Effects of Diets with Increasing Levels of Dried Tomato Pomace on the Performances and Apparent Digestibility of Growing Rabbits

Growth performance, plasma metabolites, meat quality, and meat and lipid health indices of New Zealand White rabbits as affected by dietary dried tomato pomace powder supplementation during the summer season

One hundred and twenty New Zealand White rabbits (NZW) (5-week-old; 735.27 ± 27.23 g) were kept in an open-sided house during the summer season. The experiment aims to evaluate the impacts of dried tomato pomace powder (DTPP) supplementation on rabbits' performance, blood metabolites, carcass traits, meat quality, and lipid and health indices of NZW rabbits during 5-13 weeks of age. The four treatments were a standard rabbit feed (control) and the control diet supplemented with 0.5, 1.0, and 1.5% DTPP, respectively. Rabbits fed a diet containing 1.5% DTPP showed the highest growth rate through weeks 9-13 of age despite having the lowest feed intake spanning 5-13 weeks. The best feed conversion ratio (FCR) was recorded in rabbits fed with 1.5% DTPP-supplemented diet for 5-13 weeks. Diets supplemented with 0.5 or 1.0% DTPP enhanced markedly dressing %, total edible flesh, saturated (SFAs), monounsaturated (MUFAs), and polyunsaturated fatty acid (PUFAs) contents, as well as the ∑n - 6/∑n - 3 ratio and the total n - 6 of meat. Dietary supplementation with DTPP decreased kidney, abdominal, and back fat. Diets supplemented with DTTP decreased total cholesterol, triglycerides, and very low-density lipoprotein (vLDL) concentrations. The greatest levels of linoleic acid, arachidonic and water-holding capacity in meat were observed in rabbits fed 1.5% DTPP-supplemented diets. Diets containing 1 and 1.5% DTPP improved meats' atherogenic and thrombogenic indices, meat lipid quality desired fatty acids/undesired fatty acids ratio, and meat health index. Conclusively, DTPP up to 1.5% maintained the growth performance of rabbits, boosted meat quality through increasing vitamin E, reduced fat deposition, modified fatty acid composition, and improved atherogenic, thrombogenic, and hypocholesterolemic indices of rabbit meat.

Influence of tomato processing by-product extract as dietary supplementation on growth performance, carcass characteristics and antioxidant status of growing rabbits under high ambient temperature

This study evaluated the effects of dietary supplementation of tomato processing by-product extract (TPBE) on growth performance, carcass characteristics and antioxidant status of growing rabbits under high ambient temperature. A total of eighty weaned New Zealand White (NZW) male rabbits (6-weeks-old; initial body weight, 730.28 ± 36.05 g) were randomly assigned to 4 groups. The first group was the control without supplementation; while the other groups were fed diets supplemented with 100, 200 and 250 mg TPBE/kg. The results showed that TPBE contained 211.85 mg/100g as total phenols and total flavones of 303.36 mg/100g. Rabbits fed a 250 mg TPBE-supplemented diet showed the heaviest body weight, the lowest feed intake and the best feed conversion ratio. TPBE diets reduced mortality percentage. Dietary supplementation of 250 mg TPBE had the highest dressing percentage. Plasma total protein, globulin, catalase and glutathione peroxidase of rabbits fed diets supplemented with 200 and 250 mg TPBE were high. Plasma total cholesterol, triglycerides, plasma hydrogen peroxide and malondialdehyde concentrations were decreased with dietary levels of TPBE. Rabbits fed 250 mg TPBE had higher T-AOC than the other groups. TPBE supplemented diets improved net revenue and economic efficiency. Conclusively, TPBE is containing appreciable content of polyphenols and flavonoids and the dietary supplementation of TPBE (250 mg/kg diet) had a positive impact on growth performance, reducing mortality and enhancing the antioxidant status of rabbits reared under high ambient temperature.

