The Effect of Substitution of Palm Fat with Linseed Oil on the Lipid Peroxidation, Antioxidative Capacity and Intestinal Morphology in Rabbits (Oryctolagus cuniculus)

Simple Summary

By changing the source of fat in the diet of animals, the fat content of animal products, such as meat, could be improved. The addition of linseed oil, with a high proportion of polyunsaturated fatty acids, especially n-3 α-linolenic acid, is often used in animal nutrition. Rabbit diet manipulation is effective in increasing or changing the level of fatty acids such that meat could become a functional food for humans. Since polyunsaturated fatty acids are susceptible on oxidation, an effect on animal health could arise. Therefore, we conducted a trial replacing palm fat (saturated fatty acids) with linseed oil (polyunsaturated fatty acids) in the rabbit diet to compere the oxidative status and histology of intestinal tissues. There was no significant effect in the substitution of linseed oil on the malondialdehyde concentration in urine and plasma, antioxidative capacity of water soluble or lipid soluble antioxidants, or intestinal morphology. Therefore, with an appropriate dietary strategy, the content of rabbit meat can be improved without reducing animal welfare.

Abstract

This experiment was conducted to investigate the effect of different dietary fatty acids (saturated or polyunsaturated fatty acids) supplementation on the oxidative status and intestinal morphology of adult rabbits (Oryctolagus cuniculus). Twenty-four “slovenska kunka” rabbits were randomly assigned to two different dietary treatments (12 rabbits per treatment) and fed the experimental diets between 80 and 102 days of age. The palm fat (PALM) diet with 6% palm fat and linseed (LINSEED) diets with 6% linseed oil were used. To evaluate the oxidative status of rabbits, the malondialdehyde concentration in urine and plasma and concentration of water and lipid soluble antioxidants in plasma were measured. The antioxidative capacity of the gastrointestinal tract was evaluated by measuring concentration of water and lipid soluble antioxidants in tissues and contents of the intestine. The histological structure of the small intestine and caecum was analyzed via histomorphometric analysis. No significant differences were found in either of those parameters. In summary, rabbits were exposed to high levels of polyunsaturated fatty acids with a high predisposition to oxidation, but their health and welfare were not endangered.

Physiological values of some blood indicators in selected dwarf rabbit breeds

<p>The aim of the present study was to evaluate the effect of breed on haematological and biochemical indicators in 3 dwarf rabbit breeds. In the experiment, 30 sexually intact dwarf rabbit females aged 6 mo were used. With the sole exception of white blood cells and haematocrit value, breed had the most significant effect on the majority of haematological indicators monitored. The red blood cell count was higher in the Dwarf Lop compared to the Netherland Dwarf (+1.91×10¹² cells/L; P&lt;0.05) and also the Teddy Dwarf (+1.32×10¹² cells/L; P&lt;0.05). For haemoglobin concentration, a higher value was found in the Netherland Dwarf than in the Teddy Dwarf (+39.29 g/L; P&lt;0.05) and the Dwarf Lop (+26.36 g/L; P&lt;0.05). For erythrocytic indicators, the highest values of mean corpuscular volume, mean corpuscular haemoglobin and mean corpuscular haemoglobin concentration were found in the Netherland Dwarf. The breed had a significant effect on the urea and potassium values. A higher value of urea was recorded in the Dwarf Lop compared to the Teddy Dwarf (+1.56 mmol/L; P&lt;0.05). For potassium, a higher value was found in the Netherland Dwarf compared to the Teddy Dwarf (+0.85 mmol/L; P&lt;0.05). In addition, a significantly positive correlation (P&lt;0.05) was found between the live weight of dwarf females and values of haematocrit (0.49), albumin (0.54), alanine aminotransferase (0.51), and aspartate aminotransferase (0.41), while a significantly negative correlation (P&lt;0.05) was found between their live weight and values of triacylglycerols (–0.44), alkaline phosphatase (–0.38) and inorganic phosphorus (–0.52). </p>

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.

Short communication: effect of saccharomyces cerevisiae supplementation on some biomarkers of oxidative stress in weaned rabbits during the hot-dry season

<p>A feeding trial was conducted to evaluate the effect of Saccharomyces cerevisiae (SC) supplementation on some biomarkers of oxidative stress in rabbits during the hot-dry season (temperaturehumidity index: 33.2±0.9oC). Sixty healthy weaned crossbred rabbits, aged between 5-6 wk with live weight of 612.7±60.8 g (mean±standard deviation) were used. The rabbits were divided into 5 treatment groups; SC0 receiving a control diet without supplementation of SC, and SC2, SC4, SC6 and SC8 receiving the control diet supplemented with SC at the rate of 2, 4, 6 and 8×109 colony forming units/kg, respectively. The activity of total superoxide dismutase and malonaldehyde in serum were not significantly affected, but serum catalase concentration rose (P&lt;0.05) as the SC inclusion level increased. Although further studies are required, baker’s yeast containing SC could help ameliorate the adverse effects of heat stress in rabbits.</p><p> </p>