Dietary type (carnivore, herbivore and omnivore) and animal species modulate the nutritional metabolome of terrestrial species.

Ecometabolomics could be implemented as a powerful tool in molecular ecology studies, but it is necessary to know the baseline of certain metabolites and understand how different traits could affect the metabolome of the animals. Therefore, the main objective of this study was to provide values for the nutritional metabolome profile of different diet groups and animal species, as well as to study the differences in the metabolomic profile due to the effect of diet type and species. To achieve this goal, blood samples were taken from healthy animals (n = 43) of different species: lion (Panthera leo), jaguar (Panthera onca), chimpanzee (Pan troglodytes), bison (Bison bison), gazelle (Gazella cuvieri) and fallow deer (Dama dama), and with different types of diet (carnivore, herbivore and omnivore). Each blood sample was analysed to determine nutritional metabolites. The main results this study provides are the nutritional metabolic profile of these animals based on the type of diet and the animal species. A significant effect of the dietary type was found on nutritional metabolite levels, with those metabolites related to protein metabolism (total protein and creatine) being higher in carnivores. There is also an effect of the species on nutritional metabolites, observing a metabolome differentiation between lion and jaguar. In the case of herbivores, bison showed higher levels of uric acid and cholesterol, and lower urea levels than gazelle and fallow deer. More molecular ecology studies are needed to further the knowledge of the metabolism of these animals.

In Vitro and In Situ Evaluation of Broccoli Wastes as Potential Feed for Ruminants.

The potential of broccoli wastes (florets and stems) as ruminant feed was analyzed using in vitro and in situ techniques. Both stems and florets had high moisture content (90.6 and 86.1%, respectively), but the stems contained (% dry matter) lower levels (p < 0.05) of crude protein (CP; 23.2 vs. 30.8%) and ether extract (2.91 vs. 6.15%) and tended to have greater sugars content (p = 0.071; 33.4 vs. 19.6%) than florets. Stems had greater in vitro dry matter rumen degradability (45.3%; 24 h incubation) and lower in vitro CP intestinal digestibility (82.7%) compared with florets (42.2 and 90.1%, respectively). Rumen degradability of protein was high (<85%) for both fractions. In a second experiment, diets including different proportions of broccoli were formulated and fermented in vitro. The replacement of 24% of conventional feeds (wheat, soybean meal and wheat bran) in a concentrate by dried broccoli increased the amount of organic matter fermented in vitro and the NH3-N concentrations of a mixed diet including 40% of the concentrate. Including dried broccoli in the diet produced only small modifications in the volatile fatty acid profile and did not affect CH4 emission.

Feeding Agro-Industrial By-Products to Light Lambs: Influence on Meat Characteristics, Lipid Oxidation, and Fatty Acid Profile.

The aim of this study was to assess the effects of replacing 44% of conventional feeds in a high-cereal concentrate (CON) with by-products (BYP concentrate; 18% corn distillers dried grains with solubles, 18% dried citrus pulp, and 8% exhausted olive cake) on the meat characteristics and fatty acid (FA) profile of fattening light lambs. Two groups of 12 Lacaune lambs were fed concentrate and barley straw ad libitum from 13.8 to 26.0 kg of body weight. There were no differences (p ≥ 0.130) between groups in the pH, chemical composition, color, and texture parameters and in the estimated proportions of pigments in the longissimus dorsi. Feeding the BYP concentrate reduced the concentration of thiobarbituric acid reactive substances (TBARS) in the meat after 6 days of refrigerated storage (unmodified atmosphere), probably due to the greater polyphenol content in this concentrate. Compared with CON-fed lambs, the meat and the subcutaneous fat from BYP-fed lambs had lower saturated and greater polyunsaturated FA content as well as greater n-6/n-3 FA. In summary, feeding a blend of corn distiller dried grains with solubles, dried citrus pulp, and exhausted olive cake did not change the composition of the meat but improved its antioxidant status and FA profile.

Potential of Recycling Cauliflower and Romanesco Wastes in Ruminant Feeding: In Vitro Studies.

