EFFECT OF SELENIUM SUPPLEMENTATION ON COPPER METABOLISM IN DAIRY COWS

1986 ◽  
Vol 66 (4) ◽  
pp. 1009-1018 ◽  
Author(s):  
W. T. BUCKLEY ◽  
S. N. HUCKIN ◽  
L. J. FISHER ◽  
G. K. EIGENDORF

Eight Holstein cows were fed a diet supplemented with selenium at a subtoxic level (2.37 mg kg−1 dry matter), or the same diet without selenium supplementation (0.31 mg kg−1 dry matter), for 276 d of lactation. Copper-65, a stable isotope, was administered intravenously after 14 d of adaptation to the diets, and samples of milk, blood and liver were obtained at intervals throughout the trial. The effect of selenium supplementation on copper metabolism of the cows was evaluated by determining concentrations of copper in plasma, milk and liver, by determining the activities of ferroxidase in plasma and superoxide dismutase in erythrocytes and by determining the pattern of dilution of the copper-65 tracer in plasma, milk and liver. No effect of selenium supplementation on any of the parameters of copper metabolism was observed. It was concluded that an interaction between copper and selenium did not occur under the conditions imposed in this study. Key words: Copper, selenium, interaction, dairy cows, copper stable isotope

1991 ◽  
Vol 71 (1) ◽  
pp. 167-174 ◽  
Author(s):  
K. M. Koenig ◽  
J. A. Shelford ◽  
W. T. Buckley

A method combining balance techniques with an estimate of endogenous fecal selenium (Se) was evaluated as a measure of Se absorption in dairy cows. Endogenous fecal Se was estimated based on tracer enrichment in an index tissue (or fluid) that was assumed to represent enrichment of all endogenous sources of fecal Se. Two nonlactating Holstein cows fed a low-Se diet (0.035 mg Se kg−1 dry matter) were administered 4 mg Se-76, intraruminally, each day for 5 d (days 1–5). After a 10-d equilibration period, total collections of feces and urine were made at 24-h intervals for two 5-d periods (days 16–20 and days 21–25). On day 26 the animals were sacrificed and samples of all major tissues were collected. Samples were analyzed for total Se and Se stable isotope ratios. Selenium-76 enrichment was similar in tissues considered to be contributors to endogenous fecal Se, which supported the assumption that an index tissue could be used to estimate endogenous fecal excretion of Se. Endogenous fecal Se estimated from tracer enrichment in serum and liver was 22–36% of the total fecal Se excreted. True Se absorption was 10–16% of the daily Se intake. Key words: Selenium, stable isotope, tissue distribution, endogenous excretion, absorption, dairy cows


2015 ◽  
Vol 39 (6) ◽  
pp. 583-592
Author(s):  
Danilo de Oliveira Rocha Bhering Santoro ◽  
João Chrysostomo Resende Júnior ◽  
Ronaldo Francisco de Lima ◽  
João Luiz Pratti Daniel ◽  
Matheus Balduíno Moreira ◽  
...  

ABSTRACT Little is known about the morphological response of the omasum in dairy cows that consume a high-energy diet pre-partum. The aim of this study was to investigate whether a transitional diet with high grain content is able to induce changes in omasum morphology. Six weeks before the expected calving, four Holstein cows were fed a standardization diet, and four weeks before delivery, the cows were fed a diet with high grain content (HGC) or low (LGC) grain content. After calving, all of the cows were fed a high energy lactation diet. The cows that were fed the HGC diet pre-partum had higher dry matter and nutrient intake than the cows that were fed the LGC diet. The mitotic index of the omasum epithelium was higher than the mitotic index in the rumen, but apparently the response to the diet stimuli was slower. In the cows that were fed the HGC diet, the omasum papillae were taller one week before parturition and two weeks post-partum. Cows that were fed the HGC diet had a thinner epithelium due to thinner non-keratinized layers of the omasum epithelium. We conclude that the omasum mucosa of dairy cows responds to the stimuli of a pre-partum HGC diet, which was indicated by the greater height of the omasum papillae and by the reduced thickness of the omasum epithelium. It seems that the mitotic index responds a little more slowly, but the response to the diet stimuli is stronger in the omasum epithelium than in the rumen.


2000 ◽  
Vol 80 (1) ◽  
pp. 215-219 ◽  
Author(s):  
Marina A. G. von Keyserlingk ◽  
E. Weurding ◽  
Mary Lou Swift ◽  
C. F. Wright ◽  
J. A. Shelford ◽  
...  

