scholarly journals A model for zinc metabolism in sheep given a diet of hay

1982 ◽  
Vol 47 (1) ◽  
pp. 105-112 ◽  
Author(s):  
N. F. Suttle ◽  
H. Lloyd Davies ◽  
A. C. Field

1. Four pairs of Scottish Blackface ewes were given a basal diet of hay, providing 8 mg zinc/d, and one of four levels of supplementary Zn (0, 75, 150 or 225 mg/d) continuously by intraruminal infusion.2. 65Zn (59 μCi) was given intravenously after stabilization for 14 d and the changes in specific radioactivity (SR) of plasma and faeces were monitored for a further 10 and 13 d respectiveiy. The faecal endogenous losses and absorption of Zn were estimated, using the principle of isotope dilution, by two methods using the whole or latter parts of SR: time curves.3. Faecal endogenous losses were estimated by the part area method to be 4·9, 6·4, 5·1 and 6·3 ± 0·35 mg/d at 0, 75, 150 and 225 mg supplemental Zn/d i.e. largely unaffected by Zn intake and averaging 0·11 mg/kg live weight (LW). The whole area method gave similar results.4. Urinary excretion was negligible (probably < 0·2 mg/d) for all sheep.5. The amount of Zn absorbed was assumed to equal the irreversible loss of Zn under steady-state conditions and found to remain constant at 7·6±0·39 and 10·3±0·6 mg/d when calculated by ‘whole’ and ‘part area’ methods. Zn retention did not increase with Zn intake and homoeostasis was achieved primarily by control of Zn absorption which fell from 0·75 to 0·03 or from 0·96 to 0·05 of intake, depending on method of calculation, as intakes increased.

1993 ◽  
Vol 69 (2) ◽  
pp. 455-466 ◽  
Author(s):  
E. J. Van Weerden ◽  
J. Huisman

In a study with twelve pigs of 60–70 kg live weight provided with a re-entrant cannula at the end of the ileum, and twelve intact, non-cannulated pigs, the fate of dietary doses of 100 and 200 g isomalt/kg during gastrointestinal passage was examined. From sugar analyses in ileal chyme it was calculated that 0.43 and 0.30 of the isomalt consumed was digested in the small intestine with the 100 and 200 g/kg doses of isomalt respectively. From findings on ileal energy digestibility it was calculated that, because of a secondary effect of isomalt on the digestion of the basal diet, isomalt digestibility in the small intestine was distinctly lower. In faeces no sugars were found, so faecal digestibility of isomalt was 1.00 for both doses. The bacterial fermentation in the large intestine of the isomalt not digested in the small intestine caused an increase in the faecal excretion of nitrogen and energy. This increased faecal excretion was hardly (nitrogen) or not (energy) compensated by a decreased urinary excretion.


1993 ◽  
Vol 69 (3) ◽  
pp. 721-732 ◽  
Author(s):  
J. Balcells ◽  
J. A. Guada ◽  
C. Castrillo ◽  
J. Gasa

The present study examined the effect of urea-N supplementation of a N-deficient diet on digestion and metabolism in the rumen. Five Rasa Aragonesa ewes, each fitted with a rumen cannula, were offered alkali-treated barley straw ad lib. alone or supplemented continuously via the cannula with four levels of urea-N (3, 6, 9 and 12 g/d). Rumen NH3 concentrations increased in response to urea infusion (6–128 mg/l; P < 0.001). At the highest level of rumen NH3 concentration there was a significant increase, compared with the unsupplemented treatment, in dry matter (DM) intake (846–1206 g/d; P < 0.001) and apparent digestibility of DM (0.38–0.43), organic matter (0.38–0.45) and neutral-detergent fibre (0.41–0.49; P < 0.01). Rumen outflow rates of particulate matter and potential DM disappearances, assessed using nylon bags, were not affected by the experimental treatments, although fractional rate of DM disappearance increased significantly with increasing levels of urea infusion (2.4–4.6 per h). Urinary excretion of total purine derivatives increased with N supplementation, although the response was exclusively due to an increase in allantoin excretion (26.9–66.4 mg/kg live weight (W)0.75 per d; P < 0.001). Xanthine, hypoxanthine and uric acid excretion rates were constant, averaging 1.8 (SE 0.17); 5.4 (SE 0.21) and 7.2 (SE 0.36) mg/kg W0.75 per d respectively. The maintenance of a minimum rumen NH3 concentration (approximately 50 mg/l) was necessary to avoid significant reductions in DM intake and fermentation rate. Higher levels, however, may further increase microbial N flow at the duodenum, as suggested by the response in urinary allantoin excretion over the range of rumen NH3 concentrations.


