Feed intake and liveweight of cattle on subtropical native pasture hays. 1. The effect of urea

1990 ◽  
Vol 41 (6) ◽  
pp. 1169 ◽  
Author(s):  
DW Hennessy ◽  
PJ Williamson
Keyword(s):  
Organic Matter ◽  
Experimental Design ◽  
Feed Intake ◽  
Rumen Fluid ◽  
Ammonia Concentration ◽  
Low Concentrations ◽  
Hereford Cattle ◽  
Native Pasture ◽  
Nitrogen Concentrations ◽  
Native Pastures

Twenty Hereford weaner steers and heifers, 9-months-old and of mean liveweight (� s.e.) 152 � 6 kg, were stratified according to sex and liveweight into four groups and assigned to cells in an experimental design which aimed at studying the effects of an increased urea intake on their rumen ammonia concentration, their intake of a low N native pasture hay and on their liveweight change over 49 days. The cattle on the basal hay diet maintained low concentrations of ammonia in rumen fluid (8 mg N/L) during the study and lost weight (at 50 g/day). Urea (as 15, 23, 42 and 53 g head.day) increased significantly (P< 0.01) rumen ammonia concentration (to 152 t 10.9 mg N/L), hay intake in the final 7 days (from 2633 to 3738 � 72 g organic matter/head.day) and liveweight change (to 273 � 33 g/head.day). Hay intake of the cattle increased within 14 days of supplementation with urea which was sprayed onto portions of the hay. Urinary N content, but not faeces, was increased by the urea diets. Urea intakes also increased urea nitrogen concentrations in plasma and saliva which were correlated (r=0.87). Liveweight change was maximized at daily urea intakes of 23 g/head and these gains are discussed in terms of the suitability of urea for Hereford cattle which are fed only low N native pastures

Feed intake and liveweight of cattle on subtropical native pasture hays. 2. The effect of urea and maize flour, or protected-casein

1990 ◽  
Vol 41 (6) ◽  
pp. 1179 ◽  
Author(s):  
DW Hennessy ◽  
PJ Williamson
Keyword(s):  
Fatty Acid ◽  
Feed Intake ◽  
Volatile Fatty Acid ◽  
Dry Matter ◽  
Rumen Fluid ◽  
Basal Diet ◽  
High Rate ◽  
Maize Flour ◽  
Hereford Cattle ◽  
Native Pasture

Twenty-five Hereford cattle, of both sexes and a mean liveweight (� s.e.) of 172 �5.6 kg were allocated randomly from stratified groups to five treatments in which urea (UR), urea plus maize (URM), urea plus maize flour and protected casein (URMFC) or protected casein alone (FC) were offered to individually penned cattle on a basal diet of native pasture hay (8.4 g N/kg dry matter (DM)) over 70 days. Rumen ammonia concentrations were low in cattle on the basal hay diet (mean � s.e.d.) of 17 � 10.0 mg N/L but were significantly increased (P<0.01) by a supplement of 280 g/head.day of protected casein (FC) to 70 mg N/L and increased further (1 68 mg N/L) when urea was included with maize (URM) in the treatment. Volatile fatty acid concentrations in rumen fluid were increased (P<0.05) only by URM which also resulted in higher (P< 0..01) molar proportions of propionic acid. All treatments increased (P< 0.01) the hay intake of cattle during the study with the exception of URM, which was based on a high rate of feeding (400 g/day) of maize flour. Liveweight change of cattle was increased (P<0.01) by urea (UR) and maize flour (URM) to 290 and 340 � 56 g/head.day respectively. Higher (P< 0.01) liveweight gains were recorded when protected casein was included in the diet (URMFC, FC), being 550 and 600 g/head.day respectively. The results are discussed in terms of the scope for improving the efficiency of gain in cattle on a low quality grass hay by including low rumen-degradable proteins as a supplement to grass hays.