The effect of adding 5% calcium lignosulfonate (LSO3) and heat to canola screenings on in situ ruminal and intestinal dry matter (DM) and crude protein (CP) disappearance in Holstein cows was investigated. Treatments consisted of untreated canola screenings, canola screenings that had been heated to 100 °C for 30 or 60 min and canola screenings that had 5% (wt wt−1) LSO3 added and were subsequently heated at 100 °C for 0, 30 or 60 min. Results indicate that treatment of canola screenings with 5% LSO3 and heated to 100 °C for 60 min was effective in reducing rumen degradation of DM and CP with a corresponding increase in disappearance in the lower gastrointestinal tract when compared to untreated and heat-treated canola screenings. Key words: Canola screenings, rumen by-pass protein, heat treatment, lignosulfonate


1984 ◽  
Vol 64 (5) ◽  
pp. 116-117 ◽  
Author(s):  
K. ROHR ◽  
M. BRANDT ◽  
P. LEBZIEN ◽  
H. SCHAFFT

Duodenal flow as derived from total collection and spot sampling was compared in three Friesian cows, using a re-entrant cannula without transecting the intestine. Cr2O3 was used as a single marker. Small differences in flow of dry matter, organic matter and nitrogen indicate that the spot sampling procedure may render valid results. The mean recovery of Cr2O3 was 96.7%. Key words: Cattle, duodenal flow, sampling technique, marker


1981 ◽  
Vol 61 (3) ◽  
pp. 633-638 ◽  
Author(s):  
P. L. BURGESS ◽  
J. W. G. NICHOLSON ◽  
E. A. GRANT

Two experiments were carried out, using 36 lactating Holstein cows, to determine the effect of three levels (0, 4.5 and 9.0 kg/day) of alfalfa pellets (AP) on the ad libitum consumption of early and late harvested timothy grass silages of different dry matter (DM) content. Cows consumed significantly more wilted than nonwilted silage DM for both the early and late harvested grass, although milk yields were similar for both groups. For the early harvested, wilted and nonwilted silages, feeding AP did not significantly depress silage DM intake until a level of 9.0 kg/day was reached. Total ration DM intake increased significantly with each increment of AP. With the late harvested silages, AP at the 9.0 kg/day level reduced nonwilted silage DM intake while with the wilted silage each increase of AP significantly lowered silage DM intake. Both the 4.5 and 9.0 kg/day of AP increased total DM consumption with the nonwilted silage but 9.0 kg/day of AP was required to significantly increase total DM intake for cows fed the late harvested, wilted silage. Milk yield and milk composition were not changed by the level of AP supplementation or the type of silage fed.


1991 ◽  
Vol 71 (1) ◽  
pp. 135-143 ◽  
Author(s):  
J. W. G. Nicholson ◽  
A.-M. St-Laurent ◽  
R. E. McQueen ◽  
E. Charmley

Twenty-four lactating Holstein cows were used to compare the effect of two sources of supplemental selenium with or without supplemental dl-α-tocopherol acetate, on oxidative stability of their milk. The Se sources were inorganic Se mixed in the concentrate ration or alfalfa sprayed with 20 g Se ha−1 four wk before ensiling. Half of the cows on each treatment received 3000 IU d−1 of dl-α-tocopherol acetate for the first 4 wk (Period 1) and the other half received the tocopherol for the second 4 wk (Period 2). Improvement (P < 0.01) in flavour scores due to α-tocopherol supplementation were apparent only when 0.1 mg Cu kg−1 was added to the milk to catalyze oxidation. Plasma tocopherol content was increased (P < 0.01) when tocopherol was fed regardless of Se treatment Milk tocopherol content increased (P < 0.01) when the cows were fed both supplemental Se and tocopherol; however, the increase was not significant (P > 0.05) when the tocopherol was fed without Se. Plasma and milk Se contents were higher (P < 0.01) for cows fed the Se-fertilized alfalfa than for the control cows or those fed the inorganic Se. In whole blood there were no significant differences in Se content in Period 1 but levels were higher (P < 0.01) for the cows fed Se-fertilized alfalfa in Period 2. Although feeding Se-fertilized alfalfa (802 ± 128 μg Se kg−1 DM) resulted in higher milk Se than feeding either the unsupplemented diet or the inorganic Se (398 ± 44 μg Se kg−1 DM in the concentrate) this had no effect on the oxidative stability of the milk. The results suggest adequate Se improves the transfer of dietary tocopherol to milk. Key words: Oxidized milk, tocopherol, selenium, cows


