Progress 10/01/19 to 09/30/20
Outputs
Target Audience:Target audiences for the research focused on almond hulls are the almond hullers, dairy nutritionists, feed industry, state regulatory agencies, and dairy producers. Target audiences for the research focused on hemp are the hemp growers, hemp processors, nutritionists, feed industry professionals, state regulatory agencies, and dairy producers. Target audiences for the research focused on dietary essential oils to reduce enteric emissions from dairy cattle are dairy nutritionists, feed industry professionals, state regulatory agencies, and dairy producers. Methods to approach target audiences are varied although with recent covid-19 policy outreach activities were reduced. Almond Hull Research: The results of the almond hull research were presented at industry and university meetings. Oral presentations were made at the Tulare World Ag Expo in February 2020 at the BioMass Workgroup of the Almond Board of California. Numerous Zoom meeting we conducted with directors of the Almond Board of California. Posters were presented at The Almond Conference 2020 organized by the Almond Board of California. Oral presentations were also made at the Golden State Dairy Conference 2020 (ANR) and a during an ANR webinar on byproduct feedstuff. Hemp Residue Research: Orals reports of research progress were made at meetings of the California Department of Food and Agriculture (CDFA) Inspection Advisory Board. The Advisory Board is composed of government officials, feed industry professionals, and producers from a wide array of agricultural commodities. A representative from the CDFA also visited U.C. Davis to review the research project during the animal portion of the study. Changes/Problems:One problem/challenge has been working during covid-19. The hemp study requires the modification of methods used for measure cannabionoids in blood for measurements in difference matrixes including milk, feces, urine, and adipose tissue. What opportunities for training and professional development has the project provided?Projects have involved undergraduate student research interns. These undergraduate interns gain hands-on experience with research methodology. It also allows students to apply concepts and principles obtained from formal coursework. Most undergraduate interns are involved in research to gain animal experiences for applying to programs in veterinary medicine. One former undergraduate research intern is now currently employed as a research technician on this project with a goal of applying to graduate school to study nutrition. The previous research technician was also an undergraduate student research intern. This individual gained experience with research including conducting studies, collecting data, and writing and presenting reports. This technician obtain a position to conduct feedlot nutrition research with a large private company. The postdoctoral candidate involved in the research is gaining more experience with research, developing grants, and preparing manuscripts. These activities will better prepare the individual for a position in academia, in a regulatory agency, or in industry. How have the results been disseminated to communities of interest?Findings from the research with almond hulls have been disseminated through journal publications, oral presentations at industry meetings, presentations to a State regulatory agencies, ANR webinar, and extension newsletters. The research with hemp residue is not completed so only oral updates at State advisory board meetings have been made. What do you plan to do during the next reporting period to accomplish the goals?he aim of the hemp residue study is to determine the concentration of remaining cannabinoid compounds after the extraction of CBD (cannabidiol) oil from hemp. The CBD oil has potential health benefits for animals, both human and nonhuman. The hemp industry in California is expanding rapidly in acreage. Extract of CBD oil from hemp results in a plant residue. At the present time, regulations do not permit the feeding of the hemp residue to animals (livestock). Therefore, there is an issue with disposal. Using the hemp residue as a byproduct feedstuff for livestock would be one solution for the hemp residue. Our research is evaluating the feeding of hemp residue to lactating goats. The hemp residue was fed to lactating goats to determine if any remaining cannabinoids in the hemp residue are transferred to milk, blood, feces, urine, and adipose tissue. During the next reporting period it is expected that the analysis of cannabinoids in the milk, blood, feces, urine, and adipose tissue will be completed. The State agency will review the data and decide if a next step is to determine the impact of feeding hemp residue to lactating dairy cattle. During the next review period we are continuing our earlier research with genetically edited alfalfa that is reduced lignin. The aim of this research is to increase the digestion of fiber in forages. Increasing the digestion of fiber will support higher animal performance and improve the utilization of plant organic matter by ruminants. Increasing production output of milk and meat and increasing energy obtained from forages will reduce the impact of animal agriculture on the environment by increasing product out per unit of input.