In vitro ruminal methane suppression by lauric acid as influenced by dietary calcium

2002 ◽  
Vol 82 (2) ◽  
pp. 233-239 ◽  
Author(s):  
A. Machmüller ◽  
C. R. Soliva ◽  
M. Kreuzer
Keyword(s):  
Organic Matter ◽  
Fatty Acid ◽  
Lauric Acid ◽  
Rumen Fluid ◽  
Fatty Acid Pattern ◽  
Coconut Oil ◽  
Bacterial Count ◽  
Ammonia Concentration ◽  
Fiber Fermentation

The effect of Ca supplementation on the methane-suppressing effect of lauric acid was investigated in an experiment based on a 2 × 2-factorial arrangement using the in vitro system Rusitec. Additional Ca was supplemented at 1 g kg-1 diet in the form of compounds of relatively low solubility in rumen fluid. Lauric acid (C12:0), the predominant effective medium-chain fatty acid in coconut oil, was added at a level of 50 g kg-1. Adding C12:0 did not affect bacterial count, but eliminated ciliate protozoa from fermenters. Ammonia concentration in fermentation mixture declined and volatile fatty acid pattern changed with C12:0. The apparent degradation rate of total organic matter was not altered by C12:0, but fiber fermentation was depressed (P < 0.001). Effects of Ca on microbial counts and fermentation characteristics remained low. Without additional Ca, C12:0 reduced the average daily methane release (mmol g-1 organic matter degraded) by 76%. In comparison, C12:0 only reduced methane production by 47% when additional Ca was included in the diet (interaction of C12:0 and Ca, P < 0.05). The present results suggest that the dietary content of soap-forming Ca has to be kept low in order to achieve a high methane-suppressing effect of lauric acid. Key words: Methane, lauric acid, lipids, calcium, Rusitec, ruminants

EFFECTS OF FEEDING MONENSIN TO HOLSTEIN STEERS

1980 ◽  
Vol 60 (1) ◽  
pp. 107-112 ◽  
Author(s):  
D. R. McKNIGHT ◽  
L. A. DREVJANY ◽  
G. S. HOOPER
Keyword(s):  
Experimental Design ◽  
Feed Intake ◽  
Feed Efficiency ◽  
Rumen Fluid ◽  
Corn Silage ◽  
Intake Rate ◽  
Factorial Experimental Design ◽  
High Moisture ◽  
Factor Interactions ◽  
Better Than

Three experiments were conducted to determine the effects of monensin on feed intake, rate of gain and feed efficiency of a total of 198 Holstein steers. In experiment I, 72 steers were fed ground ear corn and corn silage diets containing 0 (treatment 1), 22 (treatment 2) and 33 (treatment 3) g/tonne DM monensin for 112 days. Treatments 2 and 3 received 11 g/tonne DM monensin for the first 28 days. Daily gains were not significantly different (P > 0.05) throughout the trial and intake was slightly reduced (P > 0.05) with monensin addition. Feed efficiency in treatments 2 and 3 were improved 5.5 and 8.8% respectively, but only treatment 3 was significantly (P < 0.05) better than treatment 1. Rumen fluid from steers fed treatment 3 contained a higher proportion (P < 0.05) of propionic acid and a lower (P < 0.05) A:P ratio than did rumen fluid from treatment 1. Levels of acetic and butyric acid were reduced (P > 0.05) by monensin inclusion. In experiment II, 46 steers were fed hay crop silage and shelled corn diets containing 0 (treatment 1) and 33 g/tonne DM (treatment 2) monensin for 112 days. Gains were slightly (P > 0.05) higher and intake slightly (P > 0.05) lower on treatment 2. Monensin improved (P > 0.05) feed efficiency by 8.5%. In experiment III, 40 purchased and 40 station-reared steers were assigned by origin, in pairs, to 40 Calan electronic headgates. A 23 factorial experimental design was used to evaluate the effect of diet with or without monensin used separately and in combination with progesterone-estradiol implants. Steers were fed a high moisture ear corn and corn silage diet for 84 days. No 3-factor interactions (P > 0.05) were detected. Implant treatments gained significantly (P < 0.05) faster than either control or monensin alone. Intake was significantly (P < 0.05) lower in treatments fed monensin. Feed efficiency was improved (P < 0.05) 16% with both monensin and implant, 10% (P < 0.05) with monensin alone, and 6% (P > 0.05) with implant alone over control.

