Influence of dietary rumen-degradable protein supply on rumen characteristics and carbohydrate fermentation in beef cattle offered high-grain diets

2000 ◽  
Vol 88 (1-2) ◽  
pp. 59-77 ◽  
Author(s):  
S.M Martı́n-Orue ◽  
J Balcells ◽  
F Vicente ◽  
C Castrillo
Keyword(s):  
Beef Cattle ◽  
Carbohydrate Fermentation ◽  
Protein Supply ◽  
Degradable Protein

The effect of metabolisable protein supply at constant energy intake on the liveweight gain of bovines

1995 ◽  
Vol 1995 ◽  
pp. 154-154
Author(s):  
P N Johnson ◽  
E R Deaville
Keyword(s):  
Beef Cattle ◽  
Theoretical Basis ◽  
Initial Step ◽  
Official Method ◽  
Constant Energy ◽  
Protein Requirements ◽  
Metabolisable Energy ◽  
The Uk ◽  
Protein Supply ◽  
Degradable Protein

The metabolisable protein (MP) system (AFRC, 1992), adopted as the official method of describing the protein requirements of ruminants in the UK, introduces the concepts of effective rumen degradable protein (ERDP), digestible undegradable protein (DUP) and fermentable metabolisable energy (FME). For effective protein rationing, the aim is to match the supply of FME and ERDP, and to supply further protein requirements as DUP. This should lead to a better balance of energy and protein to meet the requirements of the animal. Diets are likely to have lower total protein contents than those presently available, leading to reductions in diet costs and nitrogen (N) excretion. The MP system was constructed primarily on a theoretical basis and this experiment was an initial step in validating it for beef cattle.

The effect of metabolisable protein supply at constant energy intake on the liveweight gain of bovines

1995 ◽  
Vol 1995 ◽  
pp. 154-154
Author(s):  
P N Johnson ◽  
E R Deaville
Keyword(s):  
Beef Cattle ◽  
Theoretical Basis ◽  
Initial Step ◽  
Official Method ◽  
Constant Energy ◽  
Protein Requirements ◽  
Metabolisable Energy ◽  
The Uk ◽  
Protein Supply ◽  
Degradable Protein

The metabolisable protein (MP) system (AFRC, 1992), adopted as the official method of describing the protein requirements of ruminants in the UK, introduces the concepts of effective rumen degradable protein (ERDP), digestible undegradable protein (DUP) and fermentable metabolisable energy (FME). For effective protein rationing, the aim is to match the supply of FME and ERDP, and to supply further protein requirements as DUP. This should lead to a better balance of energy and protein to meet the requirements of the animal. Diets are likely to have lower total protein contents than those presently available, leading to reductions in diet costs and nitrogen (N) excretion. The MP system was constructed primarily on a theoretical basis and this experiment was an initial step in validating it for beef cattle.

scholarly journals 127 Predicting Dry Matter Intake of Gestating and Lactating Beef Cows

2020 ◽  
Vol 98 (Supplement_2) ◽  
pp. 58-58
Author(s):  
Megan A Gross ◽  
Claire Andresen ◽  
Amanda Holder ◽  
Alexi Moehlenpah ◽  
Carla Goad ◽  
...  
Keyword(s):  
Beef Cattle ◽  
Milk Yield ◽  
Feed Intake ◽  
Beef Cows ◽  
Multiple Regression Equation ◽  
Validation Data ◽  
Data Set ◽  
Lactating Cows ◽  
Downward Bias ◽  
Protein Supply

Abstract In 1996, the NASEM beef cattle committee developed and published an equation to estimate cow feed intake using results from studies conducted or published between 1979 and 1993 (Nutrient Requirements of Beef Cattle). The same equation was recommended for use in the most recent version of this publication (2016). The equation is sensitive to cow weight, diet digestibility and milk yield. Our objective was to validate the accuracy of this equation using more recent published and unpublished data. Criteria for inclusion in the validation data set included projects conducted or published within the last ten years, direct measurement of forage intake, adequate protein supply, and pen feeding (no tie stall or metabolism crate data). The validation data set included 29 treatment means for gestating cows and 26 treatment means for lactating cows. Means for the gestating cow data set was 11.4 ± 1.9 kg DMI, 599 ± 77 kg BW, 1.24 ± 0.14 Mcal/kg NEm per kg of feed and lactating cow data set was 14.5 ± 2.0 kg DMI, 532 ± 116.3 kg BW, and 1.26 ± 0.24 Mcal NEm per kg feed, respectively. Non intercept models were used to determine equation accuracy in predicting validation data set DMI. The slope for linear bias in the NASEM gestation equation did not differ from 1 (P = 0.07) with a 3.5% positive bias. However, when the NASEM equation was used to predict DMI in lactating cows, the slope for linear bias significantly differed from 1 (P < 0.001) with a downward bias of 13.7%. Therefore, a new multiple regression equation was developed from the validation data set: DMI= (-4.336 + (0.086427 (BW^.75) + 0.3 (Milk yield)+6.005785(NEm)), (R-squared=0.84). The NASEM equation for gestating beef cows was reasonably accurate while the lactation equation underestimated feed intake.