1988 ◽  
Vol 59 (3) ◽  
pp. 429-436 ◽  
Author(s):  
D. Ffoulkes ◽  
R. A. Leng

1. The dynamics of protozoa were studied in two groups of rumen-fistulated cattle fed on a basal diet of molassesad lib., with oaten chaff given at 6 or 18 g/kg live weight. This diet resulted in different mixtures of protozoal species in the populations in the rumen.2. The rumen protozoa were studied by intrarumen injections of protozoa labelled in vitro with [14CH3]choline. An indication of protozoal death and fermentation of protozoal cell residues was obtained by measuring14C loss via the methane pool.3. After a single injection of labelled protozoa, the decline in the specific radioactivity (μCi/g nitrogen) of the protozoal pool in the rumen indicated that first-order kinetic processes applied. Conversely the specific radioactivity of protozoa, incubated in rumen fluid, remained constant indicating no growth in vitro, presumably owing to a rapid exhaustion of essential nutrients.4. The protozoal populations in the rumen of cattle fed on the diet with the low level of oaten chaff were mainly small ciliates; but on the higher level of chaff in the diet, the large ciliates were a higher proportion of the total protozoal population present.5. The mean pool size of protozoa in the rumen was significantly larger and the protozoal half-life tended to be longer for cattle fed on the higher level of chaff in the diet. The apparent production rate of protozoa in cattle fed on each diet was not significantly different and there were no differences in the production rate of methane. The percentage losses of label from protozoa in the rumen via the methane pool were not significantly different on the two diets and indicated that 74% of the protozoa that were apparently irreversibly lost from the rumen could be accounted for by death and lysis in the rumen and therefore only 26% of protozoa apparently entered the lower digestive tract.


Author(s):  
Jorge L Ramos-Méndez ◽  
Alfredo Estrada-Angulo ◽  
Miguel A Rodríguez-Gaxiola ◽  
Soila M Gaxiola-Camacho ◽  
Christian Chaidez-Alvarez ◽  
...  

Forty-eight (37.7±3.4 kg, initial shrunk live weight) lambs were used in a 61-d experiment to evaluate the energy value of grease trap waste (GT) at four levels of supplementation (0, 2, 4, and 6%). Supplemental GT replaced cracked corn in the basal diet. The GT contained 6.4% moisture, 3.1% impurities, and 79.8% total fatty acids (FA). Increasing GT level in diets did not affect dry matter intake and daily gain weight, but linearly increased gain efficiency and estimated dietary net energy (NE). However, the ratio of observed-to-expected diet NE decreased with increasing level of GT. The estimated NE values for GT based on FA intake were in close agreement (98 and 102% of predicted, respectively) with those NE values determined by replacement technique for 2 and 4% supplementation level. However, the observed NE value for GT supplemented at the 6% level was 9% lower than predicted. Kidney-pelvic-hearth fat increased as level of GT supplementation increased; otherwise, carcass characteristics and shoulder composition were not affected. We conclude that GT is a suitable alternative to conventional feed fats in diets for finishing lambs. The estimated NE of GT is 93% than energy value assigned by current standards for tallow and yellow grease.


Author(s):  
J.A. Guada ◽  
J. Balcells ◽  
J. Gasa ◽  
A. de Vega

Since in ruminants urinary excretion of purine derivatives is related to duodenal absorption of purines (Fujihara et al.1987;Giesecke et al.1984), it may be a valuable index to identify nutritive constraints limiting rumen fermentation and microbial synthesis.In the present experiment, the response in the urinary excretion of purine derivatives to urea supplementation of a N deficient diet was studied to test the validity of the above assumption.Five Rasa Aragonesa ewes rumen cannulated and 38, 9±2, 52 Kg mean live weight, were offered “ad libitum” OHNa treated barley straw (50 g/Kg DM) ground and pelleted.Five experimental treatments including four levels of urea supplementation(6.5, 13, 19.5 and 26 g/d) plus a negative control were arranged in a 5x5 latin square design,allowing 14 days of adaptation between experimental periods.The urea was given by continuous infusion to the rumen at a flow rate of 0.92 ml/mn during 18 h per day starting after feeding.


1957 ◽  
Vol 189 (1) ◽  
pp. 91-97 ◽  
Author(s):  
R. H. Wasserman ◽  
C. L. Comar ◽  
M. M. Nold ◽  
F. W. Lengemann

The comparative metabolism of calcium and strontium during fetal development was investigated in rats and rabbits using double tracer techniques. In general, the placental transfer from dam to fetus of strontium was about one-half that of calcium; the site of discrimination was the placental barrier. The major discrimination occurred in movement of Ca* and Sr* from dam to fetus, with little or no differential movement from fetus to dam. Under steady state conditions in the rat the relative Sr*/Ca* ratios in the fetus, maternal skeleton and diet were 0.17, 0.28 and 1, respectively. The over-all discrimination of 0.17 between fetus and diet resulted from absorption (0.42), urinary excretion (0.63) and placental transfer (0.65). In the rat it was estimated that 92% of the fetal calcium had originated from the maternal diet. In the rabbit during late pregnancy, it was determined that about 24 mg of calcium/fetus/day moved across the placenta as compared with a need of about 13 mg for fetal development.


