9 February 1996

Dont forget to keep the score in the run-up to lambing

CATTLE

ROUTINE fertility visits remain high with non-detection of oestrus again the main concern, writes Dr Tony Andrews. The number of cows in-calf when presented for pregnancy diagnosis has been high.

Fertility could fall in the next couple of months as feeding rates are cut back, partly as a result of dwindling feed supplies and also due to over-quota milk production.

Calving difficulties have fallen, as has the incidence of cystic ovaries.

Beware fatty livers, which may be due to unsupervised grazing of the rapid autumn grass growth. Downer cow incidence is also up.

The slight fall in acetonaemia (ketosis) goes against predictions (Jan 12) and may indicate that energy has been maintained at higher levels than was anticipated.

This may reflect the wider use of total mixed rations that ensure high dry matter and energy intakes. But whether this will continue during the rest of the winter is questionable. It is likely some herds will start to show falls in yield and milk protein content as the winter continues. Cows could become thinner and then suffer reduced fertility.

Mastitis incidence was down last month but half the cases seen were coliforms. Environmental mastitis is still a concern. More cows are injuring teats. Ensure adequately clean calving accommodation with clean, well-bedded cubicles or straw yards. In some instances passageways and cubicles should be inspected and cleaned more than twice a day.

Lameness fell in early January – perhaps reflecting less infection on walking surfaces due to the cold.

The return to damp, wet conditions later in the month allowed a marked rise in lameness. All types of injury and trauma were up, particularly involving the leg above the foot. This suggests slippery, poorly cleaned yard surfaces.

There has been a rise in reports of traumatic reticulitis, so-called "wire" disease (see p39). In some cases this has been due to tyres used to weigh down silage clamps disintegrating and dropping into the silage. One severe problem reported by Hants vet Jonathan Harwood involved two tyres entering the diet feeder and being partially dispensed after break-up. Infertility in growing cattle remains high again partly due to poor heat detection.

In the south-west of England there were several husk outbreaks in unvaccinated herds.

Pneumonia was the main cause for concern in calves last month with respiratory syncytial virus (RSV) a main cause. Alimentary problems were also common, including acidosis, abomasal ulcers, bloat, BVD and indigestion.

Scours were mainly caused by rotavirus, with some severe outbreaks of coronavirus. Ensure adequate colostrum intake in calves (see p39) and that supply is continued for several days to ensure continued stomach immunity.

In some instances, where colostrum has not been stored, substitutes may be required, especially when they contain anti- bodies to the causes of the disease.

SHEEP

Pregnancy toxaemia (twin lamb disease) is now being reported regularly from many areas and will continue over the next few months.

Sheep must be condition-scored monthly to identify fat levels. This should be fortnightly as lambing approaches. Before the last third of pregnancy ewes should be separated into groups according to condition and whether they contain singles, twins or multiples. Broken-mouthed ewes and ewe lambs should be placed in superior feeding groups. Any groups in poor condition or with multiple lambs should receive feed at least six weeks before lambing. This should gradually be raised up to lambing.

Ewe condition score at lambing should be about 2.5 for hill and 3.5 for lowland flocks. Over-conditioned animals will also develop twin lamb disease and it is much harder to treat or prevent them going down with it. The aim in this group, when spotted early in pregnancy, is to reduce their condition during this time. But when not detected until four to six weeks before lambing, it is important to monitor their appetite for both roughage and concentrate. Exercise helps use ketones produced. Ewes should be encouraged to walk from one feeding place to another.

Mastitis is occurring at lambing. Check all udders after lambing to ensure they are not infected and can produce sufficient colostrum.

PIGS

Adult pig ailments include outbreaks of abortion and high stillbirth numbers. Mastitis and farrowing fever were also reported.

Most pig practices have seen a rise in respiratory disease in growing pigs. One outbreak of chronic pleuropneumonia resulted in a high culling rate due to poor growth. Feed intakes of finishers were affected in some outbreaks of swine influenza. Enzootic pneumonia hit several herds, often with poor growth rates of about half the pigs as well as some showing severe clinical diseases.

Colitis in 20-40kg pigs was also seen in several herds, often of high health status. In some cases this has been due to ingredient substitution in the ration to cut feed costs, while others have responded to antibiotic therapy. Poor performance has been the result of diets with limited protein and energy.

Most piglet disease pointed to underlying infection, often modified by herd management. PRRS contributed in one herd to a pre-weaning mortality of 25-30% and lasted for over five weeks.

Piglet enteritis was rife on many farms. Overlaying of piglets has been seen in the cold weather, particularly in outdoor units. &#42


&#8226 Infertile/thin cows or heifers.

&#8226 Environmental mastitis.

&#8226 Ketosis in cows reaching peak lactation.

&#8226 Lameness and injury when floors are wet.

&#8226 Skin infections including ringworm and lice in youngstock.


&#8226 Lameness.

&#8226 Farrowing fever when hygiene poor.

&#8226 Respiratory ailments.

&#8226 Diarrhoea.

&#8226 Damp, exposure, chilling and overlaying of piglets outside.


&#8226 Condition score of ewes.

&#8226 Pregnancy toxaemia.

&#8226 Check udders for mastitis.

&#8226 Ensure ewes receive clostridial vaccination.

&#8226 Hypothermia due to exposure or inadequate nutrition.

Check the condition of ewes fortnightly in the run-up to lambing. Those in poor shape need extra feed.