Increasing magnesium intakes in relation to magnesium absorption in dry cows

2004 ◽  
Vol 71 (3) ◽  
pp. 297-303 ◽  
Author(s):  
Surasak Jittakhot ◽  
J Thomas Schonewille ◽  
Hugo Wouterse ◽  
Anton WJ Uijttewaal ◽  
Chalermpon Yuangklang ◽  
...  

Earlier studies with temporarily isolated rumen of heifers show saturation kinetics of Mg efflux across the rumen wall. Therefore, we hypothesized that high Mg intakes would not further increase the rate of Mg absorption in cows. To test our hypothesis, six ruminally fistulated non-pregnant dry cows were given diets with different Mg concentrations in a 6×6 Latin square design. Desired concentrations of Mg were attained by adding MgO to the basal diet and the Mg concentrations in the total rations were 3·8, 6·4, 9·1, 11·8, 14·1 and 17·3 g Mg/kg dry matter, which provided Mg intakes of 27·1, 44·6, 64·6, 83·5, 100·4 and 124·3 g/d, respectively. Increasing Mg intakes were associated with increased (P<0·001) faecal Mg excretion. However, apparent Mg absorption expressed as g/d was not significantly different for Mg intakes from 100·4 to 124·3 g/d while Mg absorption expressed as a proportion of intake was not significantly different for Mg intakes ranging from 64·6 to 124·3 g/d. Mg concentrations in rumen fluid after feeding increased (P<0·001) with increasing Mg intakes. Apparent absorption of Mg appeared to become saturated at a ruminal Mg concentration of 17·5 mM (Mg intake of 83·5 g/d). Group-mean post-feeding concentrations of Mg and Na in rumen fluid were significantly correlated (Pearson's r=−0·96; P=0·003, n=6). This study showed that under conditions of practical dairy cow feeding, Mg absorption was maximal at Mg intakes [ges ]84 g/d.

2020 ◽  
Vol 98 (Supplement_2) ◽  
pp. 55-56
Author(s):  
Noheli Gutierrez ◽  
Jamie A Boyd

Abstract A study was conducted to evaluate effects of increasing concentration of food grade glycerol on rumen environment and nutrient digestibility. Three ruminally cannulated Jersey steers were used in this study. The study was conducted from March to May 2019. Experimental design was a 3x3 Latin square with a 2wk adjustment period followed by a 1wk collection period. Diet was coastal bermudagrass hay based. Different forage types were introduced in the incubation process to evaluate digestibility. Glycerol was administered once a day at 0, 15, or 20% of DMI (dry matter intake). dNDF (digestible NDF) and dDM (digestible dry matter) was determined using an ANKOM Daisy II incubator inoculated with 200g fresh rumen fluid and incubated for 12, 24, 48 and 72 h at 39°C. Each vessel contained ground forage samples in filter bags in triplicate. After incubation, filter bags were rinsed with cold water and dried for 24h in a 55°C forced air oven. Data were analyzed using the Proc MIXED procedure of SAS version 9.4. There was no difference dNDF in effect of different levels of glycerol between forage types by diet. But a numerical tendency was observed that dNDF was decreased at 20% inclusion rates in comparison to 0 and 15% inclusion of glycerol in the diet. Neither steer nor run was significantly different in the study. However as expected digestibility over time was significantly different (P &lt; 0.001). A significant increase was observed in DMI with the increased levels of glycerol in the diet (P = 0.003), both the 15% and 20% levels of glycerol increased in DMI in comparison to the control (0%). It appears based on these study results that digestibility may be inhibited, as levels of dietary glycerol increase in the diet and more work needs to be done to find the optimal level of glycerol supplementation.


