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Hanigan MD, Souza VC, Martineau R, Lapierre H, Feng X, Daley VL. A meta-analysis of the relationship between milk protein production and absorbed amino acids and digested energy in dairy cattle. J Dairy Sci 2024; 107:5587-5615. [PMID: 38490550 DOI: 10.3168/jds.2024-24230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2023] [Accepted: 02/09/2024] [Indexed: 03/17/2024]
Abstract
Milk protein production is the largest draw on AA supplies for lactating dairy cattle. Prior NRC predictions of milk protein production have been absorbed protein (MP)-based and used a first-limiting nutrient concept to integrate the effects of energy and protein, which yielded poor accuracy and precision (root mean squared error [RMSE] >21%). Using a meta-data set gathered, various alternative equation forms considering MP, absorbed total EAA, absorbed individual EAA, and digested energy (DE) supplies as additive drivers of production were evaluated, and all were found to be superior in statistical performance to the first limitation approach (RMSE = 14%-15%). Inclusion of DE intake and a quadratic term for MP or absorbed EAA supplies were found to be necessary to achieve intercept estimates (nonproductive protein use) that were similar to the factorial estimates of the National Academies of Sciences, Engineering, and Medicine (2021). The partial linear slope for MP was found to be 0.409, which is consistent with the observed slope bias of -0.34 g/g when a slope of 0.67 was used for MP efficiency in a first-limiting nutrient system. Replacement of MP with the supplies of individual absorbed EAA expressed in grams per day and a common quadratic across the EAA resulted in unbiased predictions with improved statistical performance as compared with MP-based models. Based on Akaike's information criterion and biological consistency, the best equations included absorbed His, Ile, Lys, Met, Thr, the NEAA, and individual DE intakes from fatty acids, NDF, residual OM, and starch. Several also contained a term for absorbed Leu. These equations generally had RMSE of 14.3% and a concordance correlation of 0.76. Based on the common quadratic and individual linear terms, milk protein response plateaus were predicted at approximately 320 g/d of absorbed His, Ile, and Lys; 395 g/d of absorbed Thr; 550 g/d of absorbed Met; and 70 g/d of absorbed Leu. Therefore, responses to each except Leu are almost linear throughout the normal in vivo range. De-aggregation of the quadratic term and parsing to individual absorbed EAA resulted in nonbiological estimates for several EAA indicating over-parameterization. Expression of the EAA as g/100 g total absorbed EAA or as ratios of DE intake and using linear and quadratic terms for each EAA resulted in similar statistical performance, but the solutions had identifiability problems and several nonbiological parameter estimates. The use of ratios also introduced nonlinearity in the independent variables which violates linear regression assumptions. Further screening of the global model using absorbed EAA expressed as grams per day with a common quadratic using an all-models approach, and exhaustive cross-evaluation indicated the parameter estimates for BW, all 4 DE terms, His, Ile, Lys, Met, and the common quadratic term were stable, whereas estimates for Leu and Thr were known with less certainty. Use of independent and additive terms and a quadratic expression in the equation results in variable efficiencies of conversion. The additivity also provides partial substitution among the nutrients. Both of these prevent establishment of fixed nutrient requirements in support of milk protein production.
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Affiliation(s)
- M D Hanigan
- Department of Dairy Science, Virginia Tech, Blacksburg, VA 24061.