The nutritive values for ruminants of cauliflower (CAU) and Romanesco (ROM) wastes (leaves, stems and sprouts) were assessed by analyzing their chemical composition, in vitro ruminal fermentation, and in vitro intestinal digestibility. In addition, the in vitro ruminal fermentation of diets containing increasing amounts of CAU was studied. The dry matter (DM) content of leaves, stems and sprouts of both vegetables was lower than 10%, but they contained high crude protein (CP; 19.9 to 33.0%) and sugar (16.3 to 28.7%) levels, and low neutral detergent fiber (21.6 to 32.3%). Stems and sprouts were more rapidly and extensively fermented in the rumen than leaves, but there were only minor differences the fermentation profiles of both vegetables. The estimated metabolizable energy content ranged from 9.3 (leaves) to 10.8 (sprouts) MJ/kg DM. The CP rumen degradability (12-h in situ incubations) was greater than 80.0% for all fractions, and the in vitro intestinal digestibility of CP ranged from 85.7 to 93.2%. The inclusion of up to 24% of dried CAU in the concentrate of a mixed diet (40:60 alfalfa hay:concentrate) increased the in vitro rumen fermentation of the CAU diet, but did not affect methane (CH4) production, indicating the lack of antimethanogenic compounds in CAU.

Influence of feeding sunflower seed and meal protected against ruminal fermentation on ruminal fermentation, bacterial composition and in situ degradability in sheep.

The effects of treating sunflower seed (SS) and meal (SM), as well as of a mixture of both feeds (SSM; 45:55) with a solution of malic acid (1 M; 400 ml/kg feed) and heating for protection against ruminal degradation were studied. Four rumen-fistulated sheep were fed two mixed diets composed of oat hay and concentrate (40:60) and differing only in the concentrate, that contained either a mixture of untreated SS and SM (control diet) or treated SS and SM (MAH diet). A crossover design with two 24-d experimental periods was used, and each period included 10 d of diet adaptation, 9 d for in situ incubations of SS, SM and SSM, and 5 d for measuring ruminal fermentation characteristics and rumen emptying. From day 6 onwards a solution of (15NH4)2SO4 was continuously infused into the rumen of each sheep to label ruminal bacteria. Feeding the MAH diet did not affect either ruminal pH or concentrations of total volatile fatty acids and NH3-N, but decreased (p ≤ 0.01) the molar proportions of acetate and propionate and increased those of butyrate (p< 0.001). Organic matter and lipid contents of ruminal bacteria were lower whereas both N content and 15N enrichment were greater (p ≤ 0.05) in MAH-fed sheep. The in situ effective degradability (ED) of different fractions of SS, SM and SSM were calculated from the ruminal rates of particle comminution and passage, and values were corrected for microbial contamination. The MAH treatment decreased the ED of most fractions for all feeds and increased the supply of by-pass crude protein (CP) by 19.1% and 120% for SS and SM, respectively, and that of fat by 34% for SS. The MAH treatment also increased the in vitro intestinal digestibility of the by-pass CP for both SS (from 60.1% to 75.4%) and SM (from 83.2% to 91.0%). The simultaneous heating of both feeds (SSM) reinforced the protective effect of the MAH treatment and increased the by-pass CP without altering its intestinal digestibility, increasing the intestinally digested CP content by 16.8% compared with the value estimated from the results obtained for MAH-treated SS and SM incubated independently. These results indicate that the MAH treatment was effective to protect sunflower protein against rumen degradation and increased its intestinal digestibility.

Feeding Agroindustrial Byproducts to Light Lambs: Influence on Growth Performance, Diet Digestibility, Nitrogen Balance, Ruminal Fermentation, and Plasma Metabolites.

The objective of this study was to evaluate the effect of replacing cereals and protein concentrates in a high-cereal concentrate (control) for light lambs with corn distiller's dried grains with solubles (DDGS; 18%), dried citrus pulp (DCP; 18%), and exhausted olive cake (EOC; 8%) in a byproduct (BYP) concentrate on growth performance, digestibility, ruminal fermentation, and plasma metabolites. Two homogeneous groups of Lacaune lambs (13.8 kg ± 0.25 kg) were fed one of each concentrates and barley straw ad libitum until reaching about 26 kg body weight. There were no differences between groups on feed intake, average daily gain, or feed conversion ratio, but the control diet had greater (p < 0.001) dry matter digestibility. Diet had no effect on post-mortem ruminal pH and total volatile fatty acid concentrations and profile, but NH3-N concentrations were lower (p = 0.003) for the BYP-fed group compared with the control one. However, plasma concentrations of amino acids, total proteins, urea, and hepatic enzymes were not affected by the diet. In conclusion, 44% of feed ingredients in the concentrate for light lambs can be replaced with a mixture of corn DDGS, DCP, and EOC without negatively affecting growing performance and animal health.

Effect of a Diet Supplemented with Malic Acid-Heat (MAH) Treated Sunflower on Carcass Characteristics, Meat Composition and Fatty Acids Profile in Growing Lambs.

