Progress 09/01/09 to 08/31/12
Outputs
OUTPUTS: The project provided key insight into circadian regulation of intake and milk synthesis in the dairy cow. Research abstracts were presented at the American Dairy Science Association Annual Meeting in 2011 and 2012. Additionally, the resulting information has been disseminated through presentations at industry conferences including the Penn State Dairy Nutrition Workshop (Grantville, PA), Renaissance Nutrition Bucknell Nutrition Conference (Lewisburg, PA), the 22nd Discover Conference on Milk Components (Itasca, IL), Tristate Dairy Nutrition Conference (Fort Wayne, IN), and Feedworks Nutrition Conference (Brisbane, Australia). One popular press article has been published and peer reviewed publications will also be submitted. PARTICIPANTS: Dr. Kevin Harvatine, Assistant Professor of Nutritional Physiology- was responsible for oversight and management of project. Dr. Paul Bartell, Assistant Professor- Provided consultation on design and analysis of circadian data. Other Co-Investigators including Dr. Dechow, Dr. Heinrichs, and Dr. Varga provided consultation on experimental design and data analysis. Jackie Ying and Andrew Clarke, Project Assistants, assisted in organization of experiments and laboratory analysis and responsible for analysis of behavior data. L. Whitney Rottman and Mutian Niu, Graduate Assistants, wer responsible for conducting experiments and laboratory and data analysis. D. Rico, Graduate Assistant, assisted in organization of experiments and sample collection and analysis. Additional undergraduate students assisted with the project. TARGET AUDIENCES: Ruminant nutrition and lactation researchers and consulting nutritionists through scientific publications and industry conference presentations. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
First, the effect of the timing of feed intake on milk synthesis was investigated in dairy cows. Treatments were feeding a TMR once daily (1x fed) or in 4 equal meals every 6 hours (4x fed). Treatment did not affect daily milk yield, and there was no treatment by time interaction. Milk yield was different by time with peak yield at 0200 h and 2000 h and a nadir at 1400 h. The 4x fed treatment resulted in higher milk fat percent at all time points compared to 1x fed. Research integrating nutrition and animal behavior requires systems that aid in the collection of data continuously over a day. Automated systems for observation of feeding behavior and body temperature were developed and then employed in subsequent experiments. In the dairy cow there is a circadian pattern to feed intake and milk synthesis and a single total mixed ration fed once a day may not stabilize rumen fermentation and synchronize nutrient absorption and milk synthesis. The object of second experiment was to determine if feeding multiple TMRs over one day that complement the pattern of feed intake would stabilize ruminal fermentation and increase milk synthesis. Diets were control (32% NDF), a low forage diet (L; 29% NDF), and a high fiber diet (H; 34% NDF). The L and H diets were balanced to provide the same composition as the control diet when combined in a 3:7 ratio of L:H. The control (Con) treatment was fed control diet at 0900 h, the high/low treatment (HL) was fed H at 70% of total daily offering at 0900 h and L at 30% of total daily offering at 2200, and the low/high (LH) treatment was fed L at 30% of total daily offering at 0900 h and fed H at 70% of daily offering at 1300 h. Dry matter intake and digestible dry matter intake were decreased by 1.9 and 0.8 kg/d by HL compared to Con (P < 0.01 and P < 0.05). There was no difference between Con and HL for milk yield and composition, but HL tended to reduce milk fat yield compared to LH (P = 0.06). Therefor, feeding multiple rations over the day reduced intake with no impact on milk yield or body weight gain, but had little impact on other production and rumen parameters. Lastly, a retrospective analysis was conducted of two experiments that induced milk fat depression while milking three times per day at equal intervals to determine if the regulation of milk fat synthesis was variable over the day. There was a treatment, but no milking time or treatment by milking time interaction on milk fat yield. Therefore, diet-induced milk fat depression decreases milk fat yield equally over the day. In summary, the projects provided novel characterization of the circadian pattern of feed intake and its impact on milk synthesis and developed feeding strategies based on the knowledge of these circadian rhythms.
Publications
- Rico, D. E., E. R. Marshall, and K. J. Harvatine. 2012. Changes in milk composition of Holstein dairy cows within a milking. J Dairy Sci. 95(E-Suppl. 2):53.
- Cook, K., D. E. Bauman, and K. J. Harvatine. 2012. CLA and diet induced milk fat depression reduces milk fat across the entire day. J Dairy Sci. 95(E-Suppl. 2):555.
- Harvatine, K. J. 2012. Circadian patterns of feed intake and milk component variability. Proceedings of the Tri-State Dairy Nutrition Conference. Fort Wayne, IN. pp. 34-54.
- Harvatine, K. J. 2011. Why and when do cows eat. Farmshine Magazine. January 6, 2012. pg24.
