Effect of supplementing high levels of vitamin D3 on calcium homeostasis of steers fed barley-based finishing diets

2004 ◽  
Vol 84 (1) ◽  
pp. 81-89
Author(s):  
G. Aranda-Osorio ◽  
A. A. Olkowski ◽  
T. A. McAllister ◽  
A. Van Kessel ◽  
J. J. McKinnon
Keyword(s):  
Vitamin D ◽  
Calcium Homeostasis ◽  
Repeated Measures ◽  
Calcium Absorption ◽  
Barley Grain ◽  
Plasma Vitamin ◽  
Beef Tenderness ◽  
Finishing Diets ◽  
Serum Pth ◽  
Barley Silage

The objective of this study was to evaluate the effect of supplementing high levels of vitamin D3 to steers fed barley-grain-based finishing diets on Ca metabolism. Fifteen Hereford steers (607 ± 12 kg) were individually penned and fed at 0800 and 1600 with a ration consisting of 90% barley-grain-based concentrate and 10% barley silage [dry matter (DM) basis]. Steers were randomly assigned to one of three treatments: 0, 2.5 or 5 million IU (MIU) of vitamin D3 steer-1 d-1 for 7 d. Daily blood samples were obtained for measurement of serum for total and ionized Ca, parathyroid hormone (PTH) and calcitonin and plasma for vitamin D3 and 25(OH)D3. Data were analyzed by repeated measures analysis and single degree of freedom contrasts. Feed intake was depressed relative to control animals by 18 and 37% for the 2.5 and 5 MIU D3 treatments, respectively. Relative to controls, total and ionized Ca increased (P < 0.05) by 8 and 19% and 6 and 18% for the 2.5 and 5 MIU D3 treatments, respectively. Serum PTH concentrations were reduced (P < 0.05) by vitamin D3 feeding with the greatest reduction seen with animals fed the 5 MIU treatment. Calcitonin values were not (P > 0.05) affected. Relative to controls, plasma vitamin D3 concentrations increased (P < 0.05) in a quadratic fashion over time with vitamin D3 supplementation, while that of 25(OH)D3 increased (P < 0.05) in a linear fashion. It was concluded that the increase in serum calcium was stimulated by a rise in plasma vitamin D3 and the resulting increased 25(OH)D3 concentrations, which have been shown to influence calcium absorption either directly or via induced synthesis of 1,25(OH)2D3. Key words: Calcium homeostasis, vitamin D3, cattle, beef tenderness

Effect of dietary Ca manipulation, anionic salts and supplemental vitamin D3 on calcium homeostasis of finishing steers

2005 ◽  
Vol 85 (4) ◽  
pp. 521-531
Author(s):  
G. Aranda-Osorio ◽  
A. Van Kessel ◽  
A. A. Olkowski ◽  
T. A. McAllister ◽  
J. J. McKinnon
Keyword(s):  
Vitamin D ◽  
Calcium Homeostasis ◽  
Barley Grain ◽  
Total Serum ◽  
Adaptation Period ◽  
Beef Tenderness ◽  
Finishing Steers ◽  
Dietary Strategy ◽  
Supplemental Vitamin ◽  
Anionic Salt

