Dairy Science Digest

Reproductive physiologists are always trying to improve conception rates for the dairy herd. Double ovsync is one of the best tools in our toolbox to submit cows to first insemination. However, as estrus detection technology becomes more affordable and we learn more about physiology, perhaps combining the expression of estrus at insemination may improve fertility through optimizing ovulation timing.

Dr. Julio Giordano and Ana Laplacette worked with their Cornell reproduction team to investigate this theory on over 4600 cows in 2 commercial herds. “We are trying to take advantage of the power of sync of ovulation and the power of estrus” Giordano explains. “To get the best of both, synergize the two.”

The only change to the well-known Double ovsync protocol includes a delay in the final administration of GnRh before breeding. The goal, allowing the cows more time to show estrus. Take a moment to listen in to better understand the physiology of this synchronization program and how to improve your herd’s reproductive management.  

Topics of discussion

2:03       Introduction of Dr. Julio Giordano & Ana Laplacette

Delaying induction of ovulation and timed AI in a Double-Ovsynch protocol increased expression of estrus and altered first service reproductive outcomes of lactating dairy cows

DSD 5.10 | Rumen friendly fatty acids in High Oleic Beans

Soybeans and dairy cows have walked hand for decades. These oil beans are known specifically for the amino acid sequence in their high-quality protein and energy to support lactation. Recent developments in plant breeding has shifted the fat profile of the bean contain a higher amount of Oleic fat, which is easier for the rumen to digest, in certain varieties. 

Ensuring producers know how much to feed, and how to feed high oleic soybeans to the herd was the objective of a series of research projects in the pipeline of publications due to come from MSU in the coming months and years.

Topics of discussion

1:56       Introduction of Adam Lock  

Featured Article:

Effects of raw and roasted high oleic soybeans on milk production of high-producing dairy cows

Supporting Article:

Effects of increasing dietary inclusion of high oleic acid soybeans on milk production of high-producing dairy cows

Despite decades of dedicated research, the rumen still remains a bit of a ‘black box’. This month we feature an article from  Dr. Gonzalo Ferreira and his team at Virginia Tech as they try further define how undegradable fiber impacts the rumen's flow rate, and therefore productivity.

Comprehending the kinetics of degradation will assist in identifying the ideal combination of ingredients to create a profitable ration for your herd.

Could this help you make future planting decisions, as the nation is repairing from several rounds of drought? Does the ‘queen of forages’ belong in your cropping program?

Listen in to learn more!

Topics of discussion

1:48       Introduction of Dr. Gonzalo Ferreira

Featured Article:

Ruminal passage rate and digestibility of fiber from dairy cows consuming diets containing alfalfa and orchardgrass hays with different concentrations of undegradable neutral detergent fiber (uNDF)

Seems like calcium and phosphorus gather up all the attention, but there is growing awareness of the importance of magnesium – the “runner up mineral” in the dairy cow diet. Some sources of magnesium are simply more available than others. This fact has the ignited the interest of ruminant nutritionists looking to focus their research efforts on determining the most available Mg source so you can get the biggest bang for your buck.

This month we featured an article from Dr. Noelia Silva Del Rio, from UC Davis. She describes her research on the rumen availability of different popular magnesium sources and explains the importance of magnesium and how to improve the mineral status of your herd. Listen in to learn more!

Topics of discussion

1:32       Introduction of Dr. Noelia Silva

Featured Article:

Subacute Ruminal acidosis, commonly referred to as SARA, could be robbing your herd of production. When pH dips too low for too long the biology of the rumen shifts, butterfat slides and overall health of the herd is negatively impacted.

But how can you tell if your herd has SARA?

This month we invite Dr. Eric Paquet and Felix Huot, from Université Laval in Quebec Canada to explain the method of using DHI milk samples to map the prevalence of SARA in the dairy herd of Quebec.

Listen in to learn more - 

Topics of discussion

1:48       Introduction of Dr. Eric Paquet and Felix Huot

Featured Article:

Featured Article:

Background Information:

#2xAg2030; #journalofdairyscience; #openaccess; #MODAIRY; #SARA; #machinelearning; #VFA; #milk; #fattyacid; #acidosis; #FA; #dairysciencedigest; #ReaganBluel; 

When your bulk tank volume takes a plunge through the last bout of heat, do you ever wonder exactly WHY?

