Provided by the American Dairy Science Association® (ADSA®) in cooperation with Feedstuffs. If you received this issue of ADSA Dair-e-news from a friend and would like to receive your personal copy in the future, please contact
keolson@prodigy.net
Opinion and editorial content included in the
Dair-e-news
represent the views of the authors. Publication does not represent endorsement of any position by the ADSA. Depending on your email preview settings, all text may not be visible. If you find that to be the case, simply click to open the email or use the link at the top to open the web version.
|
|
Special Report - ADSA Annual Meeting Coverage
|
|
Welcome to the ADSA Annual Meeting Dair-e-news
The 2020 ADSA Virtual Annual Meeting is taking place this week in homes and offices around the world. It moves to its final day on Wednesday. Over 2,300 individuals registered for this year’s meeting making it one of the largest scientific dairy meetings ever. If you didn’t register, there is still an opportunity to do it and gain access to all the meeting information as well as the other
benefits of ADSA membership
and 90 days of complementary
access to S-PAC
. To
register just click here
. Even though we are at the last day of live programming, registration provides you access to recordings of all the previous sessions. While COVID-19 has caused the format to change, the purpose is the same, to present the premier global dairy science meeting in the world!
This year’s meeting features more than 100 hours of programming delivered through nearly 900 scientific presentations, panel discussions with live Q&A, live roundtable discussions available in several time zones, an exhibit hall, additional networking opportunities, and student competitions. As always, we will facilitate focused, meaningful, and interesting discussions about the latest dairy science and its applications. It is considered the most comprehensive dairy science meeting in the world and is where the latest ideas and findings in the industry are being discussed.
We once again are pleased to be sending "Special Editions" of this newsletter to you from the virtual meeting. An outstanding group of graduate students is working with us to help provide daily coverage of scientific sessions and other activities taking place throughout the meeting.
Remember, even if you have not yet registered, you can still join in!
Learn more and register here
. And, save the date for next year's annual meeting in Louisville, Kentucky, July 11-14, 2021. Make your plans now to attend.
|
|
|
|
Conversation with ADSA's Richard Erdman
|
Incoming American Dairy Science Association President, Richard Erdman talks with us about his plans for the coming year as well as this year's virtual event experience.
|
|
ADSA Student Affiliate Division
2020-2021 New Officers & 2020 Contest Winners
The Student Affiliate Division of the American Dairy Science Association held their virtual Awards program on June 23, 2020 to recognize the 2020 Contest winners, install officers and advisors for the coming year and celebrate another successful year. The event began with a Keynote presentation by Emily Yeiser Stepp, Vice President, National Dairy FARM Program, and a leader of the Student Affiliate Division when she was an undergraduate at The Pennsylvania State University. She shared her personal story relating how ADSA had impacted her life and career. She encouraged the group to recognize and utilize the opportunities provided by being part of ADSA.
Winners of the various awards were recognized. They are:
Recognition Winner
Genevieve Christen Award Winner Nicholas Uzee, Louisana State University
Chapter with the most miles traveled The Pennsylvania State University
1st Place Chapter Yearbook The Pennsylvania State University
2nd Place Chapter Yearbook Virginia Tech
3rd Place Chapter Yearbook Iowa State University
1st Place Annual Report - tie The Pennsylvania State University
1st Place Annual Report - tie Virginia Tech
2nd Place Annual Report - tie University of Florida
2nd Place Annual Report - tie University of Kentucky
3rd Place Annual Report University of Georgia
1st Place Website Louisiana State University
2nd Place Website University of Florida
3rd Place Website University of Georgia
Poster: Original Research 1st Place J Xu, University of Missouri
Poster: Original Research 2nd Place J. Hamilton, The Pennsylvania State University
Poster: Original Research 3rd Place E. M. Hist Enger, The Ohio State University
Dairy Foods 1st Place G.M. DeMers, The Pennsylvania State University
Dairy Foods 2nd Place A. Crews, University of Georgia
Dairy Foods 3rd Place L. M. Adams, University of Kentucky
Production 1st Place C. McGehee, Virginia Tech
Production 2nd Place M. Mosher, University of Tennessee
Production 3rd Place Alyssa Rauton, University of Georgia
Original Research 1st Place Mary Kenne Hillis, University of Georgia
Original Research 2nd Place Emma M. Wood, Cornell University
Original Research 3rd Place Ursula Abou-Rjeileha, Michigan State University
Outstanding Advisor Award Dr. Chad Dechow, The Pennsylvania State University
Outstanding Student Award Shoshana Brody, Pennsylvania State University
Officers and advisors for the coming year were announced. They are:
President Alyssa Rauton, University of Georgia
1st Vice President Jessica Schmitt, Iowa State University
2nd Vice President Jeanne Marie Cassidy, University of New Hampshire
3rd Vice President Ashley Goodwin, Virginia Tech
Secretary-Treasurer Taylor Wolfe, Pennsylvania State University
Officer at Large Rose Vaughan, North Carolina State University
1st Year Advisor Dr. Chad Dechow, Pennsylvania State University
2nd Year Advisor Dr. Elizabeth Eckelkamp, University of Tennessee
3rd Year Advisor Dr. Peter Erickson, University of New Hampshire
|
|
Genetic evaluations are all about the future
By Bailey Basiel
About 60 attendees tuned into the roundtable discussion on genetic evaluations moderated by Christine Baes from the University of Guelph. Participants represented industry, academic, and government perspectives; the panelists were comprised of J
oao Durr from the Council on Dairy Cattle Breeding, John Cole from the USDA Animal Genomics and Improvement Laboratory, Jay Weiker from the National Association of Animal Breeders, Chuck Sattler from Select Sires, Steven Larmer from Semex Alliance, and Mike Coffey from Scotland’s Rural College.
