Plasma Urea Concentrations Research Articles

Exploration of robustness indicators using adaptive responses to short-term feed restriction in suckling primiparous beef cows

Animal robustness is a complex trait of importance for livestock production systems and genetic selection. Phenotyping is essential for evaluation of the adaptation of different genotypes to changing environments. This study tested an experimental framework to induce marked deviations in the adaptive responses of suckling beef cows and to identify relevant indicators of responses to characterise individual differences in the robustness of cows. The production and metabolic responses of primiparous suckling Charolais cows to two periods of feed restriction (FR, 50% of their net energy requirements) of different durations were monitored. After calving, 13 cows (aged 39 ± 2 months, BW of 680 ± 42 kg at calving) had ad libitum access to a diet composed of hay and supplemented with concentrate to meet their energy and protein requirements. Starting at 54 ± 6 days postcalving, the cows underwent two periods of FR: 4 days of FR (FR4), which was followed by 17 days of ad libitum intake to study the recovery from FR4, and 10 days of FR (FR10), which was followed by 18 days of ad libitum intake to study the recovery from FR10. The milk yield (MY), BW, body condition score and plasma non-esterified fatty acid (NEFA), β-hydroxybutyrate, glucose and urea concentrations were measured before, during and after each FR. Among all measured variables, the MY and NEFA concentrations showed the most significant changes in response to FR. A functional data analysis approach was applied to the MY and NEFA data to model the adaptive responses and extract quantifiable indicators of deviation and recovery. Linear correlations (P < 0.03–0.07) between FR4 and FR10 were found for some indicators describing MY and NEFA levels before and after FR. The overall repeatability of MY and NEFA responses between both FR accounted for 46% based on quartile analysis performed on average responses. Moreover, the variance in both the MY and NEFA variables did not differ significantly between FR4 and FR10, despite a trend for higher variances in FR10. Altogether, (1) the calculated variables derived from the functional data analysis of the time patterns of the MY and NEFA accounted for the differences in the cow responses to FR, and (2) the animal responses appeared to show concordance between FR4 and FR10. In conclusion, short-term FR is a relevant framework for studying productive and metabolic adaptive responses in suckling cows and allows the identification of potential robustness indicators.

Obesity contributes to mortality and displays alterations in calcium, urea and hemoglobin levels in SARS-CoV-2 infected individuals.

Background & aimsObesity courses with metabolic and inflammatory changes that include, among others, higher expression of the renin-angiotensin-aldosterone system. The pathophysiology of the new coronavirus suggests an affinity for angiotensin-2 converting enzyme receptors, cytokine storm, and systemic hypercoagulability. Thus, obesity could contribute to the worse evolution of individuals with COVID-19. Here we evaluated the clinical outcome and age of SARS-CoV-2 infection in patients with higher BMI compared with normal BMI at the São Francisco de Assis University Hospital (HUSF), in Bragança Paulista, SP.MethodsRetrospective observational study with a review of medical records from June of 2020 to May of 2021 of patients positive for SARS-CoV-2 from HUSF. Demographic, anthropometric, and metabolic data were collected for correlation analysis. The study was approved by the Ethical Committee under CAAE: 34121820.3.0000.5514.Results360 medical records were analyzed, of which 125 were included. The mean age of patients with obesity was significantly lower than overweight and normal weight, both in the overall mean (p-value 0.002–66 versus 56 and 56) and in the mean age of mortality (p-value 0.003–59 versus 61 and 76). The mean plasma calcium in the last sample collected during hospitalization of patients with obesity was significantly higher than that of overweight and normal weight (p-value < 0.001–7.8 versus 8.1 and 8.6). The mean hemoglobin in the first admission sample was also significantly higher in patients with obesity compared to the other groups (p-value 0.041–12.5 versus 12.9 and 13.6). On the other hand, the plasma concentration of urea in the first sample of hospitalization of patients with normal weight was higher than in patients with overweight and obesity (p-value 0.036–90.4 versus 64.8 and 57.1).ConclusionOur findings suggest that age is not a determining factor for the death outcome in patients with obesity. However, obesity contributes to metabolic changes and mortality in SARS-CoV-2 infected patients.

