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

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.

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.


2019 ◽  
Vol 97 (8) ◽  
pp. 3550-3561 ◽  
Author(s):  
Jocelyn R Johnson ◽  
Gordon E Carstens ◽  
Wimberly K Krueger ◽  
Phillip A Lancaster ◽  
Erin G Brown ◽  
...  

Abstract The objectives of this study were to examine the relationship between residual feed intake (RFI) and DM and nutrient digestibility, in vitro methane production, and volatile fatty acid (VFA) concentrations in growing beef cattle. Residual feed intake was measured in growing Santa Gertrudis steers (Study 1; n = 57; initial BW = 291.1 ± 33.8 kg) and Brangus heifers (Study 2; n = 468; initial BW = 271.4 ± 26.1 kg) fed a high-roughage-based diet (ME = 2.1 Mcal/kg DM) for 70 d in a Calan-gate feeding barn. Animals were ranked by RFI based on performance and feed intake measured from day 0 to 70 (Study 1) or day 56 (Study 2) of the trial, and 20 animals with the lowest and highest RFI were identified for subsequent collections of fecal and feed refusal samples for DM and nutrient digestibility analysis. In Study 2, rumen fluid and feces were collected for in vitro methane-producing activity (MPA) and VFA analysis in trials 2, 3, and 4. Residual feed intake classification did not affect BW or BW gain (P &gt; 0.05), but low-RFI steers and heifers both consumed 19% less (P &lt; 0.01) DMI compared with high-RFI animals. Steers with low RFI tended (P &lt; 0.1) to have higher DM digestibility (DMD) compared with high-RFI steers (70.3 vs. 66.5 ± 1.6% DM). Heifers with low RFI had 4% higher DMD (76.3 vs. 73.3 ± 1.0% DM) and 4 to 5% higher (P &lt; 0.01) CP, NDF, and ADF digestibility compared with heifers with high RFI. Low-RFI heifers emitted 14% less (P &lt; 0.01) methane (% GE intake; GEI) calculated according to Blaxter and Clapperton (1965) as modified by Wilkerson et al. (1995), and tended (P = 0.09) to have a higher rumen acetate:propionate ratio than heifers with high RFI (GEI = 5.58 vs. 6.51 ± 0.08%; A:P ratio = 5.02 vs. 4.82 ± 0.14%). Stepwise regression analysis revealed that apparent nutrient digestibilities (DMD and NDF digestibility) for Study 1 and Study 2 accounted for an additional 8 and 6%, respectively, of the variation in intake unaccounted for by ADG and mid-test BW0.75. When DMD, NDF digestibility, and total ruminal VFA were added to the base model for Study 2, trials 2, 3, and 4, the R2 increased from 0.33 to 0.47, explaining an additional 15% of the variation in DMI unrelated to growth and body size. On the basis of the results of these studies, differences in observed phenotypic RFI in growing beef animals may be a result of inter-animal variation in apparent nutrient digestibility and ruminal VFA concentrations.


1990 ◽  
Vol 41 (6) ◽  
pp. 1169 ◽  
Author(s):  
DW Hennessy ◽  
PJ Williamson

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


1992 ◽  
Vol 54 (2) ◽  
pp. 275-280 ◽  
Author(s):  
D. Cardenas Garcia ◽  
C. J. Newbold ◽  
H. Galbraith ◽  
J. H. Topps

AbstractThe effect of including full-fat Colombian rice polishings, at 250 or 500 g/kg dry matter (DM) or defatted Colombian rice polishings (at 500 g/kg DM) on the fermentation of a basal diet of dried grass and medium-quality hay, in the rumen simulation technique (Rusitec), was investigated. With diets which contained 0, 0·25, 0·50 full-fat or 0·50 defatted, proportions of rice polishing, values for pH were depressed (7·22, 7·19, 7·11, 7·06 (s.e.d. 0·05)) and total volatile fatty acid concentrations were increased (52·8, 52·5, 75·5, 754 (s.e.d. 2·1) mmol/l) at the high levels of inclusion of rice polishings. Concentrations of ammonia (130, 140, 228, 209 (s.e, d. 64) mg/l) and total bacterial numbers (2·32, 2·70, 3·55, 442 (s.e.d. 0·82) × 108 per ml) were elevated by rice polishings inclusion. Numbers of cellulolytic bacteria (2·52, 1·74, 1·84, 2·10 (s.e.d. 0·60) × 106 per ml) and protozoa (19·8, 16·2, 15·8, 22·2 (s.e.d. 1·51) × 103 per ml were depressed (the latter significantly P < 0·01) by the inclusion offull-fat, but not by defatted, rice polishings.


