Guests: Dr. Jim Drackley, University of Illinois at Urbana-Champaign; Dr. Mike Van Amburgh, Cornell University & Dr. Jim Quigley, CargillOur Real Science Exchange pubcast always has leading scientists and industry professionals discussing the latest ideas and trends, and tonight we have three distinguished guests. Dr. Jim Drackley, Dr. Mike Van Amburgh, and Dr. Jim Quigley join us to discuss the weaning period and why it can be so traumatic for dairy calves.Dr. Drackley leads off by describing that this topic is popular because it's still a problem. The advantages of feeding more milk during the milk feeding period are clear, but there can be system failure around the weaning transition from large amounts of milk to starter. There's often some slump in growth or even calf loss in some cases. (04:40)Dr. Drackley emphasizes the importance of a properly texturized feed, starch content in calf starter, weaning age, and feeding too much hay which leads into a discussion about the importance of butyrate over propionate in rumen development. (05:31) Dr. Quigley tackles the idea of weaning age and rumen development, stating that research has found NDF digestibility isn’t mature until the calf has reached a threshold of about 15 kilograms of cumulative NFC intake. The latest NAHMS study suggested a typical weaning age in the industry of about nine weeks and this usually coincides with the NFC threshold (10:39)Dr. Van Amburgh suggests that patience may be lacking when it comes to the weaning transition. Research shows taking more time to transition from milk to solid feed in a stepwise manner can lessen or remove the post-weaning performance lag. (19:41)Dr. Van Amburgh goes on to reiterate the importance of butyrate production in rumen development and that the inclusion of simple sugars into calf starters rather than high levels of starch are beneficial. (21:26)Dr. Drackley then reaffirms the importance of a gradual transition from milk given the cow’s natural lactation curve. A calf would be receiving less and less milk each day, not an abrupt shift to a different diet which often is not mimicked in weaning transition programs. (25:18)Dr. Morrow gives the veterinarian perspective and agrees with the panel that a proper weaning transition program could take away a lot of the respiratory disease impacts on post-weaning performance. (27:14)The panel shifts to speak to the long term impacts of a poor weaning transition program. Dr. Drackley emphasizes calves who experience disease have both lower longevity and lower milk production in the herd. (29:26)Dr. Van Amburgh cites European research that showed if nutrition from weaning on didn’t achieve target body weights at certain stages of physiological development, reproductive efficiency was decreased as a heifer and as a lactating cow. (30:13)  Each panelist gives an overview of the “perfect” calf weaning program. Dr. Quigley emphasizes a slow transition with high diet quality before and after weaning (32:46)Dr. Van Amburgh further underlines the importance of calf starter diet quality, focusing on simple sugars and amino acids, rather than starch and crude protein (37:29)Dr. Drackley focuses on the fact that digestive tract development is allometric during this time in the calf’s life, where the digestive tract develops at a faster rate than the rest of the body. Ensuring the calf has adequate nutrition to support this growth is imperative, and is an important focus for future research. (41:37)Dr. Van Amburgh suggests that changing the way starter is presented to calves so they know it’s feed is critical because they may not be in an environment where they can learn from others. (48:18)The panel wraps up with one piece of advice for calf weaning programs: be patient! (50:33)Please subscribe and share with your industry friends to bring more people to join us around the Real Science Exchange virtual pub table.  If you want one of our new Real Science Exchange t-shirts, screenshot your ratin