Metabolic Body Weight Research Articles

Genetic Characterisation of Feeding Patterns in Lactating Holstein Cows and Their Association With Feed Efficiency Traits.

Feeding behaviour traits, such as number, duration or intake per feeder visit, have been associated with feed efficiency in dairy cattle. Those traits, however, do not fully capture cows' feeding patterns throughout the day. The goal of this study was to propose a new phenotype for characterising within-day feeding patterns and estimate its heritability and genetic correlations with dry matter intake (DMI), secreted milk energy, metabolic body weight and residual feed intake. Feeding patterns were evaluated using 4.8 million bunk visits from 1684 midlactation Holstein cows collected from 2009 to 2023 with an Insentec system. Feed efficiency traits were available from 6099 lactating Holstein cows at six research stations across the United States. Daily bunk visits were ordered, with Time 0 designated as the time of first feed delivery. Intake proportions were calculated by visit for each cow by dividing feed intake per visit by the total intake of the cow for that day. Feeding patterns were characterised by the area under the curve of cumulative feed intake proportions for each cow throughout the day. The feeding pattern phenotype per cow was defined as the average of areas under the curve across days, whereas consistency of feeding pattern was calculated as the natural logarithm of variance of daily area under the curve values. Estimates of heritability and genetic correlations were performed using Bayesian inference with an animal model, considering lactation, days in milk and cohort (trial-treatment) as fixed effects and animal as a random effect. Heritability estimates for average area under the curve and variance of daily area under the curve were 0.35 ± 0.05 and 0.16 ± 0.05, respectively. The genetic correlation between average area under the curve and secreted milk energy was -0.30 ± 0.14. Genetic correlations between average area under the curve and DMI, metabolic body weight and residual feed intake were not statistically significant. Variance of daily area under the curve was genetically correlated with DMI (0.47 ± 0.15), secreted milk energy (0.40 ± 0.17) and metabolic body weight (0.28 ± 0.13). The genetic correlation between variance of daily area under the curve and residual feed intake was not significant. Overall, we provided a reliable method to truly characterise feeding patterns in midlactation dairy cows. Feeding pattern and its consistency were heritable, indicating that a significant proportion of phenotypic variation is explained by additive genetic effects. Genetic correlation estimates indicate that cows with more consistent daily feeding patterns have lower DMI, lower secreted milk energy and lower metabolic body weight.

A Novel and Comprehensive Wellness Assessment for Lifestyle-Based Interventions.

While weight status and clinical laboratory measures are important in assessing obesity-related disease severity and chronic disease risk, including a broader range of emotional, psychosocial, and behavioral factors would provide greater context of an individual's overall state of wellness and could be used to better guide treatment decisions. The purpose of this research was to develop a comprehensive Lifestyle Wellness assessment for use in lifestyle-based wellness interventions and programs. A cross-sectional exploratory factor analysis (EFA) was conducted using baseline data from N=138 adults participating in behavioral weight loss trials. An unweighted least squares extraction method with oblique rotation was used. Twenty-one putative measures spanning constructs related to metabolic health, emotional health/wellbeing, body weight and composition, diet quality, and fitness were analyzed for retention. Mean body mass index (BMI) was 38.0±6.6kg/m2, mean age was 57.3±11.1years, and 77.5% of participants were female. The EFA produced a five-factor model with 13 items that explained 80.3% of the variance. The retained factors included: (1) Psychosocial State: mindfulness, resilience, quality of life, and happiness; (2) Blood Pressure State: systolic and diastolic blood pressure; (3) Lipid State: total cholesterol and LDL-cholesterol; (4) Fitness State: grip strength, jump height, and percent body fat; and (5) Body State: BMI and waist circumference. Lifestyle Wellness is a comprehensive assessment that enables innovative wellness-related research such as metabolically healthy obese phenotypes and weight-neutral interventions. Future research should include investigations in additional populations with greater age, sex/gender, and body size diversity.

Effect of interdisciplinary obesity care on metabolic markers and body weight in people with type 2 diabetes in a rural setting: A randomised controlled trial.

