Effects of the composition of grass silages on milk production and nitrogen utilization by dairy cows

1996 ◽  
Vol 62 (1) ◽  
pp. 25-34 ◽  
Author(s):  
R. J. Dewhurst ◽  
A. M. Mitton ◽  
N. W. Offer ◽  
C. Thomas
Keyword(s):  
Dairy Cows ◽  
Milk Protein ◽  
Metabolizable Energy ◽  
Protein Yield ◽  
Microbial Protein ◽  
Purine Derivative ◽  
Unit Increase ◽  
Protein Feeding ◽  
Independent Effects ◽  
To Receive

AbstractSixteen varied grass silages metabolizable energy (ME): 9·76 to 11·99 MJ/kg ethanol-corrected toluene dry matter (TDM); crude protein (CP: 149 to 211 g/kg TDM; lactic acid: 3·5 to 134·7 g/kg TDM; butyric acid 0·4 to 46·7 g/kg TDM) were offered ad libitum to early-lactation dairy cows (12 per experiment) along with a fixed allocation of 7 kg/day of a standard concentrate. Four silages were offered in each of four incomplete change-over design experiments with three 21-day periods. This design meant that each cow was allocated to receive three of the four silages evaluated in that experiment. ME intake ranged from 108 to 262 MJ/day (mean 177 (s.d. 30·2)). Similar variation was obtained with milk yields (mean 26·5 (s.d. 4·36) kg/day), fat content (mean 37·7 (s.d. 5·60) g/kg) and protein content (mean 29·0 (s.d. 2·36) g/kg). Urinary purine derivative/creatinine ratio (PD/C), an index of microbial protein measured in spot samples (two per day) averaged 2·92 (s.d. 0·757) mol/mol. Allantoin made up an almost constant molar proportion of PD excretion (mean 0·876 (s.d. 0·0377)), with a small but significant (P < 0·001) decline of 0·0132 (s.d. 0·003) per unit increase in PD/C.Maximal utilization of silage nitrogen occurred with silages having higher ME and lower CP concentrations. Urinary PD/C suggested that microbial protein yield varied in a way which would not be predicted in current schemes and that it was a major source of variation in milk protein yield under the conditions of the present experiment. Principal components regression confirmed independent effects of ME supply and MP supply (indexed by urinary PD/C) on milk protein yield. Further work should pursue the possibility of using the urinary PD/C technique to refine protein feeding at the farm level.

scholarly journals Effect of Rumen Available Protein, Amimo Acids and Carbohydrates on Microbial Protein Synthesis, Amino Acid Flow and Performance of High Yielding Cows

1993 ◽  
Author(s):  
Gabriella A. Varga ◽  
Amichai Arieli ◽  
Lawrence D. Muller ◽  
Haim Tagari ◽  
Israel Bruckental ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Amino Acid ◽  
Dairy Cows ◽  
Milk Protein ◽  
Protein Yield ◽  
Microbial Protein ◽  
Feeding Frequency ◽  
Rumen Undegradable Protein ◽  
And Performance

The effect of rumen available protein amino acids and carbohydrates on microbial protein synthesis, amino acid flow and performance of high yielding dairy cows was studied. A significant relationship between the effective degradabilities of OM in feedstuffs and the in vivo ruminal OM degradation of diets of dairy cows was found. The in situ method enabled the prediction of ruminal nutrients degradability response to processing of energy and nitragenous supplements. The AA profile of the rumen undegradable protein was modified by the processing method. In a continuous culture study total N and postruminal AA flows, and bacterial efficiency, is maximal at rumen degradable levels of 65% of the CP. Responses to rumen degradable non carbohydrate (NSC) were linear up to at least 27% of DM. Higher CP flow in the abomasum was found for cows fed high ruminally degradable OM and low ruminally degradable CP diet. It appeared that in dairy cows diets, the ratio of rumen degradable OM to rumenally degradable CP should be at least 5:1 in order to maximize postruminal CP flow. The efficiency of microbial CP synthesis was higher for diets supplemented with 33% of rumen undegradable protein, with greater amounts of bacterial AA reaching the abomasum. Increase in ruminal carbohydrate availability by using high moisture corn increased proportions of propionate, postruminal nutrients flow, postruminal starch digestibility, ruminal availability of NSC, uptake of energy substrates by the mammory gland. These modifications resulted with improvement in the utilization of nonessential AA for milk protein synthesis, in higher milk protein yield. Higher postruminal NSC digestibility and higher efficiency of milk protein production were recorded in cows fed extruded corn. Increasing feeding frequency increased flow of N from the rumen to the blood, reduced diurnal variation in ruminal and ammonia, and of plasma urea and improved postruminal NSC and CIP digestibility and total tract digestibilities. Milk and constituent yield increased with more frequent feeding. In a study performed in a commercial dairy herd, changes in energy and nitrogenous substrates level suggested that increasing feeding frequency may improve dietary nitrogen utilization and may shift metabolism toward more glucogenesis. It was concluded that efficiency of milk protein yield in high producing cows might be improved by an optimization of ruminal and post-ruminal supplies of energy and nitrogenous substrates. Such an optimization can be achieved by processing of energy and nitrogenous feedstuffs, and by increasing feeding frequency. In situ data may provide means for elucidation of the optimal processing conditions.