1972 ◽  
Vol 79 (1) ◽  
pp. 99-103 ◽  
Author(s):  
A. M. Raven

SUMMARYA 6 x 6 Latin Square balance experiment was carried out using six Friesian steers, each of which initially weighed about 304 kg. The six treatments studied were an all-hay diet and five other diets containing 20,40,60,80 and 100 % of rolled barley fortified with mineral and vitamin supplements, accompanied by correspondingly reduced proportions of hay. Each diet was fed at an estimated maintenance level of feeding.The progressive increase in the proportion of concentrate gave a significantly linear increase (P < 0·001) in both digestible and calculated metabolizable energy. The actual increase in digestible energy was from 2·62Mcal/kg dry matter (59·3% of the gross energy) on the all-hay treatment to 3·42 Mcal/kg dry matter (79·5% of the gross energy) on the all-concentrate treatment. Use of the determined digestible energy values for the all-hay and fortified barley diets to calculate the digestible energy of the four mixed diets gave results in reasonably good agreement with the determined values, the maximum difference being 0·12 Mcal/kg dry matter, which represented 3·83 % of the determined value. The losses of energy in the urine expressed as percentages of the gross energy of the diets showed a small but significantly linear decrease (P < 0·01) with increase in proportion of barley in the diet. The molar proportions of steamvolatile acids in samples of rumen fluid taken from two animals on each treatment indicated that increase in the proportion of concentrate was associated with tendencies for increase in acetic acid, decrease in propionic acid and little change in butyric acid. The mean digestibility of the organic matter was 62·6 % on the all-hay treatment and 81·8 % on the all concentrate treatment. The progressive increase in the proportion of concentrate gave a significantly linear increase (P < 0·001) in digestibility of the organic matter. Although intakes of nitrogen decreased with increase in the proportion of concentrate due to a decrease in the amount of dry matter fed, the weights of nitrogen retained were well maintained and when expressed as percentages of intake showed a significantly linear increase (P < 0·01).


2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 80-80
Author(s):  
Keira M Cruickshank ◽  
Bayissa Hatew ◽  
Amanda M Gehman ◽  
Karen M Koenig ◽  
Eduardo S Ribeiro ◽  
...  

Abstract The objective of this experiment was to determine how source of selenium (Se) affects dairy cow performance, antioxidant status, and apparent absorption and retention. Multiparous Holstein cows (n = 24; 597 ± 49 kg BW) were blocked by days in milk (161 ± 18) and randomly assigned to receive 0.3 mg/kg of either: 1) organic Se (selenized yeast; ORG; Sel-Plex-Alltech); or, 2) inorganic Se (sodium selenite; INO) premix, top dressed and mixed into a ration daily. After an 11-week adaptation period (blood and milk sampled monthly), cows received an intraruminal dose of Se77 (either Se77 yeast or NaSe77O3) followed by a 4-day period of blood and rumen fluid sampling, and total collection of feces, urine, and milk. Data were analyzed using PROC GLIMMIX in SAS with fixed effects of treatment, time, and their interaction, and random effect of block. Daily DMI (23 ± 0.6 kg), milk yield (35 ± 1.2 kg), plasma glutathione peroxidase (64 ± 4.2 U), and serum Se (0.11 ± 0.003 µg/g) were not different between treatments during the adaptation period. Serum Se77 maximum concentration and area under the curve (AUC) were not different between treatments for 72 hours following infusion, but rumen fluid Se77 AUC was higher (P = 0.02) for ORG cows. Apparent absorption (64 ± 1.3%) and retention (44 ± 1.5%) of the Se77 dose did not differ between treatments. The ORG cows had lower urinary excretion (13 vs. 17 ± 0.6%; P &lt; 0.01), higher milk excretion (6 vs. 2 ± 0.3%; P &lt; 0.01), and similar fecal excretion (36 ± 1.3%; P = 0.9) of Se77 compared to INO cows. These results indicate that ORG Se increased Se content of milk and decreased Se excretion in urine, but did not alter performance, antioxidant status, and apparent absorption and retention of Se in mid-lactation cows.


Author(s):  
Catherine L Lockard ◽  
Caleb G Lockard ◽  
Wyatt N Smith ◽  
Kendall J Karr ◽  
Ben P Holland ◽  
...  