Baes initiated the discussion by asking panelists what factors influence the selection tools they develop. Durr and Cole explained that the dairy cattle selection indices that are developed and updated every few years by the USDA and CDCB are primarily influenced by economic factors in addition to scientific advances. However, input from academics in the dairy industry, producers, and the NAAB are also accounted for in index development. Weiker reminded us that the NAAB represents its membership, which is comprised of AI companies, allowing industry to have some input in national index development as well. Industry perspectives from Sattler and Larmer stressed the importance of farm profitability in combination with producer demands. Both panelists mentioned that their respective companies have strong international markets and explained that international demands impact what genetics they market. Coffey emphasized that what producers are interested in selecting for is fluid and often influenced by dairy scientists, though changing their overall selection goals can take time. He also echoed many panel members in suggesting that genetic evaluations should reflect the demands of the future.
As the panel addressed audience questions, common themes arose in the discussion surrounding traits and technologies that are predicted to hold importance in the future. The consumer’s perception of sustainability in dairy production is likely to increase the demand for feed efficiency and greenhouse gas evaluations. Other traits that meet niche demands such as A2 or improve perception of animal welfare such as polled may become incentivized by milk processors. However, it is uncertain if gene editing technology could be used to meet these incentives because of consumer perceptions. Panelists also speculated ways evaluation methods may evolve. As precision dairying technology continues to advance, geneticists will have access to larger, more robust data sets that may allow for evaluations beyond those that use traditional additive genetic models. It was suggested that large herds could be incentivized to share enough phenotypic data to allow for non-additive evaluations and evaluations that consider re-rankings due to genotype by environment effects. It was also proposed that as producers continue to use beef on dairy the development of terminal selection indices could be profitable.
The panel members acknowledged that in our changing industry, there is still great diversity in production models in North America and internationally. From the discussion, I took away that cows of the future must be profitable and efficient, but that does not mean one cow fits all. Considerations toward animal health, fertility, and sustainability are all likely to be made in developing selection programs. While the dairy cow of the future may look different among the panelists and producers, it is clear that genetic and genomic evaluations will continue to evolve so that producers can breed cows that fit the needs of their environment and the market.
Bailey Basiel is a Master’s student at Penn State under the mentorship of Dr. Chad Dechow. She earned her B.S. in Animal Science at the University of New Hampshire and will pursue her PhD at Penn State in the fall with the continued support of Dr. Dechow and the guidance of Dr. Tara Felix. Bailey’s research interests include applied genetic selection for animal health and development of selection indices for beef on dairy matings.
|
|
Increase nitrogen efficiency in dairy cattle
By Bo Zhang
Nitrogen losses in urine and feces cause great economic cost as well as negative environmental problems. It is critical to find solution to minimize nitrogen loss. Presentations in the Ruminal Nutrition-Protein and Amino acids Session in the Wednesday morning mainly focus on dietary crude protein levels, supplementation of essential amino acids to low protein diet, and accessing bioavailability of supplemented amino acids.
Nitrogen use efficiency deceases linearly with increasing dietary CP level, as reported by Letelier et al. from the University of Wisconsin-Madison. They determined the effects of different dietary crude protein levels (13.5%, 15%, 16.5%, and 18%) on lactation performance, feed efficiency, and nitrogen use efficiency. The Feeding dietary crude protein higher than 16.5% of the dry matter did not improve cow performance in early lactation and penalized cow milk production in late lactation.
Low protein diet (15% CP) results in less milk in comparison with a reference diet (17% CP), shown by Vandaele et al. from ILVO at Melle in Belgium. Moreover, supplementation of extra rumen-protected (RP) amino acids (i.e., Lys and Met) to low protein diet increases milk production to an intermediate level and decreases nitrogen losses. Zang et al. from the University of New Hampshire showed that substitution of ground corn with soyhulls and RP-fat improved feed efficiency and milk fat yield but appeared to reduce N utilization.
Several methods are developed to measure the bioavailability of amino acids from diet or ruminal microbes. By using in situ nylon bag technique and a modified 3-step in vitro technique, Francia et al. from Univeristat Autonoma de Barcelona compared the bioavailability of three RP-Lys sources, highlighting the necessity to evaluate ruminal degradability and intestinal digestibility for evaluation of RP-Lys. Whitehouse et al. from the University of New Hampshire determined and differentiated the bioavailability of four RP-amino acids supplements using the plasma free amino acid dose-response technique. Moreover, Huang et al. from the Virginia Tech adopted a stable isotope-based approach to determine the availability of essential amino acids from microbial protein and RUP. This approach can avoid errors associated with estimates of ruminal microbial crude protein and RUP outflow, amino acids composition, and intestinal amino acids digestibility, but efforts are needed to validate the approach by comparing it to traditional in vivo methods.
Overall, the poor nitrogen efficiency in dairy cattle are gaining more attention. Further efforts are necessary to increase nitrogen efficiency and reduce nitrogen excretion to environment.