A comparison of various methods of feeding supplements of urea, sulfur and molasses to weaner heifers during the dry season in northern Queensland

1991 ◽  
Vol 31 (2) ◽  
pp. 153 ◽  
Author(s):  
SR McLennan ◽  
DJ Hirst ◽  
RK Shepherd ◽  
KR McGuigan
Keyword(s):  
Rumen Fluid ◽  
Nitrogen Concentration ◽  
Ammonia Nitrogen ◽  
Control Group ◽  
Dry Period ◽  
The Us ◽  
Native Pasture ◽  
Nitrogen Concentrations ◽  
Dry Seasons ◽  
Group 2

Over 3 dry seasons (1984-86), delivery systems of urea supplements were evaluated on weaner heifers grazing native pasture. Daily treatments per heifer were urea-ammonium sulfate (US) (28g + 6g), via the drinking water; urea-molasses (UM) (30g + 250g), via roller drum lick feeders; UM2 (60g + 1000g), via open troughs. Rainfall recordings were well above average in all dry seasons. The only liveweight response to supplementation occurred in 1986, during a dry period from June to October. During this period the liveweight performance of the US group was improved relative to the control group (+7 v. -57 g/heifer.day; P<0.05). The response of the UM2 group (+82 g/heifer.day) exceeded (P<0.05) that of all other groups. There was no response to the UM supplement (-51 g/heifer.day). Over the combined dry and following wet seasons the UM2 group grew faster (P<0.05) than all other groups. Ammonia-nitrogen concentrations in the rumen fluid of heifers, measured in the 1984 and 1986 dry seasons, were very low for the control group (7-54 mg/L rumen fluid) but were much higher in the US group 2 h after drinking (108-152 mg/L). At 18 h after drinking, the ammonia-nitrogen concentration had declined markedly in the US group (30-54 mg/L) but, in 2 of 3 observations, was still higher than that of the controls (significantly in 1 case; P<0.05).

scholarly journals The degradation and utilization of formaldehyde-treated urea by rumen microbes in vitro

1982 ◽  
Vol 54 (1) ◽  
pp. 15-24
Author(s):  
Jouko Setälä ◽  
Liisa Syrjälä-Qvist
Keyword(s):  
Organic Matter ◽  
Rumen Fluid ◽  
Total Yield ◽  
Ammonia Concentration ◽  
Tungstic Acid ◽  
Treatment Level ◽  
Microbial Protein ◽  
Buffer Solution ◽  
Rumen Microbes

Urea was treated with different levels of formaldehyde (HCHO). The HCHO percentages, on a weight basis, were 0(F0), 0.25 (F0.25) 0.50 (F0.50), 0.75 (F0.75), 1.0 (F1.0), 1.5 (F1.5), 2.0 (F2.0), 3.0 (F3.0) and 5.0(F5.0). Twenty milligrams of urea was incubated for 5 hours in 40 ml of sheep rumen fluid-buffer solution (1:1) together with 1.5 grams of substrate. The substrate consisted of vacuum-dried and milled feeds: barley (25 %), molassed beet pulp (25 %) and NaOH-treated straw (50 %). The feeds and urea were used in the same proportions as in the diet of the sheep which yielded the rumen fluid for incubation. Treatment with HCHO decreased hydrolysis of urea to ammonia. The ammonia concentration in contents offer mentors 2 hours after the start of incubation had a highly significant (P < 0.001) negative correlation (r = -0.976, n = 72) with the HCHO treatment level. Microbial protein synthesis was calculated from tungstic acid - sulphuric acid precipitation. Synthesis of protein, expressed as grams of nitrogen per 100 grams fermented organic matter was highest when F1.5-F3.0 urea was used. Treatment with more than 3 % of HCHO decreased the number of protozoa and the general activity of the microbes, thus decreasing fermentation of organic matter and lowering the yield of microbial protein. When F1.5 urea was used, the total yield (mg protein/hr) was significantly higher than with untreated urea, but the results obtained with F1.5 urea did not differ significantly from those with F0.75 or F2.0 urea.

