Dairy Day, 2004
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Item Open Access Responses of lactating holstein cows to differing levels and direction of supplemental airflow(Kansas State University. Agricultural Experiment Station and Cooperative Extension Service, 2010-12-01) Harner, Joseph P.; Smith, John F., 1962-; Miller, W.F.; Cvetkovic, B.; Brouk, Michael J.; mbrouk; jharner; jfsmithSeven heat-stressed, lactating Holstein cows were exposed to six different cooling systems to evaluate the effects of air velocity and direction of airflow. Cows were arranged in a 7 × 7 Latin-square design. Six cooling treatments were compared with a control. Supplemental airflow was provided by axial flow at one of three velocities: 500, 750, or 900 cubic feet per minute (CFM). Airflow was either from the front to rear (FRT) or from the right side (SIDE) of the cow. Combined cooling treatments were FRT-500, FRT- 750, FRT-900, SIDE-500, SIDE-750, or SIDE-900. All cooling systems used a lowpressure soaking system that operated 1 minute every 5 minutes. Respiration rates, rearudder skin surface temperature, and vaginal temperature were measured and recorded during 2 hours of treatment during seven hot and humid afternoons. Cooling systems reduced respiration rate, rear-udder skin surface temperature, and vaginal temperature. When airflow was 750 or 900 CFM, no differences were observed among treatments. When airflow was 500 CFM, rate of decline of rearudder skin surface temperature and vaginal temperature were reduced, compared with those of other treatments. These results indicate that there was no advantage to increasing airflow more than 750 CFM when using a low-pressure soaking system that wets the cattle every 5 minutes. Differences due to airflow direction were only observed when airflow was reduced to 500 CFM. At 500 CFM, airflow from head to tail was not as effective as from the side. Current recommendations of 750 CFM of airflow directed at the side of the cow are effective in reducing heat stress of lactating dairy cattle.Item Open Access Responses of lactating holstein cows to low-pressure soaking or high-pressure misting during heat stress(Kansas State University. Agricultural Experiment Station and Cooperative Extension Service, 2010-12-01) Harner, Joseph P.; Smith, John F., 1962-; Miller, W.F.; Cvetkovic, B.; Brouk, Michael J.; mbrouk; jharner; jfsmithLactating dairy cattle were used to evaluate three different cooling systems. Eight cows were arranged in a replicated Latinsquare design and assigned to each of four treatments. Treatments were control, lowpressure soaking (LPS), high-pressure misting with 1.7 gallons per minute of water (HP-1.7), or high-pressure misting with 3.4 gallons per minute of water (HP-3.4). Cows were allowed to become heat stressed in a free-stall facility, and then were moved to a tie-stall barn for 2 hours of observations during four hot and humid afternoons. Respiration rates declined when heat abatement systems were used. Respiration rates at the end of the observation period were reduced by 20, 36, and 48% for HP-1.7, HP-3.4, and LPS, respectively. Rearudder skin surface temperature was reduced at a faster rate under the HP-4 treatment than with LPS, but the two treatments did not differ in final rear-udder skin surface temperature or vaginal temperature. The HP-3.4 treatment used the greatest amount of water during the 2-hour testing period. The result was a combination of air-cooling and soaking. Results indicated that a combination of air cooling and soaking may result in faster reduction of surface temperature. When only air cooling was used (HP-1.7), heat stress was reduced, but it was less effective than either LPS or HP-3.4. Use of a low-pressure soaking system is superior to high-pressure misting unless cattle become soaked by the high-pressure system.Item Open Access Resynchronizing estrus and ovulation in open cows and heifers(Kansas State University. Agricultural Experiment Station and Cooperative Extension Service, 2010-12-01) Tiffany, S.M.; Stevenson, Jeffrey S.; jssWe compared outcomes of two protocols used to resynchronize estrus and ovulation in dairy females after found open at pregnancy checks. Replacement heifers and lactating cows in which AI occurred 41 ± 1 day earlier were presented every 2 to 3 weeks for a pregnancy check by ultrasonography. Ovaries were scanned, follicles were mapped and sized, presence of corpus luteum was noted, and GnRH was injected (day 0) . Females received PGF2" 7 days later (day 7) and then were assigned randomly to either receive estradiol cypionate (ECP) 24 hours after PGF2" (day 8; Heatsynch; n = 230) or a second GnRH injection after PGF2" (day 9; Ovsynch; n = 224). Those detected in estrus were inseminated, whereas the rest received a timed AI (TAI) between 65 and 74 hours after PGF2". Few females (5.1%) were inseminated between open diagnosis and day 8. On day 10, more ECPthan GnRH-treated females were inseminated after detected estrus (24 vs. 6%). Overall, more Ovsynch than Heatsynch females received a TAI (82 vs. 62%). Conception rates tended to be greater for females inseminated after estrus (37%) than after TAI (29%), and the tendency was more pronounced for those treated with Heatsynch (41 vs. 27%) than for those treated with Ovsynch (33 vs. 31%). Conception rates for females having elevated progesterone 7 days after the not-pregnant diagnosis were greater than conception rates of those having low progesterone in Heatsynch (42%; n = 133 vs. 25%; n = 55) and Ovsynch protocols (33%; n = 142 vs. 15%; n = 45). Conception rates were greater in heifers than in lactating cows (43 vs. 28%), regardless of protocol employed. Although overall pregnancy outcomes were similar in response to either the Ovsynch or Heatsynch protocol, inseminations performed after detected estrus before