Diurnal variation in urinary purine derivative excretion of dairy cows on different feeding patterns

1993 ◽  
Vol 1993 ◽  
pp. 177-177
Author(s):  
J.M. Moorby ◽  
R.J. Dewhurst
Keyword(s):  
Diurnal Variation ◽  
Dairy Cows ◽  
Feed Intake ◽  
Protein Yield ◽  
Microbial Protein ◽  
Purine Derivatives ◽  
Feeding Patterns ◽  
Purine Derivative ◽  
Urinary Creatinine ◽  
Lactating Dairy Cows

Diurnal variation in the yield of microbial protein from the rumen may limit the use of urinary purine derivatives (PD) to estimate microbial protein yield from the rumen when assessed using spot samples. Chen, Grubic, Ørskov and Osuji (1992) found only small differences in the urinary PD excretion in young steers, and even less variation when PD excretion was estimated as a ratio to urinary creatinine. Lactating dairy cows have a much higher feed intake than steers and as a consequence may exhibit greater diurnal variation in urinary PD excretion. An examination of data from three experiments was undertaken to assess the effects of diurnal variation in rumen microbial protein yield on urinary PD excretion.

Relationship between urinary purine derivative excretion and milk protein yield by dairy cows

1995 ◽  
Vol 1995 ◽  
pp. 124-124
Author(s):  
R.J. Dewhurst ◽  
R.T. Evans ◽  
V.J. Theobald ◽  
M.A. Neville ◽  
S. Miles ◽  
...  
Keyword(s):  
Milk Protein ◽  
Protein Yield ◽  
Microbial Protein ◽  
Purine Derivatives ◽  
Purine Derivative ◽  
Non Invasive ◽  
Food Research ◽  
Metabolisable Energy ◽  
The Uk ◽  
On Farm

The ability to predict microbial protein yield in any feeding situation is important in maximising the utilisation of feed nitrogen since it will guide decisions as to whether to take steps to improve rumen function or provide supplementary undegradable protein (UDP). The UK Metabolisable Protein (MP) system (Agricultural and Food Research Council, 1992) predicts the yield of microbial protein from the rumen according to the supply of Fermentable Metabolisable Energy (FME). This has led to an improved understanding of responses seen on farms, though there remains uncertainty about microbial protein yield. The excretion of purine derivatives (PD), allantoin and uric acid, in urine has been used as a non-invasive index of microbial protein flow to the duodenum (Chen et al, 1990) and might form the basis of an on-farm diagnostic test. In earlier work, with spot sampling of urine (Dewhurst et al, 1994), we have shown a relationship between milk protein yield and urinary PD excretion; the current work extended these studies by utilising 6-day total collections of urine.

Evaluation of milk allantoin excretion as an index of microbial protein supply in lactating dairy cows

1998 ◽  
Vol 67 (3) ◽  
pp. 371-385 ◽  
Author(s):  
K. J. Shingfield ◽  
N. W. Offer
Keyword(s):  
Dairy Cows ◽  
Milk Yield ◽  
Dry Matter ◽  
Metabolizable Energy ◽  
Cow Milk ◽  
Barley Straw ◽  
Microbial Protein ◽  
Fresh Weight ◽  
Purine Derivative ◽  
Protein Supply