- Rottman, L. W., Y. Ying, P. A. Bartell, and K. J. Harvatine. 2012. The effects of a two ration feeding regimen on intake, milk production, and rumen fermentation in dairy cows. J Dairy Sci. 95(E-Suppl. 2):247.
|
Progress 09/01/10 to 08/31/11
Outputs
OUTPUTS: Laboratory analysis of the first cross-over experiment have been completed and is ongoing for the last experiment investigating the effect of feeding strategies on feeding behavior and rumen dynamics. Thus far the resulting data has provided key insight circadian regulation of intake and milk synthesis and has been presented at three industry conferences in the past year including the Penn State Dairy Nutrition Workshop, Renaissance Nutrition Bucknell Nutrition Conference, and the 22nd Discover Conference on Milk Components. PARTICIPANTS: Kevin Harvatine, Assistant Professor of Nutritional Physiology- Responsible for oversight and management of project. Paul Bartell, Assistant Professor- Provides consultation on design and analysis of circadian data. Other Co-Investigators (Dr. Dechow, Dr. Heinrichs, and Dr. Varga) provide consultation on experimental design and data analysis. Jackie Ying, Project Assistant- Assists in organization of experiments and laboratory analysis and responsible for analysis of behavior data. L. Whitney Rottman, Graduate Assistant- Responsible for conducting experiments and laboratory and data analysis. M. Niu, Graduate Assistant- Responsible for conducting experiments and analysis of data, D. Rico, Graduate Assistant- Assists in organization of experiments and sample collection and analysis. Additional undergraduate students assist with the project. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
The first experiment investigated the effect of the timing of feed intake on milk synthesis. Treatments were feeding a TMR once daily (1x fed) or in 4 equal meals every 6 hours (4x fed). Treatment did not affect daily milk yield, and there was no treatment by time interaction. Milk yield was different by time with peak yield at 0200 h and 2000 h and a nadir at 1400 h. 4x fed resulted in higher milk fat percent at all time points compared to 1x fed. Research integrating nutrition and animal behavior requires systems that aid in the collection of data continuously over a day. Automated systems for observation of feeding behavior and body temperature have been developed. The outcome of use of these tools is expected to characterize the effect of diet and dietary strategies on the behavior and metabolism of dairy cows.
Publications
- Rottman, L. W., Y. Ying, and K. J. Harvatine. 2011. Effect of timing of feed intake on circadian pattern of milk synthesis. J Dairy Sci. 94(E-Suppl. 1):830.
|
Progress 09/01/09 to 08/31/10
Outputs
OUTPUTS: The overall objective of this project is to improve dairy farm efficiency by developing nutritional strategies that complement the diurnal pattern of feed intake and increase ruminal digestion and partitioning of nutrient(s) to milk synthesis. To meet this objective we first conducted a cross-over experiment to compared milk yield and the circadian pattern of milk yield when cows were fed once per day or multiple times per day in equal meals. Laboratory analysis of collected samples is currently being conducted and results are expected to be ready for submission to the 2011 Annual ADSA meeting. Secondly, a feed observation system was constructed for observation of feeding behavior. Briefly, a poly feed tub is suspended from an electronic load monitor wired to a control panel. Feed weight is recorded every 10 seconds and saved to an attached PC. Development and validation of analysis algorithms is currently being conducted. Additionally, a vaginal temperature probe system has been developed for observation of body temperature at a high frequency. Lastly, an experiment was conducted to characterize feeding behavior and rumen dynamics. Rumen pH was recorded every 10 minutes using indwelling pH probes (Kahne Limited), body temperature was recorded every 10 minutes using the vaginal temperature probes, rumen contents and blood were collected to represent every 3 hr of a 24 h period, and feeding behavior was observed using the automated observation system constructed. Laboratory analysis is currently being conducted. PARTICIPANTS: Kevin Harvatine, Assistant Professor of Nutritional Physiology- Responsible for oversight and management of project. Paul Bartell, Assistant Professor- Provides consultation on design and analysis of circadian data. Other Co-Investigators (Dr. Dechow, Dr. Heinrichs, and Dr. Varga) provide consultation on experimental design and data analysis. Jackie Ying, Project Assistant- Assists in organization of experiments and laboratory analysis and responsible for analysis of behavior data. L. Whitney Rottman, Graduate Assistant- Responsible for conducting experiments and laboratory and data analysis. Daniel Rico, Graduate Assistant- Assists in organization of experiments and sample collection and analysis. Additional undergraduate students assist with the project. TARGET AUDIENCES: National and international researchers with interest in ruminal and mammary metabolism. Dairy farmers and dairy nutritionists with interest in improving feed efficiency, milk synthesis, and/or cow health. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Research integrating nutrition and animal behavior requires systems that aid in the collection of data continuously over a day. Automated systems for observation of feeding behavior and body temperature have been developed. The outcome of use of these tools is expected to characterize the effect of diet and dietary strategies on the behavior and metabolism of dairy cows.
Publications
- No publications reported this period
|