Bo Zhang is a PhD student in the Department of Animal Science at UC Davis. He earned his M.S. from the University of Chinese Academy of Sciences. Under the guidance of Dr. Timothy Hackmann, he is working on how rumen microbes ferment feed and produce protein digested by cattle.
|
|
Growth, rectal temperature, health of male Holstein calves exposed to heat stress during pre-weaning
By Meghan Connelly
Heat stress exposure effects are readily researched in the dairy cow, with a common understanding of the costly outcomes for both cow and producer. However, heat stress exposure effects on calves is scarce, with a lack of literature on THI threshold and the impacts just as ambiguous. Due to this ambiguity, economic models for heat stress impacts on dairy replacement animals are adjusted from a finishing beef cattle model, leading to potential misrepresentation of the real impact for dairy replacements. Therefore, it’s critical for a more thorough understanding of what is occurring in the dairy replacement animal as current reported evidence is conflicted. Researchers at the University of Florida set out to examine heat stress effects and discovered that calves exposed to heat stress experience negative outcomes on growth.
Their objectives were to evaluate heat stress exposure on growth, rectal temperature and respiratory frequency and health, while determining the effects of heat stress abatement strategies on air velocity and temperature. Calves were randomly assigned to 1 of 3 treatments shortly after birth. These treatments were hutches in a barn without cooling, hutches in a barn with cooling fans, or 50% of a hutch covered with plywood outside the barn (heat stressed), and recorded the information on 60 calves across these three treatments.
Unsurprisingly, heat stress animals had higher respiratory frequency and rectal temperatures. When researchers evaluated heat stress effects on bodyweight and daily gain they saw no differences. However, when evaluating heat stress on wither height, they saw heat stressed animals were shorter. Calves housed under heat stress conditions were also smaller at the rump when measured. At weaning, both wither and rump height were lowest in heat stressed calves. Further, upper respiratory tract scores were higher in heat stressed calves. The researchers concluded that heat stress pre-weaning reduced frame size and may potentially impact long-term development in calves as they grow and join the milking herd. Suggesting, while heat stress is an issue in the present, its implications persist much longer.
Meghan Connelly is a PhD student in Dr. Laura Hernandez’s lab at the University of Wisconsin – Madison. Her research focuses on calcium and serotonin metabolism and how each are regulated by the mammary gland.
|
|
Milk protein concentrates: The next ingredient on the list
By Sonali Raghunath
In the ADSA 2020 virtual conference, some of oral and poster sessions were focused on processing and modification of milk protein concentrates. Milk protein concentrates (MPC) is a high protein ingredient used in food industry for various product like beverages, ice creams, yogurts, cultured dairy products and so on. However, it is noted for its poor functional properties is always a concern and hence improvement in these functional properties will open up great potential for MPC to be used in formulations in industry. Studies on processing conditions, treatment to improve the functional properties were presented by researchers. Here are some of highlights and key take away points summarized from the research which was presented by researchers in various sessions on Milk protein concentrates
Graduate student competitions
Oral session and poster sessions: “Effect of cold plasma treatment on the functional properties of MPC 85” presented by Sonali Raghunath (University of Minnesota) reported a significant increase in functionality of MPC due to cold plasma and concluded with future prospective on optimizing the process for better flexibility of the protein structure for targeted applications in industries .“Application of micro-nano-bubbles to improve the processability of Milk protein concentrate” presented by Karthik Sajith Babu (Kansas State University) focused on Micro-nano-bubbles as a physical pretreatment to improve the rehydration and flow performance of MPC. Similarly, “Effect of soluble casein isolate on the functionality and mechanical properties of milk protein concentrate (MPC 80) during storage” presented by Ying Zhu (University of Wisconsin-Madison) reported that the addition of SCI 5% or more improved the solubility and foaming capacity of MPC and didn’t affect the particle size distribution. Another research by Gunvantsinh Rathod (Kansas State University) on “Development of a novel milk protein concentrate containing whey proteins as fibrils” focused on the development of enhanced functionality using the combination of native whey protein fibrils and micellar casein in MPC with a clean label
Dairy Foods: Processing sessions
Research conducted by N. Rafiee Tari (University of Guelph), on “The effect of heat treatment conditions and pH on physicochemical properties and protein denaturation of liquid milk protein concentrates” had a significant influence in the rheological properties with a heat treatment at 85 C for 15s and also small changes in pH and heat treatment can have an impact on physicochemical properties. “Effect of temperature on the performance of plate-and-frame filtration during milk protein concentrate manufacture” & “Effect of cavitation and nanofiltration temperature on the functional properties of MPC80” by Achyut Mishra (South Dakota State University) concludes that the increase in plate-and-frame temperature improves the filtration performance as well as the Total Solids and decreased the solubility to some extent for the former research and the latter is focused on both nanofiltration and cavitation had an impact on the functionality which can be adjusted according to the needs .“Electrical resistance tomography for monitoring the rehydration characteristics of high protein dairy powders” by Karthik Sajith Babu (Kansas State University) focuses the use of ERT as a robust and low-cost method for monitoring the dissolution behavior of MPC.
Sonali Raghunath is a PhD Student in Food Science at the University of Minnesota under Dr.Tonya Schoenfuss and Dr. Kumar Mallikarjunan. She earned her M.S. in Food Science from University of Minnesota and her B.Tech in Food Technology from Anna University, India. Her current research explores the relationship between non-thermal processing methods and milk protein concentrate.
|
|
Metaphylactic treatment of calves undergoing extensive travel
By Ashley Putman
Dairy calves may be subject to extended travel early in their lives when being transported from the original farm to their next destination. Numerous stressors can be experienced during this time, including crowding, new social groups, acclimating to new surroundings, and thermal stress. Furthermore, transportation and its associated stressors challenge a calf’s immune system. Thus, calves are more susceptible to disease during this time not only due to their underdeveloped immune systems, but also because of the stressors imposed on them by transportation.