Abstract Six ruminally cannulated steers (average BW = 791 + 71 kg) were used in a replicated 3 × 3 Latin square experiment to determine the effects of roughage type on rumination, fiber mat characteristics, and rumen fermentation variables. Three roughages were included at 7% (DM basis) in a steam flaked corn-based diet; cotton burrs (CB), wheat silage (WS), or corn stalks (CS). Steers were fitted with a sensory collar to record rumination behaviors in 2-h intervals at the beginning of the experiment. Each 30-d period consisted of a 7-d of recovery, 14-d of diet adaptation, 7-d of rumination data collection (daily and bi-hourly average rumination), 1-d of rumen fluid collection, and 1-d of rumen evacuations. In situ degradation of individual roughages was determined for 4-d after period 3 evacuations. During rumen evacuations, ruminal contents were removed; the rumen fiber mat (RF) was separated from the liquid portion with a 2 mm sieve, weighed, and a subsample was dried. Data were analyzed using the MIXED procedure of SAS with steer as the experimental unit and roughage (CB, WS, and CS) as the main effect. Dry matter intake (DMI) was not different for CB and WS (P = 0.25) and greatest for steers consuming CS diet (P  &lt; 0.01). Roughage type did not influence the weight of the RF dry matter (%; DM; P = 0.92), RF weight (P = 0.69), or RF:DMI ratio (P = 0.29). Daily rumination (min/d) did not differ among roughages (P = 0.40), but min of rumination/kg of DMI was greatest for CS (18.0 min), min/kg of NDF was greatest for WS (89.8 min; P = 0.02), and min/kg of peNDF was greatest for CS (132.4 min; P  &lt; 0.01). Wheat silage had the greatest percentage of soluble DM and CB-R and CS-R (P  &lt; 0.01) had the greatest ruminal degraded DM fraction. Rumen fiber mat did not differ for roughages, although rumination min/kg of DMI and peNDF was greatest for steers consuming CS and WS. In situ degradation determined that CB-R and CS-R had the greatest percentage of ruminal degraded DM. Based on the objective of the experiment, roughage type did not influence daily rumination or fiber mat characteristics.


1998 ◽  
Vol 130 (2) ◽  
pp. 199-204 ◽  
Author(s):  
H. PEIRIS ◽  
R. ELLIOTT ◽  
B. W. NORTON

Sorghum grain was included in a basal diet of molasses (molasses 505, urea 21, sunflower meal 191, pangola grass hay 250, minerals 31 g/kg as fed) at rates of 0, 202, 391 and 707 g/kg, generating diets in which grain replaced 0 (diet A), 33 (diet B), 66 (diet C) and 100% (diet D) of the molasses and hay. The four diets were fed to groups of four Hereford steers (293–334 kg liveweight) over a 96-day period. One half of each treatment group was implanted with a growth promotant (zeranol), and all were slaughtered at a commercial abattoir at the end of the trial. The inclusion of 33% grain increased voluntary feed consumption, digestible dry matter (DM) intake (from 57·6 to 82·0 g digestible DM/kg0·75 per day and significantly increased liveweight gain from 592 to 900 g/day. Zeranol implantation also increased liveweight gain but not feed intake. Steers given only grain (diet D) had the highest liveweight gains (1127 g/day). The addition of grain to molasses diets decreased urinary N excretion and increased ammonia and volatile fatty acid (VFA) concentrations in rumen fluid. Molar proportions of propionic acid in total VFA increased from 0·15 to 0·20, and butyric acid decreased from 0·36 to 0·29 when 33% of the molasses was replaced by sorghum grain. The fat content (depth at sacral position) of the carcasses of steers given grain only (diet D) was significantly greater (14 mm) than that of steers given the basal diet of molasses (4 mm), and carcass fat contents were intermediate (10 and 11 mm) for steers given diets B and C respectively. It was concluded that the inclusion of small amounts of grain in molasses-based diets increased cattle growth principally by increasing digestible energy intake without decreasing molasses intake, thus improving the efficiency of utilization of molasses in molasses-based diets.


