Protective Factor in Colostrum That Protects Immunoglobulins

Colostrum of ruminants contains ___________ which protects immunoglobulins from digestion in GIT of calf:

Correct Answer: Trypsin inhibitor

Ruminant colostrum contains a Trypsin inhibitor that protects immunoglobulins (antibodies) from being digested by proteolytic enzymes in the gastrointestinal tract of the newborn calf.

Why This Is Important

• In ruminants, placental transfer of antibodies does NOT occur (unlike humans).
• The newborn calf is entirely dependent on colostrum for passive immunity.
• The gut of the calf can absorb intact immunoglobulins only in the first 24–36 hours of life (intestinal closure).
• Trypsin inhibitor ensures the IgG molecules reach the intestine intact for absorption.

Other Colostrum Key Facts

• Predominant immunoglobulin in bovine colostrum: IgG
• Major immunoglobulin in human colostrum: IgA
• Colostrum fed @ 10% of body weight (or 2–2.5 L/day for 3–4 days)
• Milk loses colostral properties within 72 hours (3–4 days) after parturition