 mg/kg ww). There were neither significant differences compared to roe deer (0.21 and 0.27 mg Se/kg ww) nor differences depending on location. Correlations between plasma and liver concentrations of Cu, Zn and Se were not significant in sheep. Means of vitamin E in liver samples (30.6 and 41.8 mg/kg ww) were higher in roe deer populations. This may be caused by the opportunity of selective browsing for wild ruminants, which allows access to younger plants which are higher in vitamin E.     

Mandibular fluoride concentration and its relation to age in roe deer (Capreolus capreolus L.)

1. Mandibular fluoride content was recorded in 63 roe deer (33 males, 30 females) between 9 months and 10 years of age, taken from an area in SW Germany not exposed to increased fluoride deposition. 2. Bone fluoride level was positively correlated with age (t-test, P less than or equal to 0.001), the increase in concentration being higher in younger animals and declining in older deer. 3. In the sample studied, no significant sex specific difference in mean mandibular fluoride concentration was found (t-test, P greater than 0.05).     

Density of Wild Prey Modulates Lynx Kill Rates on Free-Ranging Domestic Sheep

Understanding the factors shaping the dynamics of carnivore–livestock conflicts is vital to facilitate large carnivore conservation in multi-use landscapes. We investigated how the density of their main wild prey, roe deer Capreolus capreolus, modulates individual Eurasian lynx Lynx lynx kill rates on free-ranging domestic sheep Ovis aries across a range of sheep and roe deer densities. Lynx kill rates on free-ranging domestic sheep were collected in south-eastern Norway from 1995 to 2011 along a gradient of different livestock and wild prey densities using VHF and GPS telemetry. We used zero-inflated negative binomial (ZINB) models including lynx sex, sheep density and an index of roe deer density as explanatory variables to model observed kill rates on sheep, and ranked the models based on their AICc values. The model including the effects of lynx sex and sheep density in the zero-inflation model and the effect of lynx sex and roe deer density in the negative binomial part received most support. Irrespective of sheep density and sex, we found the lowest sheep kill rates in areas with high densities of roe deer. As roe deer density decreased, males killed sheep at higher rates, and this pattern held for both high and low sheep densities. Similarly, females killed sheep at higher rates in areas with high densities of sheep and low densities of roe deer. However, when sheep densities were low females rarely killed sheep irrespective of roe deer density. Our quantification of depredation rates can be the first step towards establishing fairer compensation systems based on more accurate and area specific estimation of losses. This study demonstrates how we can use ecological theory to predict where losses of sheep will be greatest, and can be used to identify areas where mitigation measures are most likely to be needed.     

Survival rates and causes of mortality of roe deer <Emphasis Type="Italic">Capreolus capreolus</Emphasis> in a rural landscape,eastern Poland

Game species in the cultural landscapes of Europe are exposed to several sources of anthropogenic pressure. Whilst hunting is part of coordinated wildlife management, poaching is difficult to quantify, and hence, relatively little is known about its impact on survival patterns of game species. We estimated survival and cause-specific mortality rates of 31 roe deer Capreolus capreolus in the surroundings of the Bia?owie?a Primeval Forest, eastern Poland, from 2010 to 2013. The study area consisted of large, extensively used agricultural fields and a mosaic of pine plantations, which were interspersed with natural forest stands and small agricultural fields and meadows. Roe deer were regularly hunted and the forested part of the study area was traversed by large carnivores. Annual survival rate of all deer was 0.69 and did not differ between seasons. Annual survival rates of females and males in each age class (young and adult) were similar. Poaching was a major source of mortality (6 out of 13 roe deer deaths), and poachers did not prefer any sex or age. Adult survival (0.77) was higher than survival of young individuals (0.53); this trend was stronger when poaching was excluded from the analysis. All cases of poaching were recorded between mid-September and February. Although the two parts of the study area were exposed to a similar degree of anthropogenic pressure, all poached individuals occupied home ranges in the mosaic, where the forest cover in home ranges of roe deer was significantly higher than in the field.     