Bovine respiratory disease (BRD) is one such disease that transported calves are more susceptible to. This is due to the combination of compromised host immunity, pathogen factors, and the environment that transported calves can be faced with, resulting in a bronchopneumonia associated with several viral and bacterial pathogens. Economic losses due to BRD are significant, stemming from factors such as treatment and impaired performance in afflicted animals. As such, it has been suggested to use an antimicrobial agent metaphylactically in high-risk animals, such as transported calves, in an attempt to prevent some of the negative outcomes that may arise from BRD infection.
Researchers from Texas Tech University investigated the effect of metaphylactic use of one antimicrobial agent, tildipirosin, in calves who had been transported a long distance in the first week of their lives. A total of 2,100 calves were randomly allocated to three groups: no treatment, one injection of tildipirosin, or two injections of tildipirosin given 17 days apart. Data was collected for several variables, including visual signs of BRD, lung consolidation, body weight, and several blood biomarkers. Celestino reported that although there was no difference in BRD incidence between the groups, there was a tendency for decreased mortality in calves treated with two injections of tildipirosin. Furthermore, tildipirosin appeared to have impacts on the immune system, including reducing concentrations of inflammatory markers such as haptoglobin. Overall, it was concluded that a low incidence of BRD in this study may have impacted the outcome but tildipirosin is useful for improving animal health and welfare.
Ashley Putman is a recently graduated veterinarian and PhD candidate in the Meadow Brook Endowed Laboratory at Michigan State University. Under the guidance of Dr. Lorraine Sordillo, she focuses on the physiological role of isoprostanes, a biomarker of oxidative stress, on bovine health and disease.
|
|
Tuesday's Dairy Foods posters summarized
By Tim Lott
The poster sessions from Tuesday’s Dairy Foods Posters presented research highlighted the developments and challenges in the cheese industry, milk powder industry, and other dairy products. The following article entails a summary of each poster presentation.
Brandon Selover presented an Oregon State University study regarding non-starting bacteria formation in a conveyor belt environment. Selover emphasized biofilms can survive clean-in-place (CIP) sanitation in the draining and matting conveyor and bloom during the next production day. These biofilms form in cracks and other “defects” on the conveyor belt. The results come from an investigation of a draining and matting conveyor from a cheese manufacturer that was experiencing sporadic coliform counts in finished product that did not meet microbial quality criteria.
Rodrigo Ibáñnez presented research on the influence of goat milk composition and level of alpha-casein on the yield of fat-free fresh cheese model. The take-away message from this research is that the standardization of cheesemaking protocols based on milk composition does not reduce differences in cheese yield obtained from individual milks with great genetic variability. Analysis determined that milk non-fat solids, protein content, and alpha-casein are highly correlated with cheese yield.
Carmen Licon, from Fresno State University, presented on the perception of cheese aromas. Certain microorganisms and enzymes in milk can produce molecules that can affect the perception of cheese sensory qualities. Specifically, 2-nonanone can produce floral, malty, and other perceived aromas. Results determined that the presence of 2-nonanone presented an overall neutral perception from sensory participants.
Roshan Paswan from Fort Valley University discussed the profile of fatty acid composition in relation to water activity of powder goat milk stored under different storage time and temperature. The study found no significant correlation between water activity and fatty acid contents in powdered goat milk stored at 25°C, while some fatty acids were significantly affected by water activity of powdered goat milks stored at 4°C.
Yunna Wang presented a University of Wisconsin study reviewing the effect of emulsifier synergy on partial coalescence and crystallization of milk fat on whipped cream stability. Findings from the research include that certain lipophilic-emulsifier formulas achieved higher foam firmness and combining hydrophilic emulsifiers promoted partial coalescence.
Khalid Alsaleem of South Dakota State University discussed iso-conversional kinetics to study the effect of alpha-tocopherol on the oxidation of formulated milk powders. The take-home point was that the kinetic triplet is the activation energy, the pre-exponential factor, and the kinetic model that is a fingerprint for any chemical reaction. Further, the addition of alpha-tocopherol changed the values of the kinetic triplet and delayed oxidation.
M. Ghelichkhan from the University of New Hampshire presented a comparison of iodine concentration in conventional and organic milks. The research found that season and processing appear to influence milk iodine concentration (MIC). Also, the survey found that in general, MIC of milk samples tested were safe from human consumption; however, 17% of samples were above the recommended safe level. Overall, MIC was not different between organic and conventionally produced milk.
Alina Buchilina of LSU reported on the influence of monk fruit sweetener on the physicochemical characteristics of camel milk yogurt. Overall, monk fruit sweeteners decreased the pH and increased the viscosity of camel milk yogurts. Monk fruit is a natural, zero-calorie sweetener, which presents opportunities for the use in dairy products.
Joy Waite-Cusic of Oregon State University presented the impact of butterfat content and composition on the quality of laminated pastries. The research is important due to the butterfat content of butters chosen by bakers. The results of this study indicated that increasing butterfat content does not yield “better” croissants.
Neha Singh of South Dakota State University discussed research entitled the influence of cell surface properties on the adhesion potential of environmental
Listeria
isolates to dairy foods. Conclusions of the research found that all three floor types tested supported the attachment of
Listeria
strains. Poured concreted supported highest attachment in comparison to clay brick and grout floor types.
