The Angus breed has been one of the largest adopters of AI in the world. Many cows and heifers are inseminated each year and the proportion of commercial herds using AI grows each year. Higher bull prices this year encourage commercial breeders to think seriously about using AI in their herds. What then are the considerations for commercial breeders and how do they differ from the seedstock producers? Seedstock herds and AI Seedstock Angus herds are AI users. Last year 30% of Angus registrations were sired using AI and 14% from ET. Most seedstock breeders should use some AI for the following reasons: · AI allows use of the best bulls in the world. Bulls from anywhere in the world can and are used to allow rapid genetic change. However you define "best", AI provides access to animals that are otherwise not available or are very expensive. · AI evens out the playing field for a large number of seedstock breeders. All have access to the same breeding options. It becomes a challenge of how they utilize the genetics available. · Bulls that are proven are widely used with their sons being rapidly multiplied for commercial use. · In seedstock herds, the sustained use of AI has led to dramatic change in the herds involved. Using AI has allowed some breeders to rapidly develop top quality herds with impressive commercial performance. · AI allows better linking of genetics across herds for Breedplan analysis. Seedstock herds need to be well linked to other herds for accurate assessment of their genetics. Common AI sires between herds serve this purpose. · Use of popular genetics. Some seedstock herds use AI to introduce the latest and greatest bull into their herd hoping for higher sale prices for sale stock. · The price of AI is easy to recoup if you are selling bulls and heifers at seedstock prices. Commercial herds and AI People use AI in commercial herds to: · Get greater use of an expensive bull purchased for the herd. More calves by a certain bull also increases the consistency and therefore marketability of your calf drop. · Reduce disease risks from venereal disease · Concentrate calving patterns However, AI is more expensive than natural service. To use AI, you must recoup the additional costs by increased sale prices of the steers or heifers you sell, or by

increasing the value of your replacement heifers. Will you get more for a pen of weaners if they are by AI sires or out of AI dams? Will your feeder steers bring an extra $25 per head to cover the cost of the AI? Example cost breakdown for typical A.I. program for herd of 100 cows: - 2 injections of prostaglandin @ $3.50 per injection = $700 - 2 tins tailpaint @ $11 per tin = $22 - Insemination fee @ $4 per cow (for 80% cycling) = $320 - Inseminator property visit fees = $100 - Labour > Mustering/injection one - 3 hours for two people @ $15/hour = $ 90 > Mustering/injection two/tail painting - 4 hours for two people @ $15/hour = $120 > Four days of heat detection (two half hour sessions per day) @ $15/hour = $60 > Four days of mustering/inseminating (averaging two and a half hours for two people per day) @ $15/hour = $ 300 > Semen @ $25 per straw = $ 2000 Total Cost = $ 3712 Interest @10%: 370 Conception percentage: 70 Number of calves: 56 COST PER A.I. CALF = $72.85 A backup bull is still required to follow the AI Example cost of buying an above average Angus bull ($6,000) and using him under natural mating conditions: - Working life of bull: 3 years - Bull keep: $250/year - Salvage value of bull: $1000 - Net bull cost: $5750 - Interest @10%: $600 - Joining Rate: 50 cows per bull - Conception Percentage: 90 COST PER NATURAL CALF = $47 AI programs in large scale commercial herds show variable results, especially for the first time AI users. Results from over 30 southern herds involving more than 5000 cows in total reported by John Graham DNRE, Vic, and others indicate that the number of live calves born for every 100 cows programmed is on average under 50. The range shows differences from 16% to 68% of cows programmed calving to AI. This report indicates that good results can be achieved but they shouldn't be budgeted on. Experience with AI in commercial herds shows the following results: · Lower conception rates as cows are missed · Late calving cows. Cows that do not conceive or respond to AI slip from being early calvers to the middle of the calving season or worse, to the end. · Some very poor results where few cows cycle and poor conception rates are achieved. · Extra workload. The impact of synchronising programs is that cattle run through the yards more often, heat detection is labour intensive and do-it-yourself AI operators do not achieve the high conception rates that are sometimes expected.

