Dairy Day, 2014

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Now showing 1 - 6 of 6
  • ItemOpen Access
    Preliminary studies on in situ monitoring of lactose crystallization using focused beam reflectance measurement
    (Kansas Agricultural Experiment Station and Cooperative Extension Service, 2015-04-22) Pandalaneni, Karthik; Amamcharla, Jayendra K.; jayendra
    Isothermal crystallization of lactose was studied at supersaturated concentrations (w/w) of 50%, 55%, and 60% at temperatures 20ºC and 30ºC using an in situ system, focused beam reflectance measurement (FBRM), and a refractometer. The FBRM data were compared with Brix readings taken over time using a refractometer during isothermal crystallization. Chord length distribution obtained from FBRM in the ranges of <50 μm (fine crystals) and 50 to 300 μm (coarse crystals) were observed and evaluated in relation to the extent of crystallization and rate constant results deduced from the refractometer measurements. The measured fine crystal counts increased with supersaturated concentration and temperature during isothermal crystallization. On the other hand, coarse counts were observed to increase with decreasing supersaturated concentration and temperature. The total crystal counts (coarse + fine crystals) obtained from FBRM increased as the temperature increased at all concentrations. The robustness of FBRM in understanding isothermal lactose crystallization at various concentrations and temperatures was successfully evaluated in the study.
  • ItemOpen Access
    Luteolysis and pregnancy outcomes after change in dose delivery of prostaglandin F2α in a 5-day timed artificial insemination program in dairy cows
    (Kansas Agricultural Experiment Station and Cooperative Extension Service, 2015-04-22) Stevenson, Jeffrey S.; Pulley, Stephanie Leeann; Hill, Scott L.; jss
    Three experiments were conducted to determine if a larger dose of prostaglandin F2α (PG) administered on day 6 of a 5-day Ovsynch timed artificial insemination (AI) program would induce regression of the corpus luteum to facilitate AI and pregnancy outcomes similar to a traditional 5-day program with two doses of PG. When applying a 5-day program, cows that ovulate in response to the first GnRH injection have a new corpus luteum (CL) that is 2 days younger when PG is administered in a 5- versus 7-day program. To regress successfully the younger CL, a second injection of PG must be given 24 hours after the first PG injection to prevent reduced pregnancy rate after the timed AI. These experiments demonstrated that administering 50 mg PG (10 mL Lutalyse) on day 6 produced luteolysis as efficiently as 25 mg PG (5 mL Lutalyse) administered on days 5 and 6 when the cut point for progesterone was 1 ng/mL 72 hours after the first PG injection or 48 hours after the larger PG dose. In contrast, when the cut point was 0.5 ng/mL, the larger dose of PG was less effective. Pregnancy outcomes in cows did not differ between treatment doses except in one herd (Exp. 3). Although pregnancy outcomes were reduced only in one herd with the larger PG dose, this difference may be confounded with the earlier injection of the second GnRH injection 16 hours before timed AI, rather than failure of luteolysis in response to the larger dose of PG. Delaying the timing of AI, injection of the second GnRH, or both may be warranted to allow sufficient time for progesterone to decrease to basal concentrations in response to a larger dose of PG on day 6 to prevent a reduction in fertility.
  • ItemOpen Access
    Milking time during periods of heat stress: part of the solution or part of the problem?
    (Kansas Agricultural Experiment Station and Cooperative Extension Service, 2015-04-22) Rocha, L.; Hulbert, Lindsey E.; Scortegagna, Filippe; Voelz, Benjamin; Mendonca, Luis; lhulbert; mendonca
    Milking time may be a stressful event for lactating dairy cows during summer. Increases in body temperatures because of crowding in the milk parlor holding pen may contribute to increased heat stress. The objective of this extension project was to evaluate the effectiveness of heat stress abatement in milking facilities from two Kansas commercial dairies. Vaginal temperatures at milking were lower than vaginal temperatures before milking in one of the dairies. The lower vaginal temperatures at milking, however, were not observed in the other dairy at all milkings, likely because of differences in efficacy of heat abatement strategies. Milking facilities may be one of the factors to aggravate or alleviate heat stress in lactating dairy cows during summer. Key words:
  • ItemOpen Access
    Yeast product supplementation influences feeding behavior and measures of immune function in transition dairy cows
    (Kansas Agricultural Experiment Station and Cooperative Extension Service, 2015-04-22) Yuan, Kai; Muckey, Mary Beth; Mendonca, Luis; Hulbert, Lindsey E.; Bradford, Barry J.; mendonca; lhulbert; bbradfor
    Yeast supplementation has been shown to increase feed intake and production in some studies with early lactation dairy cows, but the mechanisms underlying this effect remain unknown. The objective of this study was to assess the effects of supplementing a yeast product derived from Saccharomyces cerevisiae on production, feeding behavior, and immune function in cows during the transition to lactation. When fed for 3 weeks before calving through 6 weeks after calving, supplementation altered feeding behavior as well as responsiveness to vaccination and gut immunoglobulin secretion. Results suggest that yeast products can modulate several aspects of immune function and promote the consumption of smaller, more frequent meals.
