Role of rs2282679 in 25-hydroxyvitamin D levels and insulin resistance after a sleeve gastrectomy

BACKGROUND & AIMS

Some studies have reported links between 25-hydroxyvitamin D levels and the presence of obesity and some genetic variants. The aim of our design was to evaluate the effects of rs2282679 genetic variant of CG gene on 25-hydroxyvitamin D levels, weight loss and metabolic parameters after a robotic sleeve gastrectomy in premenopausal females with obesity.

METHODS

76 participants were enrolled. 25-hydroxyvitamin D levels, biochemical evaluation and anthropometric parameters were registered before surgery and after 3, 6 and 12 months follow up. Genotype of rs2282679 CG gene was evaluated.

RESULTS

The improvements in anthropometric parameters, blood pressure and lipid profile were similar in both genotypes (TT vs TG + GG). Basal insulin levels and HOMA-IR were greater in G allele carriers than non-carriers (Delta: 6.7 ± 1.2 mUI/L; p = 0.01) and (Delta: 1.3 ± 0.1 units; p = 0.02). 25-hydroxyvitamin D levels were lower in G allele carriers than non-carriers (Delta: 8.1 ± 1.1 ng/dl; p = 0.03). The levels of insulin and HOMA-IR remained greater in G allele carriers than non-carriers throughout all the visits. The levels of 25-hydroxyvitamin D remained lower in G allele carriers than non-G allele. The average level of 25-hydroxyvitamin D at 12 months in non-G allele carriers were above 30 ng/dl (36.0 ± 3.1 ng/dl) and the level in G allele carriers were below (24.9 ± 4.9 ng/dl).

CONCLUSIONS

rs 2282679 (GC) was related with low 25 hydroxyvitamin D levels and insulin resistance. In addition, the presence of G allele produced a decrease in the improvement of 25-hydroxyvitamin D levels and insulin resistance after weight loss during 12 months.

The significance of N-carbamoylglutamate in ruminant production

Improving the efficiency and production of grazing ruminants to support food and fiber production, while reducing the environmental footprint and meeting the welfare needs of the animals, is important for sustainable livestock production systems. Development of new technologies that can improve the efficiency of nitrogen (N) utilization in ruminants, and that are effective and safe, has important implications for ruminant livestock production. N-carbomoylglutamate (NCG) is a functional micronutrient that stimulates endogenous synthesis of arginine, which can improve survival, growth, lactation, reproductive performance, and feed efficiency in mammals. There is a growing body of evidence to support the potential of dietary NCG supplementation to improve the productive capacity and N utilization efficiency of ruminants. This review summarizes the current literature on the effects of dietary supplementation with NCG in ruminants and impacts on production and potential to reduce the environmental footprint of farmed ruminant livestock. The current literature highlights the potential for commercial application in ruminant livestock to improve productivity and N utilization efficiency.

A single FTO gene variant rs9939609 is associated with weight change and insulin resistance improvement in response to a robotic sleeve gastrectomy in individuals with severe obesity

BACKGROUND

Genetic mechanisms have been involved in the weight response secondary to bariatric surgery.

OBJECTIVE

The aim of our study was to evaluate the effects of the rs9939609 genetic variant on weight loss and metabolic parameters after sleeve gastrectomy.

SETTING

Tertiary hospital.

METHODS

A total of 95 participants were enrolled. Co-morbidities, biochemical evaluation, and anthropometric parameters were registered before and after 3-, 6-, and 12-month follow-up. Genotype of the rs9939609 fat mass and obesity-associated (FTO) gene was evaluated.

RESULTS

We grouped the participants into 2 groups: carriers of A allele (TA+AA, 69.5%) and noncarriers of A allele (TT, 30.5%). We detected a statistically significant reduction of blood pressure, biochemical, and anthropometric parameters at 3 times during follow-up. After 6 months, changes of some parameters were greater in non-A allele carriers: weight (-39.6 + 4.0 kg versus -24.6 + 2.8 kg; P = .02), waist circumference (-21.1 + 2.1 cm versus -16.2 + 1.8 cm; P = .04), insulin (-12.3 + .9 mUI/L versus -8.9.1 + .2 mUI/L; P = .02), and homeostasis model assessment of insulin resistance (-3.1 + .1 units versus -2.3 + .1 units; P = .02 ). After 12 months, changes of the aforementioned parameters remained greater in non-A allele carriers. The percentage of participants with diabetes diminished earlier in the non-A allele carriers than A allele carriers at 6-month follow-up. The percentage of participants with diabetes at the end of the study was lower in non-A allele carriers (3.4% versus 12.1%; P = .02).

CONCLUSIONS

Our data suggest that non-A allele carriers of the genetic variant (rs9939609) of the FTO gene showed a better improvement of anthropometric and insulin levels in non-A allele carriers after a robotic sleeve gastrectomy. Both improvements are associated with a lower percentage of participants with diabetes at 12 months.

Evaluation of Feed Near-Infrared Reflectance Spectra as Predictors of Methane Emissions from Ruminants

Feed chemical composition is associated with methane (CH4) formation in the rumen, and thus CH4 yields (Ym; CH4 emitted from per unit of dry matter intake) could be predicted using near-infrared reflectance spectroscopy (NIRS) of feeds fed to ruminants. Two databases of NIRS data were compiled from feeds used in experiments in which CH4 yields had been quantified in respiration chambers. Each record in the databases represented a batch of feed offered to a group of experimental animals and the mean CH4 yield for the group. A near-infrared reflectance spectrum was obtained from each feed, and these spectra were used to generate a predictive equation for Ym. The predictive model generated from brassica crops and pasture fed at a similar feeding level (n = 40 records) explained 53% of the variation in Ym and had a reasonably good agreement (concordance correlation coefficient of 0.77). The predictive ability of the NIRS calibration could be useful for screening purposes, particularly for predicting the potential Ym of multiple feeds or feed samples, rather than measuring Ym in animal experiments at high expenses. It is recommended that the databases for NIRS calibrations are expanded by collecting feed information from future experiments in which methane emissions are measured, using alternative algorithms and combining other techniques, such as terahertz time-domain spectroscopy.

Prediction of nitrogen excretion from data on dairy cows fed a wide range of diets compiled in an intercontinental database: A meta-analysis

Manure nitrogen (N) from cattle contributes to nitrous oxide and ammonia emissions and nitrate leaching. Measurement of manure N outputs on dairy farms is laborious, expensive, and impractical at large scales; therefore, models are needed to predict N excreted in urine and feces. Building robust prediction models requires extensive data from animals under different management systems worldwide. Thus, the study objectives were (1) to collate an international database of N excretion in feces and urine based on individual lactating dairy cow data from different continents; (2) to determine the suitability of key variables for predicting fecal, urinary, and total manure N excretion; and (3) to develop robust and reliable N excretion prediction models based on individual data from lactating dairy cows consuming various diets. A raw data set was created based on 5,483 individual cow observations, with 5,420 fecal N excretion and 3,621 urine N excretion measurements collected from 162 in vivo experiments conducted by 22 research institutes mostly located in Europe (n = 14) and North America (n = 5). A sequential approach was taken in developing models with increasing complexity by incrementally adding variables that had a significant individual effect on fecal, urinary, or total manure N excretion. Nitrogen excretion was predicted by fitting linear mixed models including experiment as a random effect. Simple models requiring dry matter intake (DMI) or N intake performed better for predicting fecal N excretion than simple models using diet nutrient composition or milk performance parameters. Simple models based on N intake performed better for urinary and total manure N excretion than those based on DMI, but simple models using milk urea N (MUN) and N intake performed even better for urinary N excretion. The full model predicting fecal N excretion had similar performance to simple models based on DMI but included several independent variables (DMI, diet crude protein content, diet neutral detergent fiber content, milk protein), depending on the location, and had root mean square prediction errors as a fraction of the observed mean values of 19.1% for intercontinental, 19.8% for European, and 17.7% for North American data sets. Complex total manure N excretion models based on N intake and MUN led to prediction errors of about 13.0% to 14.0%, which were comparable to models based on N intake alone. Intercepts and slopes of variables in optimal prediction equations developed on intercontinental, European, and North American bases differed from each other, and therefore region-specific models are preferred to predict N excretion. In conclusion, region-specific models that include information on DMI or N intake and MUN are required for good prediction of fecal, urinary, and total manure N excretion. In absence of intake data, region-specific complex equations using easily and routinely measured variables to predict fecal, urinary, or total manure N excretion may be used, but these equations have lower performance than equations based on intake.