Identifying cattle with superior growth feed efficiency through their natural 15N abundance and plasma urea concentration: A meta-analysis

Identifying cattle with superior growth feed efficiency through their natural 15N abundance and plasma urea concentration: A meta-analysis

15N as a marker for effed efficiency in beef cattle

A recommendation of: Gonzalo Cantalapiedra-Hijar, Isabelle Morel, Bernard Sepchat, Céline Chantelauze, Gemma A. Miller, Carol-Anne Duthie, Isabelle Ortigues-Marty, Richard J. Dewhurst Identifying cattle with superior growth feed efficiency through their natural 15N abundance and plasma urea concentration: a meta-analysis. https://doi.org/10.5281/zenodo.5783960

Metabolic Responses to Epinephrine by Periparturient Dairy Cows Fed Prepartum Diets Differing in Predicted Metabolizable Protein Supply

We determined the effects of prepartum dietary metabolizable protein (MP) supply on lipolytic and glucose response to epinephrine stimulus during the periparturient period. Twelve non-lactating cows in second or greater pregnancies were assigned to a low MP (LMP) diet formulated to provide ~900 g/day MP or a high MP (HMP) diet to provide ~1,100 g/day MP. Cows received prepartum diets from 28 days before expected parturition to day of parturition and then received a common lactation diet until 35 days postpartum. Blood was sampled weekly to day −7, daily to day 7, and weekly through day 35 relative to parturition for analysis of glucose, non-esterified fatty acids (NEFAs), 3-hydroxybutyrate (BHB), urea N, and total protein concentrations. Epinephrine challenges were conducted on day −10 before expected parturition and days 7 and 14 postpartum. Epinephrine [1.4 μg/kg body weight (BW)] was administered via jugular vein and blood was collected from the opposite jugular vein from −45 min to +120 min relative to epinephrine administration. Plasma was analyzed for glucose and NEFA concentrations. Prepartum dry matter intake (DMI) (14.7 and 12.6 ± 1.5 kg/day for LMP and HMP, respectively), postpartum DMI (21.4 and 19.4 ± 1.3 kg/day for LMP and HMP, respectively), and 4% fat-corrected milk (FCM) (37.0 and 36.8 ± 1.5 kg/day for LMP and HMP, respectively) did not differ significantly between diets. Cows fed HMP had higher plasma concentrations of urea N prepartum than cows fed LMP (14.0 vs. 7.9 ± 0.8 mg/dl). Cows fed HMP tended to have greater prepartum concentrations of total protein in plasma than those fed LMP (7.5 vs. 7.0 ± 0.2 g/dl). The area under the curve (AUC) for NEFA response to epinephrine did not differ between diets, but differed by day relative to parturition [8,284, 29,018, and 18,219 ± 2,302 min × (μeq/l) for days −10, 7, and 14, respectively]. Maximal response of NEFA concentration to epinephrine was greater for HMP than for LMP (744 vs. 438 ± 72 μeq/l). The glucose AUC did not differ between diets or among days. Lipolytic response, but not glucose response, to epinephrine was enhanced during the early postpartum period relative to the late dry period. However, those responses were not affected by prepartum MP supply.

Identifying cattle with superior growth feed efficiency through their natural 15N abundance and plasma urea concentration: A meta-analysis

Identifying cattle with superior growth feed efficiency through their natural 15N abundance and plasma urea concentration: A meta-analysis

Identifying cattle with superior growth feed efficiency through their natural 15N abundance and plasma urea concentration: A meta-analysis

Identifying cattle with superior growth feed efficiency through their natural 15N abundance and plasma urea concentration: A meta-analysis

Effect of different dietary regimens at dry-off on performance, metabolism, and immune system in dairy cows

