Comparative assessment of emulsifiers for in vitro ruminal gas production and fermentation measurements: Tween 80 is a suitable emulsifier.

Emulsifiers are essential for achieving a homogenous distribution of lipophilic supplements in in vitro rumen fluid incubations. Since emulsifiers can alter rumen fermentation, it is crucial to select one that minimally impacts fermentation parameters to reduce potential biases. This study aimed to evaluate seven emulsifiers' impact on in vitro ruminal fermentation using the Hohenheim Gas Test in order to identify the most inert emulsifier. Rumen fluids were collected from three non-lactating Original Brown-Swiss cannulated cows before morning feeding and incubated for 24 h with a basal diet in triplicates. The emulsifiers tested were ethanol, ethyl acetate, propylene glycol, glycerol, ethylene glycol, soy lecithin, and Tween® 80, each in two dosages (0.5% or 1% v/v). The untreated basal diet served as control. Compared to control, in vitro organic matter digestibility was enhanced by ethyl acetate (by 36.9 and 48.2%), ethylene glycol (by 20.6 and 20.1%), glycerol (by 46.9 and 56.8%) and soy lecithin (by 19.7 and 26.8%) at 0.5 and 1% dosage, respectively. Additionally, the 24-h methane production increased for ethanol (by 41.9 and 46.2%), ethylene glycol (by 50.5 and 51.5%), and glycerol (by 63.1 and 65.4%) for the 0.5 and 1% dosage, respectively, and 0.5% dosage for ethyl acetate (by 31.6%). The acetate molar proportion was 17.2%pt higher for ethyl acetate, and 25.5%pt lower for glycerol at 1% dosage, compared to the control. The propionate concentration was 22.1%pt higher 1% glycerol, and 15.2%pt and 15.1%pt higher for 0.5 and 1% propylene glycol, respectively, compared to the control. In summary, Tween® 80 did not significantly affect in vitro rumen fermentation parameters, making it the most suitable choice for in vitro incubations involving lipophilic substances in rumen fluid. Ethanol may be considered as an alternative emulsifier if methane production is not the variable of interest.

Bioactive Peptide Discovery from Edible Insects for Potential Applications in Human Health and Agriculture.

In the past decade, there has been fast-growing interest among researchers to discover bioactive peptides from edible insects and to evaluate their potential applications in the management of human, livestock, and plant health. This review summarizes current knowledge of insect-derived peptides and their potential role in tackling human health issues and solving agriculture problems by protecting crops and livestock against their pathogens. Numerous bioactive peptides have been identified from edible insect species, including peptides that were enzymatically liberated from insect proteins and endogenous peptides that occur naturally in insects. The peptides exhibited diverse bioactivities, encompassing antioxidant, anti-angiotensin-converting enzyme, anti-dipeptidyl peptidase-IV, anti-glucosidase, anti-lipase, anti-lipoxygenase, anti-cyclooxygenase, anti-obesity, and hepatoprotective activities. Such findings point to their potential contribution to solving human health problems related to inflammation, free radical damage, diabetes, hypertension, and liver damage, among others. Although most of the experiments were performed in vitro, evidence for the in vivo efficacy of some peptides is emerging. Evidence of the protective effects of insect-derived endogenous antimicrobial peptides in combating farm animal and plant pathogens is available. The ability of insect-derived endogenous neuropeptides to protect plants against herbivorous insects has been demonstrated as well. Nevertheless, the potency of peptides identified from insect protein hydrolysates in modulating livestock and plant health remains a knowledge gap to be filled.

Crossbred Sows Fed a Western Diet during Pre-Gestation, Gestation, Lactation, and Post-Lactation Periods Develop Signs of Lean Metabolic Syndrome That Are Partially Attenuated by Spirulina Supplementation.

