Additives: Use of Choline and Methionine in Dairy Cattle
Published: September 25, 2020
By: Juan J. Loor, PhD, Professor, Department of Animal Sciences, Division of Nutritional Sciences, University of Illinois
Urbana, IL, USA. Curso Aditivos CEIEPAA, Asociación Mexicana de Especialistas en Nutrición Animal (AMENA), 2019.
Methionine (Met) and choline (Chol) supply in dairy cows continues to be of interest
- Historically emphasis on:
- Milk protein (Met)
- Liver lipid metabolism (Met and Chol)
- More recently, i.e. from 1990s to present, interest shifting to supplementation during the transition period:
- Feeding higher-energy diets
- Reducing diet CP
- Health, etc
Considerations for “Methyl donor” supplementation in dairy cows
- Some biological compounds can donate their methyl groups – “labile methyl group”
Transition Period: A dynamic physiologic stage
- Nutrient and energy demands pre-calving differ:
- Uterus
- Fetus
- Cow
- Endocrine, immune, and metabolic systems must adapt
- Despite gradual increases in dry matter intake, cows might remain in negative nutrient and energy balance for the first ~45 ± 21 days (Grummer et al., 2008)
Inflammation and oxidative stress occur during transition period
Multifaceted causes:
- Overconditioning
- Underconditioning
- Acidosis
- Metritis
- Mastitis
- Retained placenta
- High NEFA and BHBA
- etc,
Dry-period management has an impact!!
From Nutritional standpoint, focus on carbohydrate and energy metabolism has been substantial
Link with metabolic disorders
- Ketosis
- Fatty liver
- Others
Feeding excess grain (i.e. low NDF diets) during the dry period more deleterious to the cow (Grummer et al., 2008):
- Prone to overconditioning prepartum (accumulate body fat)
- More pronounced drops in dry matter intake (DMI)
- Greater risk of ketosis
- Greater risk of fatty liver
- Other?
- Key goal:
Minimize large drops in DMI close to calving
Is choline an essential nutrient?
- Clearly essential in monogastrics (also neonatal calves)
- Building and maintaining mammalian cell structure – phosphatidylcholine and sphingomyelin, cartilage
- Prevents abnormal fat accumulation in the liver – lipotropic
- Transmission of nerve impulses – acetylcholine
- Methyl group donor for synthesis of other compounds
Common feedstuffs supply variable amounts of choline to the cow
Other considerations:
- Recycling of bile acids back to liver supplies Chol:
- Bile phosp. ~90% P-choline
- Dietary fat content enhances bile acid flow into duodenum, i.e. increases P-chol. Recycling
- Feed intake important!
Outstanding question
Micronutrient requirements in transition cows?
- Choline
- Methionine (Met)
- B vitamins:
- Niacin
- Thiamin
- Riboflavin
- B6
- Biotin
- Folate
- B12
Choline supply during transition period
- Choline metabolism in the liver is linked with Met:
- Choline may help promote remethylation of homocysteine to Met
- Enhancing Met production may increase production of the antioxidants taurine and glutathione
- Choline may also reduce hepatic TAG accumulation
- Suggested daily intake is 12.5 g/d
What level of post-ruminal choline supply might be beneficial for metabolism, oxidant status, and immune function? (Coleman et al., 2019)
Formulating amino acid balanced diets is feasible
Key concepts moving forward
- Balance diet based on MP and AA, not CP!
- Use accurate cow information in the model:
- Measure DMI!
