Environmental Impact of Breeding for Feed Efficiency
College of Agricultural and Life Sciences, Agronomy 375: Food Systems and Climate Change
- Kayla Krueger, UW-Madison Undergraduate Student, Dairy Science, kmkrueger4@wisc.edu
- Savanna Frane, UW-Madison Undergraduate Student, Biology, frane@wisc.edu
- John Faldet, UW-Madison Undergraduate Student, Agronomy, faldet@wisc.edu
Scenario
We are a distinguished group of professors that are preparing to give a presentation to our class of aspiring farmers who strive to be successful. In this lecture, we aim to give our students the tools to have a highly profitable dairy farm while mitigating greenhouse gas (GHG) emissions and preserving fertility of their herd through selective breeding techniques. We will focus on three areas throughout the presentation that we believe are vital to maintaining a productive farm without perverse impacts on the animal’s health, fertility, or the environment. These three areas are 1) how traditional or modern breeding techniques improve milk production of a cow 2) the amount of GHGs a productive cow emits and how this is effected by breeding schemes and 3) how breeding cows for high milk yield impacts the animals fertility and health. Overall, we strive to show our students how to maximize production of their farm without detrimental impacts to the cow or the environment.
Abstract
In the U.S., the number of dairy farms tend to be decreasing every year. As pictured here, Wisconsin had 173,000 farms in 1930 and only 9,900 dairy farms by 2014(Murphy, 2014). The figure below from the Wisconsin Milk Marketing Board shows that although the number of dairy farms are decreasing, milk production has increased by nearly 200%.
Breeding dairy cattle for specific traits through genetics can help manage the profitability and overall sustainability of farms. Research from the UW- Madison Dairy Science team has found that genetically selecting for a lower feed input could result in a decrease of 0.4 pounds per cow per day of dry-matter intake in the next ten years. This would save farmers about $21 million per year in feed costs (Weigel, 2015). Recently, dairy farmers have begun to select for cows with high milk production and lower feed input for a good feed efficiency ratio. A cow that is able to produce milk from less feed is deemed profitable. Due to high feed cost and inputs, this is becoming a more common breeding philosophy. The only way that farmers typically make their revenue is from milk the cows produce. Therefore, if you have cows that are genetically bred for high yield, the revenues increase. Moreover, in order to achieve high milk production yields, we as dairy farmers have unintentionally created other health issues regarding reproduction and overall fertility. If dairy farmers continue to traditionally bred cows for sole milk production purposes, tradeoffs will be prevalent. A cow that never becomes pregnant will leave the dairy farm at the end of her lactation, if not earlier. If cows are not pregnant or lactating, they are producing GHG emissions without being profitable. It is important to recognize how valuable fertility and reproduction are on a dairy in relation to profit and emissions.
Introduction
Wisconsin is second in total milk production in the country, behind California. According to the Wisconsin Milk Marketing Board , Wisconsin accounts for 29 billion lbs of milk in 2015. The overall emergence of larger dairy farms, and the continued shift to selectively breeding cows for higher milk yield has increased over time. According to the United States Department of Agriculture, between 1970 and 2006, the percent of dairy operations dropped 88%. Moreover, milk production per cow doubled between 1970 and 2006 (from 9,761 to 19,951 lbs per year). The trends we are seeing in dairy farming have transformed due to new technology, specialization, size, and many other factors.
Oltenacu, et al. (2005), explains that intensive genetic selection for increased milk production has been executed by farmers to increase overall profits. However, the increase in milk production has brought tradeoffs, such as a decline in reproductive performance (fertility), incidence of health issues, and overall decline in longevity of these dairy cows. As Dobson et al. (2007) mentions, milk production can fluctuate by genetic selection, age of the cow, days in milk, and breed of the cow. The main focus is to look at how farmers genetically select these cows for high milk yield, and the benefits and drawbacks associated with this decision.