Brenna Flynn from Cornell University presented findings of the inhibition of
Listeria monocytogenes
by lactose oxidase in UHT skim milk. Lactose oxidase showed efficacy against
L. mono
in UHT skim milk starting at day 2 and continued throughout the entire storage period was the key point of this study. This study is important due to the desire of consumer preference of “natural” additives in dairy products.
Samuel Reichler of Cornell University discussed
Bacillus cereus
group species isolated from dairy products and dairy environments that are not appropriate for use in inoculated-milk human sensory studies. This presented information is important because certain sporeforming bacteria can cause spoilage in fluid milk. The results indicated that one or more putative virulence genes were detected in the tested
B. cereus
groups though the presence of these genes does not indicate the safety of these isolates.
Achyut Mishra from South Dakota State University presented the effect of cavitation and nanofiltration temperature on the functional properties of milk protein concentrate containing 80% protein (MPC80). The study concluded that nanofiltration temperature and hydrodynamic cavitation impact the properties of MPC80.
L. Damasceno of the Federal University of Goiás-Brazil discussed the development and characterization of whey-buttermilk fermented beverages with Gabiroba pulp. The presenter indicated that the use of whey and buttermilk to produce fermented beverages is suitable for making dairy products functional and sustainable.
Tim Lott is a PhD student at Cornell University. He conducts his research on milk quality under the advisement of Martin Wiedmann.
|
|
Reproductive phenotypes: Identification, influencing factors
By Iswarya Rajesh
Reproductive failure is the major reason for culling and economic loss in a dairy herd. Exploration of various new reproductive phenotypes, closely related to the physiology, to be able to include in breeding program is gaining interest lately. Scientists reported their studies on traditional (age at first calving) and novel (estrus expression, the interval to return to vaginal discharge score of 0, and reproductive hormone concentrations) reproductive phenotypes in the block 3 - oral reproduction session in ADSA virtual 2020
.
Doyle et al. studied if the reproductive phenotypes, vaginal discharge score and reproductive hormone concentration were influenced by cow genetic merit, breed, parity, calving difficulty, feeding regimen and environmental factors. They have enrolled elite
genetic merit Holstein Friesian (EL-HF),
average
genetic merit HF (NA-HF), Danish Jersey (DKJ) and New Zealand Jersey (NZJ) and were assigned to three different feeding treatments namely control, low grass allowance (LGA) and high concentrate (HC). They observed that interval to VDS = 0 was lower in DKJ followed by NA-HF, EL-HF and NZJ and was shorter in cows with high parity (3+>2+>1+). They also classified cows into quartiles based on the fertility index and found that cows in high fertility index took a short interval for VDS=0. Calving difficulty affected that return of the VDS score to 0. They reported that EL-HF cows had greater circulating progesterone (P4) concentration than NA-HF cows. Likewise, DKJ cows had a greater circulating P4 concentration compared to NZJ. Feeding treatment affected plasma estradiol concentration (E2), where the control and LGA group cows had high E2 and P4 concentration compared to cows in HC group.
Schilkowsky et al. studied the effect of ear attached sensors (Smartbow) for the detection of estrus activity and characterization of estrus events. The smart bow sensors monitor physical activity and rumination time, which generates the estrus alert by combining both data. The estrous cycle was synchronized and ear sensors were attached in cows. They compared the data from the ear attached sensors with the visual observation signs for estrus and HeatWatch (Pressure activated tail head sensors) and they confirmed ovulation by ultrasound scans and P4 concentration of blood. From the data, they reported that Smartbow was able to successfully detect cows in estrus with a good overall accuracy of only a few false positive.
Sitko et al. studied the effect of age at first calving ( AFC) on the reproductive performance of primiparous cows that were inseminated with detected estrus and timed artificial insemination (TAI). Cows were grouped as low AFC (mean=21.4 months), medium AFC (mean = 22.1 months) and high AFC (23.5 months). They reported that AFC affected the reproductive performance, that is cows in more low and medium age at first calving were found to be pregnant than higher AFC group in cows inseminated with TAI and the proportion of cows inseminated at detected estrus was more in low and medium AFC group.
Iswarya Rajesh
is a Master's student at the University of Alberta, supervised by Dr. Ambrose. Rajesh’s work is on the Reproductive Physiology of dairy cows.
|
|
Disruption of circadian clocks in the prepartum dry period negatively affect mammary development
By Meghan Connelly
The dry period is a critical time in a dairy’s cow life as part of a successful transition into lactation is determined during this timeframe. The dry period is when major tissue reconstruction is undergone, with mammary epithelial cells undergoing cell death and then proliferation as they progress towards parturition. Future milk production is dictated by the number of mammary epithelial cells. Therefore, understanding how the environment and other management strategies may modulate total mammary epithelial cell proliferation is imperative to aid farm productivity. One such management strategy is altering light-dark cycles to manipulate the master clock, which regulates tissues in the periphery at the local level. Researchers at Purdue University discovered that disrupting circadian rhythm pre-partum negatively impacts mammary development and corresponding lactation milk yield.
Circadian clocks coordinate physiological and behavior processes over a 24h period and respond to things such as light-dark cycles. Research has shown that manipulating light and dark cycles may regulate mammary development by disrupting the master clock. Therefore, understanding how this manipulation is occurring during lactation is important. Teeple and colleagues hypothesized that disrupting the circadian timing system during the dry period would negatively alter mammary development. They set out to ask this question via exposing twelve multiparous Holstein cows to two different light dark phase cycles (control or phase-shifted chronic jet lag) for 5 weeks prepartum (n=6/treatment).