Excessive dietary intake of fats and sugars ("Western diet", WD) is one of the leading causes of obesity. The consumption of the microalga Arthrospira platensis (spirulina, Sp) is increasing due to its presumed health benefits. Both WD and Sp are also consumed by pregnant and breastfeeding women. This study investigated if gestating and lactating domestic pigs are an appropriate model for WD-induced metabolic disturbances similar to those observed in humans and if Sp supplementation may attenuate any of these adverse effects. Pigs were fed a WD high in fat, sugars, and cholesterol or a control diet. Half of the animals per diet group were supplemented with 20 g Sp per day. The WD did not increase body weight or adipose tissue accumulation but led to metabolic impairments such as higher cholesterol concentration in plasma, lower IGF1 plasma levels, and signs of hepatic damage compared to the control group. Spirulina supplementation could not reduce all the metabolic impairments observed in WD-fed animals. These findings indicate limited suitability of gestating and lactating domestic pigs as a model for WD but a certain potential of low-dose Sp supplementation to partially attenuate negative WD effects.

The major urinary protein gene cluster knockout mouse as a novel model for translational metabolism research.

Scientific evidence suggests that not only murine scent communication is regulated by major urinary proteins, but that their expression may also vary in response to metabolism via a yet unknown mechanism. Major urinary proteins are expressed mainly in the liver, showing a sexually dimorphic pattern with substantially higher expression in males. Here, we investigate the metabolic implications of a major urinary protein knockout in twelve-week-old male and female C57BL/6N mice during ad libitum feeding. Despite both sexes of major urinary protein knockout mice displayed numerically increased body weight and visceral adipose tissue proportions compared to sex-matched wildtype mice, the main genotype-specific metabolic differences were observed exclusively in males. Male major urinary protein knockout mice exhibited plasma and hepatic lipid accumulation accompanied by a hepatic transcriptome indicating an activation of lipogenesis. These findings match the higher major urinary protein expression in male compared to female wildtype mice, suggesting a more distinct reduction in energy requirements in male compared to female major urinary protein knockout mice. The observed sex-specific anabolic phenotype confirms a role of major urinary protein in metabolism and, since major urinary proteins are not expressed in humans, suggests the major urinary protein knockout mouse as a potential alternative model for translational metabolism research which needs to be further elucidated.

A High-Energy Diet and Spirulina Supplementation during Pre-Gestation, Gestation, and Lactation do Not Affect the Reproductive and Lactational Performance of Primiparous Sows.

Feeding high-energy (HED) or high-fat diets during gestation and lactation to pigs may help cover the energy requirements of high-prolific sows but may also adversely affect their reproductive performance. The microalga Arthrospira plantensis (Sp), rich in bioactive compounds, has been described to exert beneficial health effects. The present study investigated the effects of HED and Sp intake during gestation and lactation in pigs. Twenty-four primiparous crossbred sows were fed either a HED or a control diet. Half of the sows per group were supplemented with 20 g/day of Sp. Despite a higher gross energy intake, consuming the HED did not affect the sows' reproductive and lactational performance but significantly modified the colostrum fatty acid (FA) composition and tended to decrease the number of weaned piglets. The Sp supplementation did not affect the reproduction and lactation traits, but slightly affected the colostrum FA composition. A trend was observed for an interaction of diet and Sp in terms of offspring sex ratio with a 50% lower male-to-female ratio in the HED group compared to all other animals. These findings suggest that an HED and Sp intake hardly influence reproduction in sows. However, the HED modified the colostrum FA composition, whereas the Sp had only fewer effects, which may potentially affect offspring performance.

Moderate Differences in Plasma Leptin in Mares Have no Effect on Either the Amino Acid or the Fatty Acid Composition of the Uterine Fluid.

Female mammalian reproductive functions are closely linked to body condition and metabolic status. Energy homeostasis is regulated by endocrine hormones such as insulin, IGF-I, leptin, and adiponectin via the hypothalamic-pituitary-adrenal axis. These metabolic hormones and their receptors are also expressed in reproductive tissues and the embryo. We investigated the relationship between circulating leptin and the fatty acid (FA) and amino acid (AA) composition of the equine uterine fluid (UF) and peripheral blood plasma (BP) by using a mass spectrometry-based approach. UF and BP were collected from ten broodmares on days 6 and 7 post ovulation, respectively. The mares were retrospectively assigned to two groups according to their BP leptin concentrations (high leptin [> 1.6 ng/mL] versus low leptin [<0.8 ng/mL]). Specific AA and FA compositions for BP and UF were found with different levels of respective metabolite abundances. The main FAs in BP were stearic, palmitic and linoleic acid. In UF, the three most abundant FAs were eicosapentaenoic, arachidonic and stearic acid. The AA profile of BP was dominated by glycine, glutamine, serine and alanine, which were likewise among the highly abundant AAs in UF. In UF, glutamic acid had by far the highest concentration. Therefore, BP leptin concentration within a physiological range does not seem to affect the specific FA nor the AA composition of the UF. The composition of the UF may therefore be mediated by local rather than by peripheral metabolic hormones.