Reproduction and lactation are part of the same overall process. The ultimate objective of reproduction is to produce the next generation of reproductively viable offspring. This is because a cow that does not produce a calf is unworthy in the herd due to the fact she will not make milk. Most structural development of the mammary gland occurs during pregnancy. Technological advancements have helped aid the fertility issue in many herds by utilizing synchronization protocols to increase overall service rate, but is an ethical and social issue in some ways. Nevertheless, as we can see fertility and reproductive success are extremely important and a large factor of milk production and a cow's overall sustainability.
Reproduction and lactation are part of the same overall process. The ultimate objective of reproduction is to produce the next generation of reproductively viable offspring. This is because a cow that does not produce a calf is unworthy in the herd due to the fact she will not make milk. Most structural development of the mammary gland occurs during pregnancy. Technological advancements have helped aid the fertility issue in many herds by utilizing synchronization protocols to increase overall service rate, but is an ethical and social issue in some ways. Nevertheless, as we can see fertility and reproductive success are extremely important and a large factor of milk production and a cow's overall sustainability.
Modern breeding techniques have evolved with a purpose to make cows more efficient in terms of feed consumption and mitigation of GHG emissions, (Bell, 2013). Feed efficiency is typically used as a benchmark for profitability and is calculated as pounds of milk per pounds of dry matter that the cow consumes, (Wall et al. 2010). Therefore, if cows eat less feed, and produce the same or more milk, they are deemed profitable (as a large portion of costs on dairies are derived for feed). If cows are not producing milk, but are consuming feed, they continue to produce GHG emissions.
The goal of this research is to answer the question of how traditional and modern breeding techniques can be used to maximize milk production and feed efficiency of a cow with traditional techniques referring to milk production yield, and modern techniques refering to feed efficency, how these techniques impact fertility of the cow and her health in general, and if either technique of breeding technique helps with mitigation of GHGs.
Materials & Methods
Meta-analysis:We conducted a meta-analysis to find peer-reviewed academic sources on topics corresponding to breeding techniques, fertility, health of animals, and GHG emissions. Each team members searched the internet for a certain aspect of our research question.The results of each source were evaluated as a team and used to form a working hypothesis. Information from these sources was compared and contrasted to each other in the following aspects: how traditional or modern breeding techniques improve milk production of a cow, the amount of GHGs a productive cow emits and how this is effected by breeding schemes, and how selected productivity impacts the animals fertility and health.
Interview:A meeting was held with Carlos Arriaga to get his expertise on milk production and fertility by our team. He explained that as a society, we are changing the length of peak milk production after each calf is born to a cow. In short, we are making the mother have her best and highest production of milk earlier in the calves life cycle so the cow can become pregnant again sooner, leading to more milk production per year. He also asked us to think about replacement heifers. He said that for productivity reasons replacement heifers are great when needed. But until the time when that heifer is needed for breeding, she is costly to the farm in terms of feed, and costly to the environment because she is emitting GHG’s without being profitable to the farmer. We used this information to investigate further into feed efficiency ratio, fertility, and GHG emissions of cows.
Literature Review
Main findings from literary sources -GroupC-BibliographyFinalSpring2016.pdf
HypothesisAfter studying the literature, we hypothesize that traditional breeding techniques focus more on milk production while modern techniques focus more on feed efficiency ratios. Unfortunately, there are tradeoffs associated with each breeding technique that impact the cows fertility and longevity. From our research, mitigation of GHG emission (while being a small percent of total world emissions) need to be taken into account by individual farmers. The agriculture community benefits from mitigation of GHGs both in future preservation of land for agriculture use and an efficient feed to milk ratio to profit from.
