Feeding to Maximize Reproductive Performance of Your Cows and Heifers (Nutrition Update, Volume 13)
Feeding to Maximize Reproductive Performance in Cows and Heifers
Adequate and timely nutrition is essential for optimizing reproductive performance, reducing feed costs, and ensuring cows and heifers maintain appropriate body condition throughout the production cycle. Body Condition Score (BCS) targets should align with the four nutritional stages in a cow’s yearly cycle.
Stage 1: Early Pregnancy (Post‑Weaning / Start of Winter Feeding)
- Nutrient requirements: Lowest of the year
- ~50–53% TDN, ~7% CP
- Feed sources: Fall pasture, medium‑quality hay
- Target BCS: Minimum 3.0 for cows and heifers
- Key considerations:
- Animals in good condition can maintain weight.
- Thin cows must gain weight; underfeeding at this stage may compromise placental development and fetal nutrient transfer later in gestation.
- Adequate body reserves improve cold tolerance and support later reproductive success.
Stage 2: Pre‑Calving (Critical Period: 6–8 Weeks Before Calving)
90% of the fetal growth is occurring in this stage of the pregnancy as well as udder development and colostrum synthesis.
- Nutrient requirements: Increase significantly
- ~58% TDN, ~9% CP
- Higher quality hay + ~2 lbs barley typically adequate
- Target BCS at calving:
- Mature cows: 3.0
- First‑calf heifers: 3.5
- Key concerns:
- Cold weather increases forage intake by ~30%. Especially windy conditions.
- Weight loss during this period can delay return to estrus.
- Poor pre-calving energy reduces colostrum quality and affects calf vitality.
Stage 3: Lactation (Critical Period Continued)
- Nutrient requirements: Highest of the entire production cycle
- Mature cows: 60–63% TDN
- First‑calf heifers: ~65% TDN
- Protein: 11–12% CP
- Target BCS before breeding: Minimum 2.5
- Key considerations:
- Cows must produce milk, repair reproductive tissues, and prepare to rebreed.
- Animals below BCS 1.5 will not gain sufficient weight to cycle properly before breeding.
- High-quality feed is essential to support both lactation and rebreeding.
Stage 4: Breeding to Weaning
- Nutrient requirements: Declining
- Milk production decreases; calves consume more forage
- Feed sources: Well-managed pasture typically adequate
- Management considerations:
- Poor-quality pasture or inadequate intake can reduce weaning weights.
- Early weaning or creep feeding may be necessary if cows are thin or forage is limited.
Why Body Condition Matters
Cows and heifers in good body condition:
- Cycle earlier
- Conceive earlier within the breeding season
- Deliver heavier calves at weaning
- Produce stronger, more vigorous calves at birth
Ensuring good nutrition—especially during the critical periods (late gestation and early lactation)—improves herd fertility, boosts calf health, and increases the proportion of calves born in the first 20 days of calving, maximizing weaning weights and overall herd productivity.