Effect of feeding fresh forage plantain (Plantago lanceolata) or ryegrass-based pasture on methane emissions, total-tract digestibility, and rumen fermentation of nonlactating dairy cows

Plantain (Plantago lanceolata) is an herb used to reduce the forage deficit of ryegrass-based pastures during the summer. This herb is being promoted for its reduced environmental impact in terms of nitrogen emissions, particularly reducing urinary nitrogen. However, the effect of plantain on emissions of enteric CH₄, the main greenhouse gas produced from ruminant-based production systems, is not known. The aim of the present trial was to determine CH₄ emissions and rumen fermentation characteristics of nonlactating dairy cows fed 100% plantain (PLT) or 100% perennial ryegrass (RG; Lolium perenne) in 2 experiments (E1 and E2). The forages were in a vegetative growth stage in E1 and were in a reproductive growth stage in E2. Methane emissions from 16 cows in each experiment were measured in respiration chambers for 2 d. Methane emissions per unit of dry matter intake (CH₄ yield) were 15 and 28% less for cows fed PLT than those fed RG in E1 and E2, respectively. Dry matter digestibility of PLT was 7 and 27% less than that of RG in E1 and E2, respectively, and CH₄ per unit of dry matter digested was similar for PLT and RG in both experiments. There were only minor (but some significant) differences in rumen fermentation characteristics between cows fed PLT and RG in both experiments. In conclusion, CH₄ yield was lower for cows fed PLT compared with those fed RG in both experiments and this reduction was largely explained by the lesser dry matter digestibility of PLT.

Substituting ryegrass-based pasture with graded levels of forage rape in the diet of lambs decreases methane emissions and increases propionate, succinate, and primary alcohols in the rumen

Feeding 100% forage rape to sheep consistently lowers methane emissions per unit of intake (CH4/DMI) compared to those fed 100% ryegrass pasture. However, forage rape is usually supplemented with other feeds, which might impact the mitigation potential provided by forage rape. The objective of this study was to determine the effect of substituting ryegrass with graded levels of forage rape in the diet of lambs on methane emissions and rumen fermentation characteristics. Seventy wether lambs (n=14/treatment) were fed a ryegrass-based pasture substituted with 0, 25, 50, 75 and 100% of forage rape (Brassica napus; FR0, FR25, FR50, FR75, FR100, respectively) on a dry matter basis. Methane emissions and dry matter intake were measured for 48 h in respiration chambers and a rumen fluid sample was collected. CH4/DMI decreased (P < 0.01) with increasing forage rape inclusion in the diet, so that sheep fed FR100 and FR75 emitted 34 % and 11% less, respectively, than those fed FR0. CH4/DMI differences for lambs fed FR25 and FR50 were much smaller (< 6%) relative to FR0. The pH of rumen fluid decreased (P < 0.01) at higher levels of forage rape inclusion in the diet (FR75 and FR100) compared to low levels of inclusion (FR0, F25 and F50). The proportion of ruminal acetate was least in FR100 (30%) followed by FR75 (10%), FR50 (8%) and FR25 (4%) compared with FR0 (P < 0.001). The proportion of propionate plus succinate was greater for FR100 (+40%), FR75 (+28%) and FR50 (+29%) compared with FR0, with FR25 intermediate (P < 0.001). The methanol concentration, and ethanol and propanol proportions in rumen fluid were greater for FR100 compared with any other treatment (P < 0.001). In conclusion, CH4/DMI decreased at high levels of forage rape inclusion in the diet and especially feeding FR100 was associated with a pronounced shift in rumen fermentation profile, with significant presence of succinate, ethanol, propanol, methanol, valerate and caproate.

A Review: Plant Carbohydrate Types—The Potential Impact on Ruminant Methane Emissions

Carbohydrates are the major component of most ruminant feeds. The digestion of carbohydrates in the rumen provides energy to the ruminants but also contributes to enteric methane (CH₄) emissions. Fresh forage is the main feed for grazing ruminants in temperate regions. Therefore, this review explored how dietary carbohydrate type and digestion affect ruminant CH₄ emissions, with a focus on fresh forage grown in temperate regions. Carbohydrates include monosaccharides, disaccharides, oligosaccharides, and polysaccharides. Rhamnose is the only monosaccharide that results in low CH₄ emissions. However, rhamnose is a minor component in most plants. Among polysaccharides, pectic polysaccharides lead to greater CH₄ production due to the conversion of methyl groups to methanol and finally to CH₄. Thus, the degree of methyl esterification of pectic polysaccharides is an important structural characteristic to better understand CH₄ emissions. Apart from pectic polysaccharides, the chemical structure of other polysaccharides per se does not seem to affect CH₄ formation. However, rumen physiological parameters and fermentation types resulting from digestion in the rumen of polysaccharides differing in the rate and extent of degradation do affect CH₄ emissions. For example, low rumen pH resulting from the rapid degradation of readily fermentable carbohydrates decreases and inhibits the activities of methanogens and further reduces CH₄ emissions. When a large quantity of starch is supplemented or the rate of starch degradation is low, some starch may escape from the rumen and the escaped starch will not yield CH₄. Similar bypass from rumen digestion applies to other polysaccharides and needs to be quantified to facilitate the interpretation of animal experiments in which CH₄ emissions are measured. Rumen bypass carbohydrates may occur in ruminants fed fresh forage, especially when the passage rate is high, which could be a result of high feed intake or high water intake. The type of carbohydrates affects the concentration of dissolved hydrogen, which consequently alters fermentation pathways and finally results in differences in CH₄ emissions. We recommend that the degree of methyl esterification of pectic polysaccharides is needed for pectin-rich forage. The fermentation type of carbohydrates and rumen bypass carbohydrates should be determined in the assessment of mitigation potential.

Abdominal normothermic regional perfusion in controlled donation after circulatory determination of death liver transplantation: Outcomes and risk factors for graft loss

Postmortem normothermic regional perfusion (NRP) is a rising preservation strategy in controlled donation after circulatory determination of death (cDCD). Herein, we present results for cDCD liver transplants performed in Spain 2012-2019, with outcomes evaluated through December 31, 2020. Results were analyzed retrospectively and according to recovery technique (abdominal NRP [A-NRP] or standard rapid recovery [SRR]). During the study period, 545 cDCD liver transplants were performed with A-NRP and 258 with SRR. Median donor age was 59 years (interquartile range 49-67 years). Adjusted risk estimates were improved with A-NRP for overall biliary complications (OR 0.300, 95% CI 0.197-0.459, p < .001), ischemic type biliary lesions (OR 0.112, 95% CI 0.042-0.299, p < .001), graft loss (HR 0.371, 95% CI 0.267-0.516, p < .001), and patient death (HR 0.540, 95% CI 0.373-0.781, p = .001). Cold ischemia time (HR 1.004, 95% CI 1.001-1.007, p = .021) and re-transplantation indication (HR 9.552, 95% CI 3.519-25.930, p < .001) were significant independent predictors for graft loss among cDCD livers with A-NRP. While use of A-NRP helps overcome traditional limitations in cDCD liver transplantation, opportunity for improvement remains for cases with prolonged cold ischemia and/or technically complex recipients, indicating a potential role for complimentary ex situ perfusion preservation techniques.

Methane emissions and rumen metabolite concentrations in cattle fed two different silages

In this study, 18 animals were fed two forage-based diets: red clover (RC) and grass silage (GS), in a crossover-design experiment in which methane (CH₄) emissions were recorded in respiration chambers. Rumen samples obtained through naso-gastric sampling tubes were analysed by NMR. Methane yield (g/kg DM) was significantly lower from animals fed RC (17.8 ± 3.17) compared to GS (21.2 ± 4.61) p = 0.008. In total 42 metabolites were identified, 6 showing significant differences between diets (acetate, propionate, butyrate, valerate, 3-phenylopropionate, and 2-hydroxyvalerate). Partial least squares discriminant analysis (PLS-DA) was used to assess which metabolites were more important to distinguish between diets and partial least squares (PLS) regressions were used to assess which metabolites were more strongly associated with the variation in CH₄ emissions. Acetate, butyrate and propionate along with dimethylamine were important for the distinction between diets according to the PLS-DA results. PLS regression revealed that diet and dry matter intake are key factors to explain CH₄ variation when included in the model. Additionally, PLS was conducted within diet, revealing that the association between metabolites and CH₄ emissions can be conditioned by diet. These results provide new insights into the methylotrophic methanogenic pathway, confirming that metabolite profiles change according to diet composition, with consequences for CH₄ emissions.