Results
We found a correlation between genetic selection of cows for high milk production, and problems in fertility. A dairy scientist at UW-Madison, Paul Fricke, conducted a study on pregnant vs. open cows (getting cows pregnant and the money it makes). Estimating the future revenue from reproduction is extremely difficult, resulting in an approximation of the value of a pregnancy, Fricke (2005) . As we move across time on the lactation curve, , milk production first increases toward a “peak” (that typically occurs 4-6 weeks after calving) and then decreases progressively over the subsequent 9-10 months. The cycle is repeated only if the cow gets pregnant again. Eventually however the cow will be sold for a beef price, and a replacement animal will occupy her place. Non-pregnant cows are 7.5 times more likely to be culled then pregnant cows (Fricke, 2005).
Research has shown that over time, cows are having a more difficult time to get bred when compared to prior years. This could explain the controversial idea that cows with higher milk yields due to genetics have reduced fertility rates. Diep (2014) , the average cow needed 1.8 shots of artificial insemination to get pregnant. In 2000, cows needed an average of three shots. This data also shows that cows now need more time to regain fertility after giving birth.
There may be other factors that contribute to fertility issues besides genetics. Heat-stress is a huge issue, particularly in the summer months. Rorie (2015) explained that ensuring lactating dairy cows are bred to maintain a reasonable calving interval can be challenging any time of year, but especially difficult to do during the hot summer months. Heat stress can occur in lactating cows at temperatures of 80°F or higher. This is important to understand when looking at the whole picture of fertility, as there are other major contributors to consider other than genetics.
As noted above, it is not cost effective to for farmers to own cows that are difficult to breed back. Even though these cows may produce a high volume and create profit, the short amount of time they are producing milk may not be enough to keep her on the farm if she is difficult to breed back. Nevertheless, she may be able to produce milk at a high volume for a long period of time, but longevity throughout the current lactation, and many after, is critical to the farmer’s profit as well.
The main goal for farmers is to maximize their profits. To have a large profit margin, farmers sell as much milk as possible with having maximum efficiency, including both financial and sustainable. As seen below in Figure 2. Fricke (2005), are the effects of increasing a herd's overall PR (Pregnancy Rate) on milk, and total $ return/cow. As the PR increases, so will milk production and overall profit. There is a clear positive correlation between increasing fertility and increasing profit of the herd. We can note in this graph that sustainability is measured through reproduction and financial sustainability. This graph is a great example of how reproductive performance and milk production work hand in hand.
Fricke (2005) explains that technology can improve reproductive efficiency, even though cows have naturally low fertility. Therefore, dairy scientists have implemented new ways to increase the pregnancy rate and fertility by implementing systematic protocols. Farms that have a difficult time breeding cows implement these protocols, such as Presynch/Ovsynch Protocol, by administering natural existing hormones to imitate the reproduction cycle. This protocol induces estrus and synchronizes the group of treated cows to ovulate during a known time window. Insemination ensues as an event timed relative to the last hormonal administration regardless of presence of signs of heat.
Genetic selection of dairy cows based on feed efficiency, with possible impact on methane and nitrogen losses, could have a large impact on the environmental footprint of milk production.
Optimizing feed intake is critical on farms from a financial and sustainability aspect. As Bell et al. (2013) explains the main GHGs from livestock systems are methane and nitrous oxide. Research has shown that GHG emissions increase with higher yields on a per cow basis (Gerber, 2011) . Enteric Methane (CH4) emissions from ruminants are a significant contributor to GHGs and hence changes to climate (Morrby, 2014). There is no doubt that GHGs are produced by ruminants, however the total amount of emission varies greatly based on many factors such as diets, breed of dairy cow, etc.
The idea of overall modern breeding goals is sequential in recent years. The main goals of breeding cows for feed efficiency are productivity and profit. A high feed efficiency ratio reduces the maintenance cost of the animals to the farmer, reduces the number of animals needed to produce the same quantity of product, and increases the energy efficiency of the animal in order to produce less waste in the form of nitrogen and methane per unit product. It is important to use a critical eye when analyzing the entire picture when looking at genetic traits. As Wall et al. (2010) explains, selecting for traits that improve the efficiency of the system (e.g. residual feed intake, longevity) has a positive effect on system emissions as well as improving the future sustainability of the system.