Management of type 2 diabetes includes medications that can unintentionally increase obesity and insulin resistance. This unblinded, single-centre, randomised controlled trial focused on rural Australian adults with type 2 diabetes (aged 18-75 and body mass index [BMI] >30 kg/m2), measuring the effectiveness of a tailored interdisciplinary obesity care approach compared with usual diabetes care. Led by a nurse practitioner with allied health support (dietitian ± psychologist and physiotherapist), the bariatric treatment involved reducing weight-gaining medications, a 500-calories/day deficit, an unsupervised exercise program emphasising movement/strength and psychotherapy, 3-monthly to 24-months with support phone calls at weeks 2, 4, 8 and 10. Outcomes from the 224 (113 intervention/111 control) participants were differences in biomedical and physical markers within- and between-groups estimated using multivariate mixed-effects linear regression between recruitment and 6-monthly follow-ups. Greater change occurred in intervention compared with control groups at 12 and 24 months in mean: body weight (-5.9 kg [95% confidence interval, CI: -8.53, -3.23] and -9.0 kg [95% CI: -13.2, -4.77]); BMI (-2.03 kg/m2 [95% CI: -2.92, -1.15] and -3.51 kg/m2 [95% CI: -4.93, -2.08]); and glycated haemoglobin (-0.26% [95% CI: -0.69%, 0.18%] and -0.63% [95% CI: -1.17%, 0.08%]). The control group showed a significant increase in mean leptin level, resulting in a between-group difference (-27.1 [95% CI: -42.7, -11.5]). Lipids and blood pressure differences were inconclusive, while exploratory analysis showed greater decline in estimated glomerular filtration rate in the control group. The interdisciplinary obesity approach, compared with usual diabetes care, resulted in sustained weight loss and improved diabetes control over 2 years. Trial registration number: ACTRN12622000240741.

A Mix of Probiotic Strains Prevents Hepatic Steatosis, and Improves Oxidative Stress Status and Gut Microbiota Composition in Obese Mice.

The gut microbiota plays a role in fat accumulation and energy homeostasis. Therefore, probiotic supplementation may improve metabolic parameters and control body weight. In this study, mice are fed either a high-fat diet (HFD) or an HFD supplemented with oral gavage of a mixture of three probiotic strains, Bifidobacterium lactis Lafti B94, Lactobacillus plantarum HA-119, and Lactobacillus helveticus Lafti L10 for 7 weeks. It finds that probiotic supplementation modulates body weight gain, food energy efficiency, and fat accumulation caused by the HFD. This probiotic mix prevents liver damage and lipid metabolic disorders in HFD-fed obese mice. The probiotic supplementation significantly downregulates the expression of the proinflammatory cytokines interleukin-1β, tumor necrosis factor-α, and malondialdehyde (MDA) in the liver and upregulated catalase (CAT), superoxide dismutase (SOD), and nuclear respiratory factor 1 (Nrf1) expression. Mice supplemented with the probiotic mix also show different microbiota compositions, with an increase in Clostridia_UCG-014 and Lachnospiraceae_nk4a136_group and a decrease in the Dubosiella genus compared with those in mice fed only an HFD. Finally, the amounts of fecal pentanoic acid and the three bile acid species increase in mice with probiotic supplementation. Treatment with a combination of a mixture of three probiotic strains, B. lactis Lafti B94, L. plantarum HA-119, and L. helveticus Lafti L10 for 7 weeks, ameliorates the effects of HFD induced obesity in mice.

Resistance physical exercise modulates metabolic adipokines, decreases body weight, and improves glomerular filtration in patients with chronic kidney disease in hemodialysis.

Chronic kidney disease (CKD) is a condition characterized by abnormalities in kidney structure and function that persist for more than 3months. It is estimated that more than 800 million people in the world have a diagnosis of CKD. To remove the harmful metabolic substances from the body, people with CKD need to perform hemodialysis. Due to their beneficial effects against a wide range of clinical conditions, physical exercise is considered a non-pharmacological therapy. This study aimed to evaluate the beneficial effects of resistance exercise during hemodialysis on metabolic adipokines, myokines, body weight, and glomerular filtration rate in patients living with CKD. Briefly, the blood samples were collected in two moments: immediately before the start of the resistance exercise protocol and 1week after the end of the protocol. Resistance exercise protocol was performed thrice a week for 12weeks and applied during hemodialysis sessions. Here, resistance exercise increases the circulating irisin (14.56%; p = 0.0112), handgrip strength (5.70%; p = 0.0036), glomerular filtration rate (25.9%; p = 0.022) and significantly decreases adiponectin (- 55.7%; p = 0.0044), body weight (- 3.7%; p = 0.0001), glucose (- 22%; p = 0.009), and albumin levels (- 9.55%; p = 0.0001). Conversely, leptin levels (- 10.9%; p = 0.38), iron (3.05%; p = 0.705), ferritin (3.24%; p = 0.880), hemoglobin (- 0.52%; p = 0.75), total cholesterol (7.9%; p = 0.19), LDL (- 9.99%; p = 0.15) and HDL (- 4.8%; p = 0.45), did not change after resistance exercise. Interestingly, 1,25 hydroxyvitamin D levels were significantly increased (14.5%; p = 0.01) following resistance exercise. Considering the effect of sex (males vs. females), we found that irisin levels increased in females but not in males after the resistance exercise protocol. Furthermore, handgrip strength and body weight were different, indicating that males had the highest strength and weight. We demonstrated that both males and females had lower albumin levels after the resistance exercise protocol. In conclusion, we suggest that resistance exercise has beneficial effects in the CKD population by modulating adipokines and metabolic myokines and therefore can be used as a non-pharmacological adjunctive therapy in CKD patients undergoing HD.