AbstractThe potential of milk allantoin as an index ofmicrobial protein supply was evaluated in two experiments conducted with 12 multiparous Holstein-Friesian dairy cows that examined the effects of altering the supply of metabolizable energy (ME) and fermentable metabolizable energy (FME). In the first experiment, late lactation cows received a 14·3 kg dry matter (DM) per day basal diet consisting of (g/kg DM) chopped barley straw (415), soya-bean meal (322), molassed sugar-beet pulp (197), molasses (33), urea (17) and a vitamin and mineral supplement (17) for a 21-day co-variance period. During four 16-day periods, six treatments were allocated randomly to cows, consisting of potato starch (1, 2 or 3 kg DM per day) or fat supplements (0·64, 1·27 or 1·91 kg DM per day). In the second experiment, early lactation cows received 40 kg/day (fresh weight, (FW)) of silage (307 g/kg toluene-corrected dry matter, 149 g/kg DM crude protein and 11·6 MJ/kg ME). During three 21-day periods, four treatments were evaluated consisting of supplements of either 4·1 (LI) or 8·1 (12) kg fresh weight per day of a low fat concentrate (acid hydrolysis ether extract (AHEE) 45 g/kg DM) or 3·8 (HI) or 7·5 (H2) kg fresh weight per day of a high fat concentrate (AHEE 110 g/kg DM). Both experiments showed individual cow milk allantoin concentration or excretion to be poorly correlated with urinary purine derivative excretion or calculated microbial protein supply. Use of treatment mean (TM) values dramatically improved these relationships. For pooled TM (no. = 10) values from both experiments, close relationships existed between milk allantoin excretion and concentration with milk yield (r values 0·991 and 0·883, respectively). Auto-correlation with milk yield appeared to account for milk allantoin excretion and concentration being highly correlated with urinary purine derivative excretion (r values 0·908 and 0·934, respectively) and calculated microbial protein supply (r values 0·938 and 0·945, respectively). Current experimental data indicates that measurement of milk allantoin is not a reliable indicator of microbial protein supply for individual cows.

scholarly journals THE NUTRITIONAL BALANCE OF EARLY LACTATION DAIRY COWS GRAZING IN INTENSIVE SILVOPASTORAL SYSTEMS

2017 ◽  
Vol 18 (0) ◽  
Author(s):  
Elisa Sierra Montoya ◽  
Julian David Chará ◽  
Rolando Barahona-Rosales
Keyword(s):  
Dairy Cows ◽  
Negative Energy ◽  
Protein Supplementation ◽  
Metabolizable Energy ◽  
Early Lactation ◽  
Tropical Conditions ◽  
Forage Intake ◽  
Daily Milk Yield ◽  
To Receive ◽  
Daily Milk

Abstract A study was carried out to estimate the balance of metabolizable protein (MP), metabolizable energy (ME), calcium, and phosphorus in 12 recently calved (RC) and early lactation (EL, 42 - 50 days after calving) Gyr x Holstein dairy cows grazing in a Leucaena leucocephala and Cynodon plectostachyus intensive silvopastoral system (ISS) and receiving energy and protein supplementation. Dry matter (DM) availability from the grazing paddocks, nutrients offered and their balance were estimated. On average, the available forage DM per animal.day-1 was 44.7 kg for C. plectostachyus and 11.8 kg for L. leucocephala. EL cows had greater requirements of MP, ME, and minerals than RC cows. In RC cows, ME, MP, and mineral requirements were supplied by the total diet, while EL cows exhibited a negative energy balance. For both RC and EL cows, ME was the limiting dietary factor, whereas MP and P were found to be in excess. If cows were only to receive ISS forages with no supplementation, estimated daily milk yield would be 10 and 12 litters for RC and EL cows, respectively. Under tropical conditions, based on ISS forage intake, RC and EL cows can meet most of their ME, MP, calcium, and phosphorous requirements.

Effect of Metabolisable Protein on intake of grass silage and milk protein yield in dairy cows.

1994 ◽  
Vol 1994 ◽  
pp. 113-113 ◽  
Author(s):  
J.R. Newbold ◽  
B.R. Cottrill ◽  
R.M. Mansbridge ◽  
J.S. Blake
Keyword(s):  
Dairy Cows ◽  
Milk Protein ◽  
Live Weight ◽  
Protein Yield ◽  
Holstein Cows ◽  
Grass Silage ◽  
Lactating Dairy Cows ◽  
Ad Libitum ◽  
Few Data

Few data are available to evaluate the Metabolisable Protein (MP) System (AFRC, 1992) as an aid to ration formulation for dairy cows. Responses of lactating dairy cows to MP were evaluated in two experiments.In Experiment One, groups of 10 Holstein cows were offered grass silage ad libitum and 7kg DM/d of one of six (treatments 1-6) compound foods from 39d after calving, for eight weeks. All rations were isoenergetic, assuming silage intake of 11kg DM/d (typical for the herd). Ratios between MP supply (calculated from in situ protein degradability measurements) and requirement (calculated for a standard cow: 565kg live weight, 281 milk/d, 40g/kg butterfat, 33g/kg milk protein, liveweight change =0kg/d) were 1.00, 1.02, 1.06, 1.06, 1.1 and 1.17 for treatments 1-6, respectively.