Concentrate withdrawal and feed restriction are commonly used to reduce milk production and to facilitate dry-off, but may impair immune function in dairy cows. We investigated the effect of feed rations providing different amounts of nutrients in combination with feed restriction on performance, endocrine, and metabolic responses, as well as on leukocyte function before and after abrupt dry-off. Forty-three cows were studied from d 12 before until d 6 after dry-off (56 d before scheduled calving). Cows were fed experimental concentrates rich in crude protein (nitrogenic, n = 14), glucogenic precursors (glucogenic, n = 14), or lipids (lipogenic, n = 15). On d 3 before dry-off, total feed allowance was restricted to 50% in half of the animals of each dietary group, whereas feed allowance remained unchanged in the other animals. Performance parameters (milk yield, milk composition, and dry matter intake) were recorded, and daily blood and milk samples were taken and analyzed for various metabolic and endocrine parameters. Additionally, activity and mRNA abundance of several genes in leukocytes were measured at selected time points before and after feed restriction and dry-off, respectively. Feed restriction immediately resulted in a negative energy balance and decreased milk production. Concomitantly, concentrations of nonesterified fatty acids increased, whereas insulin, insulin-like growth factor-1, and glucagon decreased. After dry-off, energy balance turned positive and plasma nonesterified fatty acids decreased. Plasma glucose, insulin, and insulin-like growth factor-1 concentrations increased in all groups after dry-off. Glucose, insulin, and glucagon concentrations in plasma were higher in nonrestricted compared with restricted animals after dry-off. The experimental concentrate types marginally affected the investigated metabolic and endocrine factors, with the exception of elevated milk and plasma urea concentrations in cows fed the nitrogenic concentrate. Chemotactic and phagocytic activity of leukocytes were not affected by diets, feed restriction, or dry-off. Likewise, blood leukocyte mRNA abundance encoding for tumor necrosis factor α (TNF), heat shock protein family A (HSP70), and the glucose transporters (GLUT) 1 and 3 remained unchanged throughout the study period. Overall, the short-term negative energy balance induced by feed restriction was temporarily accompanied by metabolic adaptations, but did not alter the studied factors related to the immune system. Metabolic and endocrine adaptations supporting milk synthesis were continued during the first days after dry-off despite cessation of milking. Thus, the abrupt dry-off resulted in a short-term increase of glucose and triglyceride concentrations, with a delayed endocrine response to re-establish nutrient homeostasis in blood.

Hepato- and Nephro-Effect of Sphenostylis stenocarpa– Formulated Diet on Dexamethasone-Treated Pregnant Rats

This study sought to investigate the effect of Sphenostylis stenocarpa-formulated diet on hepatic and renal parameters of dexamethasone-treated pregnant rats. Sphenostylis stenocarpa were locally sourced from a market in Ado Ekiti. They were milled into powder and used in formulating feed for experimental animals. Fifteen female pregnant rats were divided in three groups of five each. Animals in group A were exposed to standard animal feed only. This served as the control group. Those in group B were exposed to Sphenostylis stenocarpa-formulated diet + 0.3 mg/kg body weight of dexamethasone, while those in group C were exposed to Sphenostylis stenocarpa-formulated diet. At the end of the eight days treatment, animals were sacrificed and blood sample, liver and kidney were collected. Exposure of pregnant rats to dexamethasone was observed to significantly (p&lt;0.05) increased the activities of plasma aspartate amino transaminase (AST) and alanine amino transferase (ALT) as well as the concentrations of plasma total protein, bilirubin, creatinine and urea when compared with those in animals in the control as well as those fed with S. stenocarpa-formulated diet only. The results further showed that pregnant rats fed with S. stenocarpa-formulated diet only had no significant difference on plasma hepatic and renal biomarkers when compared with those in the control group. The results of liver and kidney homogenates are similar to those observed in the plasma. Exposure of animals to dexamethasone adversely unhinged hepatic and renal biomarkers investigated in the study. The study also revealed that P. biglobosa seed is beneficial to the health of the liver and kidney of pregnant female rats.

Risk factors and implications associated with renal mineralization in chronic kidney disease in cats.

BackgroundNephrocalcinosis is a pathological feature of chronic kidney disease (CKD). Its pathophysiological implications for cats with CKD are unexplored.ObjectivesIdentify nephrocalcinosis risk factors and evaluate its influence on CKD progression and all‐cause mortality.AnimalsFifty‐one euthyroid client‐owned cats with International Renal Interest Society (IRIS) stages 2‐3 azotemic CKD.MethodsRetrospective cohort study. Histopathological kidney sections were assessed for nephrocalcinosis (von Kossa stain). Nephrocalcinosis severity was determined by image analysis (ImageJ). Ordinal logistic regressions were performed to identify nephrocalcinosis risk factors. The influence of nephrocalcinosis on CKD progression and mortality risk were assessed using linear mixed model and Cox regression, respectively. Cats were categorized by their owner‐reported time‐averaged phosphate‐restricted diet (PRD) intake, where PRD comprised ≥50%, 10‐50%, or none of food intake.ResultsNephrocalcinosis was rated as mild‐to‐severe in 78.4% and absent‐to‐minimal in 21.6% of cases. Higher baseline plasma total calcium concentration (tCa; odds ratio [OR] = 3.07 per 1 mg/dL; P = .02) and eating a PRD (10%‐50%: OR = 8.35; P = .01; ≥50%: OR = 5.47; P = .01) were independent nephrocalcinosis risk factors. Cats with absent‐to‐minimal nephrocalcinosis had increasing plasma creatinine (0.250 ± 0.074 mg/dL/month; P = .002), urea (5.06 ± 1.82 mg/dL/month; P = .01), and phosphate (0.233 ± 0.115 mg/dL/month; P = .05) concentrations over a 1‐year period, and had shorter median survival times than cats with mild‐to‐severe nephrocalcinosis.Conclusion and Clinical ImportanceHigher plasma tCa at CKD diagnosis and PRD intake are independently associated with nephrocalcinosis. However, nephrocalcinosis is not associated with rapid CKD progression in cats.

