Ad Libitum Group Research Articles

Neurodegeneration: Effects of calorie restriction on the brain sirtuin protein levels

BackgroundCalorie restriction (CR) is suggested to activate protective mechanisms in neurodegenerative diseases (NDDs). Despite existing literature highlighting the protective role of Sirtuin (SIRT) proteins against age-related neurodegeneration (ND), no study has explored the total levels of SIRT 1, 3, and 6 proteins simultaneously in brain homogenates by ELISA following intermittent calorie restriction. Applying CR protocols in mice to induce stress, we aimed to determine whether ND would be more pronounced with ad libitum (AL) or with CR. MethodsMice were randomly assigned to ad libitum (AL), Chronic CR (CCR), or Intermittent CR (ICR) groups at 10 weeks of baseline age (BL). SIRT 1, 3, and 6 protein levels were measured in the homogenized whole-brain supernatants of 49/50 weeks old mice by the ELISA method. Neuronal morphology was evaluated by the cresyl violet on the hippocampus. Neurodegeneration (ND) was assessed by the fluoro-jade and ImageJ was used for quantifications. ResultsIn the ICR group, SIRT1 levels were elevated compared to both the AL and BL groups. Similarly, the CCR group exhibited higher SIRT1 values compared to the AL and BL groups. While SIRT3 levels were higher in both the ICR and CCR groups compared to the AL and BL groups, this disparity did not reach statistical significance. SIRT6 levels were also higher in the ICR group compared to both the BL and AL groups, with the CCR group showing higher values compared to the BL and AL groups as well. Image quantification demonstrated significant neurodegeneration in the AL group compared to the CCR and ICR group, with no observed alterations in nerve cell morphology and number. ConclusionThis study revealed that the levels of SIRT 1, SIRT 3, and SIRT 6 in brain tissue were notably elevated, and there was less evidence of ND at the 50-week mark in groups undergoing continuous calorie restriction and intermittent calorie restriction compared to baseline and ad libitum groups. Our findings illustrate that CR promotes increased SIRT expression in the mouse brain, thereby potentially mitigating neurodegeneration.

Time-restricted feeding modulates gene expression related with rhythm and inflammation in Mongolian gerbils

Time-restricted feeding (TRF) has the potential to modulate circadian rhythm and widely studied in humans and laboratory mice. However, less is known about the physiological responses to TRF in wild mammals. Here, we used Mongolian gerbils, Meriones unguiculatus, to explore the effect of 6-week TRF on gene expression related with circadian rhythm and inflammation. The TRF gerbils had higher cumulative food intake than the ad libitum (AL) group, but body mass, feeding frequency/time and metabolic rate did not differ between groups. In the hypothalamus, downregulation of rhythm-related genes Per3, Cry1 and Dbp was detected in the daytime-restricted feeding (DRF) group and Cry1 was downregulated in the nighttime-restricted feeding (NRF) group. In the liver, the expression of Per1/3, Rev-erbα/β and Dbp was lower, and Bmal1 was higher in the DRF than in AL group, while NRF gerbils showed no changes. In the colon, the expression of Bmal1 and Cry1 was higher but Per3, Rev-erbα/β and Dbp were lower in the DRF than in AL group. Further, the expression of inflammation-related genes such as NF-κB, IL-1β, IL-18 and Nlrp3 was lower in the liver of DRF gerbils, and IL-1β was lower both in the hypothalamus and liver of NRF gerbils. Moreover, the genes related with inflammation such as NF-κB, Nlrp3, IL-10/18/1β and Tnf-α were positively or negatively correlated with multiple rhythm-related genes in the central and peripheral organs. In conclusion, TRF, particularly DRF, could modulate rhythm-related genes in the central and peripheral tissues and reduce hepatic expression of inflammation-related genes in gerbils.

Glucose appetition in C57BL/6J mice: Influence of nonnutritive sweetener experience, food deprivation state and sex differences

In addition to its sweet taste, glucose has potent and rapid postoral actions (appetition) that enhance its reward value. This has been demonstrated by the experience-induced preference for glucose over initially preferred nonnutritive sweetener solutions in 24-h choice tests. However, some sweetener solutions (e.g., 0.8% sucralose) have inhibitory postoral actions that may exaggerate glucose appetition whereas others (e.g., 0.1% sucralose + 0.1% saccharin, S+S) do not. Experiment 1 revealed that food-restricted (FR) male C57BL/6J mice displayed similar rapid glucose appetition effects (stimulation of glucose licking within minutes) and conditioned flavor preferences following 1-h experience with flavored 0.8% sucralose or 0.1% S+S and 8% glucose solutions. Thus, the inhibitory effects of 0.8% sucralose observed in 24-h tests were not apparent in 1-h tests. Experiment 2 evaluated the effects of food deprivation state and sweetener concentration on glucose appetition in female mice. Unlike FR mice tested with 0.1% S+S and 8% glucose, ad libitum (AL) fed mice displayed no stimulation of 8% glucose licking in the 1-h tests. A second ad libitum group (AL) tested with 0.2% S+S and 16% glucose solutions displayed stimulation of 16% glucose licking by the third 1-h test. Both AL groups, like the FR group, developed a preference for the glucose-paired flavor over the S+S paired flavor. Thus, food restriction promotes increased glucose licking but is not required for a conditioned preference. The FR male mice (Exp. 1) and FR female mice (Exp. 2) showed similar appetition responses (licking stimulation and flavor preference) to 8% glucose.