The objective of this study was to evaluate the effects of a low-Ca diet, followed by a high-Ca diet in combination with feeding of anionic salts and/or vitamin D3 on Ca and acid-base homeostasis of finishing steers. Twenty Hereford steers (448 _ 26 kg) were individually penned and fed at 0800 and 1600 with a ration consisting of 90% barley grain-based concentrate and 10% barley silage (DM basis). The experimental protocol included a 19-d adaptation period, a 14-d period of low Ca feeding, a 10-d supplemental period and a 5-d withdrawal period. During the supplemental period, anionic salts (MgSO4 and NH4Cl) were incorporated into the diet at -1500 and -3000 mEq steer-1 d-1 for 3 and 7 d, respectively. The cattle were also supplemented with one of four vitamin D3 treatments: 0, 0.6, 1.2 and 2.4 million IU (MIU) of vitamin D3 steer-1 d-1. Blood samples were obtained for measurement of total and ionized Ca, parathyroid hormone (PTH) and calcitonin, vitamin D3, 25(OH)D3 and 1,25(OH)2D3. Feed intake was depressed (P < 0.05) by anionic salt feeding but not vitamin D3 treatment. Cattle supplemented with vitamin D3 had higher total (P < 0.05) and ionized (P < 0.05) serum Ca levels than the control cattle that were only supplemented with anionic salts. Higher (P < 0.04) ionized Ca levels were seen in cattle fed 2.4 versus those fed 0.6 MIU vitamin D3. Maximum total serum Ca values were 10.11, 10.97, 11.43 and 12.24 mg dL-1 for the 0, 0.6, 1.2 and 2.4 MIU vitamin D3 treatments, respectively. Respective maximum values for ionized Ca were 5.43, 5.90, 5.98 and 6.25 mg dL-1. These values represent increases, relative to the adaptation period of 3, 12, 16 and 25% for total and 9, 18, 20 and 31% for ionized Ca for the 0, 0.6, 1.2 and 2.4 MIU D3 treatments, respectively. Circulating concentrations of vitamin D3, 25(OH)D3, and 1,25(OH)2D3 were increased (P < 0.05) by vitamin D3 feeding, however, PTH was decreased (P < 0.05), while calcitonin was not affected (P > 0.05). Anionic salt feeding induced (P < 0.05) a mild systemic acidosis. The results indicate that anionic salt feeding enhanced the response of serum Ca to vitamin D3 supplementation. Higher serum Ca levels prior to slaughter may increase intra-muscular Ca levels and enhance postmortem activity of Ca-dependant proteases responsible for myofibril degradation. The results point to a dietary strategy that with further research may prove useful in enhancing beef tenderness. Of particular interest is that serum Ca levels were elevated when vitamin D3 was supplemented at levels 25 to 50% or less than levels used in previous research. Key words: Calcium homeostasis, vitamin D3, anionic salts, beef tenderness

scholarly journals Effects of Age and Serum 25-OH-Vitamin D on Serum Parathyroid Hormone Levels

2012 ◽  
Vol 97 (11) ◽  
pp. 3989-3995 ◽  
Author(s):  
A. Valcour ◽  
F. Blocki ◽  
D. M. Hawkins ◽  
Sudhaker D. Rao
Keyword(s):  
Vitamin D ◽  
Calcium Absorption ◽  
Small Sample Size ◽  
International Workshop ◽  
Large Population ◽  
Small Sample ◽  
Reference Laboratory ◽  
Population Database ◽  
Age Related ◽  
Serum Pth

Context: Several studies define optimal serum 25-hydroxyvitamin D (25-OHD) levels based on serum PTH level reaching an asymptote. However, results differ widely, ranging from 25-OHD levels of 12–44 ng/ml: many studies are constrained by small sample size. Objective: The objective of the study was to determine the relationship between serum PTH and 25-OHD levels and age in a very large reference laboratory database. Design: This was a detailed cross-sectional analysis of 312,962 paired serum PTH and 25-OHD levels measured from July 2010 to June 2011. Results: Median PTH levels and the proportion of patients (PTH &gt; 65 pg/ml), from 63 successive 25-OHD frequency classes of 5000 patients, provide smooth, exceptionally well-fitted curves (R2 = 0.994 and R2 = 0.995, respectively) without discernible inflection points or asymptotes but with striking age dependencies. Serum 25-OHD was below the recent Institute of Medicine sufficiency guidance of 20 ng/ml in 27% (85,000) of the subjects. More importantly, 40 and 51% of subjects (serum 25-OHD &lt;20 and 10 ng/ml, respectively) had biochemical hyperparathyroidism (PTH &gt; 65 pg/ml). Conclusions: This analysis, despite inevitable inherent limitations, introduces several clinical implications. First, median 25-OHD-dependent PTH levels revealed no threshold above which increasing 25-OHD fails to further suppress PTH. Second, the large number of subjects with 25-OHD deficiency and hyperparathyroidism reinforces the Third International Workshop on Asymptomatic Primary Hyper parathyroidism's recommendations to test for, and replete, vitamin D depletion before considering parathyroidectomy. Third, strong age dependency of the PTH-25-OHD relationship likely reflects the composite effects of age-related decline in calcium absorption and renal function. Finally, this unselected large population database study could guide clinical management of patients based on an age-dependent, PTH-25-OHD continuum.

