Welcome to the Dairy Reproduction Very Special Edition! Practice Bulletin. This issue: REPRO READY WORKSHOP! Repro Ready Workshop Page 2.

Transcription

1 Sept/Oct 2012 Practice Bulletin Welcome to the Dairy Reproduction Very Special Edition! This issue of the Vet4Farm Practice Bulletin is entirely dedicated to dairy cow reproduction. This level of attention is no mistake! Reproduction done well has an enormous impact on farm production and profitability. Unfortunately exceptional results do not happen on their own, it takes substantial effort and planning to achieve them! Throughout this issue we have highlighted some of the most important areas for you to think about in your farming operation. To get the most out of mating season this year we strongly recommend you attend our: REPRO READY WORKSHOP! This year s workshop will take place on Wednesday 26 th September in Invercargill. Please call us on now to book your place! This issue: Page 1. Repro Ready Workshop Page 2. Metri-checking and Treatment Page 3. Non-Cyclers Page 4. Heat Detection Joke of the Month Page 5. Heifer Rearing Weaning to Mating Page 6. Fertility Focus Why is the 6- week in calf rate important? Page 1

2 Metri-checking and Treatment So the cows have calved, now what needs doing to get them back into calf? One of the conditions which has a large impact come mating time is the number of dirty cows in the herd. Endometritis is a low-grade inflammation of the lining of the uterus that affects fertility and increases the period from calving to conception. New Zealand studies have shown that cows with endometritis have: % higher empty rate 2. If they do conceive they are 2 3 weeks later in doing so 3. The total cost of endometritis in a 250 herd is $ $8500. Some cows are more "at risk" than other cows of having endometritis. These are cows that have had assisted calvings, retained foetal membranes, twins, or observed vaginal discharge; or have been down with milk fever/ grass staggers, induced, or unwell after calving. It should be an essential part of the farm year that these cows are checked for infection. Having said that studies have shown that checking just the at risk' cows will detect only around 30% of the cows that develop endometritis after calving so if possible the entire herd should be checked. There are two options for metri-checking Checking batches of cows every two weeks Checking the entire herd 1 month before the planned start of mating Any cow that has been calved for more than two weeks should be tested. Checking the cows in batches at two week intervals will mean that cows with endometritis are detected and treated as early as possible. Ultimately some of the cows that are treated would have eventually self-cured but treating them allows more time for the uterus to recover before mating. Treating one month out from calving means less cows will be treated but they also have less time to cycle before mating. When metrichecking 1 month before mating we can utilise the latest research which recommends palpating dirty cows for CLs. The presence of a CL is then used to determine if treatment with PG is appropriate or whether intrauterine antibiotics continues to be the best course of action. The metri-checking process can occur with minimal disruption during an afternoon milking. The cows are marked and drafted out at milking the next morning. A vet and/or tech depending on the numbers involved then comes out and infuses antibiotics directly into the uterus. We have found that this system results in the least disruption to the herd and the least time with cows off pasture. Get in touch with us now to discuss the best options for your herd and to book in times for metri-checking. Page 2

3 Non-cyclers During the post-calving recovery period a cow s reproductive tract must return to normal and cycling must start again. The first visible post-calving heat in a healthy cow that has had an uncomplicated calving should occur within 6 weeks. About 25% of late calving cows may need to be treated as non-cyclers whilst less than 10% of cows calving in the first 4 weeks after the Planned Start of Calving should require treatment. Factors contributing to a Non-cycling problem: Poorly grown heifers Young cows first calvers need an extra 10 days to start cycling Breed more friesians are treated as opposed to crossbreeds or jerseys BCS Calving condition score, condition loss post calving and condition score when mating. Abnormal calvings and uterine infections The treatment of non-cycling cows is often a large yearly expense in the Dairy herd so it is critical that we ensure you get the largest return possible from your investment. Treating non-cyclers requires planning and careful attention to heat detection. Non-cyclers decrease two of the key drivers of 6 week in calf rate the three week submission rate and the conception rate.. We recommend treatment of non-cyclers is initiated 7-10 days before Mating Start Date (MSD) to maximise early conception opportunities. In order to ensure that we identify non-cycling cows in time it is necessary to record premating heats. Tail painting 32 days prior to the mating start date will allow you to identify problem cows and they can be drafted out for treatment. Studies from New Zealand have shown by using non-cycling treatment 10 days prior to the planned start of mating that conception can be advanced by days. This equates to a cow that calves earlier so will have more days in milk for the herd. The studies showed that a net return of $80 per cow would be achieved. While treatment will not decrease your eventual empty rate it will increase the chances of the cows getting in calf to AI. The economic benefit of treating non-cycling cows decreases the later you identify and treat them. So make a plan now, have your dates on the wall and get out there early to identify the cows and ensure you get the maximum return on your investment. Page 3