Intermittent Fasting Alters O2 Consumption and Body Composition in Young Rats: Comparative Analysis between Females and Males

Objectives: Intermittent Fasting (IF), time-restrictive food intake, has been shown to improve cognitive functions and reduce age-related behavioral impairments in rodent models. Our prior studies have found that IF intervention has significantly reduced body weights and food intake in male Fsher-344 rats; however, females did not display IF-induced declines in body weights and food intake. The exact mechanism for the sex differences in body weight and food intake during IF is not fully understood. Factors such as shifts in body composition and metabolic demand may contribute to variations in body weight shifts and food consumption. We hypothesized that changes in body composition and metabolic shifts may contribute to sex differences in body weight and food consumption in response to IF. Methods: Thirty-six, two-month-old male and female Fisher-344 rats were randomly assigned to four groups: ad libitum (AL) male, IF males, AL females, IF females. The AL group had 24/7 access to food and water while the IF group had 24/7 access to water and full access to food on an every-other-day basis for four weeks. After four weeks of IF intervention, rats were introduced to a metabolic rate (respiratory gas analyzer) and a grip strength test. In addition, body scans were performed using a Lunar Piximus rodent densitometer, (GE Lunar corporation). Group differences were analyzed with two-way ANOVA per Prism Graph Pad software. Following body scans, animals were euthanized, and tissues were sectioned, weighted, and stored for future analysis (brain, skeletal muscles, and adipose tissues). Results: IF intervention resulted in reduced body mass in males (vs. AL males, p<0.0001) but not in females. Average daily food intake tended to be lowered in IF groups compared to their AL counterparts. Densitometry results revealed that the IF males had a decreased lean mass (vs. AL males, p<0.0001) and fat mass (vs. AL males, p<0.0001). Neither lean mass nor fat mass were changed in females as a result of IF. After two weeks of IF, O2 consumption was lowered in IF females compared to AL (P=0.0215 fed-state, P=0.0030 fast-state); however, no significant effect was seen in males. Grip strength was not significant among groups. Conclusions: In the present study, IF males significantly reduced body weights, as well as both fat and lean mass while females did not exhibit IF-induced changes. Interestingly, IF females displayed declines in oxygen consumption while males did not change. The decrease in oxygen consumption (slower metabolism) in IF females can be seen as a compensatory mechanism by the body to conserve energy and maintain body weights and composition shifts. The sexual dimorphic effect of body composition shifts is intriguing and the metabolic adaptations in skeletal muscle/fat tissues will be the focus of follow-up investigations. Funding source: P20GM113109 Cognitive and Neurobiological Approaches to Plasticity (CNAP) center. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

A 2-Year Calorie Restriction Intervention Improves Diet Quality Without Compromising Nutritional Adequacy: The CALERIE Trial

Background: The Comprehensive Assessment of Long-Term Effects of Reducing Intake of Energy (CALERIE) was the first randomized controlled trial of calorie restriction (CR) on biomarkers of aging and cardiometabolic health in humans without obesity. Objective: To determine diet quality and nutritional adequacy during a 2y calorie restriction intervention among healthy adults without obesity. Design: CALERIE phase 2 was a multi-site, randomized controlled trial of 2y of CR vs. ad libitum (AL) control. CR participants received extensive dietary education and support. Food diaries were completed at baseline and months 6, 12, 18, and 24 and analyzed using NDSR. Diet quality was evaluated using the PANDiet diet quality index. Nutritional adequacy was defined using sex- and age-specific Estimated Average Requirement (EAR) or Adequate Intake (AI) criteria for each nutrient. Results: 220 participants completed baseline assessments and were randomized (145 CR, 75 AL; 70% women, age 38±7 y, BMI 25.1±1.7 kg/m2); 86% completed the 2y study. The level of calorie restriction achieved averaged 11.9±0.7% during the 2y intervention. Diet quality improved in the CR group (BL 74.3±5.1%; CR average 76.3±5.3%, p < 0.0001), but not in the AL group ( p < 0.0002 between groups). Nutritional adequacy improved modestly in CR, but not in AL. More than 90% of CR participants achieved 100% of EAR or AI during CR for protein, carbohydrate, 6 of 12 vitamins (A, B1, B2, B3, B6, B12), and 5 of 9 minerals (copper, iron, phosphorus, selenium, sodium). Nutrients for which <90% of participants achieved adequacy included fiber, omega-3 fatty acids, vitamins B5, B9, C, E, and K, and the minerals calcium, magnesium, potassium, and zinc. Conclusion: A 2y CR intervention designed to promote healthy aging and comprised of comprehensive nutrition counseling promoted improvements in diet quality and maintenance or improvements in nutritional adequacy. This research was supported by grants U01AG020478, U01AG020480, U01AG020487, U01AG022132, U24AG047121, R33AG070455, and R01AG071717 from the National Institute on Aging. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Caloric restriction reduces proteinuria in male rats with established nephropathy.