Impacts
What was accomplished under these goals?
Objective 2: Completed studies on the nutritive value of almond hulls for dairy cattle. California is the world's leading producer of almonds. Field weight yields of almonds at harvest are 23% nuts, 13% debris, 14% shells, and 50% hulls. There were over 2 billion kg of almond hulls produced in 2017-18. The majority of the almond hulls are fed to livestock. Almond belongs to the stone fruit family with the peach. The almond hull is anatomically similar to the flesh portion of the peach that humans consume. Almond hulls are high in sugar and low in protein, with a high fiber composition. Study 1: Studied 12 different sources of commercial almond hulls were obtained to determine variation in chemical composition. In addition, the commercial almond hulls were hand sorted to create "pure" almond hulls. No study has reported the chemical composition of pure almond hulls. Because commercial almond hulls contain sticks and shell, the chemical composition if highly variable and dependent on the proportion of debris contamination. The shaking of trees and the subsequent ground method of harvesting the almond fruit contributes the sticks, shells, and dirt to the hulls during the hulling process. As expected, when the sticks and shells are removed, the pure hulls were higher in sugar and lower in fiber and lignin than commercial hulls. The protein content remained unchanged. There was also a difference in chemical composition related to variety. Nonpareil are higher in sugar and lower in fiber and lignin compared with pollinator varieties. Because the majority of almonds are not self-pollinating, orchards consist of multiple varieties. Pollinator varieties typically have smaller nut size, and therefore smaller hull size, so the proportion of hull to sticks/shells decreases, which lowers quality. Study 2: Retrospective look at a 5-year period of crude fiber content of almond hulls collected by the California Department of Food and Agriculture (CDFA). Almond hulls are defined by CDFA on a basis of crude fiber (CF) and moisture. Almonds hulls cannot contain more than 15% CF. Data are for samples collected by CDFA field inspectors. The violation rate per year ranged from a low of 39% to a high of 62%. Roughly 50% of the commercial almond hulls that were sampled were found to be in violation. Almond hulls that were "legal" averaged 13.5% CF while those found in violation average 17.5% CF. Study 3: Commercial almond hulls were fed at four amounts to lactating Holstein dairy cows: 0, 4, 8, and 12 lb/cow/day. Almond hulls were used as a concentrate ingredient replacing steam-flaked corn and soyhull pellets. The average feeding amount of commercial almond hulls on California dairy farms is between 3 to 5 pounds/cow/day. At this feeding level, there will be a surplus of almond hulls, which creates an environmental issue for disposal. This low amount of feeding is, in part, related to the fact that commercial almond hulls vary greatly in quality (chemical composition). Overall, feeding high amounts of almond hulls had no effect on production performance. There was an increase in milk fat percent and a decrease in milk protein percent as the amount of almond hull feeding increased. There was also an increase in rumination time as the amount of almond hulls increased. Study 4: Almond hulls from Study 1 were evaluated using in vitro and in sacco approaches to determine the impact of total debris (sticks and shells) on the fermentability and energy content of almond hulls. As expected, "pure" hulls were more fermentable than commercial almond hulls and estimated metabolizable energy concentration was higher for pure hulls. It is imperative that the almond industry try to reduce the amount of sticks and shells in commercial almond hulls that are used as a feedstuff for lactating dairy cows. Objective 2: Completed a study with Professor Frank Mitloehner that involved feeding essential oils as an approach to reduce enteric emissions of greenhouse gases. The product fed to lactating Holstein dairy cows was Agolin Ruminant. In California, Senate Bill 1383 mandates a 40% reduction in methane emissions below 2013 levels by the year 2030. The primary methane focus for dairy is manure mitigation. However, any voluntary reduction in enteric emissions from animals can be used towards the 40% reduction. Thus, there is great interest in any technology that will reduce enteric methane emissions. Cows were fed a total mixed-ration without and with supplemental Agolin. Cows were placed in head chambers at four time points during the study for a period of 12 hours for total collection of gases. Agolin reduced total methane emissions when expressed on a correct dry matter intake and methane per unit of milk. There were no effects of essential oils on production performance. The next step is to evaluate Agolin's impact on the rumen microbiota to elucidate the mechanism of action of these essential oils on rumen fermentation and greenhouse gas emissions. Objective 2: Pilot study with lactating goats that will investigate the feeding value of hemp residue. The hemp industry in California is expanding rapidly for the cannabinoid oil that has reported medicinal benefits for animals, although most of the medicinal claims are yet to be scientifically proven. The hemp residue remaining after extraction of the oil is an issue. Tipping fees at landfills are expensive, and California has passed legislation to reduce the amount of organic material entering landfills. Because of the limited amount of hemp residue, lactating goats are being used. The aim is to determine if cannabinoids are present in the milk, urine, feces, blood, and adipose tissue of goats fed hemp residue. The study is in progress.