2004 ◽  
Vol 84 (4) ◽  
pp. 731-735
Author(s):  
M. Ivan and T. Entz

Eighteen rumen cannulated sheep in three groups of six were supplemented with tea seeds at 0 (control), 3 or 6% of the dietary dry matter in a 22-d experiment. Rumen fluid samples were collected on 3 d before and on various days during the experiment. The concentration of protozoa in rumen fluid was not affected by the tea seed supplements (P > 0.05), but the numerical concentration of the Entodinium genera declined by 12% (P < 0.05) and that of cellulolytic protozoa increased by 90% (P < 0.05) due to the 6% tea seed supplement. The associated percentage in the rumen ciliate protozoa population of the cellulolytic protozoa increased (P < 0.05) and that of the Entodinium genera decreased (P < 0.05) due to the 6% supplement. There were no effects (P > 0.05) of the 3% tea seed supplement on the protozoa population parameters. Since ammonia and volatile fatty acid concentrations were not affected (P > 0.05) it was apparent that the tea seed supplements did not influence rumen fermentation. The positive effect of the 6% tea seed supplement on the ciliate protozoa population obtained in the present study was relatively modest. Because the seeds contain astringent properties, higher than 6% dietary supplements of tea seeds can be harmful to animals. It was therefore concluded that tea seeds are of no apparent value as an antiprotozoal dietary component in ruminant production. Key words: Tea seeds, ciliate protozoa, rumen fluid, sheep


1958 ◽  
Vol 38 (2) ◽  
pp. 171-180 ◽  
Author(s):  
J. M. Asplund ◽  
R. T. Berg ◽  
L. W. McElroy ◽  
W. J. Pigden

Procedures are described for determining dry matter losses and for measuring volatile fatty acid production by direct chromatographic separation of acids produced during incubation of finely ground forages in miniature artificial rumen units. The results of preliminary assays done on three samples of unknown digestibility—excellent alfalfa hay, good mixed grass-alfalfa hay, and oat straw—showed that significantly different percentages of dry matter were lost and significantly different amounts of fatty acids were produced when feeds of such diverse quality were fermented. Analysis of the data for two groups of 11 and 6 samples of hay, for which dry matter digestibility coefficients as determined with sheep were available, indicated the existence of a high degree of correlation between dry matter digestibility in vivo and both dry matter loss and fatty acid production in vitro. Differences in assay results were observed when filtered rumen fluid or washed cells from the rumen fluid of sheep fed hay or from sheep fed straw were employed as sources of inocula. Examples of unsolved problems which are pertinent to the appraisal of the efficacy of artificial rumen assays for the estimation of the nutritive value of forages are discussed.


2005 ◽  
Vol 45 (6) ◽  
pp. 665 ◽  
Author(s):  
Y. J. Williams ◽  
G. P. Walker ◽  
P. T. Doyle ◽  
A. R. Egan ◽  
C. R. Stockdale

An experiment was conducted in which cows in early lactation grazed Persian clover (Trifolium resupinatum L.) or perennial ryegrass (Lolium perenne L.)-dominant pastures at low or high pasture allowances in order to determine the effects of pasture type and level of feeding on rumen fermentation patterns. The hypotheses for grazing dairy cows were: (i) the consumption of Persian clover would result in a more rapid rate of degradation and less stable rumen fermentation patterns compared with perennial ryegrass; and (ii) the greater intake of cows grazing at high compared with low pasture allowances would also cause less stable rumen fermentation patterns. Stability of rumen fermentation refers to the level to which rumen fluid pH declines, especially for long periods of a day, indicating that the rumen is not coping with neutralising and/or removing acids. Cows grazing Persian clover had lower (P<0.05) average daily rumen fluid pH (5.7 v. 5.9), molar proportions of acetic acid (68.3 v. 70.6%) and ratios of lipogenic to glucogenic volatile fatty acid (4.6 v. 5.1) in the rumen than those grazing perennial ryegrass. They had higher (P<0.05) rumen fluid ammonia-N (26.3 v. 13.0 mg/100 mL) and total volatile fatty acid (165 v. 134 mmol/L) concentrations and molar proportions of butyric (11.3 v. 10.7%) and propionic (17.2 v. 16.1%) acids than cows grazing perennial ryegrass. Cows grazing at low pasture allowances had a higher (P<0.05) average daily rumen fluid pH (5.9 v. 5.7) and lower rumen fluid ammonia-N (18.6 v. 20.7 mg/100 mL) and total volatile fatty acid (143 v. 156 mmol/L) concentrations than cows grazing at high pasture allowances. Cows given Persian clover at the high allowance had a rumen fluid pH less than 6.0 for the entire day while rumen fluid pH was below 6.0 for at least 15 h of the day on all the other treatments. There was no effect (P>0.05) of pasture allowance on the degradation rate of perennial ryegrass dry matter, but the higher allowance of Persian clover resulted in the highest (P<0.05) rate of degradation of dry matter compared with either ryegrass treatment or the low allowance of Persian clover. The effective dry matter degradability of Persian clover was greater (P<0.05) than that of perennial ryegrass, and the effective dry matter degradability of herbage in cows grazing at low allowances was greater (P<0.05) than at higher allowances. However, future research should consider neutral detergent fibre degradation in grazing dairy cows with low rumen fluid pH levels.


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