Role of the variant rs3774261 of adiponectin gene on adiponectin levels and ratio adiponectin/leptin after biliopancreatic diversion in morbid obese subjects

OBJECTIVE

  Single nucleotide variants (SNVs) of ADIPOQ gene on different comorbidities are related to obesity and weight loss. Despite, there are no studies evaluating the effect of rs3774261 on metabolic variables after bariatric surgery. We evaluated the effect of SNV rs3774261 of ADIPOQ gene on biochemical changes after biliopancreatic diversion surgery in morbidly obese subjects for 3 years follow-up.

PATIENTS AND METHODS

One hundred and forty-nine patients (111 females/38 males) with morbid obesity (body mass index >40 kg/m2) without diabetes mellitus type 2 were enrolled. Biochemical and anthropometric evaluation were registered before and after 1, 2, and 3 years. Genotype of rs3774261 has been studied.

RESULTS

Total cholesterol, LDL-cholesterol and triglyceride levels decreased in all genotype groups during the study. Although the improvement in glucose, insulin and HOMA-IR was significant in two genotypes (AA and AG); these changes were earlier in the AA genotype than in Ag and GG genotypes. Adiponectin levels increased in a significant way in subjects with AA genotype in the 3 follow-up periods (first year delta: 16.4±0.5 ng/ml; p=0.03, second year delta: 21.3±0.5 ng/ mL; p=0.02 and third year delta: 23.6±0.7 ng/mL; p=0.01) and at 3 years in subjects with AG genotype (delta: 18.3±0.4 ng/ mL; p=0.03). The ratio adiponectin/leptin increased in a significant way in subjects with AA genotype in the 3 follow-up times (first year delta: 0.40±0.1 units; p=0.02, second year delta: 0.58±0.1 units; p=0.01 and third year delta: 0.65±0.1 ng/mL; p=0.01) and at 3 years in subjects with AG genotype (delta: 0.61±0.1 ng/ mL; p=0.02). Subjects with GG genotype did not show a significant improvement in these parameters during the follow-up.

CONCLUSIONS

G allele carriers of rs3774261 showed a delay in the improvement of glucose metabolism parameters, adiponectin and adiponectin/leptin ratio.

The gene variant rs2419621 of ACYL-CoA synthetase long-chain 5 gene is associated with weight loss and metabolic changes in response to a robotic sleeve gastrectomy in morbid obese subjects

OBJECTIVE

Genetic mechanisms have been involved in the pathogenesis of obesity and weight loss due to bariatric surgery. The aim of our work was to evaluate the effects of rs2419621 genetic variant of ACSL5 gene on weight and metabolic changes after a robotic sleeve gastrectomy.

PATIENTS AND METHODS

48 patients were enrolled. Comorbidities, biochemical and anthropometric parameters evaluation were registered before and after 3, 6 and 12 months follow up. Genotype of rs2419621 ACSL5 gene was evaluated.

RESULTS

We classified the subjects with a dominant model, in two groups: those carriers T allele (TT+CT, 37.5%) and non-carriers T allele (CC, 62.5%).  We reported a statistically significant reduction of body weight, waist circumference, percentage of excess of weight loss (EWL%), blood pressure, glucose, insulin, LDL-cholesterol and triglycerides after surgery. After 12 months, delta of (EWL%; 70.1% vs. 64,2%; p=0.04), weight (40.7+4.1 kg vs. 32.5+4.8 kg; p=0.03), waist circumference (29.1+3.1 cm vs. 22.2+2.8 kg; p=0.02) and triglycerides (51.2+9.1 mg/dl vs. 32.1+8.1; p=0.02) were higher in T allele carriers than non-T allele carriers. All comorbidities improved, but the percentage of patients with hypertriglyceridemia diminished early in the 3-month follow-up in the T-allele carriers, and at 12 months, no patient with the T allele had hypertriglyceridemia.

CONCLUSIONS

Our data showed that the genetic variant (rs2419621) of ACSL5 gene are associated with better improvement of adiposity and triglyceride levels in subjects with T allele, after a robotic sleeve gastrectomy.

319 Predicting Urinary Nitrogen Excretion from Milk Urea Nitrogen of Fresh Forage or Total Mixed Ration Fed Dairy Cows: A Meta-analysis

Urine nitrogen excretion (g/d; UN) represent a significant environmental impact for both confinement feeding and pastoral based dairy systems. It is difficult to measure UN directly due to animal handling and labor requirements, especially in forage based production systems. The currently available milk urea nitrogen (MUN) equations have been shown to overestimate UN excretion of grazing dairy cows compared with an equation using urinary creatinine and UN concentration, indicating that diet may alter the relationship between MUN and UN. This potential was explored using data retrieved (treatment means: n = 69 and 27 for fresh forage [FF] and total mixed ration [TMR] fed cattle, respectively) from the literature and new data obtained from dairy cows fed FF (n = 15) in metabolism crates was used to test the new equations. The TMR data from literature was further split into a training set (to develop the model; n = 53) and a test set (to validate the model; n = 16). There was an interaction for diet type (P &lt; 0.01) where UN (g/d) = 0.023 × MUN (mg/dL) × live-weight (kg, LW) for TMR fed cattle, (similar to a pre-established equation); however, UN (g/d) = 0.015 × MUN × LW for FF fed cattle. For FF based equations, the New MUN equation and the creatinine equation showed good precision and accuracy (Lin’s CCC = 0.79 and 0.74, respectively) and adequate predictive ability (RMSEP = 29.8 and 35.9, respectively). The new MUN equation for TMR fed cattle showed excellent accuracy and precision (Lin’s CCC = 0.87) with good predictive ability (RMSEP = 24.3) for UN excretion (observed mean = 216.5 g/d). The new equations generated during this meta-analysis provide promising predictive ability of UN excretion, which can be used for management considerations, future research, and policy making.

Effect of dietary inclusion of winter brassica crops on milk production, feeding behavior, rumen fermentation, and plasma fatty acid profile in dairy cows

This study determined feeding behavior, dry matter (DM) intake (DMI), rumen fermentation, and milk production responses of lactating dairy cows fed with kale (Brassica oleracea) or swede (Brassica napus ssp. napobrassica). Twelve multiparous lactating dairy cows (560 ± 22 kg of body weight, 30 ± 4 kg of milk/d, and 60 ± 11 d in milk at the beginning of the experiment; mean ± standard deviation) were randomly allocated to 3 dietary treatments in a replicated 3 × 3 Latin square design. The control diet comprised 10 kg of grass silage DM/d, 4 kg of ryegrass herbage DM/d, and 8.8 kg of concentrate DM/d. Then, 25% of herbage, silage, and concentrate (DM basis) was replaced with either kale or swede. Cows offered kale had decreased total DMI compared with cows fed the control and swede diets, whereas inclusion of swede increased eating time. Milk production, composition, and energy-corrected milk:DMI ratio were not affected. Cows fed with kale had a greater rumen acetate:propionate ratio, whereas swede inclusion increased the relative percentage of butyrate. Estimated microbial N was not affected by dietary treatments, but N excretion was reduced with inclusion of kale, improving N utilization. Cows fed kale tended to have increased nonesterified fatty acids and showed presence of Heinz-Ehrlich bodies, whereas hepatic enzymes such as aspartate aminotransferase, γ-glutamyl transferase, and glutamate dehydrogenase were not affected by dietary treatments. In plasma, compared with the control, swede and kale reduced total saturated fatty acids and increased total polyunsaturated fatty acids and total n-3 fatty acids. Overall, feeding cows with winter brassicas had no negative effect on production responses. However, mechanisms to maintain milk production were different. Inclusion of swede increased the time spent eating and maintained DMI with a greater relative rumen percentage of butyrate and propionate, whereas kale reduced DMI but increased triacylglycerides mobilization, which can negatively affect reproductive performance. Thus, the inclusion of swede may be more suitable for feeding early-lactating dairy cows during winter.