Reducing proteinuria is a crucial approach in preventing kidney function loss. Previous preclinical studies indicated that caloric restriction (CR) imposed at a young age protects against age-related proteinuria. However, these studies have not explored CR in established renal disease. Therefore, this study aimed to investigate the impact of CR on established proteinuria. Rats, aged 12 ± 2 weeks, were administered 2.1 mg/kg of Adriamycin. Six weeks after injection, protein excretion was measured, and a [13 N]ammonia positron emission tomography (PET) scan was conducted to assess kidney perfusion. After 7 weeks rats were divided into four groups: adlibitum (AL) and CR groups fed either a 12% or a 20% protein diet. All groups were treated for 12 weeks. Blood pressure was measured and a second PET scan was acquired at the end of the study. The animals subjected to CR exhibited a 20.3% decrease in protein excretion (p = 0.003) compared to those in the AL groups. Additionally, blood pressure in the CR group was 21.2% lower (p < 0.001) than in the AL groups. While kidney function declined over time in all groups, the 20% CR group demonstrated the smallest decline. Thus CR effectively reduces urinary protein excretion and lowers blood pressure in rats with established proteinuria.

Effect of eight-week controlled dietary modification trial on nutritional biomarkers in young Indian athletes

Objective: Present study was intended to examine the effects of dietary modification on nutritional biomarkers in young Indian male athletes. Methods: Eighty-eight footballers and hockey players were randomly segregated into ad-libitum group (ALG) and nutrition counselling group (NCG). Eight weeks of dietary modification trial was implemented on NCG, resulting in 9.5, 2.6, and 2.1 g/kgbw/day of carbohydrate, protein, and fat respectively. Rate of changes in daily nutrient intake and nutrition biomarkers were captured. Results: NCG revealed significant increases in total serum protein (5.6%, p&lt;0.001), haemoglobin (3.9%, p&lt;0.001) and vitamin E (2.9%, p&lt;0.001). They also exhibited rises in serum vitamin C (6%, p=0.004), folate (4.5%, p=0.004), ferritin (4.8%, p=0.003), calcium (4.2%, p=0.009), serum vitamins B12 (3.9%, p=0.012) and D (12.3%, p&lt;0.001). Haemoglobin levels were positively correlated with daily protein (p&lt;0.01), iron (p&lt;0.05), vitamins B12 and vitamin C (p&lt;0.05 both) intakes. Serum calcium positively correlated with daily calcium (p&lt;0.01), phosphorus and protein (p&lt;0.05 both) intakes. Serum zinc was positively correlated with daily protein, calcium, vitamin B9 and vitamin D intake, while serum ferritin and vitamin B12 were positively correlated with protein and iron intake. Post-intervention, NCG reported optimal blood levels of calcium, zinc, protein, Hb, ferritin, vitamins B12, C and E, whereas the folate and vitamin D values were suboptimal. On the other hand, the ALG revealed marginal levels of zinc and total protein as well as noticeably low levels of calcium, folate, and vitamin D. Conclusion: Enhanced blood levels of nutritional biomarkers noted after eight-weeks of controlled dietary modification was supported by positive correlations observed with the daily nutrient intakes.

Impact of nutrition education programme and controlled dietary modification on nutritional status in young male athletes