Renal Sugar Metabolites and mRNA Expression of Glucose Transporters in Meat-Type Chickens with Differing Residual Water Intake.

Molecular differences exist between birds with high residual water intake (HRWI) compared to those with low residual water intake (LRWI). Residual water intake (RWI) is defined as the difference between the water intake of a bird and the expected water intake corrected for metabolic body weight, feed intake, and body weight gain. Tissue metabolomic analysis revealed significantly increased kidney glucose, fructose, and arabitol in the LRWI group compared to the HRWI group. mRNA expression analysis of apical sodium glucose cotransporters SGLT1, SGLT4, SGLT5, and SGLT6 showed decreased expression of SGLTs 1, 5, and 6 in LRWI birds (p < 0.05), whereas SGLT4 expression was increased compared with HRWI birds (p < 0.01). An analysis of basal glucose transporters GLUT1, GLUT2, GLUT5, and GLUT9 showed significantly increased GLUT2 expression in LRWI birds compared with HRWI birds (p < 0.01). We postulate that SGLT4 is the main apical transporter in chicken kidneys and that its increased expression reduces these birds' need for water, resulting in less drinking. This is balanced by the increased expression of the basal transporter GLUT2, indicating better glucose retention, which may partly explain the physiological mechanism behind why these birds drink less water. Innately driven broiler water intake could therefore be influenced by the expression of kidney solute transporters.

Association of genomically enhanced residual feed intake with performance, feed efficiency, feeding behavior, gas flux, and nutrient digestibility in growing Holstein heifers.

Residual feed intake (RFI), a metric of feed efficiency, is moderately heritable and independent of body size and productivity, making it an ideal trait for investigation as a selection criterion to improve feed efficiency of growing cattle. The objective of this study was to examine the differences in performance, feed efficiency, feeding behavior, gas flux, and nutrient digestibility in Holstein heifers with divergent genomically enhanced breeding values for RFI (RFIg). Holstein heifers (n = 55; BW = 352 ± 64kg) with low (n = 29) or high (n = 26) RFIg were selected from a contemporary group of 453 commercial Holstein heifers. Heifers were rotated between 1 of 2 pens, each equipped with four electronic feed bunks and one pen with a GreenFeed gaseous exchange monitoring (GEM) system. Individual dry matter intake (DMI) and feeding behavior data were collected for 84-d. Body weight (BW) was measured weekly and spot fecal samples collected at weighing. Phenotypic RFI (RFIp) was calculated as the residual from regression of DMI on average daily gain (ADG) and mid-test metabolic BW (BW0.75). A mixed model including the fixed effect of RFIg classification and random effect of group was used to evaluate the effect of RFIg classification on response variables. There were no differences (P > 0.05) in BW and ADG for heifers with divergent RFIg; however, low RFIg heifers consumed 7.5% less (P < 0.05) feed per day. Consequently, low RFIg heifers exhibited a more favorable (P < 0.05) RFIp (-0.196 vs 0.222kg/d, respectively). Low RFIg heifers had 8.7% fewer (P < 0.05) bunk visit (BV) events per day and tended to have a 11.2% slower (P < 0.10) eating rate. Low RFIg heifers had 7.7% lower (P < 0.05) methane (CH4) emissions (g/d), 6.1% lower (P ≤ 0.05) carbon dioxide (CO2) production (g/d), and 5.6% lower (P ≤ 0.05) heat production (Mcal/d) than high RFIg heifers. However, CH4 yield and CO2 yield (g/kg DMI), and heat production per unit DMI (Mcal/kg DMI) did not differ (P > 0.05) between heifers with divergent RFIg. Dry matter and nutrient digestibility did not differ (P > 0.05) between heifers with divergent RFIg. Overall, heifers selected to be more feed efficient exhibited more favorable energy efficiencies and feed efficiency phenotypes. Results suggest that selection based on RFIg provides opportunities to select cattle with favorable feed efficiency phenotypes to increase the economic and environmental sustainability of the cattle industry.

Residual feed intake and gain alters the performance and carcass traits in Nellore cattle.

