– Dr. Les Anderson, University of Kentucky
The easiest road to maximum breeding efficiency in the beef cow-calf industry is through estrous synchronization and AI (ESAI). Estrous synchronization helps shorten the calving season, increases herd pregnancy rates, and helps increase calf uniformity and weight (calves are typically older).
Use of ESAI can improve productivity and revenue. Recent research from Dr. Cliff Lamb examined the short-term economic impact of a breeding system that included FTAI + natural service or just natural service in about 1,200 females on 8 different farms (Table 1). The breeding seasons began and ended on the same day in both groups on all farms. A partial budget was used to compare the positive economic impact (added revenue, reduced costs) with the negative Continue reading
– Glenn Selk, Oklahoma State University
In addition to being the greatest cause of baby calf mortality, calving difficulty markedly reduces reproductive performance during the next breeding season. Cattle suffering from calving difficulty have been reported (Brinks, et al. 1973) to have pregnancy rates decreased by 14% and those that did become pregnant to calve 13 days later at the next calving. Results from a Montana study (Doornbos, et al., 1984) showed that heifers receiving assistance in early stage 2 of parturition returned to heat earlier in the post-calving period and had higher pregnancy rates than heifers receiving traditionally accepted obstetric assistance. In this study, heifers were either Continue reading
– Carla L. Huston, DVM, PhD, ACVPM, Dept. of Pathobiology and Population Medicine, Mississippi State University College of Veterinary Medicine
The best defense against failure of passive transfer (FPT) is good colostrum management, ensuring that each calf receives an adequate amount of good quality colostrum shortly after birth.
With spring fast approaching, many of us are well into calving season. An awareness of potential post-calving complications and disorders can be helpful when preparing to deal with problems we may encounter in our beef herds. One frequent problem encountered during calving season is failure of passive transfer (FPT), which occurs when a newborn calf does not receive adequate colostrum.
The importance of colostrum: Colostrum is the first milk produced by the dam following calving. It is a rich source of immunoglobulins, fat (energy), vitamins and minerals. The major role of colostrum is to passively transfer immunity from the dam to her calf. Calves are born agammaglobulinemic, or without Continue reading
– Sandy Johnson, Extension Beef Specialist, Kansas State University
For an increasing number of producers, artificial insemination (AI) and estrus synchronization are tools that help them reach their production goals and allow them to take advantage of genetic choices only available through AI. Reduced risk of calving difficulty from use of high accuracy calving ease sires on replacement heifers is a great advantage to AI users.
Fixed-time AI protocols have allowed producers to eliminate the time and expense of heat detection and still achieve industry-acceptable pregnancy rates to AI. However, information about estrous status at AI may allow producers to target expenditures for AI more effectively. While this may seem hard to understand coming from someone who has spent years talking about fixed-time AI, let me share some research that will explain further.
First, a low cost, accurate method of heat detection is now available in the form of Continue reading
– Joseph C. Dalton, Ph.D., Professor, University of Idaho
One of the most frequent questions about AI technique focuses on the site of semen deposition, specifically, whether uterine horn breeding results in greater fertility than traditional uterine body breeding.
First, a quick review of anatomy. The cow and heifer reproductive tract includes the vagina, cervix, uterine body, two uterine horns, two oviducts and two ovaries. Following ovulation, the ovum (egg) moves down the oviduct to the site of fertilization, the ampullary-isthmic junction (AIJ). The AIJ is where the ampulla (upper portion) of the oviduct transitions into the isthmus (lower portion) of the oviduct. Following fertilization, the embryo enters the uterus a few days later.
The thought process is horn breeding, in which semen is deposited in each uterine horn during AI, should result in Continue reading
– John F. Grimes, OSU Extension Beef Coordinator
Calving season is underway to some degree for many producers. If you have not started your calving season, you likely will soon. Calving time is an exciting period for producers as they are seeing the results of their genetic choices and management decisions coming to reality. Warmer weather and green pastures will develop in the coming weeks. The calf crop will grow and develop quickly through the spring and summer months. While this is taking place, the producer will set the 2019 calf crop motion with the onset of the breeding season.
Before the start of this breeding season, I would encourage producers to critically evaluate the production goals for your herd. Do the type of cattle that you produce adequately target your chosen market? If you sell your calves as feeder calves in the fall, your goal should be to sell as many healthy feeder calves with excellent weaning weights as possible. If you retain ownership after weaning and finish your calves to harvest weights, your priorities will Continue reading
– Glenn Selk, Oklahoma State University
Although the spring calving season may still be ongoing, the next breeding season is only a few weeks away. Now is the time to schedule the old and new bulls for their pre-breeding soundness examination.
For the breeding soundness evaluation to be successful, bulls should be evaluated 30 to 60 days before the start of breeding. It is important to allow sufficient time to replace questionable bulls. Bulls could also be evaluated at the end of breeding to determine if their fertility decreased. A breeding soundness exam is administered by a veterinarian and includes Continue reading
– Justin Sexten, Ph.D., Director, CAB Supply Development
You hear more about mature cow size and growth potential of calves, now that profit ebbs and flows with the cycle. We’ve written about mature size, but not much about how to use the relevant tools to change it. So now, let’s examine the strategies and tools available, and the unintended consequences of ignoring them.
Commercial breeders can draw on more selection tools than ever before to improve the next generation of cows to match the market and ranch environments. Genomic testing can identify sires in multi-bull pastures while indexing heifer genetic potential and sorting outliers for adaptability and docility. You could start with Continue reading
– Dr. Glenn Selk, Oklahoma State University Emeritus Extension Animal Scientist
Does the severity (coldness or mildness) of the winter have an impact on spring-born calf birth weights? Ranchers have asked that question during many springs and veterinarians have speculated for years. The debate rages on! This is obviously a difficult subject to research because you cannot have a “control” group of cows to compare to a “treatment” group that is exposed to a cold winter while still running on the same pasture. Therefore research data on this subject is limited.
University of Nebraska researchers have done the next best thing. They have Continue reading
– Matt Spangler, UNL Associate Professor and Beef Genetics Extension Specialist
National Cattle Evaluation has never been static, and future changes are inevitable as science continues to advance. Photo courtesy of Matt Spangler.
The majority of beef breed associations have made (or are currently making) substantial changes to their National Cattle Evaluation (NCE). These changes ultimately benefit commercial bull buyers by providing improved Expected Progeny Differences (EPDs) and improved economic selection indices. This brief article is not meant to be an exhaustive list of the changes to NCE by breed organization, but rather to highlight changes in general and the benefits Continue reading