diff --git a/RUFAS/biophysical/animal/animal_module_constants.py b/RUFAS/biophysical/animal/animal_module_constants.py
index a62c5da2d2..da7a859201 100644
--- a/RUFAS/biophysical/animal/animal_module_constants.py
+++ b/RUFAS/biophysical/animal/animal_module_constants.py
@@ -82,10 +82,10 @@ class AnimalModuleConstants:
     MILK_LACTOSE: float = 4.85
     """Milk lactose content, percentage."""
 
-    DMI_CONSTRAINT_FRACTION: float = 0.30
+    DMI_CONSTRAINT_FRACTION: float = 0.00
     """The +/- fraction of DMI estimated allowed for ration formulation."""
 
-    DMI_REQUIREMENT_BOOST: float = 1.1
+    DMI_REQUIREMENT_BOOST: float = 1.0
     """The fraction of the dry matter intake requirement used as the basis for
     the inclusion rate bounds in user defined ration formulation method."""
 
diff --git a/RUFAS/biophysical/animal/herd_manager.py b/RUFAS/biophysical/animal/herd_manager.py
index 7a0c07a025..36c305af0c 100644
--- a/RUFAS/biophysical/animal/herd_manager.py
+++ b/RUFAS/biophysical/animal/herd_manager.py
@@ -134,6 +134,7 @@ def __init__(
 
         self.is_ration_defined_by_user = is_ration_defined_by_user
         ration_feed_config = self.im.get_data("feed")
+        RationManager.lac_cow_dry_matter_intake = ration_feed_config["lac_cow_dry_matter_intake"]
         if self.is_ration_defined_by_user:
             RationManager.set_user_defined_rations(ration_feed_config)
             RationManager.set_user_defined_ration_tolerance(ration_feed_config)
diff --git a/RUFAS/biophysical/animal/nutrients/nasem_requirements_calculator.py b/RUFAS/biophysical/animal/nutrients/nasem_requirements_calculator.py
index c47f77a3dc..3ee64f942f 100644
--- a/RUFAS/biophysical/animal/nutrients/nasem_requirements_calculator.py
+++ b/RUFAS/biophysical/animal/nutrients/nasem_requirements_calculator.py
@@ -6,6 +6,7 @@
 from RUFAS.biophysical.animal.ration.amino_acid import AminoAcidCalculator
 from RUFAS.general_constants import GeneralConstants
 from RUFAS.user_constants import UserConstants
+from RUFAS.biophysical.animal.ration.ration_manager import RationManager
 
 from .nutrition_requirements_calculator import NutritionRequirementsCalculator
 
@@ -657,13 +658,16 @@ def _calculate_dry_matter_intake(
 
         """
         if lactating:
-            parity_adjustment_factor = 1 if parity > 1 else 0
-            dry_matter_intake_estimate = (
-                (3.7 + parity_adjustment_factor * 5.7)
-                + 0.305 * net_energy_lactation
-                + 0.022 * body_weight
-                + (-0.689 - 1.87 * parity_adjustment_factor) * body_condition_score_5
-            ) * (1 - (0.212 + parity_adjustment_factor * 0.136) * exp(-0.053 * days_in_milk))
+            if RationManager.lac_cow_dry_matter_intake == 0:
+                parity_adjustment_factor = 1 if parity > 1 else 0
+                dry_matter_intake_estimate = (
+                    (3.7 + parity_adjustment_factor * 5.7)
+                    + 0.305 * net_energy_lactation
+                    + 0.022 * body_weight
+                    + (-0.689 - 1.87 * parity_adjustment_factor) * body_condition_score_5
+                ) * (1 - (0.212 + parity_adjustment_factor * 0.136) * exp(-0.053 * days_in_milk))
+            else:
+                dry_matter_intake_estimate = RationManager.lac_cow_dry_matter_intake
         else:
             dry_matter_intake_estimate = (
                 0.0226 * mature_body_weight * (1 - exp(-1.47 * (body_weight / mature_body_weight)))
diff --git a/RUFAS/biophysical/animal/ration/ration_manager.py b/RUFAS/biophysical/animal/ration/ration_manager.py
index 4d13355e25..98a11e739f 100644
--- a/RUFAS/biophysical/animal/ration/ration_manager.py
+++ b/RUFAS/biophysical/animal/ration/ration_manager.py
@@ -34,6 +34,7 @@ class RationManager:
     user_defined_rations: dict[AnimalCombination, dict[RUFAS_ID, float]] | None
     tolerance: float | None = 0.0
     maximum_ration_reformulation_attempts: int
+    lac_cow_dry_matter_intake: float
 
     @classmethod
     def set_ration_feeds(cls, ration_config: dict[str, list[int]]) -> None:
diff --git a/input/data/feed/example_Midwest_feed.json b/input/data/feed/example_Midwest_feed.json
index f0bc11ba7b..de14c207e2 100644
--- a/input/data/feed/example_Midwest_feed.json
+++ b/input/data/feed/example_Midwest_feed.json
@@ -186,6 +186,7 @@
     ],
     "tolerance": 0.1
   },
+  "lac_cow_dry_matter_intake": 27,
   "max_daily_feed_recalculations_per_year": 4,
   "allowances": [
     {
diff --git a/input/metadata/properties/default.json b/input/metadata/properties/default.json
index 2d52ff68de..51fe8ba071 100644
--- a/input/metadata/properties/default.json
+++ b/input/metadata/properties/default.json
@@ -4375,6 +4375,12 @@
       "maximum": 365,
       "default": 4
     },
+    "lac_cow_dry_matter_intake": {
+      "type": "number",
+      "description": "Fixed amount of dry matter intake (kg) for lactating cows. Set to 0 to use NASEM or NRC predicted dry matter intake.",
+      "minimum": 0,
+      "default": 0
+    },
     "allowances": {
       "type": "array",
       "properties": {