In vitro ruminal fermentation, methane production and nutrient degradability as affected by fruit and vegetable pomaces in differing concentrations.

Pomaces are food industry by-products and may serve as animal feed to increase sustainability of meat and milk production. The aim of the present study was to evaluate fermentation characteristics of dried fruit and vegetable pomaces in a short-term in vitro experiment using the Hohenheim Gas Test. A selection of six fruit (apple, aronia, orange, pomegranate, red, white grape) and three vegetable (beetroot, carrot, tomato) pomaces was tested in three concentrations (150, 300, 500 g kg-1 of dry matter (DM)) as supplement to the basal diet (hay, used as control). Three runs were performed, using rumen fluid from one of three different rumen-cannulated cows in each run. Per run, each compound was tested in duplicate. After 24 h incubation, total gas production, methane and CO2 concentration, short-chain fatty acids, in vitro organic matter digestibility as well as microbial counts were determined. In addition, the pomaces' polyphenol content including the fractions non-tannin phenols, condensed tannins and hydrolysable tannins were analysed. Most pomaces did not significantly affect rumen fermentation characteristics in any of the tested dosages and may thus be applied in ruminant nutrition without adverse effects. Aronia significantly decreased (-14.5%) the organic matter digestibility in the highest concentration whereas apple (+12%), carrot (+10%) and beetroot (+8%) increased gas formation related to digestible organic matter. The 500 g kg-1 dosage of pomegranate significantly decreased methane formation by about 28% without impairing digestibility. Pomegranate was the only pomace of those high in total tannins that contained exceptionally high amounts of hydrolysable (90% of total tannins) and proportionally low amounts of condensed tannins (10% of total tannins), indicating that the hydrolysable tannins most likely reduced the methane production. Therefore, pomegranate pomace may be an interesting option for a methane mitigating feed supplement in ruminants and should be considered for following in vivo testing.

Soybean Meal Can Be Replaced by Faba Beans, Pumpkin Seed Cake, Spirulina or Be Completely Omitted in a Forage-Based Diet for Fattening Bulls to Achieve Comparable Performance, Carcass and Meat Quality.

The aim of the study was to investigate the complete substitution of imported soybean meal in beef cattle diets and the consequences on performance, meat, and adipose tissue quality. Thirty growing crossbred Limousin bulls, with an initial bodyweight of 164 ± 13 kg and 4.3 ± 0.3 months of age, were fed a grass/maize-silage based diet with little additional concentrate (0.5:0.3:0.2). Concentrates contained either soybean meal (positive control), faba beans, pumpkin seed cake, or spirulina (Arthrospira platensis), resulting in about 226 g crude protein (CP)/kg concentrate dry matter (DM) and 158 g CP/kg total diet DM. A grain-based concentrate providing just 135 g CP/kg concentrate DM and 139 g CP/total diet DM served as a negative control. Bulls of all groups had comparable average daily gains (1.43 ± 0.1 kg) and feed intakes (6.92 ± 0.37 kg). Carcass and meat quality did not differ among groups. The fatty acid profile of meat lipids was hardly affected. These results indicate that soybean meal can be replaced by any of the tested protein sources without impairing performance or meat quality. Importantly, bulls fed the negative control achieved a fattening and slaughter performance comparable to that of the protein-supplemented groups without affecting meat and adipose tissue quality. Thus, the present findings suggest that feeding crossbred bulls a grass/maize-silage based diet does not require additional protein supplementation.

Antioxidant and Inflammatory Gene Expression Profiles of Bovine Peripheral Blood Mononuclear Cells in Response to Arthrospira platensis before and after LPS Challenge.

