Herd Illthrift/poor Performance/Weight Loss in Cattle

Phil Rogers MRCVS <philrogers@eircom.net>
Grange Research Centre, Dunsany, Co. Meath, Ireland

Causes (Major | Less common | Rare) | Remedies

CAUSES OF ILLTHRIFT: There are many causes of herd illthrift/poor performance/weight loss. MINERAL deficiency is NOT the most likely cause.

1 Restricted water intake Poor supply, contaminated water
2 Undernutrition Poor grassland management (under or over-stocking); poor winter feeding; inadequate intake/quality of protein, energy; ketosis
3 Parasitism Lungs (hoose); gut (Ostertagia, Nematodirus, Coccidia); liver (fluke); skin (mange, lice, ticks, keds, fly strike); brain (gid)
4 Infection Current, or in early life, especially chronic infection: viral (influenza; BVD/Mucosal disease/IBR; rotavirus; Corona virus; parvovirus; adenovirus; orf); bacterial (Salmonella, Johne's disease, Listeria, Leptospira, Pasteurella, Haemophilus, TB, actinobacillosis, actinomycosis); protozoal (Coccidia, Cryptosporidia, Babesia, Eperythrozoon); mycoplasmal; fungal (Mucor, Aspergillus, ringworm, zygomycosis) etc
5 Severe mineral deficiency P, Cu, Co, Se, I, and rarely Ca, Mg, Zn, Mn, Na
6 Severe vitamin deficiency B12, thiamine (CCN), and rarely A, D3, E
7 Poisoning/intoxication (especially chronic) Bacterial (E. coli, C. pyogenes etc); fungal (ergot, aflatoxin etc); plant (cottonseed (gossypol), brassica, acorn, cyanogenetic glucosides, alkaloids (especially ragwort), bracken, oxalate, fescue); ruminal lactic acidosis (grain, molasses poisoning); chemical (herbicides, fungicides, pesticides, side effect of antibiotic or therapeutic drugs (especially if over-dosed), ammonia/urea, nitrate, petroleum products, antifreeze, mineral compounds (As, Pb, F, Mg, Na, Cu, Co, Se, I, Zn, Mn); water toxicity etc); algal etc
8 Pain/inflammation Lameness (foot rot, sole abscess, laminitis, arthritis, osteomyelitis, fractures, dislocations); pain / inflammation elsewhere (sore mouth / teeth / gum / tongue; pharyngeal lesions etc; pleuritis, peritonitis, reticulitis, endocarditis, pericarditis; mastitis, sinusitis, meningitis, encephalitis, castration, dehorning)
9 Internal disorders (especially lesions present from early life) Lung (hoose, fog fever, abscess, infection, pneumonic lesions from early life); liver (abscess, liver disease); gastrointestinal tract (ruminal lactic acidosis, vagal indigestion, ruminal or omasal impaction; scour/gastroenteritis, winter dysentery, bloat, abomasal ulcer, bowel strangulation); kidney/bladder (inflammation, abscess, urolithiasis); abscess/sepsis (lungs, liver, kidneys, mastitis, peritonitis, pharyngeal injury)


10 Anaemia Nutritional (deficiency of protein/energy, Cu, Co, Fe); parasitic (lice, fluke, worms etc); haemolytic (bacterial, protozoal, viral); aplastic / toxic (plant poisoning (kale, bracken etc); haemorrhagic (warfarin); immunomediated etc
11 Allergy Lungs, gut, skin, immunomediated
12 Immunosuppression Toxic, viral; neonatal agammaglobulinaemia (insufficient colostrum in neonates)
13 Genetics Genetic defects, mannosidosis, poor genetic potential).
14 Fever See infection, intoxication, allergy
15 Cancer Lymphosarcoma, leucosis



1. IDENTIFY AND CORRECT THE CAUSAL FACTORS (see above), especially poor water intake/quality and basic faults of nutrition, poor control of parasites and infection.

2. MINERAL SUPPLEMENTS?: If herd levels of P, Cu, Se, I or Co are low or very low on blood test, it is advisable to increase their supply.

A quick way to check if mineral deficiency is involved is to give a good mineral supplement high in trace-elements. See the enclosed notes on mineral supplements. If the animals do not show a good response within 3-6 weeks, the cause is unlikely to be mineral deficiency.

If minerals are only marginally deficient in blood, further supplementation with those minerals is unlikely to improve growth rate.