1992 ◽  
Vol 55 (3) ◽  
pp. 425-430 ◽  
Author(s):  
S. Beers ◽  
A. W. Jongbloed

AbstractA total of 384 piglets from a three-way cross Yorkshire ♂ × (Finnish Landrace ♂ × Dutch Landrace♀) ♀ in the live-weight range of 11 to 25 kg were used in a feeding trial. The effect of supplementary microbial phytase from Aspergillus niger var. Van Tieghem on performance (average daily gain (ADG), average daily food intake (ADFI) and food conversion ratio (FCR)) and apparent digestibility of total phosphorus (P), in comparison with a non-supplemented basal diet or a diet supplemented with one or two levels of monocalcium phosphate (MCP), were studied.The piglets were allotted to 12 blocks. Within each block, four experimental diets were offered ad libitum for a period of 4 weeks i.e. (1) basal diet; (2) basal diet + 1·0 g P, from MCP per kg diet; (3) basal diet + 1·9 g P, from MCP per kg diet; and (4) basal diet + 1450 phytase units (PTU) per kg diet. The diets, with added chromium III oxide as a marker, were cold pelleted without steam at a temperature not above 60°C to avoid a possible inactivation of the phytase. In all diets the ratio calcium: digestible P was intended to be constant.Adding 1450 PTU of Aspergillus niger phytase enhanced the apparent digestibility of P by proportionately 0·216 when compared with diet 1 and by proportionately 0·100 compared with diet 3. In addition, significantly higher ADG and ADFI and better FCR were noted in pigs receiving supplementary microbial phytase than in pigs on any other treatment. The content of digestible P of the diet with added phytase, however, zvas between the two levels of the diets with added MCP.


1971 ◽  
Vol 40 (4) ◽  
pp. 351-364 ◽  
Author(s):  
A. Breckenridge ◽  
M. L'E. Orme ◽  
S. Thorgeirsson ◽  
D. S. Davies ◽  
R. V. Brooks

1. Administration of dichloralphenazone, a complex of chloral hydrate and phenazone (antipyrine) caused a fall in steady-state plasma warfarin concentration and loss of anticoagulant control in five subjects. 2. This effect of dichloralphenazone is due to stimulation of the drug-oxidizing enzymes of the liver endoplasmic reticulum by antipyrine, the non-hypnotic part of the complex. Administration of antipyrine caused a fall in steady-state plasma warfarin concentration in five subjects, a shortening of the plasma warfarin half-life, with increased urinary excretion of the metabolites of 14C-labelled warfarin in two subjects and increased urinary excretion of 6β-hydroxycortisol which is formed in the liver endoplasmic reticulum. 3. Administration of chloral hydrate, the hypnotic part of dichloralphenazone, caused no change in anticoagulant control but a fall in steady-state plasma warfarin concentration in five subjects. This is due to the accumulation of trichloroacetic acid which displaces warfarin from plasma protein binding sites. 4. Individual differences in the extent of enzyme induction have been shown to be related to the subjects' rates of drug oxidation. 5. In the rat administration of dichloralphenazone and antipyrine, but not chloral hydrate, caused shortening of pentobarbitone sleeping time and of the plasma [14C]pentobarbitone half-life, shortening of the zoxazolamine paralysis time and increase in the maximal velocity of N-demethylation of ethylmorphine.


Author(s):  
J.A. Martínez-García ◽  
J.C. Garcia-Lopez ◽  
P.A. Hernández-García ◽  
G.D. Mendoza-Martínez ◽  
A. Vázquez-Valladolid ◽  
...  

Background: Choline is a nutrient with numerous metabolic functions, but its requirements for ruminants are unknown. The supplementation with bypass choline could enhance productivity. Methods: Twenty-four male lambs (Rambouillet 23.5 kg±3.17 kg initial BW) were fed a basal diet with treatments which consisted of a control and oral doses of ruminally-protected choline (4 g/d RPC) and plant-based choline (4 g/d Biocholine) in a completely randomized design with initial weight as a covariate. The experiment was conducted for 42 days during which live weight, dry matter intake, carcass characteristics, blood metabolites and basic hemograms were measured. Result: The daily gain in lambs was similar between treatments. Intake was higher in lambs given Biocholine (1.32 kg/d). The L* (represents the light to dark color) value and mineral content in the meat were improved with both sources of choline. Blood triglycerides increased by RPC compared with the other treatments and cholesterol was reduced by Biocholine. Alanine transaminase (ALT) and aspartate aminotransferase (AST) activity decreased by effect of choline. Hematological parameters were affected by choline supplementation regardless of the source; erythrocyte, monocytes and lymphocytes count decreased with both sources of choline in growing lambs.


Chemotherapy ◽  
1987 ◽  
Vol 33 (5) ◽  
pp. 305-308 ◽  
Author(s):  
D.E. Schwartz ◽  
G. Eckert ◽  
J.M.K. Ekue

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