Certain breeds of dairy cows help fluctuate the overall feed efficiency results due to many factors. The Holstein accounts for a large majority of the cow population in the United States (and many other countries). It has been the breed subjected to the greatest selection intensity, for high milk production and good feed efficiency ratio for overall profit. Genetic selection tends to focus on mostly production traits (kilograms milk, kilograms fat and protein) rather than fitness (lameness, mastitis, fertility and lifespan) traits (Bell, 2013). The great response by Holsteins is represented well when Bell et al. (2013) states that Holsteins account for about 88% of the dairy cow population on farms across the globe. However, Holsteins are a larger cow that need more feed to produce this high amount of milk, due to body weight and metabolism (Bell, 2013). Nevertheless, Jersey cows are known to be the breed that are most feed efficient due to their small body weight and the ability to convert less feed into milk while maintaining high fat and protein components when compared to Holstein cows. This is important when looking at what cow breed to have in your herd if concerned about feed efficiency and emission of GHGs.
With this information in mind after our devoted work as professors, we hope to show our student/future farmers that through genetic selection and breeding to achieve a good feed efficiency ratio, they can create cows that are fertile, live a long healthy life, produce a high yield of milk, and generate less GHG emissions.
Discussion
As with all research, nothing is undisputed. There were some academic and practical restrictions we ran into when answering our research question, which are as follows.
Limitations of time: We focused mainly on cows, because they are the profitable part of the farm in terms of milk. There are typically bulls and other cattle that impact the farmers profit, but we felt that was outside the scope of our research topic.
Pillars of Sustainability: Our group focuses mainly on the environmental and economic pillars of sustainability. We show how farmers can mitigate GHG emissions by producing an efficient cow with a good feed to milk ratio, and explore ways for farmers to be profitable via genetic selection, fertility, and longevity of a cow. Giving hormones to a cow is viewed by some as unacceptable and therefore would be considered a social sustainability concern. We understand that many people are care about treatment of animals and chemicals that go into food (beef), and rightfully so. Our group considered these aspects and concluded that for the purpose of this project we view hormones given to cows for increased efficiency as being an enhancement of hormones they naturally produce. With further education and communication of this idea of added hormone that are naturally produced, we hope this viewpoint could be adopted and widely accepted by the public.
Practicality:Some of the practices noted in this website can also be very costly to farmers to pursue. For example, the usage or hormones, artificial insemination, shots, any health related issues, etc. all typically require a veterinarian or hired person. For some smalls farms, this is not always feasible. It is also very hard to properly measure GHG emissions from cows/farms. We mainly focus on the large contributors, methane and nitrous oxide, that are in close relation with the cow itself. The work of the scientific community has been significant in recent years but is not complete. Further research of GHG emission in aspects of contributors such as milk truck emissions, electricity to run farm equipment, how the cow breaks down feed, etc. may be very helpful in estimating dairy cow gross emissions. Many of our sources and studies we used do a great job of looking at GHG emission, but with this certain topic, one can never fully get all the emissions calculated for.It is also very hard to properly measure GHG emissions from cows/farms. We mainly focus on the large contributors, methane and nitrous oxide that are in close relation with the cow itself. Eventually a line has to be drawn when considering GHG emission, such as to consider milk truck emissions, electricity to run farm equipment, how the cow breaks down feed, etc. Many of our sources and studies we used do a great job of looking at GHG emission, but with this certain topic, one can never fully get all the emissions calculated for.