The residual intake and gain (RIG) aims to select animals that present low feed intake in relation to the expected. This study aimed to evaluate the associations of selection for RIG with performance and carcass traits in Nellore cattle. Initially, residual feed intake (RFI) and residual gain (RG) were determined. From this, the RIG was calculated, and the animals were classified as efficient and inefficient for RIG. The efficient animals for RIG showed higher daily weight gain (DWG), Longissimus muscle area (LMA), and mid-test metabolic body weight (MMBW) than the inefficient ones. No significant correlations were found between subcutaneous fat thickness (SFT), marbling (MAR), LMA, MMBW, and the RIG. Thus, it's concluded that the RIG is a measure that can be used to identify and select animals with higher rates of DWG and LMA without changes in the dry matter intake (DMI), SFT, and MAR. However, this index should still be observed with caution, as it may be dependent on body size. Based on the findings, the selection of animals according to the RIG can be an important factor to generate phenotypic evolution in characteristics such as weight gain and rib eye area without adverse effects on the carcass fat deposition.

Effects of metformin and curcumin in women with polycystic ovary syndrome: A factorial clinical trial

BackgroundPolycystic ovary syndrome (PCOS) is a common endocrine disorder in women, associated with dyslipidemia, insulin resistance, and hormonal imbalances. Metformin and curcumin have shown promise in improving these metabolic and hormonal parameters individually, but their combined effects in PCOS remain unclear. MethodsWe conducted a randomized, double-blind, placebo-controlled, 12-week factorial trial involving 200 women with PCOS. Participants were randomly assigned in a 1:1:1:1 ratio to receive metformin (500-mg/8 h) + placebo, nanocurcumin soft gel capsule (80-mg/8 h) + placebo, metformin (500-mg/8 h) + nanocurcumin (80-mg/8 h), or double placebo. Lipid profiles, glucose metabolism markers, hormonal parameters, body weight, and body mass index (BMI) were assessed at baseline and week 12. ResultsThe combination of metformin and curcumin demonstrated significant improvements in lipid profiles, glucose metabolism, hormonal parameters, body weight, and BMI compared to individual agents or placebo. Greater reductions in low-density lipoproteins (LDL) cholesterol, total cholesterol (TC), and triglyceride (TG) levels were observed with the combination therapy, along with increased high-density lipoproteins (HDL) cholesterol. Additionally, the combination therapy significantly improved markers of glucose metabolism and showed synergistic effects in reducing body weight and BMI. Reductions in testosterone and improvements in Follicle-stimulating hormone (FSH) and Luteinizing hormone (LH) levels were also observed with combination therapy. ConclusionThe combination of metformin and curcumin demonstrates superior efficacy in improving lipid profiles, glucose metabolism, hormonal parameters, body weight, and BMI in women with PCOS compared to individual agents or placebo. This highlights the potential synergistic effects of combining these agents for the management of PCOS.

Estimating net energy requirements of male Djallonke sheep

Context Energy requirements in sheep can vary significantly due to various factors, including age, breed, sex and environmental conditions. Genetic selection and crossbreeding further contribute to this variability. Although guidelines from the US and UK national research councils are commonly used for formulating sheep diets, they may not adequately account for the unique characteristics of sheep in Africa. Aims The study aimed to estimate the net maintenance energy requirement of male Djallonke sheep. This estimation will provide a basis for comparing the energy requirements of Djallonke sheep with national recommendations and recent estimates for other sheep breeds. Methods Sixteen entire male Djallonke sheep were selected and grouped by weight. They were then randomly allocated to four treatment groups in a 4 × 4 Latin square design. The sheep were fed to achieve intake levels ranging from 1 to 1.75 multiples of their maintenance energy requirement. Gas exchange data were collected using the GreenFeed system over a 3-day period at the conclusion of each treatment period. Heat production was calculated using the established Brouwer’s equation. A linear regression equation was developed to relate heat production to metabolisable energy intake scaled by metabolic bodyweight to calculate the net energy for maintenance. Key results The estimated net energy for maintenance for male Djallonke sheep was determined to be 0.354 MJ/kg BW0.75. This estimation indicated that the energy requirements of male Djallonke sheep exceeded the recommendations provided by the US National Research Council and the UK Agricultural and Food Research Council. However, it closely aligned with an updated estimate of 0.358 MJ/kg BW0.75. Conclusions Based on the study’s findings, male Djallonke sheep have higher energy requirements for maintenance than what is commonly recommended by existing guidelines. Therefore, it is advisable to update ration formulation software for male Djallonke sheep to better reflect their actual energy requirements for maintenance. Implications These results have practical implications for the formulation of diets and feeding management practices for male Djallonke sheep. Adhering to updated energy requirement estimates can help improve the efficiency and productivity of sheep production in the context of Djallonke sheep farming.