These comments do not infer that AI is of no practical use for commercial herds. Instead it is essential that you consider why you are using AI and be sure that you have good commercial reasons for doing so. If that is the case, then you need to make sure that you do it properly or forget it. AI is not for commercial herds that do it half heartedly. If you are going to use AI, do it well or not at all. Some commercial breeders use AI successfully. Comments from commercial producers who use AI include: "It is a quick means to improve the herd at a reasonable cost. It provides access to genetics that you would otherwise not have been able to afford and gives you much more scope to match different cow types with more suitable bulls. The multiplying effect of the investment justifies the long days." John Jackson, Toolong, Woolsthorpe, Victoria. John has used A.I. at Toolong since 1986. They A.I. 660 head annually. There are not many bulls whose progeny consistently meet the target market specifications. Using A.I. and natural joining on commercial cows allows us to extend the use of a bull thats genetic merit has been proven through their progeny's carcase feedback and on-farm evaluation. A.I. gives us the opportunity to improve the consistency of the performance of the entire herd. Not only the performance of the sale animals but the daughter's performance. It should be remembered that A.I. also allows you to make your mistakes more rapidly, and so is not for heavy speculative use of an unproven sire. Hereford Prime Certificate of Excellence 2001 producer who still uses A.I. in his commercial cow herd after sixteen years. These are the critical areas essential for commercial breeders to consider for successful AI programs. 1. Bull selection. You have two choices, use one or two PROVEN bulls that you know will do what you want or gamble with unproven bulls and take the risk that involves. The proven bulls will be more expensive to use. Semen costs will generally be $30 and up. Proven bulls will have very high accuracy figures, more than 95% accuracy for the growth traits. The unproven bulls may have figures and pictures, but until you can see some of their progeny and talk to breeders who have followed some of their progeny through as breeders and carcases, they will remain risky and some of them will disappoint. Unproven bulls will be less expensive. Some progeny test programs have semen of young test sires available at $10-$25 per dose. On property semen collection services are available for as little as $2.20 per straw. A young bull that you buy and collect fits into the unproven group. Do not put all your eggs into one basket. If you use unproven bulls, use a number of them and spread the risk. Will unproven bulls meet the objective of running an AI program? 2. Get organised. AI does not suit those who are casual and very laid back. You need to start planning well in advance to select early calving cows and to make sure the logistics are well organised. This includes feed, labour, facilities, consumables, back up bulls and records. 3. Nutrition. The key to successful AI programs is to feed the females well. Good nutrition and fertility go hand in hand. You need females calving down in strong condition score 3 and to have plenty of feed available to keep them going. Cows in early lactation have high demands on them and must be well fed to milk and cycle

early. Saving feed or supplementing cows after calving may be required in other than excellent seasons. 4. What to AI? · Well-grown maiden heifers (at least 300 kg liveweight) are the best candidates. . · Cows on their second or subsequent calves are also prime candidates. These early calvers are the most valuable in any herd. AI can not be allowed to make these females late calvers. · Heifers with their first calf at foot will often have cycling problems and lower conception rates. Avoid this group of females where possible. If you are inseminating first calvers, calve heifers a month earlier 5. Post calving interval. Cows need a minimum of 42 days from calving to the start of any AI program. To calve within a 365 day period, most cows have 83 days from calving to rebreed. On average the interval from calving to first heat is 40 to 60 days. Allowing only 42 days as a minimum means that some cows will be on their first heat at the start of the program. This first heat is less fertile and the best results occur when cows have had more sexual rest. They then only have two cycles to get back in calf within the year so a missed AI only gives one backup chance to meet yearly breeding requirements. 6. Synchronization program. Synchronization programs have been very successful in making AI manageable. Prostaglandin (PG) programs are the most common form of synchrony in the beef industry. Prostaglandin is the hormone produced by the non-pregnant uterus and destroys the corpus luteum (secretes hormones required for the establishment of pregnancy) on the ovary. It therefore induces heat. Prostaglandin injections do not work on cows during the first five days of the oestrus cycle. In the one injection technique cows are usually monitored for five days and cows on heat inseminated. The remainder are then injected and five days of heat detection follows. In the two injection technique two injections are given 11 days apart, followed by 3-5 days of insemination. The advantages of this two injection program are tight synchrony and reduced heat detection. Progesterone programs allow for set days of heat detection and A.I., and won't cause abortion when used on a pregnant animal. This allows you to resynchronize the cows for a second round of insemination. Progesterone is the hormone produced by the corpus luteum that is responsible for the establishment and maintenance of pregnancy. Progesterone can be applied either as a vaginal implant (CIDR) or as an ear implant (Crestar). The animal usually comes into heat about two days after the implant is removed. Inseminations according to observed heat will give the best results, however a single blanket insemination of all animals may be done 56 hours after removal or two blanket inseminations at 51 and 75 hours. Usually more cows will be detected on heat with this program, however conception rates will be lower and so the overall result is much the same. 7. Good yards. Quiet handling is essential for good conception rates. Your yards need to be well designed and maintained. 8. Heat detection. Where heat detection is chosen rather than mass insemination, it needs to be done carefully. Considering the cost involved in the rest of the program, shortcutting heat detection is not warranted. Heat checking should be done at least twice each day on daylight and dark. Use heat detection aids like tail paint or heat

markers. Carefully check each cow every time. The same person should do all the heat checking. Only inseminate cows if you've observed proper standing heat. If you don't see them standing correctly, don't waste a dose of semen. Cows are best inseminated 4-20 hours after the onset of standing heat 9. Use professional technicians. To get the highest possible conception results it is advisable to use technicians who are inseminating cows throughout the year. Accurate semen placement with some speed is important. The per head insemination fee that technicians charge is usually a small price to pay given the investment in drugs and semen. 10. When the AI is finished, put in the backup bull. Sire identification is preferred but in commercial herds, the odd calf you can't tell by calving date probably doesn't matter. Don't give females a free cycle between AI and covering them. Leave that for the seedstock herds. You need cows in calf quickly, not late calving females with correct sire identification. 11. Back up bulls need to be fit, active and fertile. If half a group of cows come back onto heat within a three to five day period having been synchronised for the previous heat period, one bull will be very active for that short time. AI can work in commercial herds. The cost is greater and you need to be convinced of higher returns or increased performance from replacement heifers to consider using AI in non seedstock herds. If you have any comments about the use of AI in commercial herds please contact Emma Weatherly or Bob Dent.

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