| | - V C Souza
- Department of Dairy Science, Virginia Tech, Blacksburg, VA 24061
| | - R Martineau
- Agriculture and Agri-Food Canada, Sherbrooke, QC, Canada J1M 0C8
| | - H Lapierre
- Agriculture and Agri-Food Canada, Sherbrooke, QC, Canada J1M 0C8
| | - X Feng
- Department of Dairy Science, Virginia Tech, Blacksburg, VA 24061
| | - V L Daley
- Department of Dairy Science, Virginia Tech, Blacksburg, VA 24061
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Reyes GC, Innes DJ, Ellis JL, Fox MK, Cant JP. Relationship between rate of glucose or propionate infusion and milk protein yield and concentration in dairy cows: A meta-regression. J Dairy Sci 2024; 107:2785-2796. [PMID: 37806622 DOI: 10.3168/jds.2023-23644] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Accepted: 09/16/2023] [Indexed: 10/10/2023]
Abstract
Although postruminal glucose infusion into dairy cows has increased milk protein yield in some past experiments, the same trend has not been observed in others. A meta-regression of 64 sets of observations from 29 previously published glucose and propionate infusion studies in dairy cattle, treating study and experiment (study) as random effects, was performed to establish the general effects of glucose equivalent (GlcE) infusion rate on milk true protein (MTP) yield and content, if any, and to identify independent, fixed-effect variables that accounted for the changes in MTP yield and content that were observed. Candidate explanatory variables included rate and site of infusion, diet composition and intake, body weight and lactation stage of the cows, and the change in nutrient intake between GlcE and control treatments. Across all studies, according to a model containing only the random effects of study and experiment, GlcE infusion at an average of 954 g/d increased MTP yield by 26 g/d, on average, whereas mean MTP content was not affected. Backward stepwise elimination of potential explanatory variables from a full mixed model produced a final, reduced model for MTP yield that retained a positive, second-order quadratic effect of infusion rate of GlcE and a positive, linear effect of the change in crude protein intake (CPI) between GlcE treatment and control. This change in CPI due to GlcE infusion ranged from -0.546 to 0.173 kg/d in the dataset. The model fit indicated that when CPI was allowed to drop during GlcE infusion, the effect of GlcE on MTP yield was smaller than when CPI was maintained or increased, in a manifestation of the classic protein:energy interaction. The final reduced model for MTP content contained the same explanatory variables as for MTP yield, plus a negative effect of intravenous compared with gastrointestinal infusion. Overall, the meta-analysis revealed that both MTP yield, and content were positively related to GlcE infusion rate and to the change in CPI between glucose treatment and control.
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Affiliation(s)
- G C Reyes
- Centre for Nutrition Modelling, Department of Animal Biosciences, University of Guelph, Ontario, N1G 2W1 Canada.
| | - D J Innes
- Centre for Nutrition Modelling, Department of Animal Biosciences, University of Guelph, Ontario, N1G 2W1 Canada
| | - J L Ellis
- Centre for Nutrition Modelling, Department of Animal Biosciences, University of Guelph, Ontario, N1G 2W1 Canada
| | - M K Fox
- Centre for Nutrition Modelling, Department of Animal Biosciences, University of Guelph, Ontario, N1G 2W1 Canada
| | - J P Cant
- Centre for Nutrition Modelling, Department of Animal Biosciences, University of Guelph, Ontario, N1G 2W1 Canada.
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Chandler T, Westhoff T, Overton T, Lock A, Van Amburgh M, Sipka A, Mann S. Lipopolysaccharide challenge following intravenous amino acid infusion in postpartum dairy cows: I. Production, metabolic, and hormonal responses. J Dairy Sci 2022; 105:4593-4610. [DOI: 10.3168/jds.2021-21226] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 01/25/2022] [Indexed: 01/15/2023]
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Mulliniks JT, Beard JK. BEEF SPECIES-RUMINANT NUTRITION CACTUS BEEF SYMPOSIUM: Sustainable and economically viable management options for cow/calf production through enhanced beef cow metabolic efficiency1. J Anim Sci 2019; 97:1398-1406. [PMID: 30561668 PMCID: PMC6396245 DOI: 10.1093/jas/sky476] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Accepted: 12/13/2018] [Indexed: 12/11/2022] Open
Abstract
Beef cow herds are expected to be metabolically and reproductively efficient in varied and ever changing environmental conditions. Therefore, selection and management of grazing beef cows provides unique and diverse challenges in achieving optimal production efficiency for any environment. Beef cows face dynamic and highly variable nutritional environments that periodically are inadequate in meeting nutrient and energy requirements. Nutritional management during high metabolically stressed and key physiological states can lead to increased or decreased metabolic efficiency. Conversely, cow metabolic efficiency may be reduced in many production systems due to surplus nutritional inputs and reduced exposure to environmental stressors. Alternatively, metabolically potent supplementation strategies targeting enhanced energy metabolism and endocrine mechanisms would increase beef cow metabolic and economic efficiency. Metabolic efficient beef cows adapt to environmental changes by adjusting their metabolic energy utilization in order to match current environmental conditions and remain reproductively competent. This mechanism involves adaptive processes that drive adjustments in nutrient partitioning and energy utilization efficiency. However, the variation in metabolic and reproductive efficiency among beef cows within cow/calf production systems is substantial, suggesting a lack of complete integration of nutrition, genetics, and reproduction with environmental constraints and conditions. Better integration and understanding of the interactions may lead to advancements in metabolic efficiency of the cowherd. Metabolic flexibility is recognized as an important trait in dairy production but has received little attention thus far in beef cattle. Overall, management and supplementation strategies in cow/calf systems from a mechanistic, targeted nutritional approach during key physiological periods would hasten improvements in metabolic efficiency.