PSVII-9 Improvement of feed efficiency in Korean Hanwoo cattle: investigation of feed intake and analysis of residual feed intake (RFI)

Abstract Feed efficiency is an important economic trait in beef cattle production, and improving feed efficiency can reduce production costs and environmental impact. Residual feed intake (RFI) is a useful measure of individual feed efficiency, representing the difference between the actual feed intake of an animal and its predicted feed intake based on its body weight (BW) and growth. This study aimed to investigate feed intake and analyze RFI in Hanwoo cattle to improve feed efficiency. Data were collected from 120 Hanwoo steers (9 to 11 mo old) from six different test stations across the country. Individual daily feed intake of concentrates and forage was recorded over 70 d, and BW was measured at the beginning and end of the feeding trial. Daily feed intake was calculated using the TDN values of the concentrates and forage. Expected feed intake was estimated using a linear regression model based on metabolic BW and daily gain. RFI was calculated as the difference between expected and actual feed intake. Average daily gain ranged from 1.05 to 1.71 kg/d, and average daily feed intake ranged from 5.10 to 7.72 kg/d across the test stations. RFI values ranged from -0.84 to 0.95 kg/d, indicating significant variation in feed efficiency among the animals. This study provides valuable information on feed intake and RFI in Hanwoo cattle. Further research with a larger dataset is needed to develop a genetic evaluation model for RFI and to select animals with superior feed efficiency for improving Hanwoo cattle production.

PSLBII-5 Impacts of residual feed intake measured as a heifer in drylot on mature cows and calves grazing native pasture

Abstract Selection for feed efficiency is crucial for improving economic and environmental sustainability in beef cattle production. Residual feed intake (RFIfat) is a commonly used measure of feed efficiency and is determined in a drylot setting by calculating the difference between observed and expected dry matter intake (DMI), where expected feed intake is adjusted for metabolic body weight (BW), average daily gain (ADG) and body fatness. Lower RFIfat cattle are more efficient animals as they eat less than predicted for the same growth, body size and body fatness. Limited studies have been conducted evaluating the role of RFIfat on the subsequent performance of cow-calf pairs on native range. Kinsella Composite cows and calves (n = 120) grazed native pasture from July 11 to Sept 12 (summer) and from Sept 13 to Nov 2 (fall) of 2023 were included in this study. All dams had previously been evaluated for RFIfat as a heifer (8 to 12 mo of age) using the GrowSafe Feed Intake System (Vytelle, Canada). Cow and calf ADG were subjected to an analysis of covariance using lm function from stats R core package (R Core Team, 2024), with cow age (2 to 8 yr of age) as the fixed effect and RFIfat as the covariate, analyzing separately by season. An unbalanced Tukey HDS post-hoc were applied for age and p-values &amp;lt; 0.05 were considered significant. Weight gain was assessed on cows with an initial BW on pasture of 598.4 ± 68.4 kg, and 2 to 8 yr of age, and on calves having an initial on pasture BW of 106 ± 21.5 kg, and 65 ± 14 d of age. Cow age affected (P &amp;lt; 0.01) cow ADG during summer, with the youngest dams (2 yr old) gaining more weight than older animals (7 yr old; Figure 1A). No effect of RFIfat was found on cow weight gain during summer grazing. However, during fall grazing, RFIfat affected (P &amp;lt; 0.01) cow ADG (Figure 1B). Low-RFIfat cows (efficient) had increased weight gain during fall grazing as compared with high-RFIfat cows (inefficient: Figure 1B). Calf ADG was not affected (P &amp;gt; 0.1) by cow age, cow RFIfat and cow ADG during summer and fall. We conclude that cows with low RFIfat exhibited superior body weight gain, during fall grazing on native range when forage nutrient quality and quantity become limiting.

161 Development, deployment, and calibration of genomic selection tools to improve performance traits for Canadian beef cattle