Evaluation of Molly model predictions of ruminal fermentation, nutrient digestion, and performance by dairy cows consuming ryegrass-based diets

Several studies have been conducted to improve grazing management and supplementation in pasture-based systems. However, it is necessary to develop tools that integrate the available information linking the representation of biological processes with animal performance for use in decision making. The objective of this study was to evaluate the precision and accuracy of the Molly cow model predictions of ruminal fermentation, nutrient digestion, and animal performance by cows consuming pasture-based diets to identify model strengths and weaknesses, and to derive new digestive parameters when relevant. Model modifications for adipose tissue, protein synthesis in lean body mass and viscera representation were included. Data used for model evaluations were collected from 25 publications containing 115 treatment means sourced from studies conducted with lactating dairy cattle. The inclusion criteria were that diets contained ≥45% perennial ryegrass (Lolium perenne L.), and that dry matter intake, dietary ingredient composition, and nutrient digestion observations were reported. Animal performance and N excretion variables were also included if they were reported. Model performance was assessed before and after model reparameterization of selected digestive parameters, global sensitivity analysis was conducted after reparameterization, and a 5-fold cross evaluation was performed. Although rumen fermentation predictions were not significantly improved, rumen volatile fatty acids absorption rates were recalculated, which improved the concordance correlation coefficient (CCC) for rumen propionate and ammonia concentration predictions but decreased CCC for acetate predictions. Similar degradation rates of crude protein were observed for grass and total mixed ration diets, but rumen-undegradable protein predictions seemed to be affected by the solubility of the protein source as was the intestinal digestibility coefficient. Ruminal fiber degradation was greater after reparameterization, driven primarily by hemicellulose degradation. Predictions of ruminal and fecal outflow of neutral detergent fiber and acid detergent fiber, as well as total fecal output predictions, improved significantly after reparameterization. Blood urea N and urinary N excretion predictions resulted in similar accuracy using both sets of model parameters, whereas fecal N excretion predictions were significantly improved after reparameterization. Body weight and body condition score predictions were greatly improved after model modifications and reparameterization. Before reparameterization, yield predictions for daily milk, milk fat, milk protein, and milk lactose were greatly overestimated (mean bias of 61.0, 58.7, 73.7, and 64.6% of mean squared error, respectively). Although this problem was partially addressed by model modifications and reparameterization (mean bias of 3.2, 1.1, 1.7, and 0.4% of mean squared error, respectively), CCC values were still small. The ability of the model to predict grass digestion and animal performance in dairy cows consuming pasture-based diets was improved, demonstrating the applicability of this model to these productive systems. However, the failure to predict grass digestion based on standard model inputs without reparameterization indicates there are still fundamental challenges in characterizing feeds for this model.

Milk production responses, rumen fermentation, and blood metabolites of dairy cows fed increasing concentrations of forage rape (Brassica napus ssp. Biennis)

The aim of this study was to determine animal performance, rumen fermentation, and health-related blood metabolites of dairy cows in mid lactation fed with increasing levels (30 and 45%) of forage rape (FR) in the diet. Twelve pregnant multiparous lactating Holstein-Friesian dairy cows were randomly allocated to 1 of 3 dietary treatments in a replicated 3 × 3 Latin square design. The experiment was divided into three 21-d periods. For the control diet, 13.0 kg (dry matter, DM) of grass silage, 3.0 kg DM of commercial concentrate, 2.7 kg of DM cold-pressed extracted canola meal, and 0.45 kg DM of solvent-extracted soybean meal were offered daily. For the other two treatments, 30 and 45% of the DM from silage, canola meal, and commercial concentrate were replaced in equal proportions with FR. Data were analyzed individually using linear and quadratic orthogonal polynomials. Ingestive behavior was altered by the inclusion of FR. We observed a linear increase in eating time at the expense of rumination time. Nevertheless, total DM intake was not affected by dietary treatments, averaging 19.5 ± 0.24 kg of DM/d. Milk yield increased linearly with increasing concentration of FR in the diet. Thus, feed efficiency of cows (kg of milk/kg of DM intake) increased linearly with the percentage of FR in the diet. Inclusion of FR in the diet had no effect on milk composition or milk sensory characteristics. Mean rumen pH of cows decreased linearly from the control to the 45% FR diet; however, dietary treatments had no effect on the daily amount of time that rumen pH was below 5.8 (252 ± 71.4), indicating no risk of subacute ruminal acidosis. Concentrations of total volatile fatty acids in the rumen and molar proportions of acetate and butyrate were increased with FR inclusion, whereas the proportion of propionate was linearly reduced. Excretion of uric acid and total purine derivatives tended to be greater for cows fed FR, which resulted in a trend toward a linear increase in estimated microbial N flow. However, N use efficiency was not affected by FR inclusion. Although differences for some hematological measures (increased white blood cell and neutrophils counts) and a quadratic response for glutamate dehydrogenase for cows fed FR in the diet (decreased with inclusion of 30% and increased with 45% in the diet) were observed, all values were within appropriate ranges for dairy cows. These results indicated that including FR to dairy cow diets, up to 45% of diet DM, improved milk production due to changes in volatile fatty acids and predicted microbial N flow and had no negative effects on dairy cow health or sensory characteristics of milk.

Nuclear Magnetic Resonance to Detect Rumen Metabolites Associated with Enteric Methane Emissions from Beef Cattle

This study presents the application of metabolomics to evaluate changes in the rumen metabolites of beef cattle fed with three different diet types: forage-rich, mixed and concentrate-rich. Rumen fluid samples were analysed by ¹H-NMR spectroscopy and the resulting spectra were used to characterise and compare metabolomic profiles between diet types and assess the potential for NMR metabolite signals to be used as proxies of methane emissions (CH₄ in g/kg DMI). The dataset available consisted of 128 measurements taken from 4 experiments with CH₄ measurements taken in respiration chambers. Predictive modelling of CH₄ was conducted by partial least squares (PLS) regression, fitting calibration models either using metabolite signals only as predictors or using metabolite signals as well as other diet and animal covariates (DMI, ME, weight, BW^0.75, DMI/BW^0.75). Cross-validated R² were 0.57 and 0.70 for the two models respectively. The cattle offered the concentrate-rich diet showed increases in alanine, valerate, propionate, glucose, tyrosine, proline and isoleucine. Lower methane yield was associated with the concentrate-rich diet (p < 0.001). The results provided new insight into the relationship between rumen metabolites, CH₄ production and diets, as well as showing that metabolites alone have an acceptable association with the variation in CH₄ production from beef cattle.

Milk production responses and rumen fermentation of dairy cows supplemented with summer brassicas

Forage brassicas, such as summer turnip (ST; Brassica rapa) and forage rape (FR; Brassica napus), are used as supplementary crops during summer. However, studies with lactating dairy cows fed these forages are limited and report inconsistent productive responses. The aim of this study was to determine dry matter intake, rumen fermentation and milk production responses of dairy cows in mid-lactation supplemented with and without summer ('ST' or 'FR') brassicas. Twelve multiparous lactating dairy cows were randomly allocated to three dietary treatments in a replicated 3 × 3 Latin square design balanced for residual effects over three 21-day periods. The control diet consisted of 16.2 kg DM of grass silage, 2.25 kg DM of commercial concentrate and 2.25 kg DM solvent-extracted soybean meal. For the other two dietary treatments, 25% of the amounts of silage and concentrates were replaced with FR or ST. The inclusion of forage brassicas had no effects on milk production (24.2 kg cow/day average) and composition (average milk fat and protein 43.2 and 33.6 g/l, respectively). Dry matter intake was 0.98 kg and 1.12 kg lower for cows supplemented with FR and ST, respectively, resulting in a greater feed conversion efficiency (1.35 kg milk/kg DM for ST and FR v. 1.27 kg milk/kg DM for the control diet). Intraruminal pH was lower for cows supplemented with ST compared to the control diet; however, it did not decrease below pH 5.8 at any time of the day. After feeding, the concentrations of total short-chain fatty acids (SCFAs) in rumen contents increased with ST supplementation compared to the control diet. Inclusion of FR in the diet increased the molar proportion of acetate (68.5 mmol/100 mmol) in total SCFA at the expense of propionate, measured 6 h after feeding of the forage. The molar proportion of butyric acid was greater with ST and FR supplementation (13.1 and 12 mmol/100 mmol, respectively) than in control cows. The estimated microbial nitrogen (N) flow was 89.1 g/day greater when supplementing FR compared to the control diet. Based on the haematological measures, the inclusion of summer brassica forages did not affect the health status of the animals. These results indicate that mid-lactation dairy cows fed brassicas are able to maintain production despite the reduced intake, probably due to improved rumen fermentation and therefore nutrient utilization.