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Affiliation(s)
- J Travis Mulliniks
- West Central Research and Extension Center, University of Nebraska, North Platte, NE
| | - Joslyn K Beard
- West Central Research and Extension Center, University of Nebraska, North Platte, NE
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Martineau R, Ouellet D, Patton R, White R, Lapierre H. Plasma essential amino acid concentrations in response to casein infusion or ration change in dairy cows: A multilevel, mixed-effects meta-analysis. J Dairy Sci 2019; 102:1312-1329. [DOI: 10.3168/jds.2018-15218] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Accepted: 10/23/2018] [Indexed: 12/16/2022]
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Tian W, Wu T, Zhao R, Xu J, He Y, Wang H. Responses of milk production of dairy cows to jugular infusions of a mixture of essential amino acids with or without exclusion leucine or arginine. ACTA ACUST UNITED AC 2017; 3:271-275. [PMID: 29767155 PMCID: PMC5941189 DOI: 10.1016/j.aninu.2017.05.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 05/11/2017] [Accepted: 05/17/2017] [Indexed: 12/15/2022]
Abstract
The purpose of this study was to determine effects of jugular infusion of either balanced or imbalanced amino acid mixture on milk production and composition in dairy cows. Eight mid-lactation Holstein cows were randomly assigned to 5-d continuous jugular infusions of saline (CTL), essential amino acid (EAA) mixture prepared on the profile of casein (CSN, 160 g/d), EAA mixture excluding leucine (Leu) (−Leu, 163 g/d) or EAA mixture excluding arginine (Arg) (−Arg, 158 g/d) in a duplicated 4 × 4 Latin square design with 4 infusion periods separated by a 7-d interval period. The basal diet was formulated with corn grain, soybean meal, cottonseed meal, corn silage, alfalfa hay and Chinese wildrye grass hay according to NRC (2001) and supplied 1.6 Mcal net energy for lactation (NEL) and 94.4 g metabolizable protein (MP) per kg dry matter (DM) to meet requirements for lactation. The results showed that the dry matter intake (DMI) and normal physiological status were not affected by amino acid mixture infusions. Compared with CTL treatment, the CSN treatment increased milk yield (14.9%, P < 0.001), milk lactose yield (14.5%, P = 0.001), milk fat yield (16.6%, P = 0.01), milk protein yield (18.2%, P < 0.001) and the contents of αS1-casein (αS1-CN, 11.8%, P = 0.007), β-casein (β-CN, 4.2%, P = 0.035) and κ-casein (κ-CN, 8.5%, P = 0.003). However, the −Leu and −Arg treatments had lower milk yield (6.3%, P = 0.058 and 5.7%, P = 0.073, respectively), milk protein yield (8.8%, P = 0.010 and 8.2%, P = 0.011, respectively) and the contents of αS1-CN (7.3%, P = 0.057 and 8.4%, P = 0.026, respectively), β-CN (4.2%, P = 0.033 and 3.8%, P = 0.048, respectively) and κ-CN (5.8%, P = 0.023 and 7.6%, P = 0.003, respectively) than those of the CSN treatment. Milk lactose yield (5.9%, P = 0.076) tended to decrease when Leu was removed from amino acid mixture infusate. In conclusion, the supply of casein profile can increase milk production in dairy cows, but a deficiency of Leu or Arg had negative effects on milk yield and milk protein yield.
