In October 2013 the North Coast Livestock Health and Pest Authority was called to investigate marked weight loss in a group of 16 Hereford cows. The cows ranged in age from 5-8 years and had 2-4 month old calves at foot. The cows had not picked up since calving and had not lost their winter coats. The cattle were not scouring.
The cows were drenched with Nilzan LV Oral (Levamisole75g/L, Oxyclozanide 150g/L) three months previously and a "mectin" based pour-on drench three weeks prior to the visit with no improvement seen. The cows were on a good plane of nutrition. There was ample native pasture and they were supplementary fed. The cows received about 7.5kg of cotton seed per head per week fed over 3 feeds. Approximately 15-20L of molasses was poured over the cotton seed at each feed. The cows were also supplemented with about 0.6kg of a multi-mineral powder per head per week (Table 1).The cattle usually receive an annual multi-mineral injection containing zinc, manganese, copper and selenium. However, the farmer had decided not to give the injection this year and these cows had not received a mineral injection for at least 12 months.
|Multi mineral Loose supplement||Typical analysis|
The cattle appeared bright and alert. They were in poor body condition averaging a body condition score of 1.5-2 (range 1 poor to 5 fat). Their coats were rough, long and a dull red colour. All calves looked healthy with shiny coats and were growing well. Heart rate, temperature and respiratory rate were within normal limits for all cows. Faeces were collected from four adult cows for individual worm egg counts. Blood was collected from five adult cows for copper and selenium analysis and a fluke ELISA.
The worm egg count was negative for strongyles, Nematodirus, tapeworm and coccidia in all samples. The pooled liver fluke ELISA was also negative. Serum GSHPx (selenium) levels were within normal limits. Serum copper levels were extremely low in some animals, indicating severe copper deficiency (Table 2).
|Sample ID||Serum copper (µmol/L
Copper deficiency is quite common on the mid and north coast with many soils low in available copper (Kemsley 2012). Copper availability in the soil is also strongly affected by molybdenum and sulphur levels and possibly iron as well (Kemsley 2012).
Copper functions as an enzyme activator and enzyme constituent, involving a broad range of enzymes (Westwood and Lean 2010). It is a key component of the immune system and has a basic role in iron metabolism and red blood cell maturation (Westwood and Lean 2010). Clinical findings of copper deficiency on the North Coast commonly include ill thrift, anaemia, poor coat colour and scours.
Young stock and cows in late pregnancy are the most susceptible group of animals. In this case sub-clinical copper deficiency probably developed during late pregnancy and became apparent clinically around the time of calving.
The cows were all given a 2mL subcutaneous injection of a copper supplement (60mg/mL copper glycinate) and all calves were given 1mL. It was recommended that this was repeated in six months time. A follow up phone call one week later revealed that all cows had improved significantly.