Teeple and colleagues concluded that shifting phases of the light-dark cycle decreased mammary epithelial cell proliferation and lumen to alveolar area. Lower mammary development was related to lower milk yield postpartum, with control cows producing more milk post-partum relative to cows that were exposed to light-dark cycles that disrupted circadian rhythms. Suggesting that circadian rhythm disruption in the pre-partum may negatively affect mammary development and corresponding lactation milk yield, and that maintaining a consistent management schedule could minimize milk yield loss. Further research and understanding of management strategies to provide optimal dry period management and light-dark cycles is critical for allowing for optimal mammary development and maximization of milk yield.
Meghan Connelly is a PhD student in Dr. Laura Hernandez’s lab at the University of Wisconsin – Madison. Her research focuses on calcium and serotonin metabolism and how each are regulated by the mammary gland.
|
|
Monday’s Poster Session-Dairy foods highlights research work
By Shayanti Minj
Thirteen research projects related to Dairy Foods were presented from different universities throughout the world. Although the presentations were available in a pre-recorded version, a live chat session was conducted to connect the researchers with the audience directly and answer their questions.
Research from Stellenbosch University, South Africa, presented the effect of irradiation (γ rays) treatment (at 5.0 KGy) on the composition, texture, color, odor, and microbial quality of 60-day aged artisanal hard-pressed cheese. From the findings, a decrease in the L. monocytogenes, E. coli, coliforms, and ACC counts were observed which improved the overall microbial quality of the cheese and showed no adverse effects on the physicochemical properties. However, it was suggested to follow proper GMP to prevent any post-contamination.
Another study from South Dakota State University, SD was presented, where the researchers developed an imitation mozzarella type cheese (IMC) using a dairy partial or non-dairy source of protein and fat. Among the ingredients, acid curd and micellar casein concentrate (MCC) were used in the replacement of emulsifying salts, to provide the required emulsifying capacity. No difference in the physicochemical or functional properties was reported in comparison to a control (IMC prepared from emulsifying salts). Hence, from the results, the researchers suggest that IMC can be prepared using a formulation of acid curd and MCC at a ratio of 2:1, without using emulsifying salts.
Cheese is one of the most widely used carriers of probiotics, a study from the Institute of Cheese-Making, Barnaul, Russia, reported the application of probiotics in a Russian semi-hard variety of cheese i.e., Pladolens. Two mixtures containing the starter cultures and the probiotics (Lactobacillus and Bifidobacterium) were used in the cheese-making process. The results from both the mixtures demonstrated a high survival rate of the probiotics after the press with no difference in the counts during the ripening and storage of the cheese. Overall, the results suggest high viability of probiotics in Pladolens for 3 months.
The application of probiotics has become increasingly popular to develop functional dairy foods. Researchers from Assiut University, Egypt, developed a symbiotic yogurt and demonstrated its effect by adding inulin to a probiotic yogurt in different concentrations. The results showed an increase in the viability of the probiotic bacteria (B. bifidum) with no effect on the acidity level. With increasing concentrations, the viability of the B.bifidum increased throughout storage. Hence, the authors suggest that inulin can be used for maintaining the viability of the probiotics in yogurt and can also act as an antimicrobial agent during storage.
Strawberry flavored milk is one of the popular flavored milk varieties, the manufacturing industries often face issues in maintaining the pink color of the drink, particularly during storage. To know the cause of the problem, researchers from Oregon State University, OR presented a study, identifying a microbial cause for the color loss in commercial strawberry-flavored milk samples added with FD&C Red No.40 as a coloring agent. Samples were analyzed through spread plating on strawberry milk agar and isolates were identified through 16srRNA. From the findings, the researchers identify psychrotrophic microorganisms to be responsible for color degradation in HTST strawberry-flavored milk during storage and also, suggest that the strawberry milk agar, can be used as a visualization check for detecting the color-degrading bacteria.
Another research from Oregon State University, USA was presented focusing on demonstrating a comprehensive profile of glycomacropeptide (GMP) released from the κ-casein fraction of a commercial whey protein isolate. To understand its bioactivity, the composition, and the structure of the GMP and its peptide fractions were analyzed through Orbitrap mass spectrometry combined with nano-liquid chromatography. The results showed 45 distinct forms of intact GMP and 186 GMP derived peptides. Through this study, the researchers suggest the efficacy of nano-LC/Orbitrap MS/MS as a novel analytical approach to identify GMP and GMP derived structures in whey protein isolates.
As consumers become more health-conscious, they are looking for natural ingredients rich in nutrients inside their foods. Researchers from the Federal University of Goiás, Brazil, developed a functional ice-cream using whey and buttermilk powder as one of the ingredients. The formulation containing whey and buttermilk were prepared with 5 and 15% concentrations. The results presented a very innovative product and suggest an alternative for the dairy industry, which can provide both technical and consumer health benefits.
Milk proteins being one of the most important constituents in technological aspects, another study from Federal University of Goiás, Brazil demonstrated the influence of protein content on the acidity of fermented milk beverages prepared from different levels of milk, whey, buttermilk and gabiroba pulp (Campomanesia xanthocarpa). When the acidity results were correlated with the protein content of the beverages, they observed an antagonistic effect of the ingredients with the milk acidity. However, during storage, a minor change in the activity level was reported. Hence, the researchers explain the natural acidification of milk to be a cause for the change in acidity and suggest that the casein, being an acidic component, acts as a buffer and plays an important role in controlling post acidification during storage of dairy beverages.