4 Heat detection Good heat detection has a major impact on your overall herd reproductive performance. While it seems obvious that cows not detected on heat will not get pregnant to AB, you also waste semen if heat detection is not accurate. Farmers generally regard themselves as good at heat detection yet research has shown that in 25% of seasonal calving herds heat detection errors are likely to be limiting reproductive performance. Now is a good time to review heat detection from last year and start thinking about what you need to do this year. There are two types of errors that can occur during heat detection. Cows that are genuinely on heat are not noticed/recorded. Cow is recorded as being on heat when she is not. If you miss a lot of heats your submission rate will be low and if you present cows that are not on heat for AB then your conception rate will be low. Top farmers will achieve a 95% 3-week submission rate. Signs a cow is most likely on heat: She is standing to be mounted by other cows Tail paint is removed Heat mount detector is triggered Signs a cow MAY be on heat She attempts to mount other cows Tail paint is rubbed but not removed She is restless or bellowing She has poor milk letdown Mucus around the vulva Mud marks on the flanks Heat mount detector is lost. It is important that everyone on the farm knows the signs of heat and is recording the cows involved. Normally a cow will show signs of heat every days (avg. 21 days). The average duration of a heat is 14 hours but may be as short as 2 hours or as long as 28 hours. With many farms solely relying on in-shed heat detection it is often best to designate a single, well trained, person who is confident in interpreting the signs of a cow on heat to do the job. The ideal method of heat detection is to carry out twice daily paddock heats and record all signs of heat and the cows involved. This allows you to identify not just the on-heat cows but also those who are showing early signs of heat. Recording pre-mating heats to identify non-cyclers is a great time to refresh everyone s knowledge of the signs of heat and gain confidence in heat detection before it comes to the crunch time at mating. JOKE OF THE MONTH A rancher needs a bull to service his cows but needs to borrow the money from the bank. The banker who lent the money comes by a week later to see how his investment is doing. The farmer complains that the bull just eats grass and won't even look at the cows. The banker suggests that a veterinarian have a look at the bull. The next week the banker returns to see if the vet helped. The farmer looks very pleased: "The bull has serviced all my cows, broke through the fence, and has serviced all of my neighbor's cows." "Wow," says the banker. "What did the vet do to that bull?" "Just gave him some pills," replied the farmer. "What kind of pills?" asked the banker. "I don't know," said the farmer. "But they sort of taste like chocolate." Page 4

5 Heifer Rearing Weaning to Mating Calf and heifer management on many farms is a limiting factor to herd reproductive performance. The first step to making improvements is to assess the calves and heifers in your herd. From the day a heifer is born you start the process of maximising her potential to get in calf. Good calf management must be followed up with a focus on heifers from weaning right through to their first calving. It is critical to remember that whilst we want to feed heifers to reach target weights, we also want them to have good skeletal development. The first 12 months of the heifer s life are the most important for muscle and skeletal development with it being essential that they have high quality, high protein, pasture (and/or supplementary feed) so that they achieve their targets. When you are choosing a heifer grazier for your animals there are many factors to look at but a critical one to look at is access to weigh scales. Many people rely on the eye-o-meter when it comes to heifer weights using scales ensures that you have accurate records of how the animals are doing. Knowing exact weights also allows you to identify animals that are struggling so they can be preferentially fed. Regular drenching and administration of trace elements Selenium, copper and VitB12 also has a big impact on the heifer s growth rates. A trace element supplementation program can be developed for your farms needs in conjunction with blood and herbage tests. Below are the target live weights for different breeds at different ages. Of the greatest importance is 60% liveweight target at 15 months as this is when you will be starting your mating program. They must remain on a rising plain of nutrition through mating and right through to 90% of mature liveweight at calving. Mature Cow Liveweight Jersey 440kg Xbred 480kg Friesian 535kg 6 months 30% of mature liveweight 132kg 144kg 160kg 15 months 60% of mature 264kg 288kg 320kg liveweight 22 months 90% of mature 396kg 432kg 481kg liveweight Your heifers are the future of your herd. Take the time now to ensure that you have everything you need to give them the best possible start to life which in turn will maximise their lifetime production. We are always available to discuss options with you. Page 5

6 Fertility Focus Why is the 6-week in calf rate so important? In seasonal calving herds the 6-week in calf rate has been found to be the most important means of assessing reproductive performance. The biggest drivers of the 6-week in calf rate are the 3-week submission rate and the conception rate. Cows that calve late are more likely to be non-cycling and have lower conception rates during the AI period. Extending mating to lower empty rates spreads the calving pattern which in turn has a negative impact on the subsequent mating period. So what can we do? Heat detection a missed heat results in a loss of about $200. It needs to be done well! Heat detection aids Apply tail paint 32 days prior to the planned start of mating to allow the identification of noncyclers. Use heat mount devices in addition to tail paint to improve detection rates. Improve conception rate (CR) Cow health, particularly endometritis, is known to have a severe negative effect. The first heat post calving only has a CR of 35% (as opposed to 60%) so ensure the majority of the herd is cycling before the start of mating. o Body condition, calving pattern, non-cyclers and heat detection will all affect CR as well. Bull Power Have the correct number of bulls (3% of the number of cows to be mated - plus one). o Bulls should be tested for and vaccinated against BVD and leptospirosis, have no history of illness within two months of the start of mating and must not be lame. Vet 4 Farm Ltd PO Box 7119 Invercargill 9844 Phone: 0800 VET 4 FARM ( ) admin@vet4farm.co.nz Website: Like us on Facebook Page 6