PurposeThe current study sought to assess the synergistic effects of an eight-week nutrition education program (NEP) and controlled dietary modification (CDM) on the nutrition knowledge (NK), nutrition practice (NP), and daily dietary intake of nutrition counselling group (NCG) versus ad-libitum group (ALG), as well as to identify the dietary factors predicting athletes' NP. MethodsA total of 105 male players (14–18 years) from the sports disciplines-football, hockey, swimming, and athletics-were block randomized into the NCG and the ALG. The NCG underwent an 8-week nutritional intervention (NI) that included NEP and CDM, while ALG did not participate in the NI and followed ad-libitum dietary intake. Primary data on each subject's NK, NP, daily food intake, and anthropometric measurements were collected before and after the intervention period for paired and case-control analysis. ResultsA strong association has been depicted between players’ NK and NP. Daily intake of carbohydrate, protein, calcium, and dietary fibre could be referred to as the significant positive predictors of NP, while fat intake is the negative predictor. The synergistic implementation of NEP and CDM reduced the energy deficits among the NCGby significantly increasing their daily calorie intake to an average of 97%. Protein intake was significantly increased, thus meeting 88% of the recommendation, while the increase in carbohydrate intake was insignificant, meeting 89% of the standards post-NI. Further, the NCG showed significant increases in intake of minerals like calcium, phosphorus, iron, zinc, and selenium, while the ALG had substantial reductions. The former also exhibited significant rises in vitamin A, B9, B12, C, and E intakes. The most significant spikes in macro and micronutrient intake were observed in the footballers and hockey players, who were also the groups with the largest increases in NK and NP scores. ConclusionThe equilibrium in macronutrient bifurcations and relative macronutrient and micronutrient intake post-intervention indicates the effectiveness of nutritional enactment through an 8-week controlled dietary modification and systematic nutrition education programme on the nutritional status of young athletes. Therefore, good nutrition knowledge may improve the dietary patterns and nutrition intake of athletes. Intervention studies should emphasize nutrition education, aiming for improved athletic performance.

The Effects of Dawood Fasting on The Morphology of Intestinal Mucosa in Balb/c Mice

Introduction: Long-term fasting (&gt;24 hours) can result in mucosal atrophy, reduced number of goblet cells (GCs) and Peyer’s patches (PPs), and changes in the gut microbiota. This study aimed to determine whether there is a difference in the morphology of intestinal mucosa between mice treated with Dawood fasting and those fed an ad libitum (AL) diet. Methods: An experimental study used ten mice (BALB/c) divided into two groups. One group was given food and drink AL (the AL group). The treatment group (the F group) fasted intermittently in 14-hour (5 p.m. to 7 a.m.) every other day. The study was conducted for 56 days. The faeces from the intestine were diluted 100-fold and cultured for microbiota colony counts. Haematoxylin and eosin staining was performed to observe the villus length (VL) and the area of PPs, and periodic acid-Schiff staining was used to examine the number of GCs. Results: There were no significant differences in the VL, GCs, PPs and the number of microbiota between the F group and the AL group with the respective p = 0.26 (369.54 ± 48.41 vs 307.16 ± 61.16) μm, p = 0.33 (10.42 ± 1.27 vs 9.15 ± 2.44), p = 0.8 (0.164 ± 0.069 vs 0.159 ± 0.089) mm2, and p = 0.64 (1.85 ± 0.97 vs 2.22 ± 1.43) CFU/ml. Conclusion: Dawood fasting has no effect on the histopathological condition of the intestinal mucosa, including the VL, GCs count, area of PPs and the number of microbiota in mice.

The effect of serum from calorie-restricted mouse on mTOR signaling in C2C12 myotubes.

Calorie restriction (CR) is a widely recognized dietary approach with beneficial impacts on the entire body, including enhancements in oxidative metabolism and life span extension, while maintaining nutritional balance and calorie intake. However, CR leads to reductions in skeletal muscle and fat mass due to decreased food intake. Consequently, CR significantly modifies the metabolic profile of the entire body and its tissues. The observed benefits in skeletal muscle during CR may be attributed to CR-induced signaling mediators or significant changes in blood profiles associated with CR that regulate homeostasis maintenance. This study aimed to examine the mammalian target of rapamycin signaling and mitochondrial function of skeletal muscle from mice that undergone 8 weeks of CR and cells cultured in their serum to determine whether changes in blood secreted factors during CR affect skeletal muscle cells. C57BL6/J male mice were used. For 8 weeks, these were subjected to ad libitum (AL) or 40% CR. C2C12 myotubes were subsequently treated with media containing 10% mouse serum from AL or CR for 24 h. The results indicated that 8 weeks of CR decreased muscle mass and protein synthesis response compared with the AL group. Interestingly, myotubes conditioned with CR serum exhibited an elevation in the protein synthesis response compared with those treated with AL serum. Furthermore, mitochondrial function was enhanced in both CR mice and cells treated with CR serum. These findings suggest that while CR decreases the protein synthesis response, secretory factors present in the blood during CR can activate protein synthesis and promote mitochondrial function.

Effect of ad libitum feeding of Holstein Friesian calves on immunological parameters and molecular stress on a transcriptional level

Our aim was to compare the health and performance of ad libitum (ADLIB) and restrictedly fed Holstein Friesian heifer calves. Calves were selected to ADLIB (n = 13) and control (n = 13) groups randomly. The period of ADLIB feeding lasted for 3 weeks after colostrum supplementation. The calves in the control group received the same milk replacer, which was supplied according to the restrained feeding schedule of the farm. There was no difference between the two groups in weight, weight gain or movement activity, furthermore in the values of glucose, albumin, total protein, BHB, AST, oxidant and antioxidant status incl. dROM, PAT and OSI. The IL8 gene had higher levels (non significant, p > 0.05) of expression in the ADLIB group during the first 20 days of life, which indicates that ADLIB feeding might potentiate a stronger immune response to environmental stress. The IGF1 gene showed increased expression in the ADLIB fed group at almost all time points, however the difference was already detected on the first day of the study, indicating the importance of individual differences even within the same breed. During the first 10 days INS expression was higher in the restricted group, followed by a shift by day 20 and after, when the ADLIB group showed a higher relative expression level. The observed values describe a trend that, although not significant (p > 0.05), would seem to indicate that ADLIB feeding might potentiate a stronger immune response to environmental stress.