Liveweight response following sodium chloride supplementation of beef cows and their calves grazing native pasture

1973 ◽  
Vol 13 (63) ◽  
pp. 369 ◽  
Author(s):  
GM Murphy ◽  
AW Plasto
Keyword(s):  
Sodium Chloride ◽  
Cattle Grazing ◽  
Beef Cows ◽  
Common Salt ◽  
Hereford Cattle ◽  
Native Pasture ◽  
Urinary Levels ◽  
Ad Libitum ◽  
Native Pastures

Hereford cattle grazing native pastures on the eastern Darling Downs, Queensland, were deemed sodium (Na) deficient on the basis of salivary Na and potassium (K) levels. Common salt (NaCl) was offered ad libitum to one half of the animals. Cows receiving the supplement had significantly better rates of liveweight increase (0.35 v. 0.14 kg head-1 day-1, P < 0.01) than unsupplemented cows. Calves of supplemented cows grew significantly faster than calves of unsupplemented cows (0.77 v. 0.62 kg head-1 day-1, P < 0.01). After 21 days of Na supplementation, cows in the supplemented group had mean saliva values of 139.1 m-equiv l-1 Na and 7.4 m-equiv l-1 K; these values are considered normal. Corresponding values in the unsupplemented group were 60.2 m-equiv l-1 Na and 71.7 m-equiv l-1 K, which are indicative of severe Na deficiency. Levels of this magnitude remained throughout the duration of the experiment. Blood and milk concentrations of Na and K were not affected by Na intake. Urinary levels of Na and K were attered by Na intake but were extremely variable.

The effect of nitrogen and protein supplementation on feed intake, growth and digestive function of steers with different Bos indicus, Bos taurus genotypes when fed a low quality grass hay

1995 ◽  
Vol 46 (6) ◽  
pp. 1121 ◽  
Author(s):  
DW Hennessy ◽  
PJ Kohun ◽  
PJ Williamson ◽  
DA Brown ◽  
JV Nolan
Keyword(s):  
Feed Intake ◽  
Rumen Fluid ◽  
Bos Indicus ◽  
Basal Diet ◽  
Ammonia Concentration ◽  
Protein Supplementation ◽  
Hybrid Vigour ◽  
Protein Nitrogen ◽  
Plasma Urea ◽  
Significant Difference