1987 ◽  
Vol 67 (4) ◽  
pp. 1083-1091 ◽  
Author(s):  
L. R. NDLOVU ◽  
J. G. BUCHANAN-SMITH

Nine lambs fitted with rumen cannulae were used in two 5 × 5 Latin squares to measure the effect of alfalfa hay, C4- and C5-branched- and straight-chain volatile fatty acids (C4/C5 VFAs), cell wall from alfalfa hay (ALFCW) and a soybean protein preparation on intake and rumen digestion of a basal corncob diet with urea included at 30 g kg−1. Relative to the control, alfalfa hay decreased (P < 0.05) intake of the basal diet but increased (P < 0.05) total dry matter intake. ALFCW and soybean protein did not affect intake of the basal diet and total dry matter (P > 0.05). C4/C5 VFAs increased intake of basal diet by sheep in one square (P < 0.05) but had no effect (P > 0.05) on intake with sheep in the other square. Alfalfa hay, ALFCW and soybean protein increased (P < 0.05) total VFA concentration in rumen fluid while only alfalfa hay and C4/C5 VFAs consistently increased isobutyrate, isovalerate and valerate levels in rumen fluid (P < 0.05). In comparison with the control diet, soybean protein elevated (P < 0.05) mean rumen ammonia-N levels whereas C4/C5 VFAs depressed them; however, values exceeded 17 mg dL−1 rumen fluid on all treatments. Most measures of digestion kinetics of fiber from corncobs were unaffected by supplementation (P > 0.05). Alfalfa hay and ALFCW increased (P < 0.05) rate of passage of digesta from the reticulo-rumen. It was concluded that alfalfa hay has a reduced role in improving intake of corncob diets when there is also sufficient NPN in the diet. Key words: Roughage (poor quality), volatile fatty acids, rumen ammonia levels, chromium-mordanted cell walls


2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 229-229
Author(s):  
Bokyung Hong ◽  
Beob G Kim

Abstract Two experiments were conducted to investigate the effects of phytase source and feed pelleting on digestibility of dry matter (DM), crude protein, organic matter (OM), and phosphorus (P) with different doses of phytase in pigs. In Exp. 1, ten barrows (31.4 ± 3.5 kg of BW) were individually housed in metabolic crates and allotted to a replicated 5 × 6 Latin square design with 5 diets and 6 periods. In Exp. 2, ten barrows (28.2 ± 3.2 kg of BW) were individually housed in metabolic crates and allotted to a replicated 5 × 5 Latin square design with 5 diets and 5 periods. Each period lasted 10 d consisted of a 5-d adaptation and a 5-d collection periods and the marker to marker method was used for fecal collection. In both experiments, a basal diet was prepared based on corn and soybean meal without phytase or inorganic P. Four additional diets were prepared in a 2 × 2 factorial treatment arrangement with 2 phytase sources (Buttiauxella spp. or Escherichia coli) and 2 feed forms (mash or pellet). Both experiments employed the same treatments but had different supplemental phytase doses (500 and 1,500 FTU/kg in Exp. 1 and 2, respectively). In Exp. 1, supplemental phytase increased standardized total tract digestibility of P (66.1 vs. 51.7%; P &lt; 0.001) with no effects of phytase source or feed pelleting. Feed pelleting increased digestibility of DM, crude protein, and OM (P &lt; 0.001). In Exp. 2, supplemental phytase increased standardized total tract digestibility of P (72.8 vs. 44.8%; P &lt; 0.001) with no effects of phytase source or feed pelleting. Feed pelleting increased digestibility of DM and OM (P &lt; 0.001). Taken together, supplemental phytase at 500 and 1,500 FTU/kg increases P digestibility regardless of phytase source or feed pelleting.


Author(s):  
A.M. Subuh ◽  
T.G. Rowan

In an experiment of 3 x 3 Latin Square design, 3 heifers each fitted with rumen and simple T-piece duodenal cannulae were used to determine the effects of method of processing soyabean meal (SBM), and low (LRSM) and high (HRSM) glucosinolate rapeseed meals on rumen degradabilities (RD) and intestinal digestibilities of dry matter (DM), nitrogen (N) and organic matter (0M) using a mobile nylon bag technique.Heifers were given a basal diet of hay (0.55 of DM intake) and mineralized barley with LRSM (0.45 of DM intake) to provide a ME intake of > 2 x maintenance. The diet was offered twice a day and a period of four weeks was allowed before the experiment. Methods of processing were formaldehyde (FT, 0.8 HCH0/l6g N), heat (HT, 110°C for 2 h) and untreated (UT). After processing the feedstuffs were ground and 1g samples were placed in sealed nylon bags (3-5 x 5.5 cm). The bags were placed in a plastic mesh cylinder and incubated in the rumen for 0, 12, and 24 hours.