A meta-analysis comparing four measurement methods to determine the relationship between methane emissions and dry-matter intake in New Zealand dairy cattle

Enteric methane (CH4) emissions and dry-matter intake (DMI) can be accurately and precisely measured in respiration chambers (RC), whereas automated head chambers (GreenFeed; GF) and the SF6 tracer method can provide estimates of CH4 emissions from grazing cattle. In New Zealand, most dairy cattle graze pasture and, under these conditions, DMI also has to be estimated. The objective of the current study was to compare the relationship between CH4 production and DMI of New Zealand dairy cattle fed forages using the following four measurement methods: RC with measured DMI (RC); sulfur hexafluoride (SF6) with measured DMI (SF6-DMI); SF6 with DMI estimated from prediction equations or indigestible markers (SF6); GF with measured or estimated DMI (GF). Data were collected from published literature from New Zealand trials with growing and lactating dairy cattle fed forage-based diets and data were analysed using a mixed-effect model. The intercept of the linear regression between CH4 production and DMI was not significantly different from zero and was omitted from the model. However, residual variance (observed–predicted values) increased with an increasing DMI, which was addressed by log-transforming CH4 per unit of DMI and this model was used for final data analysis. The accuracy of the four methods for predicting log CH4 per unit of DMI was similar (P = 0.55), but the precision (indicated by residuals) differed (P &lt; 0.001) among methods. The residual standard deviations for SF6, GF and SF6-DMI were 4.6, 3.4 and 2.1 times greater than the residuals for RC. Hence, all methods enabled accurate prediction of CH4 per unit of DMI, but methodology for determining both CH4 and DMI affected their precision (residuals).

Rumen digesta and products of fermentation in cows fed varying proportions of fodder beet (Beta vulgaris) with fresh pasture or silage or straw

Context Fodder beet (FB) is a popular feed for dairy cows in temperate climates due to its high yields, high digestibility, low nitrogen (N) content in the dry matter (DM) and convenience of feeding (grazing in situ). However, the risk of ruminal acidosis requires research to design feeding regimes that capture these benefits without compromising animal health. Aims To understand aspects of rumen function when FB is offered in conditions representative of practical feeding in temperate pastoral systems. Methods Two indoor experiments were undertaken; one with cows in late lactation fed fresh perennial ryegrass with three proportions of FB (0, 0.23 and 0.45) and another with non-lactating cows fed pasture silage with 0.65 FB or barley straw with 0.86 FB. Measurements included rumen pH, short-chain fatty acid (SCFA) and ammonia concentrations determined at 2-h intervals, as well as daily individual cow intakes, estimates of microbial growth and rumen dynamics. Key results The inclusion of 0, 0.23 and 0.45 FB with fresh pasture in the did not affect daily DM intakes (~14.6 kg), milk yield (~10.7 kg), microbial synthesis (129 g of N/d) or fractional outflow rates of digesta (0.16/h; 11.2 L/h) of lactating cows. The non-lactating cow ration comprising 0.86 FB with straw was inappropriate and resulted in low intakes and insufficient dietary N. Microbial growth was approximately one-third of that in cows fed pasture silage with 0.65 FB. The ruminal pH reached lower values in all treatments where FB was offered. Rumen ammonia concentrations averaged 4.4 mmol/L in cows fed pasture but was sometimes undetectable in lactating cows fed 0.45 FB and in non-lactating cows. The amount of FB in the diet affected the extent of the circadian changes in molar proportions of SCFA. Conclusions Based on the results presented here, feeding fresh FB to dairy cows should not exceed ~0.4 of their DMI with pasture (late lactation), or ~0.6 of their intake with silage (non-lactating). Implications These findings could support evidence-based recommendations for FB use, considering its effects on aspects of rumen function, such as microbial protein synthesis and pH.

The association of the rs670 variant of APOA1 gene with insulin resistance and lipid profile in morbid obese patients after a biliopancreatic diversion surgery

OBJECTIVE

A common G-to-A transition (rs670) of the Apoprotein subtype 1 APOA1 gene has been evaluated. The presence of the A allele has been related with increased activity. We investigated the role of this genetic variant (rs670) on lipoprotein levels and anthropometric parameters after biliopancreatic diversion (BPD) surgery in morbid obese patients.

PATIENTS AND METHODS

Sixty-three patients with morbid obesity without diabetes mellitus type 2 were enrolled. Biochemical and anthropometric evaluation were registered before and after one, two and three years follow-up.

RESULTS

Genotype distribution was 73% (n=46) GG, 25.6% (n=16) GA and 1.4% (n=1) AA for the rs670 polymorphism. Percent excess weight loss, anthropometric and biochemical parameters improved in both groups (GG vs. GA±AA). The decrease of fasting insulin levels at 1 years (delta: -3.7±1.4 mUI/L vs. -2.9±1.2 mUI/L; p=0.02), 2 years (delta: -4.8±0.3 mUI/L vs. -4.0±0.2 mUI/L; p=0.01) and 3 years (delta: -6.7±3.1 mUI/L vs. -3.9±2.1 mUI/L; p=0.03) was higher in A allele carriers than in non carriers. The improvement of HOMA-IR levels at 1 years (delta: -3.7±1.4 mUI/L vs. -2.9±1.2 mUI/L; p=0.02), 2 years (delta: -4.8±0.3 mUI/L vs. -4.0±0.2 mUI/L; p=0.01) and 3 years (delta: -6.7±3.1 mUI/L vs. -3.9±2.1 mUI/L; p=0.03) was also higher in A allele carriers than non-carriers. Finally, the increase of HDL-cholesterol levels at 1 years (delta: 2.2±0.6 mg/dl vs. -1.2±0.2 mg/dl; p=0.001), 2 years (delta: 2.5±0.4 mg/dl vs. 0.3±0.1 mg/dl; p=0.01) and 3 years (delta: 2.4±0.6 mg/dl vs. 0.4±2.3 mg/dl; p=0.02) was higher in A allele carriers than non-carriers.

CONCLUSIONS

This variant of the APOA1 gene showed important effects on HDL-cholesterol, HOMA-IR and insulin resistance after DBP for 3 years.

Modelling thermodynamic feedback on the metabolism of hydrogenotrophic methanogens

The magnitude of the Gibbs free energy change of the substrate transformation that supports the growth of a microbe is decreased when the concentrations of the substrates are decreased and when the concentrations of the products of metabolism are increased. Microbes require a supply of ATP for cell maintenance and growth, and coupling the transformation of substrates to products with the formation of ATP also decreases the magnitude of the Gibbs free energy change. Here we include these three thermodynamic controllers (substrate and product concentration, and ATP formation) in a model of substrate transformation by hydrogenotrophic methanogens that results in a number of realistic behaviours. First, a threshold for substrate use emerges, below which the methanogen cannot metabolise its substrate. Under this model, microbes that capture more of the Gibbs free energy change from substrate transformation in the form of ATP have greater thresholds for their substrate, in line with observations of actual microbes. Second, an apparent saturation constant emerges that is controlled by the thermodynamics of the reaction. This increases with increasing ATP synthesis per substrate, so that methanogens that conserve more ATP grow faster at higher substrate concentrations, but are less competitive at low substrate concentrations. As a result, simply changing the ATP yield (moles of ATP per mole of substrate) results in methanogens with differing ecological strategies through thermodynamic impacts on their metabolism. Third, end-product inhibition through thermodynamic feedback can limit the growth of microbes, and those that capture more ATP per substrate are limited by smaller product concentrations than those that capture less ATP.

RAS Mutation Decreases Overall Survival After Optimal Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy of Colorectal Peritoneal Metastasis: A Modification Proposal of the Peritoneal Surface Disease Severity Score

BACKGROUND

Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) are currently the most accepted treatment for peritoneal metastases from colorectal cancer. Restrictive selection criteria are essential to obtain the best survival benefits for this complex procedure. The most widespread score for patient selection, the peritoneal surface disease severity score (PSDSS), does not include current biological factors that are known to influence on prognosis. We investigated the impact of including RAS mutational status in the selection criteria for these patients.

METHODS

We studied the risk factors for survival by multivariate analysis using a prospective database of consecutive patients with carcinomatosis from colorectal origin treated by CRS and HIPEC in our unit from 2009 to 2017. The risk factors obtained were validated in a multicentre, international cohort, including a total of 520 patients from 15 different reference units.

RESULTS

A total of 77 patients were selected for local análisis. Only RAS mutational status (HR: 2.024; p = 0.045) and PSDSS stage (HR: 2.90; p = 0.009) were shown to be independent factors for overall survival. Early PSDSS stages I and II associated to RAS mutations impaired their overall survival with no significant differences with PSDSS stage III overall survival (p > 0.05). These results were supported by the international multicentre validation.