Oxidative stress and inflammatory diseases are closely related processes that need to be controlled to ensure the desirable high performance of livestock. The microalga spirulina has shown antioxidant and anti-inflammatory properties in monogastric species. To investigate potential beneficial effects in ruminants, we replaced soybean meal (SOY) in the diets of dairy cows and fattening bulls by spirulina (SPI) and analyzed plasma concentrations of antioxidants (ß-carotene, α-tocopherol, polyphenols) and serum total antioxidant capacity. Following in vitro stimulation with lipopolysaccharide (LPS), peripheral blood mononuclear cells (PBMCs) were isolated for expression analysis of inflammation- and antioxidant-defense-related genes. Plasma ß-carotene concentration was higher in SPI, compared to SOY cows, but did not differ in bulls. Plasma total phenol concentration was significantly higher in SPI, compared to SOY bulls, but not in cows. Stimulation of bovine PBMCs with LPS increased the expression of most cytokines and some antioxidant enzymes. Gene expression of PBMCs derived from SPI animals, compared to SOY animals, hardly differed. Our results indicate that in ruminants, spirulina might not have potent antioxidant and anti-inflammatory properties. Future studies should evaluate the microbial degradation of spirulina and its bioactive compounds in the rumen to provide further data on potential beneficial health effects in ruminants.

Mitochondrial DNA Depletion in Granulosa Cell Derived Nuclear Transfer Tissues.

Somatic cell nuclear transfer (SCNT) is a key technology with broad applications that range from production of cloned farm animals to derivation of patient-matched stem cells or production of humanized animal organs for xenotransplantation. However, effects of aberrant epigenetic reprogramming on gene expression compromise cell and organ phenotype, resulting in low success rate of SCNT. Standard SCNT procedures include enucleation of recipient oocytes before the nuclear donor cell is introduced. Enucleation removes not only the spindle apparatus and chromosomes of the oocyte but also the perinuclear, mitochondria rich, ooplasm. Here, we use a Bos taurus SCNT model with in vitro fertilized (IVF) and in vivo conceived controls to demonstrate a ∼50% reduction in mitochondrial DNA (mtDNA) in the liver and skeletal muscle, but not the brain, of SCNT fetuses at day 80 of gestation. In the muscle, we also observed significantly reduced transcript abundances of mtDNA-encoded subunits of the respiratory chain. Importantly, mtDNA content and mtDNA transcript abundances correlate with hepatomegaly and muscle hypertrophy of SCNT fetuses. Expression of selected nuclear-encoded genes pivotal for mtDNA replication was similar to controls, arguing against an indirect epigenetic nuclear reprogramming effect on mtDNA amount. We conclude that mtDNA depletion is a major signature of perturbations after SCNT. We further propose that mitochondrial perturbation in interaction with incomplete nuclear reprogramming drives abnormal epigenetic features and correlated phenotypes, a concept supported by previously reported effects of mtDNA depletion on the epigenome and the pleiotropic phenotypic effects of mtDNA depletion in humans. This provides a novel perspective on the reprogramming process and opens new avenues to improve SCNT protocols for healthy embryo and tissue development.

Effect of feeding hay vs. silages of various types to dairy cows on feed intake, milk composition and coagulation properties.

This research paper addresses the hypotheses (1) that milk produced from hay-fed cows differs from that of silage-fed cows and (2) that silage type has an important impact, too. Four diets differing in forage type but with equal estimated milk production potential and a forage:concentrate ratio of 0.85 : 0.15 were compared regarding their effect on feed intake, milk yield and milk properties. The forages tested were hay, grass silage, conventional short-chopped and long-chopped maize silage subjected to a novel processing technology (Shredlage®). Twenty-four dairy cows were fed two of the four diets in two consecutive runs in an incomplete (4 × 2) Latin-square design (n = 12 per diet). Each experimental period lasted 22 d, with 12 d of adaptation and 10 d of sampling. During sampling, feed intake and milk yield were recorded daily, milk composition and coagulation properties were determined four times. The composition of the diet ingredients was analysed weekly. Data were analysed with a mixed model considering feed, period and their interaction as fixed effects. Stage of lactation, milk yield and milk composition from the pre-experimental period were used as covariates in the model. Dry matter intake was lower with the long-chopped processed maize silage compared to the other three groups. There were some diet differences in intakes of net energy for lactation and absorbable protein in the duodenum, but this did not result in changes in milk yield. The milk fat content was higher with the grassland-based diets compared to the maize silage diets. No treatment effect on milk acidity and rennet coagulation properties was observed. In conclusion, there were no indications for specific physico-chemical properties of milk from a hay-based diet, and maize processing technology was not of large effect either. Future investigations should focus on sensory differentiation of the milk produced with different forages.