Abstract Genomic selection has the potential to accelerate the genetic improvement rate for difficult/expensive to measure traits such as feed efficiency and fertility traits in beef cattle. To develop genomic selection tools for Canadian beef cattle, we collected or sourced phenotypic data of feed efficiency along with other traits including carcass merit, female feed intake and fertility related traits, and their genotypes from both research and commercial herds. The phenotypic data were consolidated and recorded for contemporary groups, leading to the development of data sets including 11,292 beef cattle with residual feed intake, dry matter intake, average daily gain, metabolic body weight, 7,299 to 8,081 cattle with carcass merit traits, and 1,802 to 2,792 cows with feed intake and fertility traits after quality controls. Genotype data of the animals from various single nucleotide polymorphisms (SNP) panels were merged to the same allele format of 50K, and then imputed to 770K SNPs, and eventually to whole genome sequence variants. The refined Canadian beef cattle data sets have not only allowed us to investigate genetic architectures of the beef performance traits but also enabled the development of genomic selection tools including molecular breeding values and multiple trait selection indexes with a moderate to moderately high accuracy for the traits through a cross-validation of within reference data set. The genomic selection tools have been successfully deployed to over 10,415 breeding candidates submitted by Canadian beef producers through multiple demonstration projects. The average accuracy of the molecular breeding values and multiple trait selection index of the commercial beef cattle ranged from 0.38 to 0.49 for feed efficiency and carcass merit traits, and from 0.26 to 0.38 for female feed intake and fertility traits. Current research is focusing on calibrating the genomic selection tools with larger data sets and with more advanced genomic prediction methods.

96 Using greenhouse gas flux to estimate forage dry matter intake in ad libitum fed replacement heifers

Abstract An accurate estimate of feed intake is a critical component in determining individual animal feed efficiency. However, existing feed intake measurement systems are not designed for unprocessed, dry forage diets. Open-circuit gas flux technology measures enteric gas emissions for cattle in a pasture-based setting. If a significant relationship exists between feed intake and gas emissions, this system could be used to rank grazing cattle for forage intake and forage utilization efficiency. Our objective was to develop prediction equations to estimate forage dry matter intake using gas flux and performance data. Angus and Angus x Hereford heifers [n = 71; initial body weight (BW) 329.5 ± 31.1 kg] were used over 3 yr to measure intake, gain, and gas flux. All heifers were subject to a 21-d adaptation and 71-d intake test using individual intake technology (SmartFeed; C-Lock Rapid City, SD) with a stocking rate of 3.3 heifers per feeder. Throughout the study, heifers were fed a long-stem, unprocessed, grass hay diet (≥ 10.8% CP, 2.0 Mcal ME, and 56% TDN) with ad libitum access to a salt/mineral supplement. The GreenFeed system (C-Lock Rapid City, SD) was used to monitor oxygen (O2) consumption (means ± SD; 3364.4 ± 374.8 g/d), methane (CH4; 181.4 ± 24.3 g/d) and carbon dioxide (CO2) production (4,965.3 ± 494.5 g/d). Body weights were collected every 14 d, and average daily gain (ADG) was calculated by regressing BW on day of study. The phenotypic correlations of forage DMI with CO2, CH4, O2, and heat production (HP) were 0.72, 0.66, 0.74, and 0.74, respectively. Average daily gain and midpoint metabolic BW combined with the estimate of daily HP, O2, or CO2 accounted for 60% of the variation in forage DMI. These results suggest that forage intake can be predicted using performance data in conjunction with the GreenFeed gas quantification system.

Dissecting loci that underpin the genetic correlations between production, fertility, and urea traits in Australian Holstein cattle.

Unfavorable genetic correlations between milk production, fertility, and urea traits have been reported. However, knowledge of the genomic regions associated with these unfavorable correlations is limited. Here, we used the correlation scan method to identify and investigate the regions driving or antagonizing the genetic correlations between production vs. fertility, urea vs. fertility, and urea vs. production traits. Driving regions produce an estimate of correlation that is in the same direction as the global correlation. Antagonizing regions produce an estimate in the opposite direction of the global estimates. Our dataset comprised 6567, 4700, and 12,658 Holstein cattle with records of production traits (milk yield, fat yield, and protein yield), fertility (calving interval) and urea traits (milk urea nitrogen and blood urea nitrogen predicted using milk-mid-infrared spectroscopy), respectively. Several regions across the genome drive the correlations between production, fertility, and urea traits. Antagonizing regions were confined to certain parts of the genome and the genes within these regions were mostly involved in preventing metabolic dysregulation, liver reprogramming, metabolism remodeling, and lipid homeostasis. The driving regions were enriched for QTL related to puberty, milk, and health-related traits. Antagonizing regions were mostly related to muscle development, metabolic body weight, and milk traits. In conclusion, we have identified genomic regions of potential importance for dairy cattle breeding. Future studies could investigate the antagonizing regions as potential genomic regions to break the unfavorable correlations and improve milk production as well as fertility and urea traits.