scholarly journals Optimum roughage proportion in barley-based feedlot cattle diets: growth performance, feeding behavior, and carcass traits

2020 ◽  
Vol 98 (10) ◽  
Author(s):  
Karen M Koenig ◽  
Gwinyai E Chibisa ◽  
Gregory B Penner ◽  
Karen A Beauchemin
Keyword(s):  
Feeding Behavior ◽  
Growth Performance ◽  
Dry Matter ◽  
Carcass Traits ◽  
Barley Grain ◽  
Feedlot Cattle ◽  
Experimental Unit ◽  
Finishing Diets ◽  
Ruminal Acidosis ◽  
Barley Silage

Abstract High grain diets are fed to finishing beef cattle to maximize animal performance in a cost-effective manner. However, a small amount of roughage is incorporated in finishing diets to help prevent ruminal acidosis, although few studies have examined optimum roughage inclusion level in barley-based diets. The objective of the study was to evaluate the effects of roughage proportion in barley-based finishing diets on growth performance, feeding behavior, and carcass traits of feedlot cattle. Crossbred beef steers (n = 160; mean body weight ± SD, 349.7 ± 21.4 kg) were allocated to 20 pens that were assigned randomly to four dietary treatments (five pens of eight steers per treatment). The treatment diets contained barley silage at 0%, 4%, 8%, and 12% of dietary dry matter (DM). The remainder of the diets (DM basis) consisted of 80%, 76%, 72%, and 68% barley grain, respectively, 15% corn dried distiller’s grains, 5% mineral and vitamin supplement, and 32 mg monensin/kg diet DM. The diets were fed as total mixed rations for ad libitum intake (minimum of 5% refusal) once per day. Cattle were weighed on 2 consecutive days at the start and end of the experiment and on 1 d every 3 wk throughout the experiment (124 d). Two pens for each treatment group were equipped with an electronic feeding system (GrowSafe Systems Ltd., Calgary, Alberta) to monitor feed intake and feeding behavior of individual cattle. The data for dry matter intake (DMI), average daily gain (ADG), gain:feed (G:F) ratio, and carcass traits were analyzed as a completely randomized design with fixed effect of barley silage proportion and pen replicate as experimental unit. Feeding behavior data were analyzed similarly, but with animal as experimental unit. Averaged over the study, DMI increased linearly (11.1, 11.3, 11.7, 11.8 kg/d; P = 0.001) as barley silage proportion increased from 0%, 4%, 8%, and 12% of DM, but ADG was not affected (carcass-adjusted,1.90, 1.85, 1.87, 1.89 kg/d; P ≥ 0.30). Consequently, G:F ratio decreased linearly (carcass-adjusted, 168.9, 163.8, 158.5, 160.6 g/kg DMI; P = 0.023). When averaged over the study, proportion of barley silage in the diet had no linear or quadratic effects (P &gt; 0.10) on meal frequency, duration of meals, intermeal duration, or meal size, but eating rate decreased linearly with increasing silage proportion (P = 0.008). There was no diet effect on liver abscesses (P ≥ 0.92), and effects on carcass characteristics were minor or nonexistent. We conclude that increasing the proportion of barley silage in a feedlot finishing diet at the expense of barley grain to minimize the incidence of ruminal acidosis may decrease feed conversion efficiency.

scholarly journals Erratum: “Urinary BPA and Phthalate Metabolite Concentrations and Plasma Vitamin D Levels in Pregnant Women: A Repeated Measures Analysis”

2019 ◽  
Vol 127 (1) ◽  
pp. 019002
Author(s):  
Lauren E. Johns ◽  
Kelly K. Ferguson ◽  
David E. Cantonwine ◽  
Thomas F. McElrath ◽  
Bhramar Mukherjee ◽  
...  
Keyword(s):  
Vitamin D ◽  
Pregnant Women ◽  
Repeated Measures ◽  
Plasma Vitamin ◽  
Repeated Measures Analysis ◽  
Vitamin D Levels ◽  
Metabolite Concentrations ◽  
Phthalate Metabolite

Canola screenings as a fiber source in barley-based feedlot diets: effects on rumen fermentation and performance of steers

