Wheat forage for silage, when should it be harvested for lactating cows?

Francisco E. Contreras Govea

Typical recommendations for harvesting cereal small grains for silage have been an issue for many years. If the main goal is to maximize silage nutritive value, without considering DM yield then, the recommendation has been to harvest at boot stage. On the other hand, if the main goal is to maximize yield without sacrificing nutritive value, then the recommendations is to harvest at soft-dough stage. Harvesting at boot stage DM yield is lower by 31% (7.4 Ton/ha) relative to soft-dough stage. These recommendations have been developed from the agronomic standpoint and laboratory analysis, without feeding to dairy cows (Contreras- Govea et al., 2006; Coblentz et al., 2018).

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Cost effectiveness of three components of the bovine tuberculosis surveillance system

Lucas Pantaleon

Surveillance of infectious diseases such as bovine tuberculosis (bTB), relies on ability of participants to follow protocols. Methods to evaluate the effectiveness of animal surveillance systems use epidemiological and, for cost-effective evaluations, economic data. It is well known that the effectiveness of disease surveillance systems relies mostly on the willingness of their actors to participate and follow prescribed practices.

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Nutrient composition of olive cake is affected by storage time

Juan Sánchez Duarte & Fernando Diaz

Olive cake (Olea europea L.) is a co-product from olive oil extraction that can be composed of a mixture of skins, pulp, woody endocarps, and seeds. Depending on the oil extraction method applied, olive cake can be classified as following: 1) crude olive cake, which is the residue of the first oil extraction from whole olives by pressure; 2) exhausted olive cake, which results after oil extraction from the crude olive cake using solvents  ̶ usually hexane; and 3) destoned olive cake, which results from the partial separation of the stone and pulp by screening or ventilation.

Olive cake can represent an environmental pollution problem since small amounts are used as fuel and requires a prolonged period for degradation. Nevertheless, considering its chemical composition (Table), olive cake can be used as ruminant feed.

Nutrient (% DM)CrudeExhausted
DM (% of olive cake)91.688.9


Chemical composition and nutritive value of olive cake is affected by multiple factors, among them, storage conditions and processing techniques.

A study carried out in Madrid evaluated the influence of storage time and processing on chemical composition and in vitro rumen fermentation of olive cake (Marcos et al., 2019). Samples of crude olive cake and exhausted olive cake (subjected to a second oil extraction) were compared during six months of storage.

Chemical composition

Increasing storage time of olive cake from 1 to 6 months resulted in increased fiber and lignin concentrations. However, sugar content decreased as storage time increased from 1 to 6 months. Storage time did not affect the olive cake protein concentration (Figure 1). Fat content was higher in crude olive cake than exhausted olive cake due to the second oil extraction.

Digestibility of DM and NDF decreased as storage time increased from 1 to 6 months (Figure 2). This effect was more pronounced in exhausted olive cake compared to crude olive cake. Decreases of DM and NDF digestibility were clearly associated to changes in the nutrient composition of olive cake, as storage changed from 1 to 6 months.

Gas production and DM effective degradability in crude and exhausted olive cake decreased as storage time increased from 1 to 6 months, which is in accordance with the changes observed in the olive cake chemical composition. Gas production was greater for exhausted than crude olive cake during the first 6 months of storage.In vitro fermentation

Increasing storage time from 1 to 6 months linearly increased pH, but gas and total VFA production decreased. Similarly, acetate, propionate, and butyrate productions were linearly reduced with advancing storage time. These findings reflect the lower fermentability of fiber compared to sugars, which changed as storage time increased from 1 to 6 months. There was no effect of storage time on ammonia concentration.

In conclusion, the nutritive value of olive cake is reduced as storage time advances. This change affects negatively rumen degradability, which is mainly due to the loss of sugars and to the increase of fiber as storage time advances. Rumen degradability is greater in exhausted compared to crude olive cake during the first months of storage.


Marcos, C.N., de Evan, T., García‐Rebollar, P., de Blas, C., Carro, M.D. 2019. Influence of storage time and processing on chemical composition and in vitro ruminal fermentation of olive cake. Journal of animal physiology and animal nutrition. 103(5): 1303-1312.

© 2020 Dairy Knowledge Center. All Rights Reserved.

Lying and eating behavior of Jersey and Holstein cows

Alvaro Garcia

Cow behavior has been the subject of much research in recent years with the intention to optimize their management and well-being. The development of automated devices that constantly monitor the cow’s activity has greatly helped form this perspective. Technologies that measure remotely cattle movements, temperature, rumination, and other physiological parameters have found their way from research facilities into commercial dairy farms.

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Use your isolation time to improve your knowledge

The Dairy Knowledge Center is offering a 50 percent discount in its subscription rates for 12, 6 and 3 months for you to make good use of this down time to improve your knowledge.

Brookings (SD, USA) 03/18/2020.- The pandemic caused by the Novel Coronavirus is asking from citizens in many areas of the world to remain at home. It affects also some professionals including those working in the dairy sector, which cannot continue with their daily activities.

On the one hand, this obligatory “time out” could mean a significant drop in your income and, on the other, might leave you with a lot of free time at home. It is for this reason that the Dairy Knowledge Center wants to be solidary with colleagues and friends that work on dairy production and dairy products around the world. Farm technicians, veterinarians, agronomist and dairy farm owners, will receive a 50% discount for 12, 6, and 3 months for all subscriptions happening within the next 30 days, starting today and until April 18, 2020.

Subscription to the Dairy Knowledge Center in any of these three time periods will give you access to all contents in the sections of Insights, Additives, Feed Library and Clinical Reports, with more than 100 articles published between 2019 and 2020.