Effects of intermittent fasting on brain tissue in male Fisher-344 rats

Introduction: Intermittent fasting (IF), time-restricted food intake without any caloric restrictions, has been shown to improve cognition in animal models. Several pathways have been identified in IF-induced neuroprotection; here, we observed the effect of IF on neuroprotection targeting molecular markers of protein synthesis (mTOR), autophagy (ATG5/ LC3A), and antioxidant expression (SOD2). We hypothesized that IF would improve autophagy and antioxidant expression and reduce protein synthesis in male fisher-344 rats. Methods: Twenty-four, 10-week-old male Fisher-344 rats were randomly assigned into two groups (ad-libitum, or IF) and housed 4 per cage, on a 12:12 light: dark cycle. Ad-libitum group had 24/7 access to food and water while the IF group had 24/7 access to water and full access to food on an every-other-day basis (i.e. alternate day fasting) for ten weeks. At 20 weeks of age, animals were euthanized and brain tissues (hippocampus and cortex) were sectioned and snap-frozen in liquid nitrogen. Following homogenization, western blots were completed via Jess Protein Simple automated western blotting (Bio-Techne, Minneapolis, MN). Specific proteins of interested included, LC3 (Novas, NB100-2331), ATG5 (Novas, NB110-538185S), mTOR (Santa Cruz, sc-517464) and SOD2 (Abcam, ab68155). Compass software generated area under the curve values were used to determine protein expression. Group differences were analyzed with a two-tailed T-test per Prism Graph Pad software. Results: In cortex tissue, a significantly lower mTOR expression was observed in the IF group compared to the AL group (p&lt;.001), however, mTOR expression was not significantly different in the hippocampus. Antioxidant enzyme, SOD2, was significantly higher in IF cortex tissues (p&lt;.05) compared to AL controls. In contrast, SOD2 was significantly lower in IF hippocampal tissues (p&lt;.01) compared to controls. No significant effect was documented in the LC3 and ATG5 autophagy markers. Conclusion: In the present study, IF significantly impaired protein synthesis (via mTOR expression) in the cortex only. Previous work has also concluded the downregulation of mTOR with both calorie restriction and fasting. However, the fact that no decline was present in the hippocampus is intriguing and will be the focus of follow-up investigations. As expected, IF increased antioxidant enzyme (SOD2) expression in the cortex and interestedly, IF decreased antioxidant expression in the hippocampus. While the hippocampus is noted for its high antioxidant content, this decreased expression induced with IF warrants more research. P20GM113109 This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Caloric Restriction Decreases Radiation-Induced Normal Tissue Toxicity

<h3>Purpose/Objective(s)</h3> Improvements in radiation delivery are limited by normal tissue toxicity. Studies show that the patient's metabolic state affects radiation toxicity. It has previously been shown that caloric restriction can be used to induce radiation sensitivity in treating breast and prostate tumors. Here we investigate the effect of caloric restriction on radiation induced normal tissue toxicity in two murine models. <h3>Materials/Methods</h3> To determine the role of diet on radiation induced normal tissue toxicity two toxicity models were used to assess mice fed either an ad libitum (AL), caloric restriction (CR: 30% reduction of calories) or ketogenic diet (KD: 60mg fat). A leg shortening model was used to assess acute and long-term skin toxicity by treating one leg of 9-week old Balb/c mice with a single- fraction of 30Gy of irradiation (320kV) with the rest of the body shielded and the contralateral leg serving as an unirradiated control. Measurements of leg length of irradiated compared with control leg length were performed. To assess differences in bone marrow, gastrointestinal and cardiac toxicity, total body radiation was administered to Balb/c mice using a dose of 6.5Gy (LD 50/30) with cohorts from each experimental diet. Histologic evaluation of small intestines and bone marrow was performed after tissue collection at 0, 1, 72 hours as well as 16-18 days post TBI. Small intestinal histology was reviewed by a gastrointestinal pathologist. Serum was evaluated for cardiac troponin 1 levels using ELISA at the same time points. Statistical comparisons were made using students t-test. <h3>Results</h3> The leg shortening model revealed radiation acute skin toxicity at 2 weeks post an ad libitum or ketogenic diet with skin peeling, hair loss, and moist desquamation that lasted 3 weeks compared to the mice treated with CR that had a delayed acute skin toxicity that only lasted 1 week. Long term, the irradiated leg was notably shortened and decreased by 22% and 20% relative to the contralateral leg in the AL and KD groups with 14% leg shortening and decreased fibrosis at 120 days post treatment in the CR groups (p<0.01). Gastrointestinal toxicity was decreased after TBI in mice on CR diet with less denuded villi epithelium and less obvious change in villi length at 72 hours compared to AL diet. The CR mice at 72 hours also had less variation in nuclear size within the epithelium and less changes in Paneth cells. Bone marrow was more hypocellular in the TBI mice on ad libitum diet compared with mice in the CR cohort. Acute cardiac toxicity was evaluated with serum troponin and was less elevated 72 hours post radiation in the CR group, 0.16ng/ml compared to 0.25ng/ml in the AL mice (p=0.03). <h3>Conclusion</h3> Dietary changes impact radiation induced toxicity. Our data show that caloric restriction decreases acute skin toxicity, fibrosis, gastrointestinal and cardiac toxicity. Future research is warranted to translate this strategy to decrease radiation induced normal tissue toxicity.