Despite the gaps and limitations of this study, we believe that it is important to farmers, future farmers, and consumers to be aware of how breeding techniques influence fertility and GHG emissions. Farmers are able to profit from their herds by keeping a cow fertile, healthy, and giving her a long life because she will produce milk for the farmer. The importance of the feed efficiency ratio when considering profit for the farmer is cost. Feed is a main input on a farm, and can be very expensive. By getting the same amount of milk or more from cows while feeding them less, not only do farmers save money, but they also help to mitigate GHG emissions because an efficient cow produces less methane and nitrous oxide for the same amount of milk. Consumers then benefit from this in the marketplace where milk prices will remain reasonable because of less input costs to the farmer. Future farmers also benefit because the path is being paved for them in terms of genetic selection and breeding, and also receive a better environment from mitigation of GHGs. With less enteric Methane and Nitrous Oxide in the environment, we are hopefully combatting climate change and keeping a favorable temperature for breeding of cows.
Conclusion
Ideas from authors mentioned throughout the results helped us to conclude that there are favorable breeding conditions for cows, which increases productivity, potentially mitigating GHG emission. We found that breeding cows on feed efficiency decreases costs to the farmer, making them more profitable. This practice also makes the cow more efficient, which in turn reduces methane and nitrous oxide emission which can largely impact the footprint of milk on our generation and future generations. Also, by using certain breeding goals, we can increase the fertility and longevity of the cow, making her more productive and healthy. We hope that this information proves helpful to our (pretend) class of student, as well as all readers.
Going forward in research, we think it would be important to investigate how different kinds of feed change the feed efficiency ratio in comparison to milk production, GHG emission, and fertility. It would also be great to see more information produced about the social aspect of the research topic, seeing that so much of it is taboo still. We hope that our research inspires future farmers to adapt these practices and ideas in their own farms, as well as other curious groups to do more research on this important topic.
About the Authors
Kayla Krueger: My name is Kayla Krueger, and I am currently a Senior majoring in Dairy Science and minoring in Agricultural Business. I will be graduating in May 2016 and will be pursuing a career in pharmaceutical sales with Boehringer Ingelheim selling antibiotics and medicine to veterinarians and large farms in Central Wisconsin. I grew up in Marion, WI on a small dairy farm where we milk 60 cows and farm 400 acres of cropland. I am highly involved on campus with Badger Dairy Club and the Association of Women in Agriculture.
Savanna Frane: My name is Savanna Frane. I’m a Senior at the University of Wisconsin-Madison, where I will be graduating in May 2016 with a Biology degree. I grew up in Athens, WI, a tiny rural town. After graduation I will be working at the UW Hospital as a pharmacy technician while applying to medical schools with further hopes of becoming a radiologist.
John Faldet: My name is John T. Faldet and I am currently a Junior majoring in Agronomy in the College of Agricultural and Life Sciences at the University of Wisconsin-Madison and am from Iola WI where I grew up on a 2,000 acre cash crop farm. I am a highly active Badger on campus being in Crops Club, Multiple Bands and Choirs including the Marching and Varsity Band, Alpha Gamma Rho and have started a small business of Johnny Chix Farms, LLC in Iola, WI. This summer I will be going in internship in Bancroft, WI at Wysocki Produce Farms in the central sands as a vegetable field scout.I plan on graduating in the fall of 2016 and am ready to enter the ever diverse Agricultural Field.
Annotated Bibliography
Fricke, et al. Pregnant vs. Open: Getting Cows Pregnant and the Money it Makes. Western Dairy Management Conference, 2005. http://www.wdmc.org/2005/6Fricke.pdf
Anonymous, 2015. Understanding Genetics and Sire Summaries. Holstein Foundation, 2015. Web. http://www.holsteinfoundation.org/pdf_doc/workbooks/Gen_Sire_WKBK.pdf
Bell, MJ., and JE. Pryce. Livestock Production: Breeding Dairy Cows to Reduce. Vol. 3. Intech, 2012. Print. http://cdn.intechopen.com/pdfs-wm/40414.pdf
Diep, Francie. Breeding for High Milk Production Created Less-Fertile Cows. Popular Science. Maryland Department of Agriculture, 2014. Web. http://www.popsci.com/article/science/breeding-high-milk-production-created-less-fertile-cows.