Genetic relationships between behavioral traits and feed efficiency traits in lactating Holstein cows

The evaluation of dairy cow feed efficiency using residual feed intake accounts for known energy sinks. However, behavioral traits may also contribute to the variation in feed efficiency. Our objective was to estimate the heritability and repeatability of behavioral traits and their genetic correlations with feed efficiency and its components in lactating Holstein cows. The first data set consisted of 36,075 daily rumination and lying time records collected using a SMARTBOW ear tag accelerometer (Zoetis, Parsippany, NJ) and 6,371 weekly feed efficiency records of 728 cows from the University of Wisconsin-Madison. The second data set consisted of 59,155 daily activity records, measured as number of steps, recorded by pedometers (AfiAct; S.A.E. Afikim, Kibbutz Afikim, Israel), and 8,626 weekly feed efficiency records of 635 cows from the University of Florida. Feed efficiency and its components included dry matter intake, change in body weight, metabolic body weight, secreted milk energy, and residual feed intake. The statistical models included the fixed effect of cohort, lactation number, and days in milk, and the random effects of animal and permanent environment. Heritability estimates for behavioral traits using daily records were 0.19 ± 0.06 for rumination and activity, and 0.37 ± 0.07 for lying time. Repeatability estimates for behavioral traits using daily data ranged from 0.56 ± 0.02 for activity to 0.62 ± 0.01 for lying time. Both heritability and repeatability estimates were larger when weekly records instead of daily records were used. Rumination and activity had positive genetic correlations with residual feed intake (0.40 ± 0.19 and 0.31 ± 0.22, respectively) while lying time had a negative genetic correlation with this residual feed intake (-0.27 ± 0.11). These results indicate that more efficient cows tend to spend more time lying and less time active. Additionally, less efficient cows tend to eat more and therefore also tend to ruminate longer. Overall, sensor-based behavioral traits are heritable and genetically correlated with feed efficiency and its components and, therefore, they could be used as indicators to identify feed efficient cows within the herd.

Gut–brain bidirectional determination in regulating the residual feed intake of small-sized meat ducks

The gut-brain axis is essential in maintaining the homeostasis of neuronal system, endocrine system, and intestinal microbiota in both the afferent and efferent directions. This axis is considered to be a key mechanism that regulates feed efficiency (FE). This study aimed to investigate the regulatory mechanisms of gut-brain axis-related genes on the residual feed intake (RFI) in H-strain small-sized meat ducks. A total of 500 ducks with similar initial BW (635.2 ± 15.1 g) were selected and reared in the same experimental facility until slaughter at 42 d of age. RFI was calculated from the average daily gain (ADG), average daily feed intake (ADFI), and metabolic body weight (MBW0.75). Thirty high-RFI (H-RFI) and 30 low-RFI (L-RFI) birds were selected for further evaluation of growth performance, carcass characteristics, and blood biochemical parameter measurements. Six L-RFI and 6 H-RFI birds were then subjected to hypothalamic transcriptomic and cecal microbial sequencing analyses. Results indicated that L-RFI birds exhibited lower production performance (ADFI, FCR, and RFI) and blood biochemical indices (total cholesterol and ghrelin content) compared with H-RFI birds (P < 0.05). Gene expression differed significantly between the L-RFI and H-RFI birds, with 70 upregulated and 50 downregulated genes. The bacterial communities of L-RFI birds showed higher abundances of Bacteroides, Bifidobacterium, and Lactococcus, and lower abundances of Erysipelatoclostridium, Parasutterella, Fournierella, and Blautia compared with H-RFI birds (P < 0.05). Interactive analysis revealed bacterial communities associated with FE were significantly correlated with hypothalamic genes (P < 0.05), for example, Bacteroides was positively correlated with DGKH and LIPT2, while negatively correlated with CAPN9, GABRD, and PDE1A. Bifidobacterium showed significant correlations with ATP2A3, CALHM6, and TMEM121B. Overall, RFI was a crucial indicator of FE, regulated by interactions between brain gene expression and gut microbiota through cAMP signaling, neuroactive ligand-receptor interaction, and calcium signaling pathways. Notably, increased expression of hypothalamic genes and abundance of carbohydrate-utilization microbiota in L-RFI meat ducks improved FE by enhancing energy metabolism and volatile fatty acids absorption.

Sustained insulin treatment restoring metabolic status, body weight, and cognition in an anorexia nervosa-like animal model in mice