Preferential Partitioning of Rumen-Protected n-3 and n-6 Fatty Acids into Functionally Different Adipose Tissues.

Lipids are stored at various sites inside the body as adipose tissue (AT). These include subcutaneous, abdominal, and intermuscular locations. The AT substantially differ in their metabolic function. It is, however, unclear whether AT have specific requirements for individual essential n-3 and n-6 fatty acids (FA). If so, control mechanisms would partition FA from the blood. To investigate the hypothesis of a selective FA incorporation, 18 beef heifers were fed diets supplemented with 60 g/kg diet with lipids from either fish oil (FO) or sunflower oil (SO). The lipids had partially been rumen-protected to ruminal biohydrogenation of n-3 and n-6 FA. The AT analyzed for n-3 and n-6 FA by gas chromatography were obtained from pericardial, longissimus thoracis (LT) intermuscular, perirenal, and subcutaneous sites. The greatest proportions of n-3 and n-6 FA were found in the pericardial AT. Despite generally low abundance, n-3 FA proportions increased with FO compared to SO supplementation in all AT, but to a different extent. No such partitioning was found for the n-6 FA when supplementing SO. Concomitantly, the n-6/n-3 FA ratio was reduced with FO in all AT, except in the pericardial AT. The latter has specific metabolic functions and thus appears to be quite resistant to diet-induced changes in FA profile in order to maintain its function. The present findings showed the special role of specific n-3 and n-6 FA in bovine AT.

Alpine and lowland grazing differentially alter the reproductive tract redox milieu and amino acid composition in cattle.

An alpine environment is unique due to pasture biodiversity, with an abundant content of natural antioxidant polyphenols. The present study investigated the effects of lowland and alpine grazing on the oviduct and uterine tissue redox status and amino acid concentrations in plasma and reproductive fluids. In the first experiment, heifers grazed on lowland (H-LOW: n = 13) and on alpine (H-ALP: n = 15) pastures. In the second experiment, heifers grazed on the same lowland (HS-LOW: n = 6) and on a different alpine (HS-ALP: n = 6) pasture. The abundance of mRNA transcripts for antioxidant enzymes in the oviduct (glutathione S-transferase alpha 2, glutathione synthetase (GSS)) and the endometrium (catalase, glutathione-disulfide reductase, GSS) was less (P <  0.05), and for glutathione peroxidase 4 in the endometrium greater (P =  0.006) in the H-LOW than in the H-ALP group. The abundance of mRNA transcript for catalase was less in the endometrium in the H-LOW than in the H-ALP (P =  0.001) group. Catalase and NAD(P)H quinone dehydrogenase 1 concentrations in the oviduct were greater in the HS-LOW than in the HS-ALP group (P <  0.05). Of 32 amino acids analysed, there were differences in concentrations in the H-LOW and H-ALP group of 13, seven and 15 in plasma, oviduct and uterine fluids, respectively (P <  0.05). Comparing the HS-LOW to the HS-ALP groups, there were 13, one and three amino acids in the plasma, oviduct and uterine fluids, respectively, that were differentially abundant (P <  0.05). The grazing systems had some effect on the redox status and amino acid patterns in reproductive tissues.

Partitioning of fatty acids into tissues and fluids from reproductive organs of ewes as affected by dietary phenolic extracts.