Effects of feeding sainfoin proanthocyanidins to lactating ewes on intake, milk production and plasma metabolites

There is increasing interest in using sainfoin (Onobrychis viciifolia) to feed sheep, but it contains proanthocyanidins (PACs), and the associated effects of PAC on sheep production are not well-known. The aim of the study was to assess the effect of the presence of PAC from sainfoin, through the inclusion of polyethylene glycol (PEG), on the intake and productive parameters of local ewes bearing one male lamb. For the experiment, 20 ewes and their newborn male lambs were placed in individual indoor cages. All ewes were fed ad libitum fresh sainfoin plus 200 g/d barley. Twice daily, half of the ewes were orally dosed with only water (Sainfoin Group; n = 10), and the other half were orally dosed with 100 g/d PEG 4000 per ewe (Sainfoin + PEG Group; n = 10). Sucking lambs were permanently housed with their dams until they reached 10–12 kg BW. The intake of sainfoin was recorded daily, and its chemical composition was analysed. Weekly, the BW, body condition score (BCS), milk yields and individual milk and blood samples were recorded. At the beginning and end of the experiment, faecal samples were collected from ewes and analysed for the anthelmintic role of PAC. The chemical composition, polyphenol content and antioxidant capacity of the diet and milk were analysed. The presence of PAC did not affect the intake, BW, BCS or milk yield of the dams (P > 0.05); however, all parameters were affected by the week of lactation (P < 0.05). Milk components were affected by the week of lactation (P < 0.001), but only the polyphenol and urea contents were reduced in the presence of PAC (P < 0.01). Similarly, the presence of PAC decreased the plasma urea concentration (P < 0.01) without effect on the rest of metabolites, polyphenols and antioxidant activity (P > 0.05). The presence of PAC had no effect on parasitism (P > 0.05). In conclusion, the presence of PAC had no relevant effects on milk production, although it affected protein metabolism, as indicated by the urea contents in milk and plasma.

Impact of focus feeding on reproductive losses, prolificacy, or fecundity of estrous synchronized ewes

The aim of this study was to evaluate the impact of a focus feeding (energy-protein supplementation) after a fixed timed artificial insemination (TAI) and before the review service, on reproductive and metabolic variables. Multiparous Merino ewes (312) from a commercial flock (-30° 44´ S; -57°39´ W) grazing native pastures were synchronized with progestogens devices for 12 days (Days -14 to -2) and eCG at removal and cervical TAI (Day=0). On Day 7 post-TAI the ovulation rate (OR) was estimated, and two groups were formed: Supplemented (S; n = 155) and Control (C; n = 157). The S group was supplemented with soybean meal (1.2% of body weight) between Days 8 and 14. The review service was carried out between Days 14 and 21 using 2.5% fertile chest painted rams and the non-service return rate on Day 21 (NR-D21) calculated. Blood samples were obtained from 25 ewes of each group on Days 8, 12, 14, and 17 to evaluate no esterified fatty acid (NEFA) and urea plasma concentrations. On Day 26 OR was evaluated on the ewes with review service. Embryo losses, fertility, prolificacy, and fecundity of both services were estimated on Day 60 by transabdominal ultrasonography. No significant differences were observed in NR-D21 (65.8 vs. 63.7%), fertility (62.4 vs. 64.5%), prolificacy (1.32±0.75 vs. 1.33±0.76), fecundity (85.2 vs. 82.8%), or embryo losses from TAI service, or OR (1.16±0.37 vs. 1.15±0.36), fertility (87.7 vs. 92.4%), prolificacy (1.00±0.0 vs. 1.02±0.14) or fecundity (87.7 vs. 90.6%) of the review service for S and C groups respectively (P > 0.05). The urea concentrations increased significantly between Days 12 and 14 in S group (P < 0.05), and the NEFA concentration decreased faster with supplementation in the S group (P > 0.05). We concluded that a high energy-protein supplementation before the review service does not increases the reproductive losses from TAI, neither prolificacy nor fecundity of the review service.