  • ItemOpen Access
    Effects of postpartum treatment with non-steroidal anti-inflammatory drugs on milk production and culling risk in dairy cattle
    (Kansas Agricultural Experiment Station and Cooperative Extension Service, 2015-04-22) Carpenter, Abigail J.; Ylioja, Caroline M.; Vargas, Claudio F.; Mamedova, Laman K.; Mendonca, Luis; Coetzee, Johann F.; Hollis, Larry C.; Gehring, Ronette; Bradford, Barry J.; mamedova; lhollis; rgehring; bbradfor
    Inflammation during early lactation is common in dairy cattle, and a high degree of inflammation during this time has recently been associated with both lower productivity and greater risk of disease during that lactation. Early lactation treatments with two non-steroidal anti-inflammatory drugs were compared with a placebo treatment to evaluate effects on whole-lactation productivity and retention in the herd. Both meloxicam and sodium salicylate increased whole-lactation milk and milk protein yields by 6 to 9%, despite being administered for only 1 or 3 days in early lactation, respectively. In addition, meloxicam treatment tended to decrease the risk of cows leaving the herd during the lactation. These results indicate that postpartum inflammatory signals have long-lasting effects on lactation in dairy cattle.
  • ItemOpen Access
    Effects of milk, pasteurized milk, and milk replacer on health and productivity of dairy calves
    (Kansas Agricultural Experiment Station and Cooperative Extension Service, 2015-04-22) Hulbert, Lindsey E; Trombetta, Sophia A.; Noel, Jere A.; Moisa, Sonia J.; Montgomery, Sean P.; Hanzlicek, Greg A.; Bradford, Barry J.; lhulbert; sjmoisa; smontgom; gahanz; bbradfor
    Our objectives were to determine the health and blood parameters before, during, and after weaning of 114 Holstein heifers fed either accelerated milk replacer (MR; 28% CP, 18% fat) or non-saleable milk (3.59 ± 0.28% true protein; 4.12 ± 0.37% fat) that was either pasteurized (PM) or raw (RM; refrigerated and fed <24 h after collection). Calves were randomly assigned to feeding treatments at birth. Colostrum (1 L) was fed less than 14 hours after birth (MR and PM = pasteurized colostrum; RM = raw colostrum). All calves were bottle-fed 1.8 ± 0.20 L, 3 times daily; all calves were provided fresh water and grain ad libitum throughout the experiment. Calves began step-down weaning at age 5 weeks and completed weaning at age 6 weeks. Blood samples were collected at ages 3, 5, and 7 weeks and were analyzed for complete blood counts (CBC) using a Procyte Idexx Analyzer (IDEXX Laboratories, Inc., Westbrook, ME). Fecal scores were observed twice daily, on a 1 to 3 scale (FS1 = normal, FS2 = loose, FS3 = scours). Results showed that MR-fed calves had more (P < 0.01) observations (%obs) with FS > 2 than the PM- and RM-fed calves (2.3 vs. 1.6 and 1.7 ± 0.2 %obs, respectively). In addition, there were no differences in body weight or shoulder or hip height between treatments, but a treatment × week interaction (P = 0.05) occurred for grain consumed, with a noticeably higher increase between 6 and 7 weeks of age for MR calves. When CBC was considered, there were no differences in blood cell types, but MR-fed calves had greater mean corpuscular volume (MCV) than the other calves (P < 0.01), leading to higher resistance for iron deficiency anemia. In conclusion, these findings suggest that calf performance and feed intake are not affected by the administration of raw milk, pasteurized milk, or milk replacer. Moreover, CBC health parameters showed no significant changes due to administration of the different types of milk sources.