2004 ◽  
Vol 84 (2) ◽  
pp. 277-289 ◽  
Author(s):  
D. R. Ouellet ◽  
H. V. Petit ◽  
D. M. Veira ◽  
E. Charmley

Thirty-two dairy cows (663 ± 70; kg of BW ± SD) were allotted to a 2 × 2 factorial arrangement of treatments to evaluate the controlled release alkane capsule (CRC; C32 and C36) to estimate digestibility and dry matter (DM) intake in early and late lactation for diets based on low (LC, 30%) or high (HC, 60%) proportions of concentrate. Cows were dosed orally with a CRC into the rumen and digestibility was measured by total collection and estimated from the ratios of alkanes in the diet and faeces. Recoveries of endogenous (C31 and C33) and exogenous (C32 and C36) alkanes were higher and lower, respectively, for LC compared with HC. The effects of diet and the interaction between diet and lactation stage were well estimated (P < 0.05) when measured released rates of C32 and C36 were used to estimate DM digestibility although estimation with both alkanes indicated an effect of lactation stage, which was not observed when using data of measured DM digestibility. The faecal ratio of C31/C32 or C33/C32 showed no diet effect on DM intake estimation while measured DM intake was 22.6% higher for cows fed HC than for those fed LC. In conclusion, estimation of DM intake was inadequate although digestibility of DM was estimated from alkanes contained in the CRC. Key words: Dairy cows, alkane, intake


2003 ◽  
Vol 60 (4) ◽  
pp. 621-629 ◽  
Author(s):  
Clóvis Eduardo Sidnei Corrêa ◽  
Marcos Neves Pereira ◽  
Simone Gisele de Oliveira ◽  
Marcelo Hentz Ramos

Corn cultivated in Brazil is predominantly of hard texture, and more propense to decreased starch digestibility under late harvesting situations than dent hybrids. This work tested the utilization of dent corn as a way of extending the ensilage period without reducing animal performance, and evaluated the potential of sugarcane as a forage for high-producing dairy cows. Nine lactating Holstein cows were allocated to three 3 ' 3 latin squares and were fed 200 g of forage neutral detergent fiber per kg of dry matter as either hard texture corn ensiled at the half milk line stage of maturity, soft texture corn ensiled at the black layer stage, or sugarcane. There were no detectable differences between corn hybrids with regard to milk yield (34.2 vs 34.6 kg d-1) and composition, dry matter intake (23.0 vs 23.2 kg d-1) and total tract apparent digestibility of nutrients. Sugarcane decreased feed intake (21.5 kg d-1) and milk yield (31.9 kg d-1). Organic matter digestibility, chewing activity and rumen pH did not differ among treatments. Sugarcane seems to be a viable option to feed groups of Holstein cows during lactation stages in which nutrient demand is not at a maximum. The performance of dairy cows fed dent corn ensiled at the black layer stage of maturity was similar to the performance of cows fed flint corn ensiled at the half milk line stage.


2007 ◽  
Vol 87 (3) ◽  
pp. 455-458 ◽  
Author(s):  
Chanelle A. Toerien ◽  
John P. Cant

To establish the duration of a severe feed restriction necessary to reversibly decrease milk production in high-producing Holstein cows, milk, plasma and urine parameters were assessed every 6 h during a 24-h restriction and 18-h refeed period. The 24-h restriction decreased yields of milk, protein and lactose by more than 30% without inducing ketosis or impairing milk production post-trial. Key words: Feed restriction, dairy cows, milk yield, plasma metabolites


2002 ◽  
Vol 82 (4) ◽  
pp. 611-615 ◽  
Author(s):  
G. R. Bowman ◽  
K. A. Beauchemin ◽  
J. A. Shelford

An exogenous fibrolytic enzyme product was applied to three different proportions of a total mixed ration (TMR) and fed to dairy cows. There was no enhancement of the hydrolytic capacity of rumen fluid from cows serving as inoculum donors as a result of enzyme supplementation. In vitro dry matter degradation of the TMR at 12 h of incubation was increased by 15% when enzymes were added to the concentrate portion, and by 17% when added to the premix portion of the TMR (P < 0.05), but adding enzymes to the supplement (pelleted portion of the concentrate) had no effect. Key words: Enzymes, fresh substrate, dry matter degradation


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