David Schingoethe Symposium Recap
By: Samantha Tabert
Dr. Jill L. Anderson – Fat metabolism and utilization in growing dairy calves and heifers: What do we know and what still needs to be researched?
Dr. Jill Anderson began our morning in the David Schingoethe Symposium by first diving into the role of fat for growing calves and heifers, that role being energy intake. From there, Dr. Anderson lead into a literature review about how energy intake determines rate of gain and has an effect on development and performance. The development, specifically regarding timing of puberty, would be the key of this discussion. There are many definitions for puberty and many factors such as body composition, nutrition, and environment that all play a role in how early the onset of puberty is. Dr. Anderson explained that this is the reason she gets excited or concerned about puberty in dairy heifers. It is ideal to get the heifers into puberty earlier since having had more cycles come breeding may help them be more fertile. This would also affect age at breeding and have a great relation to mammary development. Dr. Anderson concluded that first literature review by stressing the need for more research in the areas of mammary development such as growth stage and fat supplementation, and more variety of fatty acids composition.
Dr. Anderson went on to discuss another study that found circulating lipids were impacted by flax and soy oil supplementation. This lead nicely into her conclusion on oilseed meal processing methods either Cold-pressed, which was found to have more fat than the other, or the other being Solvent Extraction. Oilseeds themselves have similarities in fatty acid profiles, placing more impact on the processing method than the source of the oilseeds for circulating lipid metabolites.
Overall, increasing fat percentage in post-weaning heifer diets, as well as realizing that the source and profile of fat may affect how they are utilized by the animal are a couple of the main points from Dr. Andersons presentation.
Mr. Cliff Ocker – Feedstuff fatty acid content, variation, techniques and implications on practical animal nutrition
Mr. Cliff Ocker from River Rock Laboratories gave us a quick overview of their company before digging into the fat of his presentation. Ocker relayed that today you can receive a fatty acid breakdown/profile on forages by NIR, an analysis his lab does that’s faster and cheaper than a GC analysis. He also mentioned that the cost of testing fatty acids has come down and if you have a consistent source of byproduct, it will pay to know what the fatty acid profile looks like. Knowing that fatty acid profile will also add value and help you avoid issues in your nutritional program. Ocker also discussed the importance of knowing what your fat source is, whether that be liquid, dry, or within feedstuffs or byproducts.
Ocker stressed that producers need to pick fat supplements based on their goal. Whether you are looking for an increase of energy without disturbing the rumen, increasing milk fat, or considering price, availability, and quality are all valuable things to think about when picking your fat source. Being aware of your cows response to a change in any nutrition form is another key point Ocker touched on. Looking into the future, the expectation is to continue towards balancing diets for individual fatty acids with energy intake, milk and milk fat yield, and essential and conditionally essential fatty acid absorption in mind.
A. S. Alharti, PhD Student – Young Scholar Presentation: Maternal supply of methionine during late-pregnancy alters in utero and neonatal development, hepatic one-carbon metabolism, and innate immune response in Holstein calves
Alharti, a PhD Student at University of Illinois- Urbana Champaign, and a Young Scholar Presentation for this Tuesday. Alharti started with the question, can we modify calf development during pregnancy altering maternal amino acid (specifically methionine in regards to their research) availability?
Alharti then discussed the possible outcomes, such as regulation of amino acid availability to the fetus by placental metabolism and fetal metabolism. As well as discussing possible consequences, such as the long term effects involving immune function, rate of gain, and milk production in postnatal life.
It was preliminarily concluded through A. Alharti’s research that enhancing maternal methionine supply during the last 3 to 4 weeks peripartum, not only seems to enhance development in utero but additionally enhances innate immune function after birth. This better immune response may also be linked with their conclusion regarding the enhancement of activity of metabolites in 1-carbon pathway, trans-sulfuration pathways and TCA cycle in liver.
Dr. Adam L. Lock – Role of fatty acid nutrition in milk fat synthesis
Dr. Adam Lock continued the morning’s discussion into the realm of milk fat synthesis. Dr. Lock described the four different ways to regulate milk fat sources and yields. One being the interdependence between de novo (de novo fatty acid synthesis) and preformed fatty acids(from the diet). As well as, milk fat depression, substitution of different sources of milk fatty acids, and C16:0 supplementation and milk fatty acids.
Dr. Lock explained that instead of only looking at preformed fatty acids, we need to be looking at increasing both preformed fatty acids along with de novo synthesis. He cited literature that showed high oleic soybean oil was able to maintain de novo levels while still raising preformed fatty acid levels leaving a nice increase in fat content % over the soybean oil and the control. A take-home message of Dr. Lock’s was that synthesis of milk fat in the mammary gland is an intertwined process between de novo synthesis of fatty acids and the incorporation of preformed fatty acids. These two, de novo and preformed fatty acids, positively interact under specific conditions.
Dr. Lock and his team found that greater than individual diet nutrient traits, dry matter intake (DMI) was actually the major factor influencing predictability in concentration and yield of milk fatty acids. While DMI is the key, increasing any of the three classes of milk fatty acids (de novo, mixed, and preformed) can produce higher milk fat yields but Dr. Lock found that pushing to increase all three is ideal.
Dr. Rodrigo I. Albornoz – Young Scholar Presentation: Diet starch concentration and starch fermentability affect energy intake and production of dairy cows during the postpartum period
Dr. Rodrigo Albornoz discussed a problem and solution strategy he worked on during his PhD at Michigan State University. The problem being that dairy cow energy and glucose demand were not being met. This was important because it had negative effects on areas like production, health, and reproductive performance. Dr. Albornoz discussed the strategic idea to increase dietary starch in order to increase diet energy density, with glucose precursors, and maximize intake. They looked at dry ground corn and high moisture corn in both a low (22%) and high (28%) starch diet to determine their results.
In what Dr. Albornoz called Cowclusion, it was discussed that the 28% dry ground corn was superior over all their testing, improving energy intake and production during the treatment period and carryover. Also discussed was that milk energy output had a large influence on energy balance. Dr. Albornoz pointed out that when comparing income over feed costs, in the low 22% starch diet HMC vs. DGC resulted in $-0.77 cow/day and in the high 28% starch diet HMC vs. DGC resulted in $-1.92 cow/day. It’s noted that we need to pay careful attention when using nutritional models to predict DMI, production, and different starch sources.
Looking into the future, one of the items Dr. Albornoz mentioned was studies to investigate effects of starch treatments on health, reproduction performance, and diets fed pre-calving and post-fresh. Other items and positive steps into the future, would be to look at new approaches for nutritional models as well as investigate the interaction between inflammatory response during the early postpartum period and long-term production.