Spatial variation in springtime food resources influences the winter body mass of roe deer fawns

It is well established that the dynamics of mammalian populations vary in time, in relation to density and weather, and often in interaction with phenotypic differences (sex, age and social status). Habitat quality has recently been identified as another significant source of individual variability in vital rates of deer, including roe deer where spatial variations in fawn body mass were found to be only about a tenth of temporal variations. The approach used was to classify the habitat into blocks a priori, and to analyse variation in animal performance among the predefined areas. In a fine-grained approach, here we use data collected over 24 years on 1,235 roe deer fawns captured at known locations and the plant species composition sampled in 2001 at 578 sites in the Chizé forest to determine the spatial structure at a fine scale of both vegetation and winter body mass of fawns, and then to determine links between the two. Space and time played a nearly equal role in determining fawn body masses of both sexes, each accounting for about 20% of variance and without any interaction between them. The spatial distribution of fawn body mass was perennial over the 24 years considered and predicted values showed a 2 kg range according to location in the reserve, which is much greater than suggested in previous work and is enough to have strong effects on fawn survival. The spatial distribution and the range of predicted body masses were closely similar in males and females. The result of this study is therefore consistent with the view that the life history traits of roe deer are only weakly influenced by sexual selection. The occurrence of three plant species that are known to be important food items in spring/summer roe deer diets, hornbeam (Carpinus betulus), bluebell (Hyacinthoides sp.) and Star of Bethlehem (Ornithogalum sp.) was positively related to winter fawn body mass. The occurrence of species known to be avoided in spring/summer roe deer diets [e.g. butcher's broom (Ruscus aculeatus) and beech (Fagus sylvatica)], was negatively related to fawn body mass. We conclude that the spatial variation in the body mass of fawns in winter in this forest is as important as the temporal variation, and that the distribution of plant species that are actively selected during spring and summer is an important determinant of spatial variation in winter fawn body mass. The availability of these plants is therefore likely to be a key factor in the dynamics of roe deer populations.     

Lipids in monogastric animal meat.

Meat from monogastric animals, essentially pigs and poultry, is from afar the most consumed of all meats. Meat products from every species have their own characteristics. For a long time, pig meat has been presented as a fatty meat because of the importance of subcutaneous adipose tissue. Actually, when the visible fat is separated, this meat is rather poor in lipids: pieces eaten as fresh meat and without transformation, such as roasts, contain less then 2% total lipids. Poultry meat has always had a reputation of leanness because of its low content in intramuscular lipids. In addition, adipose tissues, localised in the abdominal cavity, are easily separable. The progress in genetics and a better knowledge of dietary needs has allowed to improve growth performances, to increase muscle weight and, in the pig, to strongly decrease carcass adiposity. However, strong contradictions appear between transformers and nutritionists, especially concerning the pig: the former wish to have meat with adipose tissues containing a high percentage of saturated fatty acids and the latter wish meat with more unsaturated fatty acids. The consumer, however, regrets the pigs of yesteryear or the poultry bred on farmyard that had tastier meat. At the same time, however, they request meat with a low fat content, which is paradoxical.     

Meat quality of farmed red deer fed a balanced diet: effects of supplementation with copper bolus on different muscles

Supplementation with copper (Cu) improves deer antler characteristics, but it could modify meat quality and increase its Cu content to levels potentially harmful for humans. Here, we studied the effects of Cu bolus supplementation by means on quality and composition of sternocephalicus (ST) and rectus abdominis (RA) muscles (n=13 for each one) from yearling male red deer fed with a balanced diet. Each intraruminal bolus, containing 3.4 g of Cu, was administered orally in the treatment group to compare with the control group. Meat traits studied were pH at 24 h postmortem (pH₂₄), colour, chemical composition, cholesterol content, fatty acid (FA) composition, amino acid (AA) profile and mineral content. In addition, the effect of Cu supplementation on mineral composition of liver and serum (at 0 and 90 days of treatment) was analysed. No interactions between Cu supplementation and muscle were observed for any trait. Supplementation with Cu increased the protein content of meat (P<0.01). However, Cu content of meat, liver and serum was not modified by supplementation. In fact, Cu content of meat (1.20 and 1.34 mg/kg for Cu supplemented and control deer, respectively) was much lower in both groups than 5 mg/kg of fresh weight allowed legally for food of animal origin. However, bolus of Cu tended to increase the meat content of zinc and significantly increased (P<0.05) the hepatic contents of sodium and lead. Muscles studied had different composition and characteristics. The RA muscle had significantly higher protein content (P<0.001), monounsaturated FA content (P<0.05) and essential/non-essential AA ratio (P<0.01) but lower pH₂₄ (P<0.01) and polyunsaturated FA content (P=0.001) than the ST muscle. In addition, RA muscle had 14.4% less cholesterol (P=0.001) than ST muscle. Also, mineral profile differed between muscles with higher content of iron, significantly higher (P<0.001) content of zinc and lower content of calcium, magnesium and phosphorus (P<0.05) for ST muscle compared with RA. Therefore, supplementation with Cu modified deer meat characteristics, but it did not increase its concentration to toxic levels, making it a safe practice from this perspective. Despite the lower content of polyunsaturated FA, quality was better for RA than for ST muscle based on its higher content of protein with more essential/non-essential AA ratio and lower pH₂₄ and cholesterol content.     