Dobson, H., and RF. Smith. The High Producing Dairy Cow and Its Reproductive Performance. National Library of Medicine: National Institute of Health, 2007. Web. <http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2748269/>
Fricke, et al. Pregnant vs. Open: Getting Cows Pregnant and the Money it Makes. Western Dairy Management Conference, 2005. http://www.wdmc.org/2005/6Fricke.pdf
Gerber, Pierre, et al. Productivity gains and greenhouse gas emissions intensity in dairy systems. Livestock Science, 2011. Pdf. http://www.sciencedirect.com/science/article/pii/S1871141311000953
Hansen, P.J. Genetic Control of Heat Stress in Dairy Cattle - University of Florida Department of Animal Sciences. The Growing Problem of Heat Stress and the Possible Role for Genetic Strategies to Mitigate Its Effects. Florida Dairy Production Conference, 2013. Web. http://dairy.ifas.ufl.edu/dpc/2013/Hansen.pdf
Hoffmann, Irene. Climate Change and the Characterization, Breeding and Conservation of Animal Genetic Resources. Food and Agriculture Organization of the United Nations. 2009. Web. http://www.fao.org/3/a-al188e.pdf.
Kadarmideen, Haja N., et al. Genetic Parameters and Evaluations from Single-and Multiple-trait Analysis of Dairy Cow Fertility and Milk Production. Livestock Production Science, 2003. Web. http://www.sciencedirect.com/science/article/pii/S0301622602002749
Liang, D., and V.E. Cabrera. Optimizing Productivity, Herd Structure, Environmental Performance, and Profitability of Dairy Cattle Herds. Journal of Dairy Science, 2015. Web. http://dx.doi.org/10.3168/jds.2014-8856
Moorby, Jon M. Traditional vs Modern: Role of Breed Type in Determining Enteric Methane Emissions from Cattle Grazing as Part of Contrasting Grassland-Based Systems. Plos, 2014. Web http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0107861
Murphy, Brenda. "Dairy Statistics." Wisconsin Milk Marketing Board. 2014. Web. 7 May 2016. <http://media.eatwisconsincheese.com/dairyimpact/statistics/dairystatistics>.
Oltenacu, Pascal A., and Bo Algers. Selection for increased production and the welfare of dairy cows: are new breeding goals needed?. AMBIO: A Journal of the Human Environment, 2005. Web. http://www.bioone.org/doi/full/10.1579/0044-7447-34.4.311
Rorie, Rick. Breeding Lactating Dairy Cows During Hot Weather. Dairy Herd Management, 2015. Web.http://www.dairyherd.com/advice-and-tips/reproduction/breeding-lactating-dairy-cows-during-hot-weather
Thomas, Heather. How to Start a Cattle Farm: Your Guide to Breed Selection. Countryside Daily, 2015. Web. http://countrysidenetwork.com/daily/livestock/cattle/how-to-start-a-cattle-farm-your-guide-to-breed-selection/
Wall, E., G. Simm, and D. Moran. Developing breeding schemes to assist mitigation of greenhouse gas emissions. Animal, 2010. Web. http://tinyurl.com/gmdp6jo
West, Joe. Managing and Feeding Lactating Dairy Cows in Hot Weather. UGA Extension, 2014. Web.http://extension.uga.edu/publications/detail.cfm?number=B956
Weigel, Kent. "Dairy Research Could save Millions." AGRI-VIEW. UW- Madison, Department of Dairy Science, 27 May 2015. Web. 5 May 2016. <http://www.agriview.com/news/dairy/dairy-research-could-save-millions/article_8ed22352-aabc-5ba1-90c1-22f5bc84252a.html>.
Acknowledgments
We would like to thank the entire Agronomy 375 class and professors for aiding and guiding us in finishing our project. We worked hard to get it to where it is now and hope that all readers enjoy our findings on genetic breeding for milk production, its impacts on the environment, as well as the fertility of dairy cows.