Dairy Science Commons^™

Analysis Of Johne’S Disease Elisa Status And Associated Performance Parameters In Irish Dairy Cows, A. E. Kennedy, N. Byrne, A. B. Garcia, Jim O'Mahony, R. G. Sayers

Department of Biological Sciences Publications

Infection with Mycobacterium avium subspecies paratuberculosis (MAP) has been associated with reductions in milk production in dairy cows and sub optimal fertility. The aim of this study was to highlight the production losses associated with testing MAP ELISA positive in Irish dairy cows. Secondary objectives included investigation of risk factors associated with testing MAP ELISA positive. A survey of management practices on study farms was also conducted, with examination of associations between management practices and herd MAP status.

Blood samples were collected from 4188 breeding animals on 22 farms. Samples were ELISA tested using the ID Screen Paratuberculosis Indirect Screening …

Analysis Of Johne's Disease Elisa Status And Associated Performance Parameters In Irish Dairy Cows, A. E. Kennedy, N. Byrne, A. B. Garcia, Jim O'Mahony, R. G. Sayers

Department of Biological Sciences Publications

Background

Infection with Mycobacterium avium subspecies paratuberculosis (MAP) has been associated with reductions in milk production in dairy cows and sub optimal fertility. The aim of this study was to highlight the production losses associated with testing MAP ELISA positive in Irish dairy cows. Secondary objectives included investigation of risk factors associated with testing MAP ELISA positive. A survey of management practices on study farms was also conducted, with examination of associations between management practices and herd MAP status.

Blood samples were collected from 4188 breeding animals on 22 farms. Samples were ELISA tested using the ID Screen Paratuberculosis Indirect …

Effects Of Feeding Rumen-Degradable Valine On Milk Production In Late-Lactating Dairy Cows, Kayla Hultquist, David Casper

David Casper

The study objective was to determine if feeding the rumen-degradable AA Val can increase milk production comparable to recombinant bovine somatotropin (bST). Eight multiparous late-lactating (255 ± 26.4 d in milk) Holstein dairy cows were blocked by milk yield (34.1 ± 8.25 kg/d) and randomly assigned to 1 of 4 treatments in a replicated 4 × 4 Latin square design with 21-d periods (7 d for dietary adaptation and 14 d for data collection). Treatments were control (CON), a single injection of recombinant bST (rbST), and Val fed at 40 (V40) and 80 g/d (V80). Cows were fed a total …

Evaluation Of Calving Indicators Measured By Automated Monitoring Devices To Predict The Onset Of Calving In Holstein Dairy Cows, V. Ouellet, E. Vasseur, W. Heuwieser, O. Burfeind, X. Maldague, É. Charbonneau

Physiology Collection

Dystocias are common in dairy cows and often adversely affect production, reproduction, animal welfare, labor, and economics within the dairy industry. An automated device that accurately predicts the onset of calving could potentially minimize the effect of dystocias by enabling producers to intervene early. Although many well-documented indicators can detect the imminence of calving, research is limited on their effectiveness to predict calving when measured by automated devices. The objective of this experiment was to determine if a decrease in vaginal temperature (VT), rumination (RT), and lying time (LT), or an increase in lying bouts (LB), as measured by …

Dry Period Plane Of Energy: Effects On Glucose Tolerance In Transition Dairy Cows, S. Mann, F. A. Leal Yepes, M. Duplessis, J. J. Wakshlag, T. R. Overton, B. P. Cummings, D. V. Nydam

Physiology Collection

Overfeeding energy in the dry period can affect glucose metabolism and the energy balance of transition dairy cows with potential detrimental effects on the ability to successfully adapt to early lactation. The objectives of this study were to investigate the effect of different dry cow feeding strategies on glucose tolerance and on resting concentrations of blood glucose, glucagon, insulin, nonesterified fatty acids (NEFA), and β-hydroxybutyrate (BHB) in the peripartum period. Cows entering second or greater lactation were enrolled at dry-off (57 d before expected parturition) into 1 of 3 treatment groups following a randomized block design: cows …

Bioavailability Of Ruminally Or Abomasally Infused L-Carnitine In Holstein Heifers, K. Olagaray, C. Armendariz, A. Bellamine, S. Jacobs, E. Titgemeyer, B. Bradford

Kansas Agricultural Experiment Station Research Reports

This study evaluated the relative bioavailability of carnitine delivered by different methods in dairy cattle. Four Holstein heifers were used in a split-plot design to compare ruminally or abomasally infused L-carnitine. The study included 2 main-plot periods, with infusion routes allocated in a crossover design. Within main-plot periods, each of 3 subplot periods consisted of 4-d infusions separated with 4-d rest periods. Subplot treatments were infusion of 1, 3, and 6 g L-carnitine daily. Doses were increased within a period to minimize carryover. Treatments were delivered in two 10-h infusions daily. Blood was collected before the start of infusions and …

Bioavailability Of Rumen-Protected Carnitine In Lactating Dairy Cows, K. Olagaray, J. Shaffer, C. Armendariz, A. Bellamine, S. Jacobs, E. Titgemeyer, B. Bradford

Kansas Agricultural Experiment Station Research Reports

For this study, 56 lactating Holstein cows (143 ± 72 days in milk) were used in a randomized complete block design to evaluate 2 rumen-protected products compared to crystalline carnitine. Treatments were a) control, b) 3 grams/day crystalline L-carnitine (raw), c) 6 grams/day raw, d) 5 grams/day 40COAT (40% coating, 60% L-carnitine), e) 10 grams/day 40COAT, f) 7.5 grams/day 60COAT (60% coating, 40% L-carnitine), and g) 15 grams/day 60COAT. Treatments were top-dressed to diets twice daily. The 14-day experiment included a 6-day baseline-measurement period with the final 2 days used for data and sample collection and an 8-day treatment period …