scholarly journals Milk protein yield and mammary metabolism are affected by phenylalanine deficiency but not by threonine or tryptophan deficiency

2016 ◽  
Vol 99 (4) ◽  
pp. 3144-3156 ◽  
Author(s):  
L. Doepel ◽  
I.I. Hewage ◽  
H. Lapierre
Keyword(s):  
Milk Protein ◽  
Protein Yield ◽  
Mammary Metabolism

scholarly journals Post-ruminal supplies of glucose and casein, but not acetate, stimulate milk protein synthesis in dairy cows through differential effects on mammary metabolism

2020 ◽  
Vol 103 (7) ◽  
pp. 6218-6232
Author(s):  
M.A.C. Danes ◽  
M.D. Hanigan ◽  
S.I. Arriola Apelo ◽  
J.D.L. Dias ◽  
M.A. Wattiaux ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Dairy Cows ◽  
Milk Protein ◽  
Differential Effects ◽  
Mammary Metabolism

scholarly journals Addition of glycerol to lactating cow diets stimulates dry matter intake and milk protein yield to a greater extent than addition of corn grain

2017 ◽  
Vol 100 (8) ◽  
pp. 6139-6150 ◽  
Author(s):  
D.L. Bajramaj ◽  
R.V. Curtis ◽  
J.J.M. Kim ◽  
M. Corredig ◽  
J. Doelman ◽  
...  
Keyword(s):  
Dry Matter ◽  
Milk Protein ◽  
Protein Yield ◽  
Dry Matter Intake ◽  
Corn Grain

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.

Responses of the bovine mammary glands to absorptive supply of single amino acids

2003 ◽  
Vol 83 (3) ◽  
pp. 341-355 ◽  
Author(s):  
J. P. Cant ◽  
R. Berthiaume ◽  
H. Lapierre ◽  
P. H. Luimes ◽  
B. W. McBride ◽  
...  
Keyword(s):  
Amino Acids ◽  
Blood Flow ◽  
Amino Acid ◽  
General Circulation ◽  
Milk Protein ◽  
Mammary Glands ◽  
Protein Yield ◽  
Yield Response ◽  
Peripheral Tissues ◽  
Energy Metabolites

In this review, we discuss the mechanismsof responses of various tissues of the lactating dairy cow, particularly the mammary glands, to perturbations in supply of single amino acids that result in observed milk protein yields. Additions of methionine, lysine, histidine or leucine to the absorptive supply cause arterial concentrations of these amino acids to increase, mammary extractions to drop and mammary blood flow to decrease. Single subtractions of essential amino acids have the opposite effect. Changes in mammary blood flow that have been recorded can be explained as attempts by the mammary glands to restore intracellular ATP balance in the face of altered concentrations of energy metabolites in the general circulation. In a quantitative sense, milk protein yield is relatively insensitive to fluctuations in arterial amino acid concentrations but can be stimulated by any one of a number of amino acids. In this context, it is suggested that the designation of a limiting amino acid is not appropriate to the purpose of predicting milk protein yield. Rather, milk protein synthesis appears to operate at a predetermined rate set by external communications of milk withdrawal rate, physiological state and overall nutritional status. Utilization of amino acids (AA) by splanchnic and peripheral tissues, in coordination with the mammary setpoint, offsets imperfections in the dietary AA supply. How strongly an individual AA influences the mammary setpoint, arterial concentrations of energy metabolites, and mammary AA transport capacity will determine the magnitude of the milk protein yield response when its absorptive supply is changed. Key words: Dairy cows, milk protein, amino acid

scholarly journals Associations Between Winter Herd Management Factors and Milk Protein Yield in Ontario Dairy Herds

1997 ◽  
Vol 80 (11) ◽  
pp. 2790-2802 ◽  
Author(s):  
J.M. Sargeant ◽  
K.D. Lissemore ◽  
S.W. Martin ◽  
K.E. Leslie ◽  
B.W. McBride
Keyword(s):  
Milk Protein ◽  
Protein Yield ◽  
Dairy Herds ◽  
Herd Management ◽  
Management Factors

RESPONSE OF LACTATING COWS TO THE INTRAVENOUS INFUSION OF AMINO ACIDS

1972 ◽  
Vol 52 (2) ◽  
pp. 377-384 ◽  
Author(s):  
L. J. FISHER
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Milk Production ◽  
Milk Protein ◽  
Corn Silage ◽  
Protein Yield ◽  
Plasma Amino Acids ◽  
Lactating Cows ◽  
Limiting Amino Acid ◽  
High Level

High, low, and zero quantities of methionine, histidine, or lysine were infused intravenously into lactating cows fed a corn–corn silage–urea ration to assess whether any of these amino acids were limiting for milk production. Feed intake was significantly higher (P < 0.05) with the low level of methionine infusion than with either the high level or saline infusions. Milk yield was not affected (P > 0.05) by any treatments, but protein yield was significantly greater (P < 0.05) with the low than with the high or zero levels of infusion of methionine, and the infusion of either level of histidine significantly decreased (P < 0.05) milk protein yield compared with zero level of infusion. The changes in levels of plasma amino acids that occurred during these studies have been interpreted as implying that methionine was the first limiting and either valine, leucine, or isoleucine was the second limiting amino acid for milk production.

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.

scholarly journals Association of UDP-galactose-4-epimerase with milk protein concentration in the Chinese Holstein population

2020 ◽  
Vol 33 (11) ◽  
pp. 1725-1731
Author(s):  
Cong Li ◽  
Wentao Cai ◽  
Shuli Liu ◽  
Chenghao Zhou ◽  
Mingyue Cao ◽  
...  
Keyword(s):  
Protein Concentration ◽  
Milk Protein ◽  
Association Studies ◽  
Regulatory Region ◽  
Protein Yield ◽  
Strong Linkage Disequilibrium ◽  
Phenotypic Variance ◽  
Production Traits ◽  
Fat Percentage ◽  
Chinese Holstein

Objective: An initial RNA-Sequencing study revealed that UDP-galactose-4-epimerase (GALE) was one of the most promising candidates for milk protein concentration in Chinese Holstein cattle. This enzyme catalyzes the interconversion of UDP-galactose and UDP-glucose, an important step in galactose catabolism. To further validate the genetic effect of GALE on milk protein traits, genetic variations were identified, and genotypes-phenotypes associations were performed.Methods: The entire coding region and the 5’-regulatory region (5’-UTR) of GALE were re-sequenced using pooled DNA of 17 unrelated sires. Association studies for five milk production traits were performed using a mixed linear animal model with a population encompassing 1,027 Chinese Holstein cows.Results: A total of three variants in GALE were identified, including two novel variants (g.2114 A>G and g.2037 G>A) in the 5’-UTR and one previously reported variant (g.3836 G>C) in an intron. All three single nucleotide polymorphisms (SNPs) were associated with milk yield (p<0.0001), fat yield (p = 0.0006 to <0.0001), protein yield (p = 0.0232 to <0.0001) and protein percentage (p<0.0001), while no significant associations were detected between the SNPs and fat percentage. A strong linkage disequilibrium (D’ = 0.96 to 1.00) was observed among all three SNPs, and a 5 Kb haplotype block involving three main haplotypes with GAG, AGC, and AGG was formed. The results of haplotype association analyses were consistent with the results of single locus association analysis (p<0.0001). The phenotypic variance ratio above 3.00% was observed for milk protein yield that was explained by SNP-g.3836G >C.Conclusion: Overall, our findings provided new insights into the polymorphic variations in bovine GALE gene and their associations with milk protein concentration. The data indicate their potential uses for marker-assisted breeding or genetic selection schemes.

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