Timely Reminders & Handy Hints for November

  • Pink eye in calves - we are coming up to the Pink Eye season in calves.  A single dose of Piliguard vaccine given 3-6 weeks before the risk period will significantly reduce the risk of an outbreak.
  • Covexin 10 - if you have unexplained deaths in young stock every year despite using 5 in 1 vaccine, you should consider using Covexin 10 in 1 vaccinate, which provides additional protection against two other major clostridial diseases - Clostridium sordelli and Clostridium perfringens type A.
  • Last year we saw a case of several acute deaths in calves which had been worm drenched through the milk.  This is a very timely reminder, not to add worm drench, especially levamisole or abamectin, to milk.  Each season we see 2-3 cases of either levamisole toxicity or abamectin toxicity in calves under 100kg.
  • Poa aquatic (also known as Glyceria maxima) is a grass that proliferates in wet areas of paddocks and drains.  Under the right environmental conditions it can accumulate cyanide - which can be fatal if ingested.  Sudden death in a wet paddock could be potentially due to cyanide.  If you have suspicions contact your vet for identification of the grass.
  • Polioencephalomalacia (P.E.) - this nervous condition of calves is now the most common disease of calves that we see over the summer months.  Polioencephalomalacia (PE or CCN) is considered to be associated with a change of diet from a fibrous stalky diet to a lush, rapidly growing grass diet.  High sulphur intakes have also been incriminated.  P.E. is a vitamin B1 deficiency.  Clinically, calves with P.E. show nervous signs.  They may appear blind, staggery and develop muscle tremors, before becoming recumbent, with severe convulsions and die.  We traditionally see P.E. cases from late November, peaking late Dec/early Jan.

Individual calves, if treated early enough with injectable Vitamin B1, respond well and make a full recovery.  In the face of an 'outbreak', it is well worth considering the prophylactic use of an oral drench of Vitamin B1, for the entire mob of calves.

Making the most from mating

Recommended mating lengths of 10 weeks are considered optimal to ensure all cows are calved by the 10th of October (if the PSM was the 23rd of October) to retain a healthy calving spread.  In this scenario a 10 week mating period would have bull removal occurring on the 1st of January.

The number of lactation days is one of the key economic drivers of your farms profitability.  Therefore success of mating should be measured in how quickly they get in calf (3 and 6 week in-calf rate) as well as the empty rate.  The reality of a 10 week mating period is that cows have just over 3 cycles to get back in calf.  The average cow has a ~50% chance of getting in calf at each cycle.  If given every opportunity she would have a 12.5% chance of being empty after 3 cycles.  However if she was to miss the first round of AI she will have a 25% chance of being empty.  Likewise if a heat is missed in the second round she has a 50% chance of being empty!

If your 3 week submission rate is tracking below the >90% target, review your heat detection practices immediately and look to get non-cyclers examined and treated.  Ideally all eligible non-cyclers (calves >40 days) should be mated inside of 3 weeks.  This involves hormonal treatment by day 11 of mating at the latest, or day 18 to achieve 3 cycles within 70 days.  Failure to take proactive action will result in not only a protracted calving spread but also a higher empty rate.

All eligible cows not mated after day 24 of mating should also be examined and treated accordingly.

Avoid Over Milking

Mating is only a matter of weeks away.  The daily drafting of on heat cows can cause disruption to the milking routine.  This can result in over milking which is a risk factor for mastitis.  Now is the ideal time to make sure all staff are milking your cows in a way that reduces the chance of them getting mastitis.  Quickly check the following before milkings get busier with heat detection:

  • Does every teat of every cow get teat-sprayed every milking?
  • Is there an easy recipe to follow so that anyone can make up the teat-spray?
  • Does everyone break the vacuum before removing the cups?
  • Is there a BMSCC trigger level above which the herd gets stripped?
  • Can everyone recognise the signs of over milking?
    • Red or blue teats when the cups comes off
    • A ring of swelling at the top of the teat
    • Open teat ends
  • Can everyone recognise mastitis?

If over milking is occurring you may have to hang up clusters between rows or possibly not use the last few clusters.  Above all make sure everyone is aware that over milking is possible due to disruption caused by drafting and is a risk factor for mastitis.  Have a successful mating.

Nursing Downer Cows

A recent conference session with Victorian vet Phil Poulton, PhD, highlighted the importance of nursing care given to downer cows.  A recently published study of Phil's showed 43% of cows with good nursing care recovered after 10 days - regardless of the initial cause of being down - compared to only 6%  with poor nursing care.  Downer cows are prone to a host of secondary problems including nerve damage, dislocated hips, muscle and spinal problems, which can be minimised when nursed appropriately.

Good nursing care includes:

  • Providing shelter from cold and rain (ideally in a clean, dry shed)
  • Thick bedding of hay, straw, sawdust, rice hulls or sand
  • Barriers to prevent crawling and walking (if unable to walk when lifted)
  • Lifted 1-2 times daily when able to support some weight, lowered when unable
  • Rolled several times daily to take pressure off lower leg
  • Access to high quality feed and water
  • Teat disinfection twice daily, milking if udder leaking
  • Moved using front-end loading bucket, not hip lifters.

For more detailed information see the Dairy Australia website or contact your prime vet.