1991 ◽  
Vol 66 (3) ◽  
pp. 381-398 ◽  
Author(s):  
J. Gasa ◽  
K. Holtenius ◽  
J. D. Sutton ◽  
M. S. Dhanoa ◽  
D. J. Napper

Four lactating Friesian cows with permanent cannulas in the rumen and proximal duodenum were given early (EC)- or late (LC)-cut grass silage ad lib., each with either 3 or 9 kg concentrate dry matter (DM)/d in a 4 x 4 Latin square design starting about 10 weeks after calving. Feed was offered twice daily at 08.30 hours and 15.30 hours. Periods lasted 5 weeks and measurements were made in the last 15 d. The higher amount of concentrates increased total DM intake but reduced silage DM intake and the fractional rate of degradation of silage-fibre DM. Later cutting date of silage had no effect on DM intake or the fractional rate of degradation of silage-fibre DM but reduced potential degradability of silage fibre. Dilution rate of CoEDTA in rumen fluid was greater during the day (eating period) than during the night (resting period). Dilution rates measured at the duodenum were lower than those measured in the rumen, but neither was affected by diet. Silage-particle passage rates were measured by use of ytterbium-labelled silage fibre (Yb-fibre) and chromium-mordanted faecal particles (Cr-faeces) and samples were taken at the duodenum and in the faeces. Values for slower rate constant (k1) and transit time were higher and for faster rate constant (k2) were lower for Yb-fibre than for Cr-faeces, but differences in total mean retention time were inconsistent. Values for k1 for both markers and k2 for Yb-fibre only were similar at both sampling sites, but values for k2 for Cr-faeces were lower in the faeces. No diet effects were established with Yb-fibre but, with Cr-faeces, k1 was reduced by more concentrates and EC-silage. Daily mean weights of wet digesta, liquid, neutral-detergent fibre (NDF) and indigestible NDF in the rumen were greater with LC-silage but were unaffected by the amount of concentrates whereas weight of rumen DM was increased by the amount of concentrates only. Maximum rumen fill occurred at 18.00 hours with all diets. Particle-size distribution of rumen contents did not vary markedly during the day. Mean particle size was generally greater with LC-silage than EC-silage. Very small particles, passing through the 0.3 mm screen, constituted about half the rumen DM. It is concluded that rumen fill could have limited intake of LC-silage but not EC-silage. The reduced silage intake with greater concentrate intake was associated with a reduction in fibre degradation rate and an increase in rumen DM fill but no other consistent effects on weight or kinetics of rumen fractions were established.


1982 ◽  
Vol 62 (2) ◽  
pp. 467-471
Author(s):  
R. M. TAIT ◽  
C. GASTON ◽  
J. R. HUNT ◽  
G. M. BARTON

Eight sheep were used in two 4 × 4 latin square digestion trials substituting alfalfa meal with unsteamed or steamed muka (foliage) at levels of 20, 40 or 60%. Including muka at all levels depressed (P < 0.05) the digestibility of dry matter, organic matter, crude protein and acid detergent fiber compared with the control alfalfa meal diet. When calculated by difference, the digestibility of muka dry matter and organic matter was not affected (P < 0.05) by either the level of its inclusion in the diets or by steaming. The mean dry matter and organic matter digestibilities of muka were 29.2 and 30.4%, respectively. The protein content of muka was 5.0% and the estimated protein digestibility at the 60% level of inclusion was only 6.6%. With unsteamed muka, the digestibility of acid detergent fiber calculated by difference averaged −11.9%, suggesting the presence of factors which depressed the digestibility of fiber in the basal diet. Steaming appeared to reduce this depression. A growth trial was conducted with lambs where alfalfa meal, as the sole roughage source, was compared to the same diet with 20% of the alfalfa replaced by steamed muka. Growth rates were not different (P > 0.05) being 142 and 138 g/day, respectively. A taste panel evaluation of the carcasses found no adverse effects on flavor due to the inclusion of steamed muka in the diet. Key words: Lodgepole pine muka, nutritive value, sheep


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