Impacts of Dietary Supplementations of Orange Peel and Tomato Pomace Extracts as Natural Sources for Ascorbic Acid on Growth Performance, Carcass Characteristics, Plasma Biochemicals and Antioxidant Status of Growing Rabbits

Simple Summary

There has been growing interest in using natural feed additives in to enhance animal performance and meat quality for human consumption. Citrus fruit residues can act as potential natural resources of antioxidants, which comprise a considerable quantity of ascorbic acid. Tomato pomace powder has a good nutritional value because of its content of essential amino acids and fatty acids besides its high content of antioxidants. This work examined the impact of dietary orange peel and tomato pomace extract supplementations at level of 200 mg/kg on growth performance, plasma biochemicals, carcass characteristics and antioxidant status of growing male rabbits. Dietary supplementations of orange peel and tomato pomace extracts could effectively improve growth performance, antioxidative status, modulate ascorbic acid level in plasma and meat and lower the plasma total cholesterol.

Abstract

The effect of dietary orange peel (OPE) and tomato pomace extract (TPE) supplementations on growth performance, plasma biochemicals, carcass characteristics and antioxidant status of growing male rabbits were investigated. A total of 96 rabbits (5 weeks old) were distributed into four groups. The first group received untreated pelleted diet (control). The second group was fed a diet containing ascorbic acid (AA; 1.0 g/kg diet), while the third and fourth groups consumed diets supplemented with 200 gm of OPE or (TPE, respectively. Our results indicated that OPE and TPE contained 59, 14.03 mg ascorbic acid/100 g DM, respectively. Growth performance, except feed conversion ratio, and carcass weight were improved by dietary supplementations. Dietary supplementations decreased kidneys, abdominal, back fats and ether extract of meat. Plasma protein and globulin levels were high in rabbits fed AA and TPE-supplemented diets. Low plasma total cholesterol and LDL-cholesterol concentrations were observed in rabbits fed the supplemented diets. Plasma AA was increased in rabbits fed AA and OPE-supplemented diets. Rabbits fed OPE and TPE-supplemented diets had great SOD activity. The best economic efficiency was recorded by rabbits fed the supplemented diets. Dietary supplementations of OPE and TPE could effectively improve growth performance, antioxidative status, modulate AA level in plasma and meat and lower plasma total cholesterol and LDL.

Characterization and management strategies for process discharge streams in California industrial tomato processing

The California tomato industry is the leading processor of tomatoes in the world. Accordingly, it produces a large amount of solid and liquid byproducts during processing. Some of these byproducts are under-utilized and discarded. There is increasing demand for the conversion of tomato byproducts into value-added products. This study reviews the characteristics of solid residue and process water discharge streams generated at different stages of tomato processing in addition to their current management strategies. Furthermore, relevant policy that governs management of solid and liquid organic byproducts for California tomato processors is discussed. Finally, recommendations for novel and sustainable management strategies are explored.

Rabbit metabolic response and selected meat quality traits: Evaluation of dietary PLX® 23 and LycoBeads® feed supplement

Effects of dietary supplementation of verbascoside and lycopene, alone and in combination, on some blood parameters, plasma oxidative status and meat quality traits in intensively reared rabbits were investigated. The test lasted 60 days and was conducted on 200 weaned-rabbits, divided into four groups of 50 animals each (5 animals each cage × 10 repetitions). The control group (CON) received a fattening feed without any feed supplements, whereas the experimental groups received the following: the first, an integration in 22 g of PLX^® 23 (Lippia citriodora extract; VB group) per ton of feed; the second, an integration in 100 g of LycoBeads^® (Solanum lycopersicum extract; LIC group) per ton of feed; and the third, an integration of both feed supplements in combination at the same doses (LIC+VB group). The dietary supplementation with Lippia citriodora and Solanum lycopersicum resulted in an improvement of the blood lipid profile, oxidative plasma markers, and hepatic and renal activity of treated growing rabbits. Feed additives also produced meat with a lower content in SFA and an increased PUFA content, and inhibited the lipid oxidation improving the oxidative stability of rabbit meat. The dietary supplementation, even reporting no effects on productive parameters and carcass yield, showed an improvement on several blood parameters, as indicator of animal welfare, and on quality and healthy meat markers.

