Bovine Malnutrition Study Guide

Overview and Clinical Importance

Malnutrition in cattle represents a multisystemic disorder arising when dietary intake fails to meet requirements for energy, protein, minerals, or vitamins. This condition is particularly important in beef cattle during late gestation, early lactation, and periods of environmental stress. Malnutrition predisposes animals to secondary conditions including pregnancy toxemia, hepatic lipidosis, infectious diseases, and reproductive failure. Understanding the pathophysiology, clinical signs, diagnosis, and management of bovine malnutrition is essential for NAVLE success.

Pathophysiology of Bovine Malnutrition

Energy Balance and Metabolism

Cattle require energy for maintenance, growth, reproduction, and lactation. When dietary energy intake is insufficient, animals enter a negative energy balance (NEB). During NEB, the body mobilizes fat reserves through lipolysis, releasing non-esterified fatty acids (NEFAs) into circulation. If NEFAs exceed the liver's capacity for beta-oxidation and export as very-low-density lipoproteins (VLDLs), hepatic lipidosis develops.

Late gestation represents a critical period because fetal energy demands increase dramatically while rumen capacity decreases. At day 130 of gestation, net energy maintenance (NEm) requirement for pregnancy is approximately 0.33 Mcal/day; by day 250, this increases to 3.33 Mcal/day. Protein requirements similarly increase from 9.1 g available protein/day at day 130 to 95.2 g/day at day 250.