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Affiliation(s)
- Wen Tian
- College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, China
| | - Tianyou Wu
- Shanghai Bright Holstan Co., Ltd, Zhabei 200436, China
| | - Rui Zhao
- Shanghai Bright Holstan Co., Ltd, Zhabei 200436, China
| | - Jinhao Xu
- College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, China
| | - Yao He
- College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, China
| | - Hongrong Wang
- College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, China
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Differences in plasma metabolomics between sows feddl-methionine and its hydroxy analogue reveal a strong association of milk composition and neonatal growth with maternal methionine nutrition. Br J Nutr 2015; 113:585-95. [DOI: 10.1017/s0007114514004036] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The aim of the present study was to determine whether increased consumption of methionine asdl-methionine (DLM) or its hydroxy analoguedl-2-hydroxy-4-methylthiobutanoic acid (HMTBA) could benefit milk synthesis and neonatal growth. For this purpose, eighteen cross-bred (Landrace × Yorkshire) primiparous sows were fed a control (CON), DLM or HMTBA diet (n6 per diet) from 0 to 14 d post-partum. At postnatal day 14, piglets in the HMTBA group had higher body weight (P= 0·02) than those in the CON group, tended (P= 0·07) to be higher than those in the DLM group, and had higher (P< 0·05) mRNA abundance of jejunal fatty acid-binding protein 2, intestinal than those in the CON and DLM groups. Compared with the CON diet-fed sows, milk protein, non-fat solid, and lysine, histidine and ornithine concentrations decreased in the DLM diet-fed sows (P< 0·05), and milk fat, lactose, and cysteine and taurine concentrations increased in the HMTBA diet-fed sows (P< 0·05). Plasma homocysteine and urea N concentrations that averaged across time were increased (P< 0·05) in sows fed the DLM diet compared with those fed the CON diet. Metabolomic results based on1H NMR spectroscopy revealed that consumption of the HMTBA and DLM diets increased (P< 0·05) both sow plasma methionine and valine levels; however, consumption of the DLM diet led to lower (P< 0·05) plasma levels of lysine, tyrosine, glucose and acetate and higher (P< 0·05) plasma levels of citrate, lactate, formate, glycerol,myo-inositol andN-acetyl glycoprotein in sows. Collectively, neonatal growth and milk synthesis were regulated by dietary methionine levels and sources, which resulted in marked alterations in amino acid, lipid and glycogen metabolism.
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Burd NA, Hamer HM, Pennings B, Pellikaan WF, Senden JMG, Gijsen AP, van Loon LJC. Substantial Differences between Organ and Muscle Specific Tracer Incorporation Rates in a Lactating Dairy Cow. PLoS One 2013; 8:e68109. [PMID: 23826365 PMCID: PMC3694909 DOI: 10.1371/journal.pone.0068109] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Accepted: 05/25/2013] [Indexed: 11/18/2022] Open
Abstract
We aimed to produce intrinsically L-[1-(13)C]phenylalanine labeled milk and beef for subsequent use in human nutrition research. The collection of the various organ tissues after slaughter allowed for us to gain insight into the dynamics of tissue protein turnover in vivo in a lactating dairy cow. One lactating dairy cow received a constant infusion of L-[1-(13)C]phenylalanine (450 µmol/min) for 96 h. Plasma and milk were collected prior to, during, and after the stable isotope infusion. Twenty-four hours after cessation of the infusion the cow was slaughtered. The meat and samples of the various organ tissues (liver, heart, lung, udder, kidney, rumen, small intestine, and colon) were collected and stored. Approximately 210 kg of intrinsically labeled beef (bone and fat free) with an average L-[1-(13)C]phenylalanine enrichment of 1.8±0.1 mole percent excess (MPE) was obtained. The various organ tissues differed substantially in L-[1-(13)C]phenylalanine enrichments in the tissue protein bound pool, the highest enrichment levels were achieved in the kidney (11.7 MPE) and the lowest enrichment levels in the skeletal muscle tissue protein of the cow (between 1.5-2.4 MPE). The estimated protein synthesis rates of the various organ tissues should be regarded as underestimates, particularly for the organs with the higher turnover rates and high secretory activity, due to the lengthened (96 h) measurement period necessary for the production of the intrinsically labeled beef. Our data demonstrates that there are relatively small differences in L-[1-(13)C]phenylalanine enrichments between the various meat cuts, but substantial higher enrichment values are observed in the various organ tissues. We conclude that protein turnover rates of various organs are much higher when compared to skeletal muscle protein turnover rates in large lactating ruminants.