Publications
- Type:
Journal Articles
Status:
Accepted
Year Published:
2020
Citation:
Nutritional composition of almond hulls. E.J. DePeters, K.L. Swanson, H.M. Bill, J. Asmus, J.M. Heguy. Applied Animal Science 36: 761-770. 2020.
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Progress 02/20/19 to 09/30/19
Outputs
Target Audience:Information collected during the research will be applicable to the livestock and dairy industries, plant breeders, and nutriton professionals. Changes/Problems:One challenge related to the production of forage from field plots is weather conditions during the growing season. Weather conditions cannot be controlled. For example, it would be beneficial to the study is the summer months had high environmental temperatures since high temperatures are associated with low forage quality. High temperatures during the study would allow a better challenge to the reduced lignin approach. High temperatures would allow use to assess if lignin synthesis between conventional and low lignin varieties as lignin relates to forage quality. What opportunities for training and professional development has the project provided?Postdoctoral candidate presented research findings at annual scientific meetings as well as to industry conferences including the California Animal Nutrition Conference and the CA ARPAS Continuing Education Program. How have the results been disseminated to communities of interest?Peer reviewed Getachew, G., E.A. Laca, D.H. Putnam, D. Witte, M. McCaslin, K.P. Ortega, and E.J. DePeters. 2018. The impact of lignin downregulation on alfalfa yield, chemical composition, and in vitro gas production. J. Sci. Food Agric. 98:4205-4215. Abstracts Swanson. K., H. Bill, G. Getachew, J. Asmus, H. Bartlett, D. Putnam, and E. DePeters. 2019. Effect of reduced-lignin alfalfa hay on milk production and feed intake of lactating Holstein cows. 2019 Western Alfalfa & Forage Symposium, November 19-21, 2019 Reno, Nevada Swanson. K., H. Bill, G. Getachew, E. Laca, D. Putnam, and E. DePeters. 2019. Effect of lignin down-regulation in alfalfa hay on digestibility and in vitro gas production. 2019 Western Alfalfa & Forage Symposium, November 19-21, 2019 Reno, Nevada What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Objective 2 of the Project: Three projects were conducted to evaluate the impact of down-regulated lignin alfalfa as a forage for lactating dairy cattle. The aim was to compare the nutritive value of a reduced-lignin cultivar with a non-genetically edited control alfalfa. The hypothesis was that reducing lignin will increase digestibility to support increased milk production while reducing nutrients lost in feces to support sustainability of a dairy enterprise. Two cultivars of alfalfa were produced. One cultivar was genetically edited to reduce the synthesis of lignin by targeting a gene in the lignin synthesis pathway. The commercial name for this cultivar is HarvXtra. There was a non-modified control (conventional) alfalfa. Both cultivars were roundup ready. Both cultivars had two cuttings. Thus, there were four lots of alfalfa hay: reduced-lignin Cut 1, reduced-lignin Cut 2, Control Cut 1, and Control Cut 2. Project 1: In vitro rumen gas production and in vitro digestibility (Daisy ANKOM system) of four lots of alfalfa hay. Each in vitro run was done in triplicate and samples within each run were done in triplicate. Project 2: In vivo sheep digestion study to determine the apparent digestibility of alfalfa hay in response to reduced lignin. Eight wether sheep were used in a 4x4 replicated Latin square design. Each lot of alfalfa hay was pelleted and fed as the only dietary ingredient to wether sheep. Each sheep was fitted with a harness and fecal collection bag for total fecal collection. Fecal collects were for 7 