2000 ◽  
Vol 80 (1) ◽  
pp. 161-168 ◽  
Author(s):  
S. J. Pylot ◽  
J. J. McKinnon ◽  
T. A. McAllister ◽  
A. F. Mustafa ◽  
J. Popp ◽  
...  
Keyword(s):  
Control Diet ◽  
Latin Square ◽  
Dietary Treatment ◽  
Barley Grain ◽  
Feedlot Cattle ◽  
Beef Steers ◽  
Ruminal Fermentation ◽  
Finishing Diets ◽  
And Performance ◽  
Barley Silage

Two experiments were conducted to determine the feeding value of canola screenings in combination with barley grain for beef steers. Four dietary treatments were used. These included canola screenings:barley grain ratios of 100:0; 75:25, 50:50, and 25:75 (as-fed basis). In a metabolic trial, the effects of dietary treatment on ruminal fermentation parameters were determined in a 4 × 4 Latin square design experiment using four ruminally fistulated steers. In a production trial, 66 individually fed steers were used in an 83-d finishing trial to determine the performance and carcass characteristics of feedlot cattle fed different levels of canola screenings. A barley grain/barley silage-based control diet was also fed for comparison purposes. Ruminal pH decreased (P < 0.05) while total volatile fatty acid concentrations increased (P < 0.05) as the level of barley grain in the diet increased. Ruminal NH3–N followed a pattern (P < 0.05) similar to that of pH. Inclusion level of canola screenings had no effect on DM intake. However, ADG and feed efficiency increased (P < 0.05) as the level of barley grain in the diet increased. Increasing the level of barley grain in the finishing diet decreased (P < 0.05) lean meat yield and increased (P < 0.05) carcass fat. It was concluded that canola screenings can be included as a source of fiber in barley-based diets. However, levels in excess of 500 g kg−1 reduced the performance of feedlot steers. Performance and cost of gain with 250 and 500 g kg−1 canola screenings in barley-based finishing diets were comparable with those fed an 800 g kg−1 barley grain and 200 g kg−1 barley silage diet. Key words: Canola screenings, ruminal fermentation, feedlot steer performance

scholarly journals Importance of Extra-Renal CYP24A1 Expression for Maintaining Mineral Homeostasis

2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. A234-A234
Author(s):  
Melody Shi ◽  
Alexander Grabner ◽  
Myles Wolf
Keyword(s):  
Vitamin D ◽  
Mrna Expression ◽  
Calcium Absorption ◽  
Clinical Importance ◽  
P Value ◽  
Loss Of Function ◽  
Vitamin D Metabolism ◽  
Severe Hypercalcemia ◽  
Functional Measure ◽  
Serum Pth

Abstract Calcium homeostasis involves a complex interplay between kidneys, parathyroid glands, intestine and bone. Specifically, 1,25(OH)2D3 is a key calciotropic hormone which stimulates intestinal calcium absorption. A growing body of evidence suggests that circulating levels of 1,25(OH)2D3 depend not only on its synthesis under the action of PTH in the kidneys, but also its catabolism by 24-hydroxylase, herein referred to as CYP24A1. The clinical importance of CYP24A1 has been demonstrated by human loss-of-function mutations, which lead to severe hypercalcemia due to exaggerated levels of 1,25(OH)2D3. Despite its growing importance, little is known about its tissue-specific contributions to normal vitamin D metabolism. To explore the physiology of CYP24A1 and delineate renal-specific effects of CYP24A1 in calcium metabolism, we generated a mouse with constitutive kidney-specific deletion of Cyp24a1 (Six2Cre-Cyp24flox). Six2 marks the nephron progenitor population throughout nephrogenesis. We hypothesized that hypercalcemia as seen in CYP24A1 inactivating mutations is related to lack of both renal and extrarenal expression, and that renal deletion does not lead to severe hypercalcemia. To confirm Cyp24a1 deletion, we measured mRNA expression in the kidney using qPCR and RNA in situ hybridization. All mice were fed a standard commercial rodent diet and followed longitudinally for five months with interval calcium measurements. At time of termination, serum PTH levels were measured along with vitamin D-dependent calcium transporters as a functional measure of 1,25(OH)2D3 action. Cyp24a1 expression was significantly knocked down in total kidneys from Six2Cre-Cyp24flox mice as compared to intestinal expression suggesting successful gene deletion. Compared to age-matched wildtype controls, Six2Cre-Cyp24flox mice were mildly but persistently hypercalcemic (diff between means= 0.46 mg/dL, p-value: 0.03, n=8 per group). As expected, 1,25D-dependent calcium transporters in the kidney (Calb1, Trpv5, Slc8a1, Atp2b1) and intestine (Trpv6, s100g) were all increased, consistent with increased systemic 1,25(OH)2D3 activity. PTH levels were appropriately suppressed in the Six2Cre-Cyp24flox mice (diff between means=83 pg/mL, p-value 0.2, n=9 control, n=3 exp) as were renal cyp27b1 mRNA expression. These data suggest that renal CYP24A1 is important for systemic 1,25(OH)2D3 regulation, but the lack of severe hypercalcemia supports critical contributions of extra-renal CYP24A1.