- Optimize microbial CP synthesis
- Meet projected AA deficiencies:
- Use RUP
- Use RP-amino acids
- “Problem”:
- Lack of knowledge on functional roles of EAA
- EAA deficiencies vary according to stage of lactation:
- Transition period
Typical practical amino acid balancing guidelines
- Feed a blend of high quality fermentable feeds and adequate physical effective fiber to optimize rumen function and milk production
- Feed adequate but not excessive levels of RDP (AA and ammonia) to optimize rumen function and achieve targeted levels of MUN
- Feed high-Lys protein supplements, maybe in combination with a proven RP-LYS supplement, to achieve a level of Lys in MP that comes close to meeting the optimal concentration for your model
- Feed a RP-Met supplement (or analog) in amounts needed to achieve optimum Lys/Met ratio in MP…fine tune as needed for maximal milk protein concentrations
- Limit RUP supplementation to what the “cows say” is needed…
- Monitor Histidine levels in MP, particularly if feeding lower amounts of RUP or low corn diets
Benefits of amino acid balancing
- Reduced RUP requirements for similar or higher milk yield and milk component concentrations (1.5 to 2.0% units less of DM)
- Increased milk yield, particularly in early lactation cows (2 to 3.5 kg/d)
- Increased milk component concentrations (0.15 to 0.25% unit increases in protein and 0.10 to 0.20% unit increases in fat)
- Healthier transition cows
- Growing evidence of healthier embryos and better breeding
- Increased overall herd profitability
Limiting amino acids and colimiting amino acids
Positive effect of Met supply is unquestionable!
Co-limiting amino acids?
- Histidine
- Threonine
- Leucine
- Tryptophan
Methionine (Met) supply during transition period – why important?
- Low levels of serum Met postpartum are associated with severe hepatic lipidosis (Shibano and Kawamura, 2006)
- Rate of hepatic metabolism in high-producing cows nearly doubles after parturition (Reynolds et al., 2003)
- Other than Histidine, Met is the only amino acid for which net uptake by the liver increases between pre- and postpartum (Larsen and Kristensen, 2013)
- Activity of key enzymes in 1-carbon metabolism in liver increases around parturition (Zhou et al., 2017)
Key points to keep in mind
- Some micronutrients have physiological functions beyond serving as building blocks for tissue growth
- Examples include nutrients involved in the 1-carbon metabolism pathway:
- Methionine, choline, betaine, and folate (Methyl donors)
- Some B vitamins
- Little information on intake, duodenal flow, and apparent ruminal synthesis of B vitamins
- Enhanced supply of such nutrients during the periparturient period can help improve performance, metabolism and immune function
- Need more information on adequate levels to maintain health status and performance
Does nutrition of the pregnant cow influence the calf?
- Nutrient imbalance during dry period
- No major effect unless markedly inadequate:
- Amino acids used for gluconeogenesis at greater rate
- Reduced calf survival post-birth
- Adequate crude protein prepartum important
- Energy overfeeding/overconditioning of the cow:
- Little evidence for a profound effect on fetal growth or development
Metabolism by pregnant uterus and fetus is dynamic
- Placenta consumes ~65% of glucose uptake
- Fetal glucose use is 50-60% of total oxidative metabolism
- Amino acid uptake by uterus ~70% of maternal supply
- Placenta has nutrientsensing signaling pathways
- Sensitive to hormones, could alter nutrient delivery and abundance of transporters
- Protein supply during pregnancy can induce short- and long-term effects: e.g. rodents (Fleming et al., 2015)
- ↓ availability to placenta and fetus
- ↑ fetal weight
- ↑ postnatal body weight
Feeding for dual purpose with dual benefit
- Adequate micronutrient supply to the cow and fetus can be achieved through the diet
- There is potential to use “rumenprotection” technology
Key points to keep in mind
- Enhanced maternal supply of methionine in late-pregnancy:
- Direct and indirect effect on fetal growth
- Are key organs of the calf “programmed”??
- The placenta responds to both, greater total nutrient supply and methionine:
- Nutrient signaling mechanisms are altered
- Better understanding of the likely outcomes is needed
- Early gut microbiome appears susceptible to nutritional programming:
- Vertical transfer from cow to fetus????
- Meaning to hindgut function and the calf???
- Need better understanding of potential long-term effects
Related topics:
Authors:
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1 de junio de 2022
Excellent. what will be the ratio of protected choline and methionine if we will use in combination? thank you.
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29 de septiembre de 2020
Nice article
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