The objective of the study was to assess the effects of feeding sunflower meal (SM) and seeds (SS) protected against rumen degradation on carcass characteristics and composition and fatty acid (FA) profile of lamb meat. The protection of SM and SS was achieved by treating both feeds with malic acid at 150 °C for 2 h (MAH treatment) and in a previous study this treatment was shown to decrease ruminal degradability of protein of both feeds and fat degradability of SS. Two homogeneous groups of 12 lambs each were fed ad libitum high-cereal concentrates and cereal straw from 14 to 26 kg of body weight. The two concentrates differed only in the treatment SM and SS, which were included either untreated (control) or MAH treated. The MAH-fed lambs had greater thickness of dorsal fat (p = 0.016) and greater (p ≤ 0.016) values of the color parameters a* (redness) and C* (chromaticity) of the Rectus abdominis muscle. However, there were no differences in carcass measurements and in water-holding capacity, chemical composition, pH, color, or fatty acid of Longissimus muscle. In summary, the MAH treatment resulted in only subtle changes in meat composition and quality.

Effects of Feeding Multinutrient Blocks Including Avocado Pulp and Peels to Dairy Goats on Feed Intake and Milk Yield and Composition.

Twelve Murciano-Granadina dairy goats were divided into two homogeneous groups, which were fed either a control diet composed of 40% alfalfa hay and 60% concentrate or a diet based on 40% alfalfa hay, 40% concentrate and 20% multinutrient blocks, including 14.8% avocado pulp and peels (APP). Total dry matter (DM) intake was similar (p = 0.709) for both diets, but APP-fed goats had lower (p = 0.024) concentrate intake and tended (p = 0.063) to have lower fat intake compared with those fed the control diet. The average intake of blocks was low (66.4 g DM/d), which was attributed to avocado lipids oxidation and rancidity. Neither milk yield (p = 0,921) nor the efficiency of energy and nitrogen use were affected (p = 0.909 and 0. 840, respectively) by the diet, but milk fat tended to be greater (p = 0.057) in the APP-fed goats compared with the animals fed the control diet. Other milk components were similar (p ≥ 0.110) for both diets, and only subtle changes in the milk fatty acid profile were observed. In summary, the intake of blocks containing avocado wastes by dairy goats was low probably due to avocado lipids oxidation causing off-flavors and reduced palatability.

Evaluation of Brassica Vegetables as Potential Feed for Ruminants.

The objective of this study was to analyze the chemical composition, in vitro ruminal fermentation, and intestinal digestibility of discarded samples of four Brassica vegetables: Brussels sprouts (BS), white cabbage, Savoy cabbage, and red cabbage, and to assess the effects of including increasing amounts of BS in the concentrate of a dairy sheep diet on in vitro fermentation, CH4 production, and in situ degradation of the diets. All cabbages had low dry matter content (DM; <16.5%), but their DM had high crude protein (19.5-24.8%) and sugars (27.2-41.4%) content and low neutral detergent fiber (17.5-28%) and was rapidly and extensively fermented in the rumen. Rumen degradability of protein at 12 h of in situ incubation was greater than 91.5% for all cabbages, and in vitro intestinal digestibility of protein ranged from 61.4 to 90.2%. Replacing barley, corn, and soybean meal by 24% of dried BS in the concentrate of a diet for dairy sheep (40:60 alfalfa hay:concentrate) increased in vitro diet fermentation and in situ degradability of DM and protein, and reduced in vitro CH4/total volatile fatty acid ratio. In vivo trials are necessary to confirm these results.

Influence of storage time and processing on chemical composition and in vitro ruminal fermentation of olive cake.

Olive oil extraction generates olive cake (OC) that could be used in ruminant feeding. However, the chemical composition of OC is affected by multiple factors, being therefore highly variable. The objective of this study was to analyse the influence of storage time and further processing: crude, exhausted (subjected to a second oil extraction) and cyclone (obtained from a cyclone separator) on nutritive value of OC samples. Twelve samples (six crude and six exhausted) were obtained monthly from the same pond from 1 to 6 storage months, and nine samples (three crude, three exhausted and three cyclone) were obtained monthly from a different pond from 6 to 9 months storage. Chemical composition was analysed, and OC samples were fermented in vitro with sheep rumen fluid. Increasing storage time up to 6 months decreased sugars and total soluble polyphenols content but increased fibre content in OC. Dry matter effective degradability (DMED) decreased linearly (p < 0.001) by 35.9 and 45.5% as storage time augmented from 1 to 6 months for crude and exhausted OC, respectively. Crude OC had lower DMED values than exhausted OC (averaged values 0.255 and 0.294 g/g, respectively). Both potential production and rate of gas production were lower (p ≤ 0.018) in crude compared with exhausted OC, which was attributed to the high fat content of crude OC (≥86 g/kg dry matter). For samples stored longer than 6 months, cyclone had greater (p < 0.05) DMED than crude and exhausted OC (averaged values 0.207, 0.164 and 0.164 g/g, respectively). The results indicate that ruminal degradability of OC is reduced with advancing storage time, but only subtle changes were observed during the first two months. Cyclone showed greater degradability than crude and exhausted OC, but differences between crude and exhausted OC became negligible after five storage months.