scholarly journals Urinary BPA and Phthalate Metabolite Concentrations and Plasma Vitamin D Levels in Pregnant Women: A Repeated Measures Analysis

2017 ◽  
Vol 125 (8) ◽  
pp. 087026 ◽  
Author(s):  
Lauren E. Johns ◽  
Kelly K. Ferguson ◽  
David E. Cantonwine ◽  
Thomas F. McElrath ◽  
Bhramar Mukherjee ◽  
...  
Keyword(s):  
Vitamin D ◽  
Pregnant Women ◽  
Repeated Measures ◽  
Plasma Vitamin ◽  
Repeated Measures Analysis ◽  
Vitamin D Levels ◽  
Metabolite Concentrations ◽  
Phthalate Metabolite

scholarly journals Calcium Absorption Measured by Stable Calcium Isotopes (42Ca & 44Ca) among Northern Chinese Adolescents with Low Vitamin D Status

2002 ◽  
Vol 10 (1) ◽  
pp. 61-66 ◽  
Author(s):  
Warren T K Lee ◽  
Jack C.Y. Cheng ◽  
Ji Jiang ◽  
Pei Hu ◽  
Xiaopeng Hu ◽  
...  
Keyword(s):  
Vitamin D ◽  
Calcium Intake ◽  
Calcium Absorption ◽  
Bone Mineralization ◽  
Northern China ◽  
Urinary Calcium ◽  
Chinese Adolescents ◽  
Plasma Vitamin ◽  
Calcium Excretion ◽  
Vitamin D Status

An adequate calcium intake and vitamin-D status is important for bone mineralization in adolescents. In Northern China, calcium intake and plasma vitamin-D level of adolescents is low due to low consumption of dairy foods and inadequate sunshine exposure. True fractional calcium absorption (TFCA) in Chinese adolescents has never been performed. This study aims to evaluate nutritional adaptation namely, TFCA and urinary calcium excretion among Chinese adolescents in northern China.

Effect of feeding sunflower seeds on the performance, carcass characteristics, meat quality, retail stability and sensory characteristics of pasture-fed and feedlot finished beef

2007 ◽  
Vol 87 (1) ◽  
pp. 15-27 ◽  
Author(s):  
J. A. Basarab ◽  
J. L. Aalhus ◽  
M. A. Shah ◽  
P. S. Mir ◽  
V. S. Baron ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Polyunsaturated Fatty Acids ◽  
Meat Quality ◽  
Dry Matter ◽  
Dietary Treatment ◽  
Barley Grain ◽  
Finishing Diets ◽  
Organoleptic Characteristics ◽  
Dietary Treatments ◽  
Barley Silage