The effects of methionine supplementation upon milk composition and production of forage-fed dairy cows

1999 ◽  
Vol 79 (2) ◽  
pp. 235-241 ◽  
Author(s):  
D. Pacheco-Rios ◽  
W. C. McNabb ◽  
J. P. Hill ◽  
T. N. Barry ◽  
D. D. S. Mackenzie
Keyword(s):  
Dairy Cows ◽  
Milk Fat ◽  
Milk Protein ◽  
Whey Proteins ◽  
Protein Composition ◽  
Milk Composition ◽  
Metabolizable Energy ◽  
Protein Nitrogen ◽  
Methionine Supplementation ◽  
And Control

Two experiments (mid- and late lactation) were conducted to test whether methionine (Met) limited milk production in Friesian cows fed sole diets of fresh perennial ryegrass–white clover pasture. In mid-lactation (exp. 1), 26 cows were assigned to one of three treatments: ruminally protected oral DL-Met (15 g d−1), continuous intrajugular infusion of L-Met (15 g d–1) and control. Twelve animals from exp. 1 were used during late lactation (exp. 2) and distributed in two experimental groups: ruminally protected oral DL-Met (15 g d−1) and control. Dry matter, metabolizable energy, crude protein and Met intakes, milk yield and composition and blood Met, cysteine and urea were measured. Oral and intravenous Met supplementation increased blood Met concentration by 50–90% compared with controls. Met supplementation did not alter the concentration of milk fat, protein or lactose in either experiment. Met supplementation had no significant effects on yields of fat, lactose, casein, whey proteins or non-protein nitrogen during mid-lactation. In late lactation, Met supplementation did not affect milk protein composition or yield of milk components, with exception of a decrease (P < 0.05) in the yield of β -casein. Intravenous Met supplementation increased (P < 0.05) the efficiency of conversion of pasture N to milk protein in mid-lactation. Key words: Dairy cows, methionine, ruminally protected methionine, milk protein, casein, fresh pasture diets

scholarly journals Assessment of rumen bacteria in dairy cows with varied milk protein yield

2019 ◽  
Vol 102 (6) ◽  
pp. 5031-5041 ◽  
Author(s):  
M.Y. Xue ◽  
H.Z. Sun ◽  
X.H. Wu ◽  
L.L. Guan ◽  
J.X. Liu
Keyword(s):  
Dairy Cows ◽  
Milk Protein ◽  
Protein Yield ◽  
Rumen Bacteria

Milk allantoin excretion in relation to Fermentable Metabolisable Energy supply over a 26 to 33 kg/d range of milk yields in Holstein/Friesian dairy cows

1996 ◽  
Vol 1996 ◽  
pp. 90-90
Author(s):  
K.J. Shingfield ◽  
N.W. Offer
Keyword(s):  
Dairy Cows ◽  
Narrow Range ◽  
Microbial Protein ◽  
Purine Derivative ◽  
Spot Urine ◽  
Holstein Friesian ◽  
Metabolisable Energy ◽  
Total Urine ◽  
Protein Supply ◽  
On Farm

Widescale on-farm assessment of microbial protein supply by urinary purine derivative (PD) excretion in dairy cows is restricted by the necessity for a total urine collection. Evaluation of urinary creatinine (c) excretion as a marker of urinary output, indicated the use of spot urine sampling to be unreliable (Shingfield et al 1995a). Further investigations have indicated that, based on mean treatment measurements, milk allantoin excretion and concentration are closely correlated with fermentable metabolisable energy (FME) supply, over a narrow range of milk yields (Shingfield et al 1995b). The current experiment evaluates the potential of milk allantoin excretion and concentration as a index of microbial protein supply over a much wider range of milk yields.

Sign in / Sign up

Export Citation Format

Share Document