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Affiliation(s)
- Nicholas A. Burd
- Top Institute Food and Nutrition (TIFN), Wageningen, The Netherlands
- Department of Human Movement Sciences, NUTRIM School for Nutrition, Toxicology and Metabolism, Maastricht University Medical Centre+ (MUMC+), Maastricht, The Netherlands
| | - Henrike M. Hamer
- Top Institute Food and Nutrition (TIFN), Wageningen, The Netherlands
- Department of Human Movement Sciences, NUTRIM School for Nutrition, Toxicology and Metabolism, Maastricht University Medical Centre+ (MUMC+), Maastricht, The Netherlands
| | - Bart Pennings
- Top Institute Food and Nutrition (TIFN), Wageningen, The Netherlands
- Department of Human Movement Sciences, NUTRIM School for Nutrition, Toxicology and Metabolism, Maastricht University Medical Centre+ (MUMC+), Maastricht, The Netherlands
| | | | - Joan M. G. Senden
- Top Institute Food and Nutrition (TIFN), Wageningen, The Netherlands
- Department of Human Movement Sciences, NUTRIM School for Nutrition, Toxicology and Metabolism, Maastricht University Medical Centre+ (MUMC+), Maastricht, The Netherlands
| | - Annemie P. Gijsen
- Department of Human Movement Sciences, NUTRIM School for Nutrition, Toxicology and Metabolism, Maastricht University Medical Centre+ (MUMC+), Maastricht, The Netherlands
| | - Luc J. C. van Loon
- Top Institute Food and Nutrition (TIFN), Wageningen, The Netherlands
- Department of Human Movement Sciences, NUTRIM School for Nutrition, Toxicology and Metabolism, Maastricht University Medical Centre+ (MUMC+), Maastricht, The Netherlands
- * E-mail:
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Intravenous supplementation of acetate, glucose or essential amino acids to an energy and protein deficient diet in lactating dairy goats: Effects on milk production and mammary nutrient extraction. Small Rumin Res 2013. [DOI: 10.1016/j.smallrumres.2012.12.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Pennings B, Pellikaan WF, Senden JMG, van Vuuren AM, Sikkema J, van Loon LJC. The production of intrinsically labeled milk and meat protein is feasible and provides functional tools for human nutrition research. J Dairy Sci 2011; 94:4366-73. [PMID: 21854909 DOI: 10.3168/jds.2011-4451] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2011] [Accepted: 05/18/2011] [Indexed: 01/18/2023]
Abstract
Administration of labeled, free amino acids does not allow direct assessment of in vivo dietary protein digestion and absorption kinetics. Consequently, dietary protein sources with labeled amino acids incorporated within their protein matrix are required. The aim of the present study was to produce intrinsically L-[1-(13)C]phenylalanine-labeled milk and meat protein that would permit in vivo assessment of postprandial protein digestion and absorption kinetics in humans. One lactating dairy cow was continuously infused with 420 μmol of L-[1-(13)C]phenylalanine/min for 96 h, with plasma and milk being collected before, during, and after isotope infusion. Twenty-four hours after infusion, the cow was slaughtered to produce intrinsically labeled meat. Levels of L-[1-(13)C]phenylalanine enrichment as high as 40 mole percent excess (MPE) in milk and 1.5 MPE in meat protein were achieved. In a subsequent human proof-of-principle experiment, 2 healthy young males (25±1 yr; 66.2±5.2 kg) each ingested 135 g of L-[1-(13)C]phenylalanine intrinsically labeled minced beef, after which plasma samples were collected at regular time intervals. Plasma L-[1-(13)C]phenylalanine enrichments increased during the first 90 min following beef ingestion, reaching peak plasma enrichment levels of 0.61±0.04 MPE. Whole-body net protein balance, assessed by continuous infusion of L-[ring-(2)H(5)]phenylalanine and L-[ring-(2)H(2)]tyrosine, was higher in the postprandial period compared with basal values (6.4±0.1 vs. -4.5±0.1 μmol/kg per h). In conclusion, the production of intrinsically L-[1-(13)C]phenylalanine-labeled milk and meat protein is feasible and provides functional tools to investigate in vivo protein digestion and absorption kinetics in humans.