scholarly journals 84 Effect of incorporating forage pea (c.v. Pisium sativum L.) into cereal hay on ruminal fermentation and apparent digestibility when fed to beef heifers

2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 73-73
Author(s):  
Alex Pursley ◽  
Bill Biligetu ◽  
Tom Warkentin ◽  
Bart Lardner ◽  
Greg B Penner
Keyword(s):  
Beef Cattle ◽  
Factorial Design ◽  
Latin Square ◽  
Nitrogen Retention ◽  
Apparent Digestibility ◽  
Ruminal Fermentation ◽  
Microbial Protein ◽  
Beef Heifers ◽  
Inclusion Rate ◽  
Protein Supply

Abstract The objective was to evaluate the effect of inclusion rate of pea hay in barley and oat hay when fed to beef cattle. Six ruminally-cannulated heifers (407 ± 38 kg) were used in a 6 × 6 Latin square with a 2 × 3 factorial design and 25-d periods. Treatments included barley or oat hay blended with pea hay to achieve inclusion rates of 0, 15, or 30% (DM basis). Pea inclusion increased DMI (P = 0.03) by 0.75 kg/d, and generally reduced sorting (P ≤ 0.006) against NDF and ADF compared to the cereal-only treatments. Pea inclusion decreased CP digestibility by 2.87% relative to cereal-only treatments, but did not affect the predicted microbial protein supply or nitrogen retention (P ≥ 0.77). Pea inclusion did not affect total ruminal SCFA concentration, but increased the molar proportions of acetate and butyrate and decreased the molar proportion of propionate (P ≤ 0.01). While cereal type did not affect DMI (P = 0.36) or total SCFA concentration (P = 0.61), use of oat hay improved DM digestibility (67.73 vs. 63.22% for oat and barley, respectively; P < 0.001) and increased nitrogen retention (P = 0.03) when compared to barley. Overall, incorporating pea into cereal hay increased DMI, reduced CP digestibility, and altered ruminal fermentation.

An evaluation of prediction equations incorporated in a computer program to ration beef cattle

1988 ◽  
Vol 46 (2) ◽  
pp. 169-179 ◽  
Author(s):  
H. D. St C. Neal ◽  
M. Gill ◽  
J. France ◽  
A. Spedding ◽  
S. Marsden
Keyword(s):  
Beef Cattle ◽  
Computer Program ◽  
Agricultural Research ◽  
Live Weight ◽  
Metabolizable Energy ◽  
Mathematical Basis ◽  
Agricultural Research Council ◽  
The Mean ◽  
Protein Supply ◽  
On Farm

AbstractEquations for the prediction of forage dry-matter intake, metabolizable energy (ME), rumen degradable protein and undegraded protein, based on those in the current Agricultural Research Council system, were incorporated into a computer program designed to be used by livestock advisors for on-farm rationing of beef cattle. The predictions of silage intake and live-weight gain are compared with experimental data.Voluntary intake of grass silage was generally over-estimated by the program by proportionately at least 0·06, with a root mean square error of ±0·18 of the mean observed silage intake for the all-silage rations. The prediction of ME requirement for observed production had an error of +0·15 of average ME intake but the calculations of ME intake were themselves dependent on the predictions of the ME concentrations of the silages and supplements. Similarly the comparison of protein supply with requirement was highly dependent on the value assigned to N-degradability. However, the program can be used to assess how changes in the input values would affect ration formulation.The mathematical basis of the program is described in the Appendix.

Responses of British Friesian steers with or without implants of oestradiol-17β to undegradable dietary protein

1988 ◽  
Vol 46 (2) ◽  
pp. 181-193 ◽  
Author(s):  
J. R. Newbold ◽  
P. C. Garnsworthy ◽  
P. J. Buttery ◽  
D. J. A. Cole ◽  
W. Haresign
Keyword(s):  
Agricultural Research ◽  
Live Weight ◽  
Soya Bean ◽  
Metabolizable Energy ◽  
Protein Nutrition ◽  
Agricultural Research Council ◽  
Bean Meal ◽  
Soya Bean Meal ◽  
Protein Supply ◽  
Degradable Protein