This study examined the effects of whole sunflower seed (WSS) supplementation on production parameters, carcass traits, and organoleptic characteristics of beef from steers slaughtered directly off pasture or after receiving a finishing diet. Ninety-six yearling steers (410 kg; SD = 44 kg) were randomly allocated to three pasture (P) dietary treatments: (1) supplemented with P-WSS (n = 48), (2) supplemented with cracked barley grain (P-BAR, n = 24), and (3) not supplemented (P-CON, n = 24). Steers rotationally grazed meadow bromegrass-alfalfa pasture for 66 d during the summer and consumed WSS and BAR at a rate of 0.75 and 1.79 kg head-1 d-1, respectively. At the end of summer grazing half the steers from each pasture dietary treatment group were moved to a feedlot (F) where they were fed high barley-based finishing diets. The remaining 48 steers continued with their dietary treatments on stockpiled pasture for an additional 47 d (SD = 11) until they were slaughtered directly off pasture. In the feedlot, half the steers from each pasture dietary treatment were fed either a control [83% rolled barley, 10% alfalfa hay, 5% barley silage, 1% molasses and 1% vitamin/mineral mix on a dry matter (DM) basis; F-CON] or a F-WSS diet (68% rolled barley, 15% WSS, 10% alfalfa hay, 5% barley silage, 1% molasses and 1% vitamin/mineral mix on a DM basis) for a further 94 d until slaughter. Supplementation of BAR on pasture increased average daily gain (ADG), while supplementation of WSS had no effect on ADG compared with no supplementation (0.73 vs. 0.58 vs. 0.55 kg d-1, P = 0.023). Inclusion of 15% WSS in the finishing diet decreased ADG (1.46 vs. 1.72 kg d-1, P = 0.038), dry matter intake (DMI) (11.6 vs. 12.6 kg d-1, P = 0.058) and had no effect on feed to gain ratio (8.0 vs. 7.4 kg d-1, P = 0.160). Provision of WSS on pasture or in finishing diets had no effect on carcass traits and organoleptic characteristics of beef from steers slaughtered directly off pasture or after receiving a finishing diet. Slaughtering steers directly off pasture, regardless of pasture dietary treatment, adversely affected most carcass merit, meat quality and retail appearance and acceptability parameters compared with steers finished on a high-barley grain diet. These results indicate that increasing the dietary polyunsaturated fatty acids threefold in the pasture dietary treatment or greater than eightfold in the finishing diets had a small negative effect on animal growth rate and no adverse effect on carcass merit, meat quality and retail acceptability. Key words: Polyunsaturated fatty acids, retail acceptability, beef cattle

scholarly journals Serum parathyroid hormone (PTH) levels in smokers and non-smokers. The fifth Tromsø study

2005 ◽  
Vol 152 (1) ◽  
pp. 39-45 ◽  
Author(s):  
R Jorde ◽  
F Saleh ◽  
Y Figenschau ◽  
E Kamycheva ◽  
E Haug ◽  
...  
Keyword(s):  
Vitamin D ◽  
Renal Excretion ◽  
Calcium Absorption ◽  
Serum Levels ◽  
Calcium Balance ◽  
Serum Parathyroid Hormone ◽  
Lower Serum ◽  
Hydroxyvitamin D ◽  
25 Hydroxyvitamin D ◽  
Serum Pth

Objective: Smoking is associated with reduced bone density and calcium absorption, and reduced serum levels of vitamin D. A compensatory increase in serum parathyroid hormone (PTH) would therefore be expected as a result of an altered calcium balance. However, reports on PTH levels in smokers are conflicting. As serum PTH levels give important information on the calcium balance, the PTH levels in smokers are of interest. Subjects and methods: In the fifth Tromsø study, smoking status was recorded and serum PTH measured in 7896 subjects. Intakes of calcium and vitamin D were evaluated with a food-frequency questionnaire. In a follow-up study on 205 subjects, serum 25-hydroxyvitamin D, calcium absorption, and renal excretion of calcium were measured in addition. Results: The serum PTH levels were significantly lower in smokers than non-smokers (3.1±1.4 vs 3.6±1.9 pmol/l in males; 3.1±1.5 vs 3.6±1.8 pmol/l in females (P < 0.001) after correcting for confounding variables, linear regression). In the smokers, there was no association between number of cigarettes smoked and serum PTH. One year after quitting smoking, serum PTH levels were similar to those of people who had never smoked. The smokers had significantly lower intake of vitamin D, lower serum levels of 25-hydroxyvitamin D and lower calcium absorption. The intake of calcium and the renal excretion of calcium were similar to that in non-smokers. Conclusions: Smokers have lower serum PTH levels than non-smokers. This cannot be explained by the predictors of serum PTH measured in our study.

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