Rabbit Feces as Feed for Ruminants and as an Energy Source

Simple Summary

This paper investigates the potential use of rabbit feces as a source of nutrition for ruminants and as an energy source. Feeding rabbit feces to ruminants or biogas production with rabbit manure may reduce the competition between human food and animal feed, provide a partial solution to some environment problems, and reduce treatment and disposal cost of manure. The in vitro rumen digestibility of rabbit feces was experimentally measured to assess its value as a feed for ruminants. In parallel, in order to extract the information about its potential nutritive and energetic value, the whole and partial relationships between the nutrient constituents of the rabbit feces and/or crop forages were investigated by chemometric analysis and also validated by near-infrared spectroscopy (NIRS). The results of this work indicated that rabbit feces has potential value as a ruminant feed and for biogas production.

Abstract

There are prospects for using novel feeds from various sources to provide ruminants with alternative sources of protein and energy such as by-products, and animal wastes. Rabbit feces are a concentrated source of fiber and could have commercial potential both as input biomass in anaerobic processes for biogas production, as well as a fibrous source for ruminal degradation. The aims of this work were to assess the potential as ruminant feeding and as biogas production of rabbit feces, in comparison with 12 crops. The chemical composition and the potential and experimental in vitro true digestibility (IVTD) and neutral detergent fiber digestibility (NDFD) of 148 feces samples were determined by using chemical methods, Daisy system digestibility and/or NIRS predictions. The average biomethane potential (BMP) was 286 ± 10 l_CH4/kg SV with −4% vs. the crops average. Milk forage unit (milk FU), IVTD and NDFD of feces were 0.54 ± 0.06 milk FU/kg DM, 74% ± 3% and 50% ± 5%, respectively, with comparisons of −19%, −11% and −24% vs. the crops average. Reconstruction of the potential values based on the chemical constituents but using the crop partial least square model well agreed with the NIRS calibrations and cross-validation. In a global NIRS calibration of the feces and crops the relative predicted deviation for IVTD, NDFD and milk FU were 3.1, 2.9 and 2.6, respectively, and only 1.5 for BMP. Running the Daisy system for rabbit feces in rumen fluid gave some inconsistencies, weakened the functional relationships, and appeared not to be correlated with the potential values of IVTD and NDFD. Nevertheless, the energetic potential of feces appears to be similar to some conventional crops at different degrees of maturity. Thus we conclude that rabbit feces has potential value as a ruminant feed and for biogas production.

Effects of Dietary Fatty Acids on Lipid Traits in the Muscle and Perirenal Fat of Growing Rabbits Fed Mixed Diets

Simple Summary

Polyunsaturated fatty acids in human foods have been shown to have health benefits. We investigated the potential to incorporate them into rabbit meat by adding them to the diet. Good relationships between dietary fatty acids (FAs) and their content in longissimus dorsi muscle and perirenal fat of rabbits was established, especially the latter. The results should make it possible to enhance the polyunsaturated fatty acid content of rabbit meat, with benefits to the health of human consumers.

Abstract

The aim of this study was to evaluate the effects of various raw materials (spirulina, curcuma, tomato pomace, false flax, linseed, chia, perilla seeds) as suitable polyunsaturated fatty acid n-3 (n-3 PUFA) sources, on the lipid traits in the longissimus dorsi muscle and perirenal fat of growing rabbits. The fatty acid (FA) analyses of the diets, carried out by gas chromatography, differed over a wide range on the basis of the highly varied ingredients in 27 experimental formulations. Among the 29 identified FAs, three from feeds were catabolized in the rabbits, five were de novo synthesized and stored chiefly in the muscle. It was possible to linearly characterize the incorporation from the feed to the muscle of 16 FAs. This study has confirmed that the dietary inclusion of various raw materials could be considered as a way of enriching the n-3 PUFA of rabbit meat. A proposal for the prediction of n-3 PUFA from dietary α-linolenic acid (C18:3 n-3) and a panel of another 10 FAs has been made for intramuscular fat (R² = 0.94) and perirenal fat (R² = 0.96).