IntroductionAnorexia Nervosa (AN) is a psycho-socio-biological disease characterized by severe weight loss as result of dieting and hyperactivity. Effective treatments are scarce, despite its significant prevalence and mortality. AN patients show lower basal insulin levels and increased metabolic clearance, leading to weight loss, cognitive deficits, and hormonal imbalances. Low-dose polymer insulin could potentially reverse these effects by restoring brain function, reducing fear of weight gain, encouraging food intake, and restoring fat depots. This study evaluates an insulin delivery system designed for sustained release and AN treatment. MethodsAN-like model was established through dietary restriction (DR). On days 1–25, mice were on DR, and on days 26–31 they were on ad libitum regimen. An insulin-loaded delivery system was administered subcutaneously (1% w/w insulin). The impact of insulin treatment on gene expression in the hippocampus (cognition, regulation of stress, neurogenesis) and hypothalamus (eating behavior, mood) was assessed. Behavioral assays were conducted to evaluate motor activity and cognitive function. ResultsThe delivery system demonstrated sustained insulin release, maintaining therapeutic plasma levels. Diet restriction mice treated with the insulin delivery system showed body weight restoration. Gene expression analysis revealed enhanced expression of CB1 and CB2 genes associated with improved eating behavior and cognition, while POMC expression was reduced. Insulin-polymer treatment restored cognitive function and decreased hyperactivity in the AN-like model. ConclusionThe PSA-RA-based insulin delivery system effectively restores metabolic balance, body weight, and cognitive function in the AN model. Its ability to steadily release insulin makes it a promising candidate for AN treatment."

Influence of age and sex on longitudinal metabolic profiles and body weight trajectories in the UK Biobank.

Accurate characterization of how age influences body weight and metabolism at different stages of life is important for understanding ageing processes. Here, we explore observational longitudinal associations between metabolic health and weight from the fifth to the seventh decade of life, using carefully adjusted statistical designs. Body measures and biochemical data from blood and urine (220 measures) across two visits were available from 10 104 UK Biobank participants. Participants were divided into stable (within ±4% per decade), weight loss and weight gain categories. Final subgroups were metabolically matched at baseline (48% women, follow-up 4.3 years, ages 41-70; n = 3368 per subgroup) and further stratified by the median age of 59.3 years and sex. Pulse pressure, haemoglobin A1c and cystatin-C tracked ageing consistently (P < 0.0001). In women under 59, age-associated increases in citrate, pyruvate, alkaline phosphatase and calcium were observed along with adverse changes across lipoprotein measures, fatty acid species and liver enzymes (P < 0.0001). Principal component analysis revealed a qualitative sex difference in the temporal relationship between body weight and metabolism: weight loss was not associated with systemic metabolic improvement in women, whereas both age strata converged consistently towards beneficial (weight loss) or adverse (weight gain) phenotypes in men. We report longitudinal ageing trends for 220 metabolic measures in absolute concentrations, many of which have not been described for older individuals before. Our results also revealed a fundamental dynamic sex divergence that we speculate is caused by menopause-driven metabolic deterioration in women.

Responses to incremental nutrient supply on energy and protein metabolism in preweaning dairy calves

Recently reviewed development objectives and feeding practices in young dairy calves require an adaptation of nutrient recommendations set for milk replacer (MR) composition. Nutrient requirements of calves younger than 21 d of age, and those of calves fed with high levels of MR are insufficiently quantified. The efficiency at which macronutrients are utilized, particularly protein, substantially diminishes with age, and little data exists for the first weeks of life. In addition, in older preruminant and ruminant calves, protein and energy can be simultaneously limiting for protein gain. Whether this also applies to calves in the first weeks of life is unknown. Therefore, this study aimed to quantify the responses in protein and fat gain to incremental supply of protein, fat, or lactose to MR in very young calves. Thirty-two groups of 3 mixed-sex Holstein-Friesian newborn calves (3.4 ± 1.6 d of age), were randomly assigned to 1 of 4 dietary treatments applied for 19 d: a basal MR (23.3% crude protein, 21.2% crude fat, and 48.8% lactose, percentages of dry matter), provided at 550 kJ/kg of metabolic body weight (BW0.85) per day (CON; n = 24), or the basal MR incrementally supplied with 126 kJ of digestible energy per BW0.85 per day as milk fat (+FAT; n = 23), lactose (+LAC; n = 24), or milk protein (+PRO; n = 23). Calves were fed MR in 2 daily meals and had ad libitum access to water, but did not have access to calf starter nor any other solid feed. After 2 wk of adaptation to their respective diets, groups of calves were placed for 1 wk in an open-circuit respiration chamber for nitrogen and energy balance measurements (5 d). The incremental nutrient efficiencies indicate what percentage of extra intake of nutrients is retained. In this study, we observed that with every 100-g increase in protein intake, 52% was converted into protein deposition, and 44% contributed to heat production. Similarly, a 100-g increase in fat intake resulted in 67% being stored as fat, 22% being released as heat, and only 5% being retained as protein. Likewise, a 100-g increment in lactose intake led to 49% being stored as fat, with 38% being released as heat. Additional protein intake was not deposited as fat; extra energy intake (fat and additional lactose) increased postabsorptive N efficiency in young calves.