Impact of feeding management strategy on overall weight gain, growth dynamics of selected organs and growth rate and development of the mammary gland in Preweaned heifers

The aim of the study was to analyse the influence of feeding management, favouring a reduction in the intake of liquid feed and an increase in the consumption of solid feed, in preweaning heifers on their growth performance and the growth rate of gastrointestinal organs and mammary gland (MG) and MG structural components mammary parenchyma (PAR) and mammary fat pad (MFP). Eighteen heifers (Polish Holstein-Friesian), after a 6-day adaptation, at age 14 days were randomly assigned to one of three treatment groups (n = 6): I (initial), R (restricted) or AL (ad libitum). The heifers of I group were euthanized immediately and the R and AL calves at 62 days of age, after a feeding treatment period lasting 48 days. The R and AL heifers, had free access to a starter concentrate (SC) and were fed milk replacer (MR) three times daily, according to the following schedules: for the R treatment, the daily ration was calculated according to Nutrient Requirement of Dairy Cattle (NRC, 2001) to maintain an average daily weight gain of 500 g, and the AL group was given unlimited access to MR for 30 min, at each feeding. In the R treatment heifers the daily intake from MR of crude protein (CP) was 129 g and metabolizable energy (ME) 2.9 Mcal were 1.9 times lower and from SC of CP was 90 g and ME 1.56 Mcal were 2.9 times higher compared with those nutrients intake in the AL treatment. The feeding management protocol for the R group, despite the unlimited availability of SC, did not cover the energy demand during the preweaning period in heifers as indicated by the lower concentration of glucose and the higher concentration of non-esterified fatty acids and urea, compared with AL treatment. The R diet slowed body weight gain and reduced the weights of the liver and kidneys at 62 days of age. Also, most critically, the R diet inhibited the growth of MG, PAR and MFP, as well as CP content of MG structural components, compared to the calves fed the AL diet. The proposed alternative feeding management with MR offered 3-times a day with free access for 30 min, enhances the body weight gain and the growth of the MG and its structural components. The results indicate that 1) the proposed alternative feeding management with MR offered 3-times a day with free access for 30 min, enhances the rate of body and MG and its structural components weight gain, and 2) that despite the increasing intake of starter concentrate, milk replacer is the main source of nutrients in preweaning heifers and in terms of body and organ growth gain, compensatory increased starter concentrate intake is insufficient.

L-serine improves lipid profile, performance, carcass weight and intestinal parameters in feed restricted broiler chickens during the hot-dry season.

The study evaluated effects of L-serine on lipid profile, performance, carcass weight and small intestinal parameters in heat-stressed broiler chickens subjected to feed restriction. Broiler chickens were divided into four groups, comprising 30 each. Group 1, feed restriction (FR); Group 2, feed restriction + L-serine (200mg/kg) (FR + L-serine); Group 3, ad libitum (AL); Group 4, ad libitum + L-serine (200mg/kg) (AL + L-serine). L-serine was administered orally from days 1 to 14, and feed restriction was performed on days 7-14. Serum harvested from blood samples on days 21, 28 and 35 was evaluated for lipid profile. Feed and water intake, live weight gain, organ and carcass weight were measured. At 35days old, broiler chickens (n = 7) per group were sacrificed to evaluate small intestinal morphology. Temperature-humidity index in the pen (30.88 ± 0.81) was above thermoneutral zone, indicating that chickens were subjected to heat stress. Concentrations of low-density lipoprotein, total cholesterol and total triglycerides were lower (p < 0.05), while higher concentration of high-density lipoprotein was recorded in L-serine groups than in the controls. Feed intake and live weight gain on day 35 in L-serine groups were higher (p < 0.05) than in controls. In L-serine groups, liver, spleen, pancreas and heart weight were higher, but abdominal fat was lower than in FR and AL groups. Villus height:crypt height ratio and area of villus surface were highest in L-serine groups than any other group. In conclusion, L-serine decreased low-density lipoprotein, increased feed intake, live weight, organ and carcass weight, villus height:crypt height ratio and villus surface area.