Evaluation of dietary interventions with regard to fertility problems often observed in ruminant livestock is of global interest. Though the effects of polyphenol supplementation in ruminants on digestion and food quality are well described, the impact on reproductive tissues and fluids remains scarcely investigated. These compounds protect dietary unsaturated fatty acids (FA) from oxidation and biohydrogenation and thus saturation. In addition, modification of the expression of genes associated with FA metabolism may occur. Therefore, we characterized for the first time the FA profiles of reproductive tissues and fluids and investigated their potential modification by dietary polyphenols in 22 cyclic ewes. The animals were randomly divided into four groups and fed a basal diet of meadow hay and one of four concentrate types either non-supplemented (control) or supplemented with grape seed extract, Acacia mearnsii bark extract (13 g/kg dry matter (DM) each) or a combination of both (26 g/kg DM). After 10 weeks of feeding, the animals were slaughtered. Samples of reproductive (oviduct, uterus) and metabolically differently active tissues (liver, muscle, adipose) as well as of plasma and fluids from oviduct and uterus were analysed for their FA composition. In addition, the expression of lipid metabolic and antioxidant genes was analysed in all tissues except the adipose tissue. Fatty acid profiles in tissues and fluids as well as gene expression in tissues significantly differed between the different fluids and tissues. In contrast, only a few diet and matrix (fluid or tissue) × diet interactions were observed. Still, the FA profile of the uterus was the only one not at all affected by the diet. The mRNA expression was not affected by the diet for most of the genes investigated, which might in part be explained by the similar plasma polyphenol concentrations found at slaughter. Overall, our findings contribute to an improved understanding of the characteristic FA composition of reproductive tissues and fluids in sheep. In addition, the effect of polyphenols on different tissues, fluids and tissue gene expression has been confirmed as described in other animal species.

Vascular Endothelial Growth Factor A and VEGFR-1 Change during Preimplantation in Heifers.

Vascular endothelial growth factor A (VEGFA) plays a critical angiogenic role in the endometrium of placentalia during preimplantation. The role of VEGFA and its receptors is not fully characterised in bovine reproduction. We analysed the mRNA expression of VEGFA isoforms 121, 165 and 189, and VEGF receptors 1 and 2 in three experimental settings (A, B and C). We compared intercaruncular endometrium of cyclic to pregnant heifers at Days 12, 15 and 18 post insemination (Day 0), and between Day 15 and Day 18 conceptuses (A). We further compared caruncular versus intercaruncular endometrium at Day 15 (B), and endometrium of heifers carrying embryos originating from somatic cell nuclear transfer (SCNT) versus in vitro fertilisation (IVF) at Day 18 (C). Endometrial VEGFA protein was localised and quantified. Pregnant heifers displayed lower intercaruncular endometrial mRNA expression of VEGFA-121 (p = 0.045) and VEGFA-189 (p = 0.009) as well as lower VEGFA protein abundance (p < 0.001) at Day 15. The VEGFA protein was localised in intercaruncular luminal, glandular epithelium and in tunica muscularis of blood vessels. At Day 15, caruncular endometrium displayed higher VEGFA mRNA expression than intercaruncular endometrium (p < 0.05). Intercaruncular endometrial VEGFA protein at Day 18 was higher in abundance in SCNT than in IVF (p = 0.038). Therefore, during preimplantation in cattle, there may be a need for timely physiological reduction in intercaruncular endometrial VEGFA expression in favour of the caruncular area to facilitate a gradient towards the implantation sites. A higher expression of VEGFA in SCNT may predispose for later placentation abnormalities frequently observed following SCNT.

Effect of supplementation of pelleted hazel (Corylus avellana) leaves on blood antioxidant activity, cellular immune response, and heart beat parameters in sheep1.