To best understand the why, the Virgina Tech dairy team collected tissue samples from the mammary gland of cows in controlled environmental chambers. This month we invite Dr. Ben Corl to explain the cellular changes observed in the alveoli, epithelial and even immune cells of the mammary gland of cows undergoing a controlled heat stress challenge.  

Additionally, he’ll describe the changes in gene expression in those same tissue samples that controls protein production and mammary health.

This continuation of our heat stress series features two papers titled:

Topics of discussion

1:28       Introduction of Dr. Ben Corl

Background Information:

#2xAg2030; #journalofdairyscience; #openaccess; #MODAIRY; #heatstress; #alveoli; #milk; #mammarydevelopment; #mammary; #dairysciencedigest; #ReaganBluel;

Florida researchers began a generational study in 2007 that is still years in the making. It all began with the investigation of the impact of heat stress on dry cows to measure changes that might occur to the calf incubating inside the hot dam, like a crock pot.

In addition to seeing negative production impacts on mama, the researchers began to measure numerous changes in the damaged calf coming out of the heat stressed dry cow. This month’s edition, we’ll be interviewing Dr. Jimena Laporta, of the University of Wisconsin, to better understand the physiological changes of the calf that results in lost production for her entire life. She and her team measured changes in mammary and adrenal gland development.

Several separate papers have been peer reviewed over the 17 years of research. Many are linked at the bottom of the show notes for additional reference.

Listen in to understand how heat stressed dry cows can destroy your favorite cow families’ production records.

This month features two released paper titled:

Topics of discussion

1:58       Introduction of Dr. Jimena Laporta

Background Information:

Choline, a pseudovitamin, is required by all mammals including the dairy cow for many essential functions. Research in supplementing rumen protected choline really took off about twenty years ago, however continues today to best understand how this feed through additive can positively influence profitability.

The findings we discuss are published in the recently released paper titled: Exploring choline's important roles as a nutrient for transition dairy cows

Topics of discussion

1:19       Introduction of Dr. Usman Arshad

Featured article: Exploring choline's important roles as a nutrient for transition dairy cows

#2xAg2030; #journalofdairyscience; #openaccess; #MODAIRY; #Choline; #transition; #transitiondairy; #vitamin; #fattyacid; #negativeenergybalance; #TMR; #dairysciencedigest; #ReaganBluel;

DSD 5.3 | Slight modifications of CIDR Sync - help or hinder?

In this time of heifer inventory shortage – getting heifers pregnant (in a timely fashion) is even more important than ever.

Contract heifer growers in California sought the help of Dr. Fabio Lima and his team at UC Davis to best understand the use of a 6-day CIDR sync with variable rates of GnRH could increase pregnancies when bred to sexed semen.

The findings we discuss are published in the recently released Journal of Dairy Science article titled: Effect of 200 μg of gonadorelin hydrochloride at the first GnRH of a CIDR Synch program on  ovulation rate and pregnancies per AI in Holstein heifers.

Listen in to hear the results and nuanced details of controlling reproductive structures using timed AI protocols.

Topics of discussion

1:03       Production costs of heifer rearing - survey results

Articles also discussed in the podcast:

Studies showing the implication of progesterone for double ovulation (a proxy for twining) and progesterone. https://doi.org/10.3168/jds.2018-14410

#2xAg2030; #journalofdairyscience; #openaccess; #MODAIRY; #gnrh; #CIDRsync; #twinning; #pregnancy; #heiferdevelopment; #TAI; #lutenizing; #dairysciencedigest; #ReaganBluel;

Getting the fresh cow off to a strong start has ripple effects for her entire lactation. Subclinical mastitis rarely gets treated due to an unawareness or a lack of interest in pulling her from the tank. Nisin is a naturally occurring antimicrobial that’s been used widely as a food preservative. Dr. Zelmar Rodriguez and his team from Michigan State University looked at using this familiar antimicrobial to treat subclinical mastitis. The result, reduced clinical cases of mastitis.

Listen in to learn more about the return on investment of using Nisin on subclinical mastitis found in the first week of milk using CMT.

These findings are published in the recently released paper titled: Economic impact of treatment of subclinical mastitis in early lactation using intramammary nisin

Topics of discussion

1:20       Introduction of Dr. Zelmar Rodriguez

#2xAg2030; #journalofdairyscience; #openaccess; #MODAIRY; #nisin; #earlylactation; #subclinical; #mastitis; #treatment; #dairysciencedigest; #ReaganBluel;