Biofilm formation is a constant concern in dairy processing environments and Listeria monocytogenes, a high-risk pathogen can colonize and form resilient biofilms. Researchers from South Dakota State University, USA presented a study where genetic determinants of different Listeria isolates were investigated through whole-genome sequencing and associated with the biofilm formation in dairy processing floors. From the results, the researchers suggest that capsular, glycan, biotin, and chitin genes, identified from L. monocytogenes and L.inoccua, and biotin, chitin, and LTP genes identified from L.welshimeri could be responsible for adhesion and biofilm formation.
Another study from Oregon State University, reported the ability of the non-starter cultures present in low levels in Cheddar cheese whey, to form biofilms on food contact surfaces. The results show that the non-starter bacteria can eventually outgrow at manufacturing surfaces and can potentially form biofilms within the 18h production shift. Hence, the authors suggest that these findings can be used to develop a sanitation schedule in cheese industries.
A study from Cornell University, NY, described the fermentation kinetics of dairy sugars from acid whey by dairy relevant yeasts, S.cerevisiae, K.marxianus, and B.claussenii, and studied the alcoholic fermentation. From the findings, the authors suggest that a better understanding of the dairy sugar utilization through the fermentation process by yeasts can help to optimize the process to derive beneficial ingredients from acid whey and utilize in the production of value-added beverages.
Spore forming bacteria are one of the indicator microorganisms to determine the quality of the dried milk. A study from Kansas State University demonstrated the ability of DPA (dipicolinic acid) fluorescence spectra and chemometrics to classify non-fat dried milk (NDM) based on spore counts. From the results, the researchers suggest the potential of the fluorescence spectrometry to develop classification models of NDM based on spore levels.
Another study from Kansas State University demonstrates the ability of whey protein hydrolysates (WPH) as a binding agent and its effect on the physical properties of the agglomerated whey protein isolates (WPI). The results showed a significant influence of the WPH concentration, pre-wet, and the flow rate on the elongation of the WPI agglomerate, and hence, the researchers suggest that the pre-wet mass had the most impact followed by flow rate and WPH concentration on the physical properties of the WPI agglomerates.
Shayanti Minj is
currently a Ph.D. candidate at the Dairy and Food Science Department of South Dakota State University, under the supervision of Dr. Sanjeev Anand. Minj is working on developing a novel bioactive ingredient formulation utilizing whey protein hydrolysates and encapsulated probiotics.
|
|
Acidosis: Role played by hindgut in addition to rumen
By Iswarya Rajesh
Dairy cows are fed with high grain diet due to increasing demand for energy after parturition. This sudden switching of diet cause stress making cows prone for acidosis either clinical or sub acute form. It will lead to systemic inflammation affecting animal production, health, welfare and economic loss due to involuntary culling.
A study on by Cao and collogues in
Northwest A&F University Yangling, Shaanxi, China and Harvard Medical School Boston,
studied the effect of increasing dietary particle size in the form of physically effective neutral detergent fibre content (peNDF) on the feed digestibility in rumen to curb sub acute ruminal acidosis. They found that feeding cows with diet containing high particle size increased the chewing and rumination time, thereby increasing the rumen PH, which makes sense as bicarbonate in saliva while chewing may neutralize the acidic PH in the rumen. They have also found high acetate and low propionate; a fatty acid, inhibits the digestive process in cows fed with high peNDF. In addition, the dietary particle size found to affect the blood metabolite and fibrinolytic enzyme contents.
Megan et al. from Iowa State University Ames studied the effect of hindgut acidosis in metabolism, inflammation and production in lactating cows infused with lipopolysaccharide (LPS) starch in the abomasum. The cows were followed for 11 days and classified into three experimental periods as period 1 (P1; 1-5days), period 2 (P2 ;6-7days) and period 3 (P3; 8-11days). The P1 was considered as control followed by LPS infusion of 0.2 µg/kgBW on day 1 of P2 which is followed 0.8 µg/kgBW and 1.2 µg/kgBW on day 1 and day 3 of P3 along with abomasal infusion of starch. As a result, LPS infusion decreased fecal score, milk yield and DMI and altered leukocyte dynamics and increased inflammatory markers (SAA and LBP) and the starch infused cows had a markedly reduced fecal PH and had diarrhoea. Despite the reduced fecal pH, they found no difference in milk yield and milk composition. Circulating glucose, insulin, NEFA, BHBA and inflammatory markers were not affected by starch infusions.
Megan et al. on a second experiment studied the effect of starch infusion in feed restricted animals, similar to the previous study, the P1 was considered as control and cows were feed restricted on P 2 followed by feed restriction plus abomasal starch infusion on P3. Similar to their previous study, starch infusion decreased fecal pH, fecal score, decreased milk urea nitrogen and did not alter the inflammatory markers.
Hindgut acidosis may not contribute to a systemic inflammation in cows as large intestine is rather robust towards acidosis says, Megan.
Megan et al. stated the issue of global warming and consequently economic loss due to heat stress in dairy cows. They have also addressed that hyperthermia which might increase other health problem such as ruminal acidosis by tissue hypoxia, lipopolysaccharide translocation and oxidative damage to the cells. Therefore, they explored strategies that are less expensive and easy to implement like antioxidants to mitigate heat stress as they reduce the oxidative stress. Cows were grouped in to four categories thermoneutral control (TN-CON), heat stress control (HS-CON), thermoneutral antioxidant (TN -AP) and heat stress antioxidant (HS-AP). Overall, they observed an increased temperature and inflammation, decreased production and altered metabolism in heat stressed animals and antioxidant supplementation though did not mitigate the inflammation caused by heat stress, it found to alter the metabolites.