Effects of fat source and dietary sodium bicarbonate plus straw on the conjugated linoleic acid content of milk of dairy cows

The effects of fat source (0.7 kg of fatty acids from extruded soybeans or palmitic acid), of sodium bicarbonate (0.3 kg) plus straw (1 kg) and the interaction of these treatments on the content of conjugated linoleic acid (CLA) in the milk of dairy cows were examined. During nine weeks a group of 10 cows received a ration with palmitic acid and bicarbonate plus straw (ration PAB). During three periods of three weeks a second group of 10 cows received successively a ration with extruded soybeans and bicarbonate plus straw (ration ESB), a ration with palmitic acid without bicarbonate or straw (ration PA), and a ration with extruded soybeans without bicarbonate or straw (ration ES). Rations ES and ESB increased the content of polyunsaturated fatty acids in milk, but decreased milk fat content, compared to rations PAB and PA. Ration ESB led to the greatest milk CLA content, by a synergy between the high amount of dietary fat, and the action of bicarbonate plus straw, favouring trans11 isomers of CLA and C18:1, presumably via a ruminal pH near neutrality. Ration ES favoured trans10 isomers, not desaturated in the mammary gland, so that the milk CLA content was lower than with ration ESB, and resulted in the lowest milk fat content. In conclusion, a ration supplemented with both extruded soybeans and bicarbonate plus straw, was an efficient way to increase the CLA content in the milk of dairy cows.     

Metabolic evidence of a 'rumen bypass' or a 'ruminal escape' of nutrients in roe deer (Capreolus capreolus)

As short chain fatty acids produced in the forestomach are insufficient to satisfy the energy requirements of the concentrate selecting roe deer (Capreolus capreolus), it is proposed that these animals may have other mechanisms to avoid energy losses due to microbial fermentation. Nutrients bypassing down the ventricular groove (rumen bypass) or ruminal escape of unfermented or partially fermented nutrients may be two alternatives. As metabolic evidence for incomplete fermentation in the forestomach we investigated: (1) the abundance of the sodium-dependent glucose co-transporter (SGLT1) in the duodenum; (2) enzyme activities of maltase, saccharase and alpha-amylase in duodenal and pancreatic tissue; and (3) the proportion of essential, polyunsaturated fatty acids in depot fat samples from ruminants of different feeding type and--for comparison--from animals with a simple stomach. The high abundance of SGLT1, high enzyme activity and the high proportion of polyunsaturated fatty acids in the concentrate selecting ruminants support the hypothesis of rumen bypass or ruminal escape of nutrients in roe deer and reflect differences in nutrient utilization by ruminants that belong to different feeding types.     

Copper residues in meat from wild artiodactyls hunted with two types of rifle bullets manufactured from copper

Copper content in muscle and the presence of bullet fragments were assessed in samples from red deer (Cervus elaphus), roe deer (Capreolus capreolus), fallow deer (Dama dama) and wild boar (Sus scrofa) (total of 46 animals) which had been hunted with two types of solid copper bullets. Also, the release of copper from bullets or fragments remaining in muscle was tested. For bullet type “B”, a fragment was detected in only 1 out of 34 carcasses whereas for type “A”, fragments were detected in all 12 carcasses, with up to 24 fragments (maximum size, 5?×?7?×?2 mm). Median copper concentrations around the shot wound (0–30 mm distance) were 1.25 and 1.77 mg/kg fresh weight for bullet types B and A, respectively, and thus in the expected range for venison. Around bullet fragments that had remained in muscles, the copper content increased significantly. In roe deer longissimus muscle that had been exposed for 7 days at +7 °C to bullets of type B, up to 1,000 mg/kg copper (fresh weight) was found in a distance of 0–2 mm. However, in a distance of 10–20 mm, maximum copper contents were <10 mg/kg fresh weight. Bullet fragments can constitute physical hazards and will release copper under acidic conditions as those prevailing in meat. Removal of bullet fragments prior to culinary preparation should ensure that a recommended dietary copper intake of 1.25 mg per adult consumer per day is not exceeded. From a food hygiene viewpoint, non-fragmenting bullets seem to be preferable.     