AbstractThe ability of the protein nutrition scheme proposed by the Agricultural Research Council (ARC, 1980, 1984) to predict responses to protein supply was examined in two experiments. In experiment 1, groups of nine British Friesian steers implanted with oestradiol-17β and nine non-implanted steers were fed from 133 to 300 kg live weight on each of four all-concentrate diets (metabolizable energy (ME) = 12 MJ/kg dry matter (DM)) containing ratios of soya-bean meal and formaldehyde-treated soya-bean meal such that undegradable protein (UDP) concentration was 19, 25, 32 or 42 g/kg DM. Rumen degradable protein (RDP) concentration was relatively constant (111 to 116 g/kg DM). Implantation did not affect DM intake (DMI, g/kg M0·75). Both live-weight gain (LWG) and food conversion efficiency (FCE) (LWG/DMI) were greater (P < 0·05) for the implanted cattle (LWG = 1·41 (s.e. 0·04) kg/day; FCE = 0·24 (s.e. 0·02)) than for the non-implanted cattle (LWG = 1·23 (s.e. 0·05) kg/day; FCE = 0·22 (s.e. 0·02)). There were no dietary effects on either DMI or FCE. In the non-implanted steers, UDP did not affect LWG but, for the implanted steers, there were positive, linear responses in LWG to both UDP concentration (P = 0·048) and UDP intake (P = 0·026). In experiment 2, groups of eight implanted steers were fed from 132 to 300 kg live weight on each of six diets (ME = 12 MJ/kg DM, soya-bean meal and formaldehyde-treated soya-bean meal as chief protein sources) supplying 17, 26, 34, 39, 54 and 82 g UDP per kg DM and concentrations of RDP up to 1·5 times ARC recommendations. There was no effect of UDP on either DMI or FCE but positive, linear responses in LWG to both UDP concentration (P = 0·019) and UDP intake (P = 0·010). In both experiments, mean DMI exceeded that predicted by ARC (1980) (P < 0·05). LWG predicted by the ME system and the ARC protein scheme was not significantly different from observed LWG for non-implanted steers, but was an underestimate of observed LWG for implanted steers (P = 0·002 in experiment 1, P < 0·001 in experiment 2). Observed responses in LWG to UDP concentration were also poorly predicted (regressions of observed on predicted LWG: experiment 1, r2 = 0·12, residual s.d. = 0·126; experiment 2, r2 = 0·004, residual s.d. = 0·119). It was concluded that oestradiol-17p has significant effects on responses in LWG to UDP, which are not predicted by the current ARC (1980, 1984) protein nutrition scheme.

The response of store lambs to protein supplementation of alkali treated straw based diets

1984 ◽  
Vol 1984 ◽  
pp. 11-11
Author(s):  
Susan M. Marchment ◽  
E.L. Miller
Keyword(s):  
Food Intake ◽  
Microbial Activity ◽  
Dietary Protein ◽  
Protein Supplementation ◽  
Factors Affecting ◽  
Chemical Factors ◽  
Protein Supply ◽  
Physical And Chemical ◽  
Voluntary Food Intake ◽  
Degradable Protein

Factors affecting voluntary food intake (VFI) in ruminants are well documented and suggest that both physical and chemical factors are involved. An understanding of VFI controls is important for the formulation of economical diets to achieve maximum levels of production.The effect of protein supply on VFI is unclear. While the need for rumen degradable protein (RDP) to maximise microbial activity and consequently VFI is clearly established ARC (1960), the effect of undegraded dietary protein (UDP) on VFI is equivocal.

Response of lactating ewes grazing grass to variations in effective rumen degradable protein and digestible undegradable protein supply from concentrate supplements

2000 ◽  
Vol 71 (2) ◽  
pp. 369-379 ◽  
Author(s):  
R. G. Wilkinson ◽  
L. A. Sinclair ◽  
J. Powles ◽  
C. M. Minter
Keyword(s):  
Protein Synthesis ◽  
Milk Fat ◽  
Solid Phase ◽  
Milk Composition ◽  
Early Summer ◽  
Microbial Protein ◽  
Microbial Protein Synthesis ◽  
Herbage Intake ◽  
Protein Supply ◽  
Degradable Protein

AbstractThe response of lactating ewes grazing grass to variations in effective rumen degradable protein (ERDP) and digestible undegradable protein (DUP) supply from concentrates was investigated. During the spring and early summer of 1993, 36 Friesland and 12 Finn Dorset ewes were offered continuous access to permanent pasture (Lolium perenne) and allocated to one of six concentrates (1·2 kg/day) formulated to be iso-energetic and to supply 149 (H), 126 (M) or 103 (L) g ERDP and 70 (A) or 45 (B) g DUP per kg dry matter (DM) in a 3 ✕ 2 factorial design. Herbage intake was estimated using the n-alkane technique and herbage samples obtained for analysis. Ewe milk yields, milk composition, live weights (LW) and condition scores (CS) were recorded weekly. The DM and nitrogen degradability characteristics of the grass samples and concentrates were determined using four Friesland wether lambs fitted with permanent rumen cannulae. Throughout the experiment the grass ERDP: FME ratio was lower than the optimum for maximal microbial protein synthesis. However, using a rumen solid phase outflow rate of 0·05 per h, estimated concentrate ERDP and DUP supplies were similar to those predicted. Increasing concentrate ERDP supply had no effect on herbage intake or LW and CS change but reduced milk fat concentration (P < 0·05) and increased milk lactose concentration (P < 0·05) and the yields of milk (P < 0·01), protein (P < 0·05) and lactose (P < 0·01). There were no significant effects of concentrate DUP supply. In conclusion, it is suggested that concentrate ERDP increased microbial protein synthesis and metabolizable protein supply, a proportion of which may have been deaminated to provide precursors for milk lactose synthesis, such that the marginal response in milk protein yield was 0·210.

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