Assessment of Parkia biglobosa on Hepatic and Renal Biomarkers of Dexamethasone-Exposed Pregnant Rats

Aim: This study sought to investigate its effect on hepatic and renal biomarkers of female pregnant rats.&#x0D; Place and Duration: This work was carried out in the Department of Medical Biochemistry and Department of Science Laboratory Technology, Ekiti State University, Ado Ekiti between January and June 2021.&#x0D; Methodology: Locust bean seeds were purchased from an open market in Ado Ekiti, Nigeria and were processed using standard method. Fifteen female pregnant rats were divided into three groups of five each. Animals in group A were exposed to standard animal feed only. This served as the control group. Those in group B were exposed to animal feed mixed with locust beans + 0.3 mg/kg body weight of dexamethasone, while those in group C were exposed to animal feed mixed with locust beans only. At the end of the eight days treatment, animals were sacrificed and blood sample, liver and kidney were collected.&#x0D; Results: Exposure of pregnant rats to dexamethasone was observed to significantly (p&lt;0.05) increased the activities of plasma aspartate amino transaminase (AST) and alanine amino transferase (ALT) as well as the concentrations of plasma total protein, bilirubin, creatinine and urea when compared with those in animals in the control as well as those treated with P. biglobosa only. The results further showed that administration of P. biglobosa only had no significant effect on plasma hepatic and renal biomarkers except urea which was significantly lower than those in the control group as well as those treated with dexamethasone. The results obtained from liver and kidney homogenate respectively are similar to those observed in the plasma.&#x0D; Conclusion: Exposure of animals to dexamethasone adversely unhinged hepatic and renal biomarkers investigated in the study. The study also revealed that P. biglobosa seed is beneficial to the health of the liver and kidney of pregnant female rats.

Identifying cattle with superior growth feed efficiency through their natural 15N abundance and plasma urea concentration: A meta-analysis

Identifying cattle with superior growth feed efficiency through their natural 15N abundance and plasma urea concentration: A meta-analysis

The Impact of Re-Mating Interval and Genotype on Physiological Response of Rabbits after First Kindling

This is an experiment aimed to study the effect of re-mating interval on rabbit does after first kindling on hormonal (insulin, leptin, and T3) and metabolites (triglycerides, urea, and glucose) levels. DNA damage in ovary cells of rabbit does during the 2nd parity was also studied. Two varieties were used: APRI (synthetic line) and Baladi Black (BB, Egyptian breed). A total number of 120 mature rabbit does (60 does for each breed) were 6 months of age and were used at the beginning of the breeding season. Does of each breed were divided into three equal groups according to reproductive rhythm. The 1st group was postpartum (PP). The 2nd group was 11 days after parturition (P11). The 3rd group was post-weaning (PW). There were significant (P&amp;ge;0.05) differences in plasma leptin concentration during 1st parity. The highest value of plasma leptin concentration was recorded by the PW group at mating. Also, there were significant differences in plasma insulin and T3 hormones concentrations of doe rabbits. The highest value of plasma insulin concentration was recorded by the PW group at mating in 1st parity and the highest value of plasma T3 hormone concentration was recorded for the PS group at mating. While there were insignificant differences during 2nd parity in T3 hormone concentration in rabbits, the differences of plasma glucose and triglyceride concentrations of doe rabbits during 1st parity and 2nd parity were significant. However, the highest significant value of plasma glucose concentration was recorded by the PW group at mating. On the other hand, there were insignificant differences in plasma urea concentration of doe rabbits during 1st parity and 2nd parity. Finally, no significant effects were observed on comet length, head diameter, tail length, or DNA % tail.

