09/01/2023
Why are there so many AI protocols around!?🧐
When you are preparing to start an AI program, or even an ET program, you may have noticed that there is an ocean of information out there and a list of synchronisation protocols as long as your arm!
It is not uncommon for this to become overwhelming – but don't worry, we've got you!
So let’s take a deep dive into why there are so many variations and how to make sure you are using the right program for your herd.
✅Breed - not every breed responds the same to various products. Bos indicus animals like brahmans have different requirements when it comes to progesterone and other hormones. This is because they metabolise them at a slower rate. On the other end of the scale, you have high producing dairy cows who have an extremely fast rate of hormone metabolism. Therefore, for best results, bos indicus herds, bos ta**us herds and dairy herds need to be treated differently (1,2,3,4).
✅Age – heifers and cows have different nutritional requirements and are at different stages of their physiological development. Hormone metabolism and production vary in alignment with these different production stages. Heifer programs will therefore have different dose rates to cow programs (5,9).
✅Body condition/lactation status – nutrient intake drives hormone function. Animals that are lactating or that are in lower body condition often struggle to produce hormones at the right level and time to grow an egg, ovulate and maintain a pregnancy. There are products that can support animals through this period (as long as they are on a rising plane of nutrition), therefore, when designing a program for these animals there may be some tweaks to the standard program you normally use (6,7).
✅EU accreditation – farms that have EU accreditation also have restrictions on the use of oestradiol products, meaning other products need to be used which can change the length and timings of interventions in a program (8,10).
✅Products – like all things, over time the products we use in AI programs change. As we have learnt more about cow physiology, new products have been developed to try and both shorten the time needed to run a program and to improve the results. Due to this, the protocols associated with certain products have also changed. So when running a program, it is important to match the products with the type of protocol being used – it is often not as easy as replacing one product with another and expecting the same outcome! (11)
✅Fixed Time AI, Heat Detection or a Combination of Both – fixed time AI programs are very different to heat detection programs, with the biggest difference being that you don’t need to watch animals come on heat in fixed time AI. Different products are used to induce ovulation so its not a one size fits all approach. There are also options where programs can incorporate both – meaning another variation!
⁉️ So how do you know what program to use?
This is where your repro vet comes in! 🎉
They have the expertise in animal physiology, an understanding of your herd production goals and an in depth understanding of how reproductive hormones and veterinary drugs work. This means they can tailor a program to suit your individual needs. 🐮
References:
1. E.O.S. Batista, R.V. Sala, M.D.D.V. Ortolan, E.F. Jesus, T.A. Del Valle, F.P. Renno, C.H. Macabelli, M.R. Chiaratti, A.H. Souza, P.S. Baruselli (2020), “Hepatic mRNA expression of enzymes associated with progesterone metabolism and its impact on ovarian and endocrine responses in Nelore (Bos indicus) and Holstein (Bos ta**us) heifers with differing feed intakes”, Theriogenology, v. 143, pp. 113-122
2. G.A. Bó, P.S. Baruselli, M.F. Mart´ınez, (2003) “Pattern and manipulation of follicular development in bos indicus cattle”, Animal Reproduction Science, v. 78, pp. 307-326
3. MM Izzo, M Humphris, L Pryor, A Perry and JM Morton (2018) “Reproductive performance of cows after fixed-time artificial insemination with ovulation synchronisation and re-synchrony in southern Australian dairy herds”, Australian Veterinary Journal, v. 96, no. 4
4. Roberto Sartori, Lindsay U. Gimenes, Pedro L.J. Monteiro Jr, Leonardo F. Melo, Pietro S. Baruselli, Michele R. Bastos (2016) “Metabolic and endocrine differences between Bos ta**us and Bos indicus females that impact the interaction of nutrition with reproduction”, Theriogenology, v. 86, pp. 32-40
5. T. C. Bruinjé, J. P. Rosadiuk, F. Moslemipur, H. Sauerwein, M. A. Steele, and D. J. Ambrose (2021), “Differing planes of pre- and postweaning phase nutrition in Holstein heifers: II. Effects on circulating leptin, luteinizing hormone, and age at puberty”, Journal of Dairy Science, v. 104, pp. 1153-1163
6. Michael J. D'Occhio, Pietro S. Baruselli, Giuseppe Campanile (2019) “Influence of nutrition, body condition, and metabolic status on reproduction in female beef cattle: A review”, Theriogenology, v. 125, pp. 277-284
7. Ricardo C. Chebel, Luís G. D. Mendonça, and Pietro S. Baruselli (2018) “Association between body condition score change during the dry period and postpartum health and performance”, Journal of Dairy Science, v. 101, pp. 4595-4614
8. David Hawkins (2013) “Progesterone Based Synchrony Programmes in Dairy Cattle – Recent New Zealand Research”, Jornadas Pro Leche
9. Richard Núñez-Oliveraa, Federico Cuadroa, Alejo Menchacaa (2019) “Is prostaglandin F2α administration at the beginning of a progesterone and estradiol-based treatment for FTAI an effective strategy in Bos ta**us heifers?”, Animal Reproduction Science, v. 210
10. Marcos G. Colazo, Reuben J. Mapletoft (2014), “A review of current timed-AI (TAI) programs for beef and dairy cattle”, Continental Veterinary Journal, v. 55
11. Lucas Oliveira e Silva, Alessio Valenza, Rodrigo Lemos Olivieri Rodrigues Alves, Mateus Anastacio da Silva, Taynara Jaqueline Barreiro da Silva, Jessica Cristina Lemos Motta, Jessica Nora Drum, Guilherme Madureira, Alexandre Henryli de Souza, Roberto Sartori (2021), “Progesterone release profile and follicular development in Holstein cows receiving intravaginal progesterone devices”, Theriogenology, v. 172, pp. 207-215