Effects of fat source and dietary sodium bicarbonate plus straw on the conjugated linoleic acid content of milk of dairy cows

Abstract

The effects of fat source (0.7 kg of fatty acids from extruded soybeans or palmitic acid), of sodium bicarbonate (0.3 kg) plus straw (1 kg) and the interaction of these treatments on the content of conjugated linoleic acid (CLA) in the milk of dairy cows were examined. During nine weeks a group of 10 cows received a ration with palmitic acid and bicarbonate plus straw (ration PAB). During three periods of three weeks a second group of 10 cows received successively a ration with extruded soybeans and bicarbonate plus straw (ration ESB), a ration with palmitic acid without bicarbonate or straw (ration PA), and a ration with extruded soybeans without bicarbonate or straw (ration ES). Rations ES and ESB increased the content of polyunsaturated fatty acids in milk, but decreased milk fat content, compared to rations PAB and PA. Ration ESB led to the greatest milk CLA content, by a synergy between the high amount of dietary fat, and the action of bicarbonate plus straw, favouring trans11 isomers of CLA and C18:1, presumably via a ruminal pH near neutrality. Ration ES favoured trans10 isomers, not desaturated in the mammary gland, so that the milk CLA content was lower than with ration ESB, and resulted in the lowest milk fat content. In conclusion, a ration supplemented with both extruded soybeans and bicarbonate plus straw, was an efficient way to increase the CLA content in the milk of dairy cows.     

Effects of dietary incorporation of different antioxidant extracts and free-range rearing on fatty acid composition and lipid oxidation of Iberian pig meat

This investigation was designed to evaluate the effects of feeding either free range or in confinement using concentrated diets with the same ingredients and oil source (5.5% of olive oleins) but with different antioxidant supplementation [control diet with a basal level of α-tocopheryl acetate (control); 200 mg/kg synthetic all-rac-α-tocopheryl acetate (Eall-rac); 200 mg/kg natural RRR-α-tocopheryl-acetate (ERRR-); flavonoid extract-enriched diet (AFlav); and phenolic compound-enriched extract (APhen)] on the fatty acid composition and lipid oxidation of Iberian pig muscle longissimus dorsi. The α-tocopherol concentration was significantly higher in muscles from free-range and ERRR- pigs than in muscles from Eall-rac pigs, and γ-tocopherol was only detected in muscles from free-range pigs. Longissimus dorsi muscles from free-range pigs had a significantly lower content of saturated fatty acids and higher content of polyunsaturated fatty acids than muscles from the other five groups of pigs fed in confinement; however, no significant effect on monounsaturated fatty acids was observed. No effect of dietary antioxidant supplementation (synthetic or natural α-tocopherol, flavonoid extract, or phenol extract) on the fatty acid composition of muscles was observed. A significant influence of dietary treatment on lipid oxidation was observed after 3 (P < 0.01), and 7 and 10 (P < 0.001) days of refrigerated storage, respectively. The lowest thiobarbituric acid-reactive substances (TBARS) values were found in pork chops from the free-range and ERRR- groups, intermediate values from the Eall-rac group, followed by AFlav and APhen, while the highest TBARS values corresponded to muscles from pigs fed the control concentrate. The source of α-tocopherol had a significant effect on lipid oxidation (P < 0.05), whereas the AFlav and APhen groups had similar TBARS values.     

Effect of dietary conjugated linoleic acid and selenized yeast on the concentration of fatty acids and minerals in rats

The main objective of this study was to evaluate the influence of diets enriched in individual conjugated linoleic acid (CLA) isomers, their mixture, and/or selenized yeast (Se-yeast) on the concentration of CLA isomers, long-chain polyunsaturated fatty acids (PUFA) and Se in the heart, muscles and liver of rats. The investigation was performed on 73 female Wistar rats (8 weeks of age, 200 g initial BW). After one week sub-maintenance feeding, rats received diets supplemented with 1% individual CLA isomers or 1 or 2% of a CLA isomers mixture, without or with 1.2 mg Se/kg (as Se-yeast) for 29 days. Feeding diets with 2% CLA isomer mixture reduced feed intake and body weight gain of rats, while addition of trans10,cis12 CLA and Se-yeast resulted in the highest body weight gain. CLA supplementation generally elevated the concentration of CLA isomers in heart and muscles significantly, although cis9,trans11 CLA accumulated preferentially. Regardless of the presence of Se-yeast, the dietary enrichment with CLA isomers caused a reduction in the capacity of A9-desaturase. Addition of Se-yeast to diets with individual CLA isomers or a 1% mixture of CLA isomers elevated the accumulation of CLA isomers in the heart and muscles, whereas all treatments with supplemented CLA and Se-yeast increased the accumulation of Se in rats compared with animals fed the diet containing Se only. Furthermore, CLA isomer supplementation decreased the concentration of PUFA and total fatty acids in the heart and muscles compared with control rats. Moreover, addition of CLA isomers interfered in the conversion of linoleic and linolenic acids to higher metabolites due to competition of CLA isomers for the same enzymes (delta6-, delta5-, delta4-desaturases and elongase).