days. Apparent digestibility will be determined for dry matter, organic matter, acid detergent fiber (ADF and ADFom), and neutral detergent fiber (aNDF and aNDF om). Project 3: Lactating dairy cows were fed total-mixed rations to compare reduced-lignin alfalfa compared with control alfalfa in a 4x4 replicated Latin square approach. Total-mixed rations (TMR) contained 40% forage and 60% concentrate ingredients. The only difference in the TMR was the alfalfa cultivar/cut. There were four lots of alfalfa hay and thus four different TMR. Chromic oxide was added to the TMR as an external marker to determine apparent digestibility. Project Outputs: Project 1: Reduced-lignin alfalfa was lower in lignin content. The rate of fermentation for the slowly fermented fraction (structural carbohydrates) was higher for reduced-lignin alfalfa than Control. Project 2: Apparent digestibility of dry matter and acid detergent fiber were great for reduced-lignin alfalfa than Control. Apparent digestibility of neutral detergent fiber (aNDF) was not different (P < 0.11). Project 3: Production performance of lactating Holstein cows was not different for type of forage, reduced lignin alfalfa versus conventional alfalfa. Leverage Funding: Research was supported by a gift from Forage Genetics international to supplement the CA Agricultural Experiment Station support. Summaries: Four primiparous and four multiparous Holstein cows were used in a 4x4 Latin Square design with four 21-day periods. The four total mixed-rations (TMR) were identical in ingredient composition with the exception of the alfalfa hay portion of the diet. The four treatments were HarvXtra Cut 1, HarvXtra Cut 2, Control Cut 1, and Control Cut 2. Chromium was added to all diets as an external marker to determine apparent digestibility. Samples of feces were collected during the last 7 days of each period. Feed refusal samples and TMR samples were collected daily during the sampling period. Four milk samples were collected from each cow including both morning and evening milkings using proportional milk samplers. Fecal grab samples were collected in the morning and the evening for 4 days during the sampling period. Fecal samples were mixed and sent with ground TMR and feed refusal samples to Cumberland Valley Analytical Services (Waynesboro, PA) for composition analysis by wet chemistry. Milk samples were analyzed using an Infrared Milk Analyzer (Bentley 150). Data were analyzed using R version 3.5.1 and a linear mixed effects model with cultivar (HarvXtra vs. Control), cut (1 vs. 2), period (1-4), and square (primiparous vs. multiparous) as fixed effects and cow as a random effect. Cows consuming the Control diets tended to have higher dry matter intake (DMI) and crude protein (CP) intake (P < 0.1) and consumed significantly (P < 0.01) more acid detergent fiber (ADF) and neutral detergent fiber (NDF). There was no effect of either cultivar or cut on milk production and the content and yield of milk fat, protein, and lactose. For digestibility parameters, there were no differences for DM, NDF, ADF, or CP digestibilities amongst HarvXtra vs. Control, but for all parameters TMR containing HarvXtra Cut 2 and Control Cut 2 were significantly (p<0.01) more digestible than TMR containing HarvXtra Cut 1 and Control Cut 1, respectively. Impacts: 1. Reduced-lignin content of alfalfa impact in vitro estimates of nutrient availability. 2. Reduced-lignin content of alfalfa improved apparent digestibility in vivo (sheep), but the changes were less than expected. 3. Reduced-lignin content of alfalfa did not impact production performance of lactating cows. 4. Currently we are evaluating the impact of delayed harvest, 28 day versus 35 day for reduced-lignin alfalfa.
Publications
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