Two studies were undertaken at Grafton, NSW, to determine the effects of supplementing a subtropical hay diet with a mixture of non-protein nitrogen (urea) and protein (protected casein), on the feed intake and growth of 20 steers of four genotypes (Study I), and on the digestive and metabolic functions of 16 of the steers that were fistulated in the rumen (Study 2). All steers were reared in the one subtropical environment. They consisted of backcross Hereford (H) (H x BH), backcross F1 (BH x BH) and backcross Brahman (B x BH), all of 50% heterosis, and a first-cross F1 of 100% heterosis (BxH). Steers in both studies were confined in pens and offered a basal diet of chaffed pasture hay (digestibility 52f 1.4% and nitrogen [N] content of 6.1 � 0.2 g/kg dry matter [DM]) supplemented with minerals only (low N diet; 8 steers) or with urea or formaldehyde-treated casein and cottonseed meal (high N diet; 12 steers) for 49 days. There were eight steers, for each of the two diets in Study 2, which were fed for 30 days. There was a diet x genotype interaction (P < 0-05) in the daily DM intake (DMI) of hay by steers in Study 1. The mixed N supplement increased ( P < 0.05) DM1 (per kg liveweight) by 14% in HxBH and by 13% in BxBH steers, but there was no significant effect of the supplement on the DM1 of BxH and BHxBH steers. Daily liveweight change was increased (P < 0.05) by the supplement from -30 to 250 (s.e.d � 40) g/steer and there was no significant difference between genotypes. N supplementation increased ( P < 0.05) rumen volume (63 to 87 � 7.6 L) and fluid residence time (491 to 822 � 76.9 min) (P < 0.05) in BHxBH steers, but the increases in other genotypes were not significant. Rumen ammonia concentration (30 to 61 � 3 7 mg N/L) and plasma urea concentration (56 to 94 � 6-0 g N/L) were increased (P < 0.05) by supplementation. Total protozoa density in rumen fluid was greater (P < 0.05) in BxBH than HxBH steers but did not differ significantly between supplemented and unsupplemented steers. The HxBH steers had the lowest density of small entodiniomorph protozoa when N-supplemented, which was less (P < 0.05) than that in BxBH steers which had the greatest density. Supplementation increased (P < 0.05) N retention but only B x BH steers had a positive N balance. These experiments indicated that there are some physiological differences between genotypes. The BxH genotype with the high hybrid vigour had a high DM1 on the low digestibility hay diet without the N supplements and it transferred more urea from the plasma pool to the gut. The backcross steers (HxBH and BxBH) had low DM1 which increased when supplemented. The high content B. indicus steers (BxBH) had positive net retentions of N, but the results indicated that rumen protected proteins may be more usefully fed to steers with a lower B. indicus content.

Feed intake and digestion by Holstein steer calves consuming low-quality grass supplemented with lasalocid or monensin

1993 ◽  
Vol 73 (4) ◽  
pp. 869-879 ◽  
Author(s):  
D. L. Galloway Sr. ◽  
A. L. Goetsch ◽  
A. Patil ◽  
L. A. Forster Jr. ◽  
Z. B. Johnson
Keyword(s):  
Organic Matter ◽  
Feed Intake ◽  
Free Choice ◽  
Volatile Fatty Acids ◽  
Rumen Fluid ◽  
Latin Square ◽  
Neutral Detergent Fiber ◽  
Cereal Grain ◽  
Digestible Organic Matter ◽  
Forage Intake

Holstein steer calves were fed late vegetative bermudagrass or mature bromegrass free choice in three Latin-square experiments to determine influences of ionophore type and level, supplementation with cereal grain, and source of low-quality grass on feed intake and digestion. In exp. 1, neither lasalocid nor monensin given at 0.5 mg kg−1 of body weight (BW) affected intake or digestion with either forage source. In exp. 2, steers received lasalocid or monensin at 0, 0.5 or 1.0 mg kg−1 of BW. Neutral detergent fiber digestibility was not depressed by ionophores and was slightly greater (P < 0.05) for ionophores at 1.0 than at 0.5 mg kg−1 of BW. Digestible organic matter intake with bermudagrass was slightly greater with ionophores at 1.0 than at 0.5 mg kg−1 of BW, but an opposite difference between ionophore levels occurred with bromegrass (ionophore level × forage source interaction; P < 0.07). The concentration of total volatile fatty acids in rumen fluid at 4 h post-feeding was lower (P < 0.05) for monensin than for lasalocid; the acetate/propionate ratio was decreased by ionophores and was lower for monensin than for lasalocid (P < 0.05). In exp. 3, lasalocid at 0.5 mg kg−1 of BW did not affect intake or digestion or interact with supplemental corn (7.2 g kg−1 of BW) or forage source. In conclusion, level of ionophore maximizing digestible organic matter intake may vary with characteristics of source of low-quality forage. However, when present, effects of ionophores on digestibility or energy intake may be relatively small. Key words: Cattle, ionophore, forage, intake, digestion