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Affiliation(s)
- B Pennings
- Top Institute Food and Nutrition (TIFN), Wageningen, the Netherlands
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Appuhamy JADRN, Knapp JR, Becvar O, Escobar J, Hanigan MD. Effects of jugular-infused lysine, methionine, and branched-chain amino acids on milk protein synthesis in high-producing dairy cows. J Dairy Sci 2011; 94:1952-60. [PMID: 21426986 DOI: 10.3168/jds.2010-3442] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2010] [Accepted: 12/13/2010] [Indexed: 01/28/2023]
Abstract
In addition to lysine and methionine, current ration-balancing programs suggest that branched-chain amino acid (BCAA) supply may also be limiting in dairy cows. The objective of this study was to investigate whether BCAA, leucine, isoleucine, and valine become limiting for milk protein synthesis when methionine and lysine supply were not limiting. Nine multiparous Holstein cows with an average milk production of 53.5±7.1 kg/d were randomly assigned to 7-d continuous jugular infusions of saline (CTL), methionine and lysine (ML; 12 g and 21 g/d, respectively), or ML plus leucine, isoleucine, and valine (ML+BCAA; 35 g, 15 g, and 15 g/d, respectively) in a 3×3 Latin square design with 3 infusion periods separated by 7-d noninfusion periods. The basal diet consisted of 40% corn silage, 14% alfalfa hay, and a concentrate mix, and respectively supplied lysine, methionine, isoleucine, leucine, and valine as 6.1, 1.8, 4.7, 8.9, and 5.3% of metabolizable protein. Dry matter intake (23.9 kg/d), milk yield (52.8 kg/d), fat content (2.55%), fat yield (1.33 kg/d), lactose content (4.77%), lactose yield (2.51 kg/d), and milk protein efficiency (0.38) were similar across treatments. Protein yield and protein content were not significantly different between ML (1.52 kg/d and 2.88%, respectively) and ML+BCAA (1.51 kg/d and 2.83%, respectively), but they were significantly greater than that of CTL (1.39 kg/d and 2.71%). Cows that received ML+BCAA had less milk urea nitrogen content (10.9 mg/dL) compared with milk of CTL cows (12.4 mg/dL) and ML cows (11.8 mg/dL). Whereas high-producing cows responded positively to methionine and lysine supplementation, no apparent benefits of BCAA supplementation in milk protein synthesis were found. Infusion of BCAA may have stimulated synthesis of other body proteins, probably muscle proteins, as evidenced by decreased milk urea nitrogen.
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Affiliation(s)
- J A D R N Appuhamy
- Department of Dairy Science, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
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Al-Trad B, Reisberg K, Wittek T, Penner G, Alkaassem A, Gäbel G, Fürll M, Aschenbach J. Increasing intravenous infusions of glucose improve body condition but not lactation performance in midlactation dairy cows. J Dairy Sci 2009; 92:5645-58. [DOI: 10.3168/jds.2009-2264] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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Schei I, Boman I, Volden H. Effects of genetic capacity on milk production and on plasma metabolites in dairy cows during post-ruminal or intravenous carbohydrates or amino acid infusions. Livest Sci 2008. [DOI: 10.1016/j.livsci.2007.10.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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