CONCLUSIONS

By including RAS mutational status, we propose an updated RAS-PSDSS score that outperforms PSDSS alone providing a quick and feasible preoperative assessment of the expected overall survival for patients with carcinomatosis from colorectal origin undergone to CRS + HIPEC.

Normothermic regional perfusion vs. super-rapid recovery in controlled donation after circulatory death liver transplantation

BACKGROUND & AIMS

Although there is increasing interest in its use, definitive evidence demonstrating a benefit for postmortem normothermic regional perfusion (NRP) in controlled donation after circulatory death (cDCD) liver transplantation is lacking. The aim of this study was to compare results of cDCD liver transplants performed with postmortem NRP vs. super-rapid recovery (SRR), the current standard for cDCD.

METHODS

This was an observational cohort study including all cDCD liver transplants performed in Spain between June 2012 and December 2016, with follow-up ending in December 2017. Each donor hospital determined whether organ recovery was performed using NRP or SRR. The propensity scores technique based on the inverse probability of treatment weighting (IPTW) was used to balance covariates across study groups; logistic and Cox regression models were used for binary and time-to-event outcomes.

RESULTS

During the study period, there were 95 cDCD liver transplants performed with postmortem NRP and 117 with SRR. The median donor age was 56 years (interquartile range 45-65 years). After IPTW analysis, baseline covariates were balanced, with all absolute standardised differences <0.15. IPTW-adjusted risks were significantly improved among NRP livers for overall biliary complications (odds ratio 0.14; 95% CI 0.06-0.35, p <0.001), ischaemic type biliary lesions (odds ratio 0.11; 95% CI 0.02-0.57; p = 0.008), and graft loss (hazard ratio 0.39; 95% CI 0.20-0.78; p = 0.008).

CONCLUSIONS

The use of postmortem NRP in cDCD liver transplantation appears to reduce postoperative biliary complications, ischaemic type biliary lesions and graft loss, and allows for the transplantation of livers even from cDCD donors of advanced age.

LAY SUMMARY

This is a propensity-matched nationwide observational cohort study performed using livers recovered from donors undergoing cardiac arrest provoked by the intentional withdrawal of life support (controlled donation after circulatory death, cDCD). Approximately half of the livers were recovered after a period of postmortem in situ normothermic regional perfusion, which restored warm oxygenated blood to the abdominal organs, whereas the remainder were recovered after rapid preservation with a cold solution. The study results suggest that the use of postmortem normothermic regional perfusion helps reduce rates of post-transplant biliary complications and graft loss and allows for the successful transplantation of livers from older cDCD donors.

Parenteral administration of l-arginine to twin-bearing Romney ewes during late pregnancy is associated with reduced milk somatic cell count during early lactation

Maternal milk is the primary source of nutrition for suckling mammals, and its yield and composition are important determinants of survival during the early neonatal period. The objective of this study was to examine whether parenteral administration of l-Arg to twin-bearing ewes, during mid to late pregnancy, influenced prepartum maternal mammary gland development and subsequent lactation performance in the early postpartum period (14 d). At 80 d of pregnancy, multiparous Romney ewes were housed indoors in group pens, split into 2 cohorts, and fed a lucerne-based pellet diet, formulated to meet 100% of National Research Council-recommended requirements for twin-bearing pregnant ewes, once a day. Cohort 1 was administered l-Arg (72.7 mg/kg of live weight via i.v, 3 times a day) from d 100 of pregnancy until d 140. At d 140, ewes were euthanized and maternal mammary tissues were collected for analysis of the biochemical indices total DNA, RNA, protein, protein synthetic efficiency (protein:RNA), cell size (protein:DNA), transcriptional efficiency (RNA:DNA), and the abundance of mammalian target of rapamycin (mTOR) and mTOR^Ser2448 protein. Cohort 2 was administered an identical l-Arg regimen as cohort 1, but from d 100 until parturition. Milk was collected over a 14-d period (d 1, 4, 7, 10, and 14) to assess milk yield and composition. In cohort 1, total mammary DNA (cell number) tended to be higher in l-Arg ewes, with no change in total mammary RNA or protein content, biochemical indices of protein synthetic efficiency, cell size or transcriptional efficiency, or mTOR protein abundance or phosphorylation. In cohort 2, milk composition analysis from l-Arg ewes showed lower (d 7-14) milk somatic cell counts, greater crude protein percentage from d 7 to 10 but lower at d 14, and altered absolute concentrations of some free AA (d 7 and 14) compared with controls. We propose that parenteral administration of l-Arg during late pregnancy is associated with increased mammary gland cellular content and decreased somatic cell counts during early lactation.

Digestion and nitrogen excretion by Holstein–Friesian cows in late lactation offered ryegrass-based pasture supplemented with fodder beet

Recent changes in New Zealand dairying have included incorporation of fodder beet (FB) into rations. The present trial explored the impact of substituting different proportions of ryegrass-based pasture with FB for cows fed ad libitum in late lactation. The objective was to measure effects of FB on intake, digestion and urinary nitrogen (N) excretion using 16 Holstein–Friesian cows with a permanent rumen fistula. Before the 9-day indoor measurement period, cows were adapted to feeding 0%, 20%, 40% or 60% FB (bulbs and tops) with medium quality ryegrass-based pasture (191 g CP and 517 g neutral detergent fibre (aNDF)/kg DM; DM digestibility 0.634) over 2 weeks. However, it became apparent that a diet of 60% FB was detrimental to cow health, with two cows developing acidosis. The allocation of FB was reduced and the actual intakes were 23% and 45% of DM intake during the trial. Feeding FB substantially reduced N intake and urinary N excretion. The lower level (23%) of FB resulted in greater DM digestibility, albeit with a small reduction in N and aNDF digestibility. However, the higher level (45%) of FB reduced N and aNDF digestibility by 7.1 and 12.1 percentage units respectively, relative to pasture. Daily creatinine excretion was lower than published measurements from cattle fed dry diets, and circadian variation in urinary N:creatinine ratios suggests a need for caution when attempting to predict daily urinary N excretion from spot samples.

Polymorphism rs3123554 in the cannabinoid receptor type 2 (CB2R) gene is associated to metabolic changes after biliopancreatic diversion surgery

INTRODUCTION

The role of genetic variants of the CB2R gene in weight loss after a dietary intervention has been investigated in few studies, none of which has been conducted after bariatric surgery.

OBJECTIVES

The aim of this study was to assess the effect of the genetic variant (rs3123554) of the CB2R gene on cardiovascular risk factors and weight loss secondary to a biliopancreatic diversion.

DESIGN

The study simple consisted of 147 patients with morbid obesity. Biochemical and anthropometric parameters were measured at baseline and at each visit during 3 years (1, 2, and 3 years).

RESULTS

Percent excess weight loss, body mass index, weight, waist circumference, fat mass, blood pressure, fasting glucose, LDL cholesterol, total cholesterol, insulin, HOMA-IR, and triglyceride levels improved in both genotype groups. Decreases in fasting insulin levels and HOMA-IR were higher in non-A allele carriers as compared to A allele carriers.

CONCLUSIONS

Our data suggest that patients with morbid obesity who undergo bariatric surgery and carry the A allele of variant rs3123554 of the CB2R gene have greater weight. This allele has no influence on weight loss after surgery, but results in a lower decrease in insulin levels and insulin resistance.

Evaluation of a sheep rumen model with fresh forages of diverse chemical composition

The sheep rumen submodel MollyRum14 was evaluated on its methane and VFA predictions against data from respiration-chamber trials conducted with sheep fed perennial ryegrass, white clover, chicory, forage rape, turnip (leafy and bulb varieties), swedes, kale, or forage radish. We assessed the model's response to substrate degradation rate (settings that affect the rate of cellulose and hemicellulose digestion) and to fermentation stoichiometry (settings that alter nonglucogenic to glucogenic short-chain fatty acid ratios). Model predictions were evaluated against data for methane production (pCH4: g/d), methane yield (yCH4: g/kg DMI), and acetate to propionate ratio (A:P). The predictive ability of the model for both pCH4 and yCH4 was superior for perennial ryegrass than for other forages. Except for swedes and chicory, predictions for yCH4 were correctly ranked across the forages evaluated. Except for forage rape, robust predictions were obtained for all forages using fast degradation kinetics and a predominantly acetogenic stoichiometry. Model predictions for forage rape were enhanced using slow degradation kinetics and a predominantly propionic stoichiometry. These results indicate that MollyRum14 is suitable to predict methane emissions from sheep fed a variety of fresh forages including annual fodder crops. However, a clear understanding of degradation rates and stoichiometries is needed to enhance the utility of the model as a predictive tool. This would allow continuous adjustment of digestion rates and stoichiometries to be potentially tailored to individual forage species.

