A one-year study has been undertaken to help decision making in suckler cow nutrition and improve calving and fertility outcomes by metabolic profile (MP) testing.

MP testing is widely used in the dairy industry as a nutritional decision-making tool for milking cows and pre-calving cows, however it is not as commonly used in suckler herds.

The study was led by myself as a SAC ruminant nutritionist and Lorna MacPherson, SAC’s Dairy consultant and was funded by the Scottish Government’s Knowledge Transfer Innovation Fund (KTIF) where the farmers involved were keen to look at nutritional management around calving and how that affected the cow’s nutritional status and subsequent fertility.

The project included 12 farms from across Angus and Fife working with Thrum’s veterinary practice in Kirriemuir and Cameron Greig Veterinary practice in Milnathort.

There were 15 cows per farm – giving 180 in total – which were selected for MP testing based on their expected calving date so that they were blood sampled around one-month pre-calving. The same 15 cows were tested one month into lactation and body condition scores were recorded at each sampling period. No heifers were included in the study.

Key findings were:

• More than 60% of cows had low blood urea, indicating they were short of effective rumen degradable protein (ERDP) in the pre-calving ration. Sufficient ERDP is important for good rumen function and efficient digestion of feed. Low levels may also impact on colostrum quality and milk production. 37% of cows lacked protein after calving – when most of these cows were housed and not at pasture.

• Half of the cows tested pre-calving had high blood NEFAs (non-esterified fatty acids) signifying that they were mobilising body fat reserves at an excessive rate. Post-calving, 20% of cows also had high NEFAs which has been shown in dairy cattle to reduce the chances of them getting back in calf.

• Around 30% of cows were deficient in magnesium pre-calving, and if left uncorrected could lead to metabolic problems such as milk fever or slow calving syndrome at calving time. Post-calving, 25% of cows were deficient in magnesium and at risk of grass staggers when turned out, if magnesium supplementation was not corrected.

• Trace element status in all herds was adequate, with deficiencies in protein and energy being of far greater concern. Many of the herds were oversupplying trace elements (iodine in particular). This is an area that could be better managed to reduce costs associated with over-supplementation.

• MP testing in two herds identified several cows struggling with a disease issue (indicated by low blood albumin levels). Liver fluke was subsequently diagnosed in both herds which had been dosed previously for fluke.