Hazel leaves (Corylus avellana) fed to sheep resulted in decreased methane emissions without negatively affecting feed intake and were found to have antioxidant properties in vitro. The objective of this study was to evaluate effects of hazel leaves, rich in tannins, on blood antioxidant activity, cellular immune response, and heart beat parameters in sheep. Four experimental pellets were produced by mixing alfalfa and hazel leaves in different proportions, including alfalfa alone as a control, 30% and 60% of hazel leaves, the latter also with 3.8% polyethylene glycol (PEG). Six adult, nonpregnant, nonlactating female sheep (71 ± 5.7 kg of body weight) were allocated to 4 treatments in a 6 × 4 crossover design with four 18-d periods. The diet consisted of experimental pellets and ryegrass-dominated hay (ratio 80% to 20% in dry matter), resulting in hazel leaf proportions of approximately 0%, 25%, and 50% in the total diet. Blood samples were collected at the end of each period to determine plasma total phenol concentration and markers of oxidative status as well as peripheral blood mononuclear cells (PBMC) activation and proliferation response in vitro. Heart rate (HR) and HR variability parameters were measured for 2 consecutive days in each period, during different activities (i.e., eating pellets or hay, or lying). Treatments were compared with multiple comparisons and contrast analysis was used to test for linear and quadratic relations. Compared with control, feeding a high dosage of hazel leaves enhanced (P = 0.006) the plasma total antioxidant capacity, which linearly (P = 0.016) increased with increasing level of hazel leaves in the diet. The total phenol concentration and activities of the antioxidant enzymes superoxide dismutase, catalase, and glutathione reductase in the plasma were not different (P ≥ 0.23) among the treatments; however, the latter slightly increased linearly (P = 0.047) with increasing hazel leaves proportion. No differences were observed in the activation and proliferation of PBMC among treatments. The HR decreased linearly (P ≤ 0.009) during pellet eating and lying and the root mean square of successive differences of interbeat intervals (RMSSD) increased linearly (P = 0.037) when lying with increasing level of hazel leaves in the diet. In conclusion, our findings indicate that hazel leaves are a promising supplement to improve oxidative status with no effect on cellular immune response and cardiac stress level of sheep.

Partitioning of Rumen-Protected n-3 and n-6 Fatty Acids is Organ-Specific in Growing Angus Heifers.

Dietary polyunsaturated fatty acids (PUFA), especially n-3 and n-6 fatty acids (FA), play an important role in the regulation of FA metabolism in all mammals. However, FA metabolism differs between different organs, suggesting a distinct partitioning of highly relevant FA. For the present study in cattle, a novel technology was applied to overcome rumen biohydrogenation of dietary unsaturated FA. Angus heifers were fed a straw-based diet supplemented for 8 weeks with 450 g/day of rumen-protected oil, either from fish (FO) or sunflower (SO). The FA composition in blood and five important organs, namely heart, kidney, liver, lung, and spleen, was examined. In blood, proportions of polyunsaturated FA were increased by supplementing FO compared to SO. The largest increase of eicosapentaenoic acid (EPA) proportion was found with FO instead of SO in the kidney, the lowest in the lung. Docosahexaenoic acid (DHA) was increased more in the liver than in kidney, lung, and spleen. The heart incorporated seven times more EPA than DHA, which is more than all other organs and described here for the first time in ruminants. In addition, the heart had the highest proportions of α-linolenic acid (18:3n-3) and linoleic acid (18:2n-6) of all organs. The proportions of polyunsaturated FA in the lung and spleen were exceptionally low compared to heart, liver, and kidney. In conclusion, it was shown that the response to FO in the distribution of dietary n-3 FA was organ-specific while proportions of n-6 FA were quite inert with respect to the type of oil supplemented.

Bovine embryo elongation is altered due to maternal fatty acid supplementation.

The pre-implantation period is prone to embryonic losses in bovine. Embryo-maternal communication is crucial to support embryo development. Thereby, factors of the uterine fluid (UF) are of specific importance. The maternal diet can affect the UF composition. Since omega 3 fatty acids (omega 3 FA) are considered to be beneficial for reproduction, we investigated if dietary omega 3 FA affected factors in the UF related to embryo elongation. Angus heifers (n = 37) were supplemented with either 450 g of rumen-protected fish oil (omega 3 FA) or sunflower oil (omega 6 FA) for a period of 8 weeks. Following cycle synchronization and artificial insemination, the uteri were flushed post mortem to recover the embryos on day 15 of pregnancy. The UF and tissue samples of endometrium and corpus luteum (CL) were collected. Strikingly, the embryo elongation in the omega 3 group was enhanced compared to the omega 6 group. No differences were observed in uterine prostaglandins, even though the endometrial concentration of their precursor arachidonic acid was reduced in omega 3 compared to omega 6 heifers. The dietary FA neither led to differential expression of target genes in endometrium nor CL nor to a differential abundance of low-density lipoprotein cholesterol, cortisol or amino acids in the UF. Interestingly, the omega 3 group displayed a higher plasma progesterone concentration during luteal growth than the omega 6 group, possibly promoting embryo elongation. Further research should include an ovarian perspective to understand the functional link between dietary omega 3 FA and reproductive outcome.