Omentin-1 Changes following Biliopancreatic Diversion and Relationship with Cardiovascular Risk Factors

INTRODUCTION

Omentin-1 might play a role in the pathogenesis of insulin resistance and obesity. The aim of the present study was to evaluate the influence of weight loss after biliopancreatic diversion on serum omentin-1 concentrations. Material and Methods A Caucasian population of 24 morbid obese patients was analyzed before and after 12 months of a biliopancreatic diversion surgery. Biochemical and anthropometric evaluation were realized at basal visit and at 12 months. Body weight, fat mass, waist circumferences, blood pressure, fasting blood glucose, fasting insulin, insulin resistance (HOMA-IR), lipid concentrations and omentin-1 were measured.

RESULTS

After bariatric surgery and in both gender groups (males vs. females); BMI, weight, fat mass, waist circumference, blood pressure, glucose , total cholesterol, LDL cholesterol, triglycerides, HOMA-IR and fasting insulin decreased in a statistical manner from basal values. Omentin-1 levels increased after bariatric surgery and in both gender the improvement was similar (males vs. females); (delta: -87.1 ± 19.0 ng/dL; p = 0.02 vs. -93.8 ± 28.1 ng/dL; p = 0.03). In the multiple regression analysis adjusted by age and sex; BMI kg/m2 (Beta -0.32: 95% CI -3.98 to -0.12) and insulin UI/L (Beta -0.41: 95% CI -8.38 to -0.16) remained in the model with basal omentin-1 levels as dependent variable. The regression model with post-surgery omentin-1 levels as dependent variable showed as independent variables BMI kg/m2 (Beta -0.13: 95% CI -7.69 to -0.09) and insulin UI/L (Beta -0.24: 95% CI -5.69 to -0.08), too.

CONCLUSION

This study showed a significant increase in omentin-1 levels after weight loss secondary biliopancreatic diversion surgery. A weak negative correlation with BMI and basal insulin levels was detected.

Adiponectin gene variant RS rs266729: Relation to lipid profile changes and circulating adiponectin after bariatric surgery

BACKGROUND

ADIPOQ rs266729 have been associated with body mass index and metabolic parameters.

OBJECTIVES

Our aim was to assess the contribution of this genetic variant on lipid profile and serum adiponectin levels after biliopancreatic diversion surgery in morbidly obese patients in a 3-year prospective study.

SETTING

Tertiary Hospital.

METHODS

A prospective cohort study (sample) of 149 patients with morbid obesity was evaluated. Biochemical and anthropometric parameters were studied at baseline and every year for a 3-year-follow-up period.

RESULTS

Percentage of excess weight loss (65.9% versus 66.0%:ns), body mass index, weight, waist circumference, fat mass, blood pressure, fasting glucose, low-density lipoprotein cholesterol, total cholesterol, insulin, homeostasis model assessment of insulin resistance, and triglyceride levels improved in both genotype groups. A decrease in fasting insulin levels, homeostasis model assessment of insulin resistance, total cholesterol, low-density lipoprotein cholesterol, and triglycerides was higher in non-G-allele carriers than G-allele carriers. The increase of adiponectin levels (at 1 yr) found after 1 (delta: 16.2 ± 3.1 ng/mL versus 2.1 ± 1.0 ng/mL; P = .02), 2 (delta: 24.2 ± 3.1 ng/mL versus 3.1 ± 1.1 ng/mL; P = .02), and 3 years (delta: 33.2 ± 3.9 ng/mL versus 4.7 ± 1.8 ng/mL; P = .01) was higher in non-G-allele carriers than G carriers. At all times, adiponectin levels were higher in patients with genotype CC.

CONCLUSIONS

Non-G allele of ADIPOQ gene variant (rs266729) is associated with increases in adiponectin levels and better improvement of low-density lipoprotein cholesterol, triglycerides, insulin, and homeostasis model assessment of insulin resistance after biliopancreatic diversion massive weight loss than G-allele carriers.

Milk production and composition, nitrogen utilization, and grazing behavior of late-lactation dairy cows as affected by time of allocation of a fresh strip of pasture

Eighty late-lactation dairy cows were used to examine the effects of allocating a new pasture strip of a sward based on ryegrass (Lolium perenne L.) in the morning (a.m.; ∼0730 h) or in the afternoon (p.m.; ∼1530 h) on milk production and composition, nitrogen (N) utilization, and grazing behavior. Cows grazed the same pasture strips for 24 h and were offered the same daily herbage allowance. Herbage composition differed among treatments; p.m. herbage had greater dry matter (DM; 22.7 vs. 19.9%), organic matter (OM; 89.5 vs. 88.9%), and water-soluble carbohydrate (10.9 vs. 7.6%) concentrations and lesser crude protein (20.5 vs. 22.2%) and neutral detergent fiber (48.8 vs. 50.4%) concentrations compared with a.m. herbage. Total fatty acids (FA), α-linolenic acid, and polyunsaturated FA (PUFA) were greater in a.m. herbage, whereas monounsaturated FA were greater in p.m. herbage. Estimates of herbage DM intake did not differ among treatments. Daily milk yields and milk fat and milk protein concentrations were similar among treatments, whereas milk fat (684 vs. 627 g/cow), milk protein (545 vs. 505 g/cow), and milk solids (milk fat + milk protein) yields (1,228 vs. 1,132 g/cow) tended to be greater for cows on p.m. herbage. Rumenic acid and total PUFA in milk were greater for cows on a.m. herbage, whereas oleic acid was greater for cows on p.m. herbage. Estimates of urinary N excretion (g/d) did not differ among treatments, but urinary N concentrations were greater for cows on a.m. herbage (5.85 vs. 5.36 g/L). Initial herbage mass (HM) available (kg of DM/ha) and instantaneous HM disappearance rates (kg of DM/ha and kg of DM/h) did not differ, but fractional disappearance rates (0.56 vs. 0.74 per hour for a.m. vs. p.m., respectively) differed. Under the current conditions, timing of pasture strip allocation altered the herbage nutrient supply to cows; allocating a fresh strip of pasture later in the day resulted in moderate increases in milk and milk solids yields in late-lactation dairy cows. Conversely, a greater concentration of precursor FA in a.m. herbage resulted in a greater concentration of beneficial FA in milk, compared with cows on p.m. herbage.

Diurnal variation in urine nitrogen and creatinine concentrations from lactating cows grazing ryegrass-dominant pasture in autumn and late spring–summer

In dairy production systems based on grazed pasture, urine patches are the main source of nitrogen (N) losses via leaching and gaseous emission pathways. The volume and N concentration of urine influences the amount of N in a urine patch. We conducted systematic urine sampling to determine the diurnal variation in concentrations of N and creatinine (a proxy for urine volume), and the N : creatinine ratio, to identify the sampling required for accurately estimating the daily mean concentrations of N and creatinine. Nine groups (n = 6) of multiparous Friesian and Friesian × Jersey cows in autumn (220 ± 26 days-in-milk, milked twice daily) and nine groups (n = 6) in late spring–summer (228 ± 24 days-in-milk, milked once daily) were sequentially withdrawn from the farm herd at approximately weekly intervals and each group was offered a fresh allocation of ryegrass-dominant pasture twice daily after milking for 3 days (including at the equivalent time in the afternoon in late spring–summer when they were milked once daily). For each of the 18 different groups of cows, individual urine samples were collected on Day 3 at 1100 hours, 1500 hours (afternoon milking), 1800 hours and 0700 hours (the following morning milking), and, subsequently, analysed for total N and creatinine concentrations. In autumn, urine-N concentrations were higher (P = 0.0002) at 1800 hours (5.8 g N/L) than they were at 1500 hours or 0700 hours (mean of 4.2 g N/L). In late spring–summer, the concentrations were higher (P < 0.001) at 1100 hours (8.0 g N/L) than they were at 1500 hours, 1800 hours or 0700 hours (mean of 6.3 g N/L). The urine N : creatinine ratio was 214 mol/mol in autumn and 148 mol/mol in late spring–summer, but did not vary among sampling times during the day. The highest concentrations of N were in urine samples collected ~3 h post-allocation of fresh feed when cows had grazed actively and consumed the majority of the herbage available. For accurate estimates of the daily mean urine N concentration, sample collections should be timed to encompass this diurnal variation. For the N : creatinine ratio, which was more stable through the day, the timing of sample collection is less important for estimating a daily mean.