¡Click in https://dairyknowledgecenter.com/subscriptions/ and sign today for a 50 % discount!

Dairy Knowledge Center

The Dairy Knowledge Center (DKC) is a global platform where we share innovatory practices on dairy herd management and applied research. The multidisciplinary team at the DKC researches and adds ideas and strategies to help leaders in the dairy sector obtain a competitive advantage in their operations. Innovation is the main cultural value at the DKC.

Working together with a vast network of external cooperators, academic leaders and partners, we explore ideas that will transform the future of the dairy industry.

Artificial hay aroma on dairy cow performance

Alvaro Garcia

Dairy production can be improved by increasing feed intake without negatively affecting animal health and well-being. This requires a thorough understanding of intake mechanisms and rumen health. In intensive production systems the right balance between fermentable (starch and sugars) and fibrous carbohydrates (effective fiber) is critical to maintain a healthy rumen. When this balance is altered not also rumen fermentation is modified, but also the motility of the pre-stomachs. This can result in higher incidence of acidosis and displaced abomasum, among other metabolic problems.

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Dietary DDGS and ammonia and hydrogen sulfide emissions

Alvaro Garcia

Greater ethanol production has increased the availability of one of its coproducts, distillers dried grains with solubles (DDGS). Once starch in corn is fermented to ethanol, the nutrients in the remaining mash that will end-up as DDGS, concentrate nearly three-fold. Research studies have explored the maximization of DDGS in dairy cow diets and its impacts on overall performance.

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Colostrum management and failure in passive transfer of immunoglobulins

Fernando Diaz


This article was published previously in the Portal de Especialistas en Novillas de Zoetis.

Dairy calves are born without any acquired immunity because immunoglobulins (Ig) cannot cross the structure of the placenta during pregnancy. As a result, calves depend on an adequate colostrum intake to acquire the necessary Ig and thus strengthen their immune system. Insufficient absorption of IgG in newborn calves can have negative consequences such as a decrease in the growth rate and future productive performance as well as an increase in the risk of contracting diseases and even death.

An indicator to assess whether colostrum management is adequate is the concentration of IgG in blood serum samples of calves between 2 and 7 days of life. When IgG values are less than 10 mg/mL, it is considered a failure in passive immunity transfer (FPT). Although colostrum feeding is the most important phase of a calf rearing program, several recently published works show high rates of FPT in commercial dairy farms.

Researchers from Prince Edward Island University, Canada, conducted an evaluation of the FPT in 207 Holstein calves and calves from 30 dairy farms located in Nova Scotia and Newfoundland. The authors (Elsohaby et al., 2019) found that approximately half of the animals (43.3%) showed IgG FPT. These results could be due to the low quality of colostrum fed on these farms, since half of the colostrum samples analyzed were of poor quality (IgG below 50 g/L). Another work carried out in Germany in which IgG concentrations were evaluated in 227 Holstein calves in four farms indicated that 30% of the animals showed FPT (Costa et al., 2019).

Similar results have been published in extensive production systems. A recent study (Abuelo et al., 2019) evaluated the concentrations of IgG in 253 calves of 23 Australian dairy farms and showed that the average prevalence of calves with FPT in the herds was 41.9%. Like the Canadian work discussed above, only 47.9% of colostrum samples showed adequate concentrations of IgG.

Although continuous monitoring of passive immunity transfer in newborn calves should be a routine practice on farms to evaluate colostrum management, only 6.2% of US dairy farms monitor FPT on a regular basis (NAHMS, 2014).

In addition to the quality and quantity of colostrum supplied, other factors related to the management of colostrum such as feeding time, method of administration (bottle, bucket or esophageal probe), storage (fresh, chilled or frozen) and colostrum pasteurization (intensity, duration) are associated with success in passive immunity transfer. To guarantee this transfer, it is necessary to provide at least 3 liters of quality colostrum during the first 2 hours after birth and at least another 2 liters within the next 4 hours.

About the author

Fernando Diaz is the Director of the Dairy Knowledge Center. He works as a Dairy Nutrition and Management Consultant at Rosecrans Dairy Consulting, providing consultation to dairies and feed companies, including nutrition and feeding management, forage and crop plans, ingredient procurement, and research and product development of new feedstuffs, additives, and technologies for dairy cows. Fernando lives in Brookings, South Dakota and can be reached at fernando@dairykc.com.

© 2020 Dairy Knowledge Center. All Rights Reserved

Dairy cow postpartum stimulation with equine chorionic gonadotropin

Andrés Haro & Alvaro Garcia

To achieve their greatest reproductive potential, dairy cows need to conceive as soon as possible after calving. Endocrine changes, referred to as the return to post-partum ovarian activity, occur after uterine involution and function normalization of the hypothalamus-hypophysis-ovarian axis. The use of equine chorionic gonadotropin (eCG) in lactating cows can induce post-partum ovarian activity causing follicle growth to resume.

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Effect of stearic or oleic acid supplementation on milk performance and energy partitioning

Ishaya U. Gadzama & Fernando Díaz

High producing dairy cows require energy dense diets during periods of negative energy balance. Energy deficiency can reduce milk production and negatively affect milk composition, as well as increase the susceptibility of cows to metabolic disorders such as ketosis, fatty liver, and downer cow syndrome. One way to increase the energy density of dairy diets is to increase the amount of nonstructural carbohydrate. However, feeding high starch diets promote greater ruminal propionate production and predispose cows to rumen acidosis and milk fat depression. Fat is a rich source of digestible energy with 2.25 times more energy than starches and digestible fiber found in common grain or forage sources.

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