Effects of Feeding Rumen-Protected Sunflower Seed and Meal Protein on Feed Intake, Diet Digestibility, Ruminal, Cecal Fermentation, and Growth Performance of Lambs.

The objective of this study was to analyze the efficacy of a treatment (MAH) of sunflower seed (SS) and meal (SM) with a malic acid solution (1 M; 400 mL/kg) and heating (150 °C, 2 h) to protect protein against rumen degradation and to improve the growth of lambs. Two homogeneous groups of 12 Lacaune lambs each (14.2 ± 0.35 kg body weight) were fed either a concentrate including untreated SS and SM or a concentrate with MAH-treated SS and SM. Lambs were fed concentrate and barley straw ad libitum for 40 days (about 26 kg body weight); feed intake and growth of lambs were recorded; blood samples were taken on days 0, 20, and the slaughter day for analysis of urea-N and amino acid-N; diet digestibility was determined; and ruminal and cecal samples were collected after slaughter. The in vitro incubation of both concentrates with sheep ruminal fluid for 12 h showed that the MAH-treatment tended to reduce NH3-N concentrations and increased propionate production. However, there were no differences (p > 0.05) between groups in any of the tested variables in the in vivo trial.

Nutritive Value of Tomato Pomace for Ruminants and Its Influence on In Vitro Methane Production.

The objective of this study was to determine the variability in nutritive value for ruminants of tomato pomace (TP) samples and analyze its effect on in vitro fermentation when it was included in a high-concentrate diet. Twelve TP samples were obtained from two processing plants at weekly intervals and analyzed for chemical composition, in vitro rumen fermentation, and intestinal digestibility. The chemical composition of TP did not differ between processing plants and only slight variations were observed among sampling times. Tomato pomace had a low dry matter content (<300 g/kg), a high content of neutral detergent fiber, crude protein, and ether extract (572, 160, and 82.7 g/kg dry matter on average, respectively), and was rapidly fermented in the rumen. Protein degradability at 16 h in situ incubation was 510 g/kg and in vitro intestinal digestibility of protein was low (430-475 g/kg). Replacing soybean meal and barley straw by dried TP increased the in vitro fermentation rate and the production of volatile fatty acids and reduced NH3-N concentrations without affecting CH4. In summary, TP samples showed little variability in nutritive value over sampling time and TP of up to 180 g/kg could be included in high-concentrate diets without negatively affecting rumen fermentation.

Protecting protein against ruminal degradation could contribute to reduced methane production.

Ruminants have a low efficiency of nitrogen (N) utilization that has negative implications for animal production and the environment, but reducing the ruminal degradation of protein can help to reduce N losses. The objective of this study was to evaluate the inclusion of sunflower meal (SM) and sunflower seed (SS) protected against ruminal degradation in high-cereal diets on in vitro ruminal fermentation and CH4 production. Samples of SS and SM were sprayed with a solution of malic acid 1 M (400 ml/kg sample) and dried at 150°C for 1 hr as a protective treatment. Four diets were formulated to contain either 13 (low) or 17 (high) g of crude protein (CP)/100 g dry matter (DM), and included SM and SS either untreated (13CON and 17CON diets) or treated as before described (13TR and 17TR diets). Diets were incubated in vitro with rumen fluid from sheep for 8 and 24 hr. The treatment did not affect (p ≥ 0.57) total volatile fatty acid (VFA) production at any incubation time, but it reduced (p < 0.05) NH3 -N concentrations by 19.2 and 12.5% at 8 and 24 hr respectively. Both CH4 production and CH4 /VFA ratio were lower (p < 0.02) in TR than in CON diets at 8 hr, but differences disappeared (p > 0.05) at 24 hr. The treatment increased the molar proportion of propionate (p = 0.001) and reduced that of isovalerate (p = 0.03) at 8 hr compared with CON diets, but only a reduction of isovalerate proportion (p = 0.03) was detected at 24 hr. There were no treatment x crude protein level interactions (p > 0.05) in any parameter, but high-protein diets had greater NH3 -N concentrations (p < 0.001) and lower VFA production (p < 0.001) than low-protein diets at 24 hr. The treatment reduced protein degradation, and CH4 production was decreased by 4.6 and 10.8% for low- and high-protein diets, respectively, at short incubation times without affecting VFA production, thus improving fermentation efficiency and decreasing polluting emissions.