Fatty liver, can abundance expression hepatic lipid associated protein predict it?
Another study conducted by the researchers from
University of Wisconsin-Madison used 25 transition cows to study the abundance expression of hepatic lipid associated protein and its association with liver triglyceride content (LVTG) in the transition cows. The cows in this study were grouped as control (n=12) and fatty liver induced (FLI; n=13) group. They over fed the energy diet (crack corn) for the cows in FLI group prepartum and monitored for the clinical ketosis (cows with blood BHB ≥3.0 mm). Though there was no major difference in metabolites like fatty acids, serum beta hydroxy butric acids, hepatic lipid associated proteins (HLAP) between two groups, time had a significant effect on these metabolites and HLAP in post partum cows. Regarding the association of HLAP abundance and LVTG, phosphorylated perilipin (PPLIN) were able to predict LVTG and adipose triglyceride lipase (ATGL) tended to predict the LVTG. However, further exploration on the impact of coordinated regulation of HLAP on fatty liver is needed says, Holdorf.
Iswarya Rajesh
is a Master's student at the University of Alberta, supervised by Dr. Ambrose. Rajesh’s work is on the Reproductive Physiology of dairy cows.
|
|
Changes in biomarkers of metabolic stress during late gestation of dairy cows associated with colostrum volume
By Meghan Connelly
Colostrum is essential for successful transfer of passive immunity to calves in order to allow for immune protection until they reach sufficient adaptive immunity. Research has looked at colostrum feeding recommendations in order to provide successful passive transfer, as when failure of passive transfer occurs, increased risk of morbidity and mortality ensues. However, production of colostrum in the periparturient cow has posed a challenge in ensuring sufficient colostrum is available in order for producers to aid their calves in successful passive transfer. Part of the challenge of colostrum quantity is believed to be derived from the periparturient cow having varying levels of metabolic activity, which results in varying levels of colostrum production and quality.
Rossi and colleagues wondered if there was an association between colostrum yield and metabolic activity during colostrogenesis. So, they conducted an observational study on two Michigan farms and followed 2 cohorts per farm, with 21 cows per cohort. Measurements of inflammation and oxidative status as well as metabolites critical in nutrient utilization were measured. IgG concentration and colostrum volume was also recorded. Cows that were considered high colostrum producers had lower glucose, higher BHBA, higher BUN and higher magnesium concentrations relative to the lower producing colostrum counterparts. When evaluating oxidant status, cows that produced higher colostrum yields also had increased statuses of oxidants.
Collectively, this study demonstrated that cows that produced higher amounts of colostrum had increased metabolic demands due to increased nutrient utilization. Additionally, these cows also had elevated oxidant status, but with no changes in biomarkers of inflammation or lipid mobilization. Suggesting that part of the alterations in colostrum quantity is controlled by the dam’s metabolic and oxidant status. An extension of such an observational study would be benefitted by following throughout an entire year. As this would pose useful as season variability would be able to be added into the explanation and shed light on how colostrum quality and metabolism of the transition cow may be impacted across seasons.
Meghan Connelly is a PhD student in Dr. Laura Hernandez’s lab at the University of Wisconsin – Madison. Her research focuses on calcium and serotonin metabolism and how each are regulated by the mammary gland.
|
|
Thanks to our Corporate Sustaining Members
|
|
We appreciate your ongoing support of ADSA and the
Journal of Dairy Science
®
Ag Processing Inc.
ANDHIL LLC
Arm & Hammer Animal Nutrition & Food Production
Darling Ingredients Inc.
Diamond V
Global Agri-Trade Corporation
Grande Cheese Company
Lallemand Animal Nutrition
Pioneer
Quali Tech, Inc.
Renaissance Nutrition Inc.
Zinpro
Zoetis
Zook Nutrition & Management Inc.
|
|
Did you know that your ADSA Professional Membership, which is the least expensive of all national animal-related professional societies, includes all of the following benefits with no additional fees, charges or suggested donations?
*
Electronic access to the
Journal of Dairy Science®
*
ADSA Annual Meeting registration at reduced member rates
*
Discover Conference registration at reduced member rates
* Large Dairy Herd Management 3rd edition e-book at reduced member rates
*
S-PAC: Free access to ADSA Annual Meeting, past JAM and ADSA divisional abstracts
*
S-PAC subscription at reduced member rates
* A strong voice of advocacy for the animal sciences, animal agriculture and research
*
Access to ADSA's large and growing recorded symposia library
*
ADSA News
(semi-annual association newsletter)
*
ADSA Dair e-news
(ADSA weekly industry newsletter)
*
Access to member directory
*
Peer recognition through ADSA, Foundation and Sponsored Award Program
*
Discounted page charges in
Journal of Dairy Science®
*
Broad author recognition through ADSA/Elsevier press release program
*
Linked In and You Tube sites for ADSA
*
Quality networking with academic, government and industry professionals
*
Travel awards for all graduate students attending Discover Conferences
*
Opportunity to serve peers via committee and officer positions
|
|
American Dairy Science Association
1800 South Oak St., Suite 100, Champaign, IL 61820
|
|
|
|
|
|
|