Contribution of Ruminal Fungi, Archaea, Protozoa, and Bacteria to the Methane Suppression Caused by Oilseed Supplemented Diets.

Dietary lipids can suppress methane emission from ruminants, but effects are variable. Especially the role of bacteria, archaea, fungi and protozoa in mediating the lipid effects is unclear. In the present in vitro study, archaea, fungi and protozoa were selectively inhibited by specific agents. This was fully or almost fully successful for fungi and protozoa as well as archaeal activity as determined by the methyl-coenzyme M reductase alpha subunit gene. Five different microbial treatments were generated: rumen fluid being intact (I), without archaea (-A), without fungi (-F), without protozoa (-P) and with bacteria only (-AFP). A forage-concentrate diet given alone or supplemented with crushed full-fat oilseeds of either safflower (Carthamus tinctorius) or poppy (Papaver somniferum) or camelina (Camelina sativa) at 70 g oil kg-1 diet dry matter was incubated. This added up to 20 treatments with six incubation runs per treatment. All oilseeds suppressed methane emission compared to the non-supplemented control. Compared to the non-supplemented control, -F decreased organic matter (OM) degradation, and short-chain fatty acid concentration was greater with camelina and safflower seeds. Methane suppression per OM digested in -F was greater with camelina seeds (-12 vs.-7% with I, P = 0.06), but smaller with poppy seeds (-4 vs. -8% with I, P = 0.03), and not affected with safflower seeds. With -P, camelina seeds decreased the acetate-to-propionate ratio and enhanced the methane suppression per gram dry matter (18 vs. 10% with I, P = 0.08). Hydrogen recovery was improved with -P in any oilseeds compared to non-supplemented control. No methane emission was detected with the -A and -AFP treatments. In conclusion, concerning methanogenesis, camelina seeds seem to exert effects only on archaea and bacteria. By contrast, with safflower and poppy seeds methane was obviously reduced mainly through the interaction with protozoa or archaea associated with protozoa. This demonstrated that the microbial groups differ in their contribution to the methane suppressing effect dependent on the source of lipid. These findings help to understand how lipid supplementation and microbial groups interact, and thus may assist in making this methane mitigation tool more efficient, but await confirmation in vivo.

Regulation of 11ß-hydroxysteroid dehydrogenase type 1 following caloric restriction and re-feeding is species dependent.

Evidence in the current literature suggests that expression and activity of 11ß-hydroxysteroid dehydrogenase type 1 (11ß-HSD1), a key regulatory enzyme in glucocorticoid metabolism, is elevated in the liver and reduced in visceral adipose tissue and skeletal muscle following caloric restriction (CR). In order to investigate the influence of CR on 11ß-HSD1 in more detail, we assessed expression and activity of 11ß-HSD1 in several tissues in two independent CR and re-feeding animal models. Levels and activity of 11ß-HSD1 after CR and re-feeding were measured [mouse liver and pig liver, pig visceral adipose tissue and pig skeletal muscle] using semi-quantitative RT-PCR, Western Blot analysis, and HPLC. After CR, no significant difference on mRNA levels was detected in mouse liver. But 11ß-HSD1 mRNA expression was upregulated after subsequent re-feeding. In contrast, 11ß-HSD1 protein expression after CR was significantly up-regulated, while no difference was detected after re-feeding. Interestingly, upregulation of protein after CR (1.4-fold) was lower than the increase in enzymatic activity (2.6-fold). Furthermore, while no difference was observed in protein levels after two weeks re-feeding, 11ß-HSD1 activity increased 2.5-fold. In pig tissues neither 11ß-HSD1 mRNA levels, protein expression or enzyme activity were influenced after CR and re-feeding. Overall, the results demonstrate species-dependent differences in regulation of 11ß-HSD1 following CR and suggest the presence of an additional regulation step for 11ß-HSD1 activity in mouse liver.