Polyphenol-rich extract of Ocimum gratissimum leaves prevented toxic effects of cyclophosphamide on the kidney function of Wistar rats

BackgroundCyclophosphamide (CP) is one of the potent and low cost chemotherapy used in clinical setting against a variety of tumors. However, its association with nephrotoxicity limits its therapeutic use. Ocimum gratissimum leaf is a medicinal plant with numerous pharmacological and therapeutic efficacies, such as antioxidant, anti-inflammation, and anti-apoptotic properties.MethodsThe present study was designed to evaluate the protective effect of Ocimum gratissimum (OG) against CP-induced kidney dysfunction in rats. Rats were pre-treated with 400 mg/kg b.w. of leave extract of Ocimum gratissimum (Ocimum G.) for 4 days and then 50 mg/kg b.w. of CP was co-administered from day 5 to day 7 along with Ocimum G. Markers of renal function and oxidative stress, food and water intake, electrolytes, aldosterone, leukocytes infiltration, inflammation and histopathological alteration were evaluated.ResultsObvious renal inflammation and kidney injuries were observed in CP treated groups. However, administration of leave extract of Ocimum G. prevented oxidative stress, kidney injuries, attenuated inflammation, increased aldosterone production and reduced sodium ion and water loss in rats. The plasma creatinine, urea and urine albumin concentration were normalized after the administration of Ocimum G. extract in rats treated with CP. Ocimum G. also decreased the plasma concentrations of Interleukin-(IL)-6, C-reactive protein and activity of myeloperoxidase and malondialdehyde in CP treated rats.ConclusionOcimum G. prevented kidney injury and enhanced renal function via inhibiting inflammation and oxidant-induced CP toxicity. The efficacy of Ocimum G. is related to the presence of various phytochemicals in the plant.

Divergent regulation of lncRNA expression by ischemia in adult and aging mice

Elderly patients have increased susceptibility to acute kidney injury (AKI). Long noncoding RNAs (lncRNA) are key regulators of cellular processes, and have been implicated in both aging and AKI. Our aim was to study the effects of aging and ischemia–reperfusion injury (IRI) on the renal expression of lncRNAs. Adult and old (10- and 26–30-month-old) C57BL/6 N mice were subjected to unilateral IRI followed by 7 days of reperfusion. Renal expression of 90 lncRNAs and mRNA expression of injury, regeneration, and fibrosis markers was measured by qPCR in the injured and contralateral control kidneys. Tubular injury, regeneration, and fibrosis were assessed by histology. Urinary lipocalin-2 excretion was increased in old mice prior to IRI, but plasma urea was similar. In the control kidneys of old mice tubular cell necrosis and apoptosis, mRNA expression of kidney injury molecule-1, fibronectin-1, p16, and p21 was elevated. IRI increased plasma urea concentration only in old mice, but injury, regeneration, and fibrosis scores and their mRNA markers were similar in both age groups. AK082072 and Y lncRNAs were upregulated, while H19 and RepA transcript were downregulated in the control kidneys of old mice. IRI upregulated Miat, Igf2as, SNHG5, SNHG6, RNCR3, Malat1, Air, Linc1633, and Neat1 v1, while downregulated Linc1242. LncRNAs H19, AK082072, RepA transcript, and Six3os were influenced by both aging and IRI. Our results indicate that both aging and IRI alter renal lncRNA expression suggesting that lncRNAs have a versatile and complex role in aging and kidney injury. An Ingenuity Pathway Analysis highlighted that the most downregulated H19 may be linked to aging/senescence through p53.

247 Metabolic Adaptation to Short-term of Dietary Nutrient Imbalances in Mid Lactation Dairy Cows

Abstract This study investigated the short-term metabolic and endocrine responses to different levels of concentrate formulated to particularly provide one major macronutrient source. Based on parity number, lactational stage, milk yield and BW, 9 mid lactating cows (211 ± 19 d in milk) were grouped into 3 blocks of 3 animals each. Concentrate supplements (aminogenic: rich in crude protein and nitrogen sources; glucogenic: high content of carbohydrates and glucogenic precursors; lipogenic: high lipid content) were fed in a factorial arrangement at 3 increasing levels for 3 d each. Milk yield, BW and feed intake were recorded daily. Blood and milk were sampled every 3 d at the end of each concentrate level. Statistical analysis was carried out using a mixed model with concentrate supplement and level as fixed, and block and animal as random factors. Milk fat, protein, lactose and urea contents were determined. In blood, concentrations of various metabolites, endocrine factors and enzyme activities (e.g. glucose, non-esterified fatty acids (NEFA), β-hydroxybutyrate, urea, cholesterol, triglycerides, insulin, glucagon, ASAT, GGT, GLDH) were measured. Milk yield, milk composition and BW were not affected by diets and concentrate levels. Feed intake increased in cows receiving the aminogenic and lipogenic diet. Milk und plasma urea concentrations were clearly elevated in the aminogenic and to a lesser extent in the lipogenic treatment compared to the glycogenic diet (P &amp;lt; 0.05). Glucose concentrations in plasma were not affected by treatments, whereas insulin and glucagon increased only in the aminogenic treatment with concomitantly reduced NEFA concentrations (P &amp;lt; 0.05). Activities of ASAT, GGT and GLDH as well as the total antioxidant capacity were not affected by diets (P &amp;gt;0.05). To conclude, immediate metabolic and endocrine responses occurred due to the short-term dietary changes. Particularly a surplus of nitrogen supply affected metabolic responses and stimulated insulin and glucagon secretion.