Effects of addition of urea to a low nitrogen diet on the rumen digestion of a range of roughages

1999 ◽  
Vol 50 (6) ◽  
pp. 1091 ◽  
Author(s):  
R. M. Dixon
Keyword(s):  
Organic Matter ◽  
Synthetic Fibre ◽  
Rumen Fluid ◽  
Ammonia Concentration ◽  
N Content ◽  
Insoluble Organic Matter ◽  
Low Nitrogen

Four steers were given 2 diets consisting of oat hay and molasses which contained either no urea or 4% urea. Sixteen roughages (including cottonwool, straws, alkali-treated straws, and grass and legumes hays) were incubated in synthetic fibre bags in the rumen for 24 h, and the disappearance from the bags of insoluble organic matter (OM) was determined. In steers given molasses containing 4% urea, rumen ammonia concentrations exceeded 100 mg N/Lfor only about 5 h during the 24-h cycle and were <50 mg N/L within about 4 h after feeding. In steers given molasses without urea, rumen ammonia concentration averaged 7 mg N/L. The depression in OM disappearance from synthetic fibre bags due to the low rumen ammonia concentrations, expressed as a percentage of the disappearance at the higher rumen ammonia concentration, ranged among the roughages from 24 to 87%, and was inversely related to the N content of the roughage. In additional experiments the differences in ammonia concentration between rumen fluid sampled from the ventral sac of the rumen and fluid extracted from synthetic fibre bags were small compared with the differences between diets. These results indicated that the effect of low rumen ammonia concentrations on microbial digestion in the rumen varied widely among roughages.

Supplementation of a tropical grass diet with forage legumes and Sapindus saponaria fruits: effects on in vitro ruminal nitrogen turnover and methanogenesis

2003 ◽  
Vol 54 (7) ◽  
pp. 703 ◽  
Author(s):  
H. D. Hess ◽  
L. M. Monsalve ◽  
C. E. Lascano ◽  
J. E. Carulla ◽  
T. E. Díaz ◽  
...  
Keyword(s):  
Organic Matter ◽  
Volatile Fatty Acids ◽  
Rumen Fluid ◽  
Ammonia Concentration ◽  
Calliandra Calothyrsus ◽  
Methane Release ◽  
Arachis Pintoi ◽  
Sapindus Saponaria ◽  
Fermentation Pattern

In two in vitro experiments with the RUSITEC-apparatus, Brachiaria dictyoneura was tested alone and with legumes at dietary proportions of 1/3, 2/3, or 3/3 of Arachis pintoi (Expt 1) and 1/3 of Arachis pintoi, Cratylia argentea, or Calliandra calothyrsus (Expt 2). In Expt 2, all diets were evaluated with and without 80 mg/g diet of Sapindus saponaria fruits. In Expt 1, the stepwise replacement of the grass by A. pintoi curvi-linearly increased rumen fluid concentrations of ammonia, volatile fatty acids, bacteria, and protozoa. Methane release rates were 1.7, 7.3, 8.8, and 9.0�mmol/day. With increasing legume proportion, more organic matter and protein were degraded, the latter being only partially recovered as ammonia. In Expt 2, 1/3 of A. pintoi basically had the same effects as in Expt 1. Cratylia argentea was less effective in modifying the fermentation pattern. In association with a higher nutrient degradation and rumen ammonia concentration, C. argentea and A. pintoi increased methane release to about 3- and 4-fold levels. Calliandra calothyrsus reduced nutrient degradation and methane release per gram of organic matter degraded. Tannins, predominant in C. calothyrsus, might have affected methanogenesis. Sapindus saponaria reduced methanogenesis by 11% on average in grass-alone and legume-supplemented diets.

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