Effects of forage quantity and access-time restriction on feeding behaviour, feed efficiency, nutritional status, and dairy performance of dairy cows fed indoors

Optimising feed is a key challenge for dairy livestock systems, as forage stock shortages are increasingly frequent and feed is the biggest operating cost. The aim of this experiment was to evaluate the effects of reducing forage quantity and access time on dairy performance and animal nutritional status during indoor feeding. Twenty-seven Montbéliarde and Holstein cows were randomly allocated to three groups of nine cows balanced by breed, parity, days in milk, and milk yield. The three groups were given 3.9 kg DM/day of second-cut hay and 4.5 kg/day of concentrate and either i) ad libitum access to first-cut hay (Ad Libitum group; AL), ii) 10.5 kg/day of first-cut hay (Quantity-restricted group; QR), or iii) 10.5 kg/day of first-cut hay but with access time restricted to only 2 h in the morning and 2 h in the afternoon (Quantity-and-Time-restricted group; QTR). Milk yield, composition and coagulation properties, cow nutritional status (weight, body condition score, blood metabolites) and cow activities were recorded. The AL group ingested 10 % more feed than the QR group and 16 % more feed than the QTR group. Organic matter digestibility was lower in the AL group than in the QR and QTR groups whereas feed efficiency did not differ. Milk yield was not significantly different among the three groups. Compared to the QR and QTR groups, the AL group had significantly higher milk fat (35.9 vs 32.9 and 32.8 g/kg of milk) and milk protein content (29.5 vs 27.7 and 28.5 g/kg of milk). QR and QTR cows mobilised their body fat, resulting in a lower final body condition score, and tended to have a lower blood non-esterified fatty acid concentration than the AL group. QTR cows showed greater body fat mobilisation, but their final corrected BW was not different from AL cows. Access-time restriction did not impact fat and protein content but led to decreased casein, lactose contents and casein-to-whey protein ratio. The forage savings achieved through this feed management practice could prove economically substantial when forage prices increase. This practice can be of interest in grassland systems to overcome certain climatic hazards without having to resort to purchases or to increase the farm's forage autonomy.

Effects of Different Calorie Restriction Protocols on Oxidative Stress Parameters in a Transgenic Mouse Model of Breast Cancer.

Aging and diseases related to aging, such as cancer, have been linked to oxidative stress. On the other hand, calorie restriction (CR) is one of the most effective interventions to slow down aging and prevent a variety of diseases such as cancer in preclinical models. CR has also been reported to modify oxidative stress. The aim of this study was to investigate the effects of different CR protocols and aging on oxidative stress parameters in the MMTV-TGF-α breast cancer mouse model in a cross-sectional study. Female mice were randomly enrolled in three groups: ad libitum (AL), chronic calorie restriction (CCR, 15% CR) or intermittent calorie restriction (ICR, three weeks AL followed by one week 60% CR in cyclic periods) starting at the age of 10 weeks until 81/82 weeks of age. Liver samples were analyzed for malondialdehyde (MDA), catalase (CAT), superoxide dismutase (SOD), glutathione (GSH), and glutathione peroxidase (GSH-Px) levels. At week 49/50, the GSH level increased significantly in the CCR group compared to the AL and ICR-R groups which had higher mammary tumor (MT) incidence rates. Additionally, liver MDA levels in ICR groups were significantly increased, while aging led to decreased CAT and SOD activities in all CR groups. The application of different CR protocols did not have any significant effect on MDA, CAT, and SOD parameters in the liver at week 81/82. These results suggest that although GSH may interfere with MT development at the systemic level, many of the oxidative stress parameters may have more local effects on tumor development than the systemic effects.

Moringa oleifera Seed at the Interface of Food and Medicine: Effect of Extracts on Some Reproductive Parameters, Hepatic and Renal Histology.