Supplementation of macro algae (Azolla pinnata) in a finishing ration alters feed efficiency, blood parameters, carcass traits and meat sensory properties in lambs

The effects of dietary supplementation with Azolla pinnata (a macro algae) on lamb performance, blood parameters, carcass traits and meat quality were investigated. Thirty fat-tail uncastrated male Moghani lambs with an initial average body weight (BW) of 28 ± 1.4 kg were allocated to one of three dietary treatments (10 lambs/treatment) by stratified randomisation based on BW. Lambs were fed ad libitum for 90 d with a standard finishing diet containing sun-dried Azolla at 0, 10 and 20 % (DM basis) levels. Results showed that the feed intake tended to be lower (P = 0.074) in Azolla supplemented lambs, the values were 1.73 and 1.69 and 1.48 kg DM/d, for 0, 10 and 20 % Azolla, respectively. Plasma urea and creatinine concentrations were lower in Azolla supplemented lambs than control group (P < 0.05). BW was not affected by dietary supplementation of Azolla (P> 0.05) but inclusion of Azolla in the feedlot ration improved (P = 0.004) feed conversion ratio. Hot and cold carcass weights were greater (P = 0.009) for lambs fed with 10 % Azolla (24.9 and 24.4 kg), than for the control group (22.5 and 22.1 kg, respectively). Other carcass traits and longissimus muscle chemical composition were not impacted by Azolla supplementation (P > 0.05). Lambs that were supplemented with 20 % Azolla in the feedlot ration had greater odor intensity scores (P = 0.01) compared with the control group. The sensory properties of meat were not altered by 10 % Azolla diet. Azolla supplementation at 10 % and 20 % had no effect on meat quality attributes (P > 0.05). From these results, the supplementation of Azolla pinnata at 10 % level is recommended as a feed source to improve feed conversion ratio and carcass weights for Moghani lambs, without compromising meat quality and sensory properties.

Supraphysiological concentration of urea affects the functional competence of Holstein-Friesian (Bos taurus) sperm

To understand the effects of urea on sperm functional attributes, fresh bull semen (n = 12) was subjected to four different concentrations (mg/mL) of urea to mimic the physiological (0.04 and 0.13), supraphysiological (0.43) concentrations and control (0 mg/mL). Sperm membrane integrity, kinematics, chromatin integrity, and mitochondrial membrane potential were assessed at different time points (before incubation, 0, 1, 2, and 4 h) of incubation. The concentration of urea in serum and seminal plasma was estimated and correlated with the ejaculate rejection rate and sperm functional attributes. The relative expression of urea transporter gene transcripts (UT-A and UT-B) was assessed in sperm and testis (control) using real-time PCR. The supraphysiological concentration of urea affected sperm kinematics, viability, functional membrane integrity, and acrosome integrity within 1 h of incubation (p < 0.05). Sperm head area decreased (p < 0.05) at 0 h and subsequently increased at 1 h of incubation in all media except supraphysiological (0.43 mg/dL) concentration of urea. Seminal plasma urea concentration showed a significant negative correlation with sperm motility, membrane integrity, and mitochondrial membrane potential (p < 0.05), but had a positive correlation with the ejaculate rejection rate (r = 0.69). Relative expression of the urea transporter genes revealed that UT-A was expressed only in the testis. In contrast, UT-B was expressed in both the testis and sperm, suggesting UT-B's role in regulating urea transport in sperm. At a supraphysiological level, urea adversely affected sperm functional attributes, osmoadaptation and may affect fertility.