Blackburn, Jarrod Jeffrey2018-12-052018-12-052019-05-01http://hdl.handle.net/2097/39370Two studies were conducted that focused on either the accuracy of hand-held near infrared spectrophotometer (NIR) units and two on-farm testing methods compared to conventional 105°C oven drying of corn silage or the use of a starling resistant supplement in total mixed rations (TMR) for lactating dairy cattle. Study 1 evaluated the accuracy of three NIR units (Digi-Star Moisture Tracker, Topcon Agriculture, Fort Atkinson, WI), food dehydrator (FD) (Nesco®, Two Rivers, WI), and a Koster Tester (KT) (Koster Moisture Tester, Inc., Brunswick, OH) to conventional 105°C forced air oven drying. Samples were taken at four Kansas dairy farms and analyzed for DM daily for 20 d. Two calibrations were tested within each NIR unit: NIRu was the DM predicted from the factory-preset calibration, and NIRc was a bias-adjusted DM prediction based on the average difference of oven-dried corn silage and NIRu over the 20-d study. Average oven DM of corn silage was 38.38% ± 0.59 for the 20-d experiment. All three NIRu measurements were lower (P<0.05) than the oven value. While all 3 NIRc predictions were similar (P>0.05) to oven value. KT value was similar (P>0.05) to the oven, while FD value was over estimated DM. (P<0.05). The hand-held NIRS units accurately predicted DM content of the corn silages when the factory preset calibrations were corrected for bias. While the food dehydrator over-estimated the DM of the corn silage and the Koster Tester accurately predicted DM. Study 2 was designed to evaluate the lactation performance of post-peak dairy cattle when using a starling resistant grain supplement. Sixteen prim- and multiparous Holstein cows were housed individually in a tie-stall barn, milked 3x daily, and fed 2x daily. Cows were fed two nutritionally similar diets: 1. TMR with grain in mash form and 2. TMR with grain supplement in a pellet with a 0.953-cm diameter. This study was designed as a single reversal experiment with two 14 d periods with the first 7 d used for an adaptation period and the last 7 d used for data collection in each period. Dry matter intake (DMI), water intake, and milk production was recorded daily. Feed ingredients, TMRS, refusals, and milk samples were collected the last 3 d of each period for analysis. TMRs and refusals were analyzed for particle size distribution with a Penn State Particle Separator. The pelleted supplement had a higher (P<0.05) percentage of DM retained on the 8.0-19.0mm sieve than the mash supplement as the pellet diameter was >8.0mm and could not pass through that sieve. There was no effect of diet (P>0.05) for DMI, feed efficiency, milk component percentage, and protein yield. There was a diet effect (P<0.05) for milk production, fat-corrected milk, energy-corrected milk, solid-corrected milk, and fat yield with lower observed values when cows were fed the pelleted supplement. This leads to the conclusion while a 0.953-cm diameter pellet will reduce starling consumption, it may result in lower milk production of post-peak Holstein cows.en-US© the author. This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).http://rightsstatements.org/vocab/InC/1.0/ForageFeed moisturePelletBirdGrain105°C ovenThesis