The lipid-rich Seed of Moringa oleifera has been promoted as an effective water clarifier. Aside its vital nutritional application as an emerging food additive, the seed has continued to gain a wider acceptance in various global ethnomedicines for managing several communicable and lifestyle diseases, howbeit, its potential toxic effect, particularly on fertility and pregnancy outcomes has remained uninvestigated; the effect of Moringa oleifera seed (MOSE) aqueous-methanol extracts on fertility and pregnancy outcome, was investigated in vivo using female Wistar rats that were divided into 50, 100, 300 and 500 mg per kilogram body weight. Group six was given Moringa oleifera seed treated water ad-libitum (ad-libitum group). Organs harvested for histological assessment included ovary, uterus, liver and kidney. In addition to HPLC fingerprint and a preliminary peptide detection, we determined the physico-chemical characteristics and mineral content of MOSE using standard methods. Data were analyzed with significance at p ≤ 0.05. There was no significant difference in the estrus cycle, mating index, gestation survival index, gestation index, fertility index and sex ratio among all groups. Gestation length was reduced in some groups. While the male pup birth weight was comparable among the different groups, female pups birth weights were significantly reduced in 50 and 100 mg groups. Anogenital distance indices of female pups in ad libitum group were significantly increased. Pathologies were observed in liver and kidneys of dams while kidneys of pups presented a dose dependent reduction in the number of glomeruli. There were no observed pathological changes in the ovary and uterus. This study showed for the first time in rodents, that the lipid-rich MOSE is unsafe to the kidney of rodents while the lipid-free MOSE appears to be safe at doses up to 300 mg/kg body weight. Findings from this study suggested that the female pups were masculinized. In conclusion, the lipid-rich seed extracts of MOSE appear to be unsafe during pregnancy, induce hepatic and renal toxicity while the lipid-free MOSE excludes inherent toxicity as the hydrophobic part has been linked to toxicity as observed in this study due to the developmental programming effect on female offspring in rodents.

Early-onset dietary restriction maintains mitochondrial health, autophagy and ER function in the left ventricle during aging

Dietary restriction (DR) exerts healthy benefits, including heart functions. However, the cardioprotective role of DR is till controversial among researchers due to the variation of DR conditions. The present study focuses on the protective effect of early-onset DR on cardiac injury using mitochondrial structure and expression of protein associated with mitochondrial homeostasis, autophagy and endoplasmic reticulum (ER) function as measures. 2-month-old mice were fed with a breeding diet ad libitum (AL) or DR (60% of AL) for 3 (Young) or 20 (Aged) months. Body weight increased with aging, whereas DR treatment kept body weight consistent. DR mice exhibited a higher relative heart weight than AL mice. DR mice displayed lower plasma glucose levels, compared with AL groups. Furthermore, Aged-AL, but not Aged-DR mice, had increased collagen content and morphological distortions in the left ventricle (LV). Aged-DR mice had a higher ATP and lower TBARS in the LV than Aged-AL mice. Mitochondrial morphology was detected by electron microscopy; Aged-AL mice had increased abnormal morphology of mitochondria. Treatment with DR reduced abnormal mitochondrial accumulation. Aging elevated the protein expressions of mitochondrial functions and ER-induced apoptosis. Aging downregulated autophagy related proteins and chaperones in the heart. Dietary restriction reversed those protein expressions. The present study demonstrated a beneficial effect of early onset DR on cardiac aging. The age-dependent mitochondrial dysfunction and protein quality control dysregulation was significantly reversed by long-term DR, demonstrating a concordance with the beneficial effect in the heart.

76 Growth and Health of Limousin Crossbred Dairy-beef Calves in an Automated Feeding System

Abstract The objective of this study was to determine growth and health of Limousin crossbred dairy-beef calves fed alternative milk allowances in an automated group feeding system. The study was conducted at the University of Minnesota West Central Research and Outreach Center’s, Morris, MN dairy. Forty-eight Limousin-sired crossbred calves were assigned to feeding groups by birth order during two calving seasons from September to December 2019 and March to July 2020. Calves were introduced to the Holm &amp; Laue HL100 Programmable Calf Feeder (Holm &amp; Laue GmbH &amp; Co KG, Westerronfeld, Germany) at 5 d and were randomly assigned to one of two treatments. Treatments for calves were 8 L/d (8L) or ad libitum (AL) milk allowance. Calves were weaned from the automated feeder at 56 d. Data were analyzed using PROC MIXED of SAS. Independent variables for analyses were the fixed effects of season of birth, sex of calf (M or F), treatment group and sex of calf nested within season of birth was a random effect. No differences (P &amp;gt; 0.05) were found between 8L or AL groups for birth weight. The AL calves (109.4 kg) had higher (P &amp;lt; 0.01) weaning weight than 8L calves (95.3 kg). Furthermore, the AL calves had higher (P &amp;lt; 0.01) hip height (95.6 cm) and greater (P &amp;lt; 0.01) heart girth (110.2) compared with 8L calves (93.8 cm and 104.8 cm, respectively). The AL calves (1.14 kg/d) had higher average daily gain at weaning compared to 8L calves (0.91 kg/d). Males calves were not different (P = 0.39) for average daily gain compared to female calves (1.07 kg/d versus 0.98 kg/d). Drinking speeds of AL calves were lesser (P &amp;lt; 0.05; 1,222 mL/min) than the 8L calves (1,453 mL/min). The AL calves and 8L calves were not different for hygiene scores or health scores. The results from this study indicate advantages to feeding dairy-beef calves ad libitum whole milk during the pre-weaning period.