Comparison of rumen in vitro fermentation of temperate pastures using different batch culture systems

In vitro batch culture systems are popular because they are relatively inexpensive and allow the screening and testing of large amounts of samples in a short time. Most of the batch culture systems have been designed for the evaluation of gas produced during fermentation of substrates and different designs have been compared between laboratories, but very little work is published where methane production or volatile fatty acid production is compared. The aim of this study was to determine the degree of agreement between two different in vitro batch culture systems, from different laboratories when measuring in vitro fermentation kinetics and end products using pasture samples as substrates. The two systems were a manual and a fully automated pressure-based system. Duplicates of pasture samples were incubated in three consecutive runs. Concordance correlation coefficients between systems and estimates of variance components (pasture, incubation run and random error) for each system were determined for all measured variables. There were poor correlations between systems for most of the variables except for time to produce half of the asymptotic gas production and acetate molar proportion of volatile fatty acids. However, for both systems most of variance was due to pasture sample and then incubation run. The poor agreement between systems might be explained by the different laboratory protocols. Therefore, comparisons of absolute values from different batch culture systems or experiments must be done carefully. Alternatively, more standardisation in terms of sample preparation and incubation procedure may be needed to compare in vitro fermentation products among systems.

Sheep numbers required for dry matter digestibility evaluations when fed fresh perennial ryegrass or forage rape

Research trials with fresh forages often require accurate and precise measurement of digestibility and variation in digestion between individuals, and the duration of measurement periods needs to be established to ensure reliable data are obtained. The variation is likely to be greater when freshly harvested feeds are given, such as perennial ryegrass (Lolium perenne L.) and forage rape (Brassica napus L.), because the nutrient composition changes over time and in response to weather conditions. Daily feed intake and faeces output data from a digestibility trial with these forages were used to calculate the effects of differing lengths of the measurement period and differing numbers of sheep, on the precision of digestibility, with a view towards development of a protocol. Sixteen lambs aged 8 months and weighing 33 kg at the commencement of the trial were fed either perennial ryegrass or forage rape (8/treatment group) over 2 periods with 35 d between measurements. They had been acclimatised to the diets, having grazed them for 42 d prior to 11 days of indoor measurements. The sheep numbers required for a digestibility trial with different combinations of acclimatisation and measurement period lengths were subsequently calculated for 3 levels of imposed precision upon the estimate of mean dry matter (DM) digestibility. It is recommended that if the standard error of the mean for digestibility is equal to or higher than 5 g/kg DM, and if sheep are already used to a fresh perennial ryegrass or forage rape diet, then a minimum of 6 animals are needed and 4 acclimatisation days being fed individually in metabolic crates followed by 7 days of measurement.

Prevalence of bovine milk pathogens in Azorean pastures: mobile versus fixed milking machines

The aims of the present study were (1) to evaluate the influence of using mobile (n=47) or fixed (n=45) milking machines in Azorean herds on the apparent prevalence of several milk pathogens in bulk tank milk (BTM) and (2) to determine whether separated subclinical mastitic cows can serve, in real time, as predictors of milk pathogen prevalence for the remaining animals at the herd level. The use of a mobile or fixed milking machine influenced (P≤0.05) the prevalence of Staphylococcus aureus (72.3 per cent; n=34 v 51.1 per cent; n=23, respectively) and Klebsiella species (46.8 per cent; n=22 v 26.7 per cent; n=12, respectively). S aureus (95 per cent CI OR 1.1 to 6.0) and Klebsiella species (95 per cent CI OR 1.0 to 5.8) were 2.5 times more likely to increase in the BTM of herds using mobile milking machines. The prevalence of coagulase-negative staphylococci (100 per cent; n=92), Escherichia coli (75.0 per cent), Corynebacterium bovis (57.6 per cent), Enterococcus species (55.4 per cent), Streptococcus dysgalactiae (51.1 per cent), Streptococcus uberis (41.3 per cent), Actinomyces pyogenes or Peptostreptococcus indolicus (41.3 per cent) and Streptococcus agalactiae (32.6 per cent) in BTM remained similar among the herds. κ coefficients were always <0.70, indicating intra-herd disagreement of the prevalence of milk pathogens between BTM and separated milking cows. Milking hygiene should be improved in pastures, focusing specifically on herds that use a mobile milking machine. The segregated cows at milking time are not good predictors of milk pathogens in BTM.

Ultrasonography to investigate the effect of supplementing whole milk with complex carbohydrates and specific amino acids on curd retention in the abomasum of dairy calves

AIM

To determine whether the retention time of curd in the abomasum of calves was influenced by supplementing milk with a plant-derived carbohydrate and amino acid supplement, evaluated non-invasively using ultrasonography.

METHODS

Female dairy calves aged between 2-6 days of age were sourced from a commercial farm in March 2013. All calves were fed whole milk until weaning (4 L per day); 21 calves were supplemented with a probiotic until 18 days of age, and thereafter with a plant-derived complex carbohydrate and amino acid supplement until weaning, and 22 calves were just fed whole milk. Treatment groups were balanced for age, weight and breed. At 9-14, 24-29 and 52-57 days of age, the abomasum of each calf was examined using ultrasonography immediately before and after feeding, 1 and 2 hours after feeding, and then at 30 minute intervals until curd was no longer visible in the abomasum. Abomasal volume and curd size were recorded to assess retention time of curd in the abomasum.

RESULTS

At 9-14 days of age, mean retention time of curd in the abomasum was similar (4.6 hours) in both groups. At 24-29 days of age, when the supplemented calves had been receiving the supplement for approximately 10 days, mean curd retention time was longer by 1.4 (SE 0.28) hours in supplemented compared with unsupplemented calves (p<0.001). At 52-57 days of age, mean retention time was longer by 0.7 (SE 0.34) hours compared to unsupplemented calves (p=0.05).

CONCLUSION

Using ultrasonography, changes in abomasal content could be followed non-invasively over time and it was demonstrated that the plant-derived complex carbohydrate supplement increased the curd retention time in the abomasum. We speculate that the increased retention time enables an increased availability of nutrients following a more complete digestion of milk, thereby improving animal performance.

Effect of two polymorphisms of the resistin gene (rs10401670 and rs1862513) on resistin levels and biochemical parameters in morbidly obese patients 1 year after a biliopancreatic diversion surgery

BACKGROUND & AIMS

Two single nucleotide polymorphisms (SNPs) of the resistin gene RETN have been described: rs10401670 and rs1862513. The objective of this study was to investigate the effect of these SNPs on changes in serum resistin levels, biochemical parameters and weight after biliopancreatic diversion surgery in morbidly obese patients without diabetes mellitus.

METHODS

A sample of 155 patients with morbid obesity without diabetes mellitus was enrolled. Anthropometric and biochemical evaluations were realized at the basal visit and at 12 months. The percentage of subjects with hypertension and hyperlipidemia was also reported.

RESULTS

Initial percentage excess weight loss, body mass index, weight, waist circumference, fat mass, blood pressure, low-density lipoprotein cholesterol, total cholesterol, triglycerides levels, insulin and the homeostasis model assessment for insulin sensitivity (HOMA-IR) improve after 12 months. No differences in these improvements were detected between the two genotypes (wild vs mutant group) in each SNP analysis. Resistin levels only changed after surgery in wild genotypes of both SNPs (rs1862513 and rs10401670). The improvement in insulin levels was lower in the mutant group of rs1862513 (-3.4 ± 0.4 UI/dl vs -2.3 ± 0.2 UI/dl; P < 0.05) and rs1040167 (-3.3 ± 0.2 UI/dl vs -1.9 ± 0.3 UI/dl; P < 0.05). The decrease of HOMA-IR was lower in mutant group of rs1862513 (-1.4 ± 0.1 units vs -0.9 ± 0.3 units; P < 0.05) and rs10401670 (-1.2 ± 0.2 units vs -0.9 ± 0.3 units; P < 0.05).

CONCLUSIONS

The main result of this study was that the mutant genotype of two SNPs of the RETN gene (rs1862513 and rs10401670) was associated with a lack of change in resistin secondary to biliopancreatic diversion. The improvement in insulin levels and HOMA-IR was also lower in these patients.