the scheduled TAI reduced days to eventual conception and tended to increase conception rates, particularly after Heatsynch.Item Open Access Inseminations at estrus induced by the presynch protocol before timed artification insemination(Kansas State University. Agricultural Experiment Station and Cooperative Extension Service, 2010-12-01) Phatak, A.P.; Stevenson, Jeffrey S.; jssA controlled field study examined conception rates after two timed-AI (TAI) breeding protocols conducted on two commercial dairy farms. Estrous cycles in postpartum lactating cows were presynchronized with two injections of PGF2" given 14 days apart (Presynch) and then, after 12 days, the standard Ovsynch protocol (injection of GnRH 7 days before and 48 h after an injection of PGF2", with one TAI at 12 to 16 hours after the second GnRH injection) or Heatsynch protocol (injection of GnRH 7 days before an injection of PGF2", followed 24 h later by 1 mg of estradiol cypionate (ECP) and one TAI 48 hours after ECP) was applied. Experimental design allowed for AI to occur any time after the second Presynch injection and during the designed breeding week when estrus was detected. Of the 1,846 first services performed, only 1,503 (rate of compliance = 81.4%) were performed according to protocol. Numbers of cows inseminated, logistic-regression-adjusted conception rates, and days in milk (DIM) were for inseminations made: 1) during 14 days after first Presynch injection (n = 145; 22.6%; 54 ± 0.4 DIM); 2) during 12 days after second Presynch injection (n = 727; 33%; 59 ± 0.2 DIM); 3) during 7 days after the first GnRH injection of Ovsynch or Heatsynch (n = 96; 32.1%; 74 ± 0.5 DIM); 4) after estrus as part of Heatsynch (n = 212; 44.6%; 76 ± 0.3 DIM); 5) after TAI as part of Heatsynch (n = 154; 21.1%; 76 ± 0.4 DIM); 6) after estrus as part of Ovsynch (n = 43; 48.7%; 77 ± 0.7 DIM); and 7) after TAI as part of Ovsynch (n = 271; 24.4%; 77 ± 0.3 DIM). Conception rates when AI occurred after one Presynch injection were less than when AI occurred after two Presynch injections. Conception rates for those inseminated after either Presynch injection did not differ from those inseminated after combined Heatsynch + Ovsynch. Cows in the Ovsynch and Heatsynch protocols inseminated after estrus during the breeding week had greater conceptions rates than those receiving the TAI, but overall conception rates did not differ between protocols. Among cows inseminated after detected estrus, conception was greater for cows in the Heatsynch + Ovsynch protocol (77 ± 0.4 DIM) than for those inseminated after either Presynch injection (54 ± 0.4 or 59 ± 0.2 DIM). We concluded that conception rates after Heatsynch and Ovsynch were similar under these experimental conditions, and that delaying first AI improved fertility for cows inseminated after detected estrus.Item Open Access Impact of dried seaweed meal on heat-stressed lactating dairy cattle(Kansas State University. Agricultural Experiment Station and Cooperative Extension Service, 2010-12-01) Cvetkovic, B.; Shirley, John E.; Brouk, Michael J.; mbroukTwenty-four lactating Holstein cows were used to determine the production response to the inclusion of brown seaweed in the basal diet during summer heat stress. Cows were blocked by lactation number, days in milk, and energy-corrected milk and then allotted to either a control or control + brown seaweed diet. Cattle on the brown seaweed diet were fed 4 ounces per cow per day for 7 days , and then 2 ounces per cow per day for 14 days, before the start of the experiment. All cattle were housed in a tie-stall barn, fed individually, and milked twice daily. Cows fed brown seaweed produced more (P<0.01) milk (77.6 vs 73.8 lb) and milk protein than controls did. But the addition of brown seaweed did not reduce respiration rates, rectal temperature, or rear-udder skin temperature. This indicated a similar heat-stress response for treated and control cows. Other studies have shown a reduction in respiration rates and body temperature when stressed cattle were fed brown seaweed. Further investigation is necessary to determine the factors that resulted in the observed milk and milk-protein responses in this study.Item Open Access Impact of soaking cows housed in a tunnel-ventilated, evaporative-cooled barn in Thailand(Kansas State University. Agricultural Experiment Station and Cooperative Extension Service, 2010-12-01) Armstrong, D.V.; Smith, John F., 1962-; Wuthironarith, V,; Harner, Joseph P.; Brouk, Michael J.; jfsmith; mbrouk; jharnerTen multiparous lactating Holstein cows were arranged in a replicated 5 × 5 Latin Square design to evaluate the effect of soaking frequency and volume of water per soaking on lactating cows housed in a tunnel-ventilated and evaporative-cooled freestall barn. Rectal temperature, respiration rate, and body surface temperatures were measured every 5 minutes. Treatments were: control (C); soaking every 5 minutes with 0.26 gallons (5L); soaking every 5 minutes with 0.53 gallons (5H); soaking every 10 minutes with 0.26 gallons (10L); or soaking every 10 minutes with 0.53 gallons (10H). Average ambient temperature and humidity were 86.5ºF and 68% outside the barn, and 80.4ºF at 86% inside the barn, respectively. Water having a temperature of 80.6ºF was applied manually from the shoulder to the tail. Treatments were applied after three initial measurements were assessed. Seventeen measurements were made during treatment application and five measurements after the treatments were stopped. Air velocity over the shoulder of the cows was 4 mph. Respiration rate and body surface temperature for all treatments were less than those of the control, except for rear udder surface temperature in the 10L treatment. Rectal temperature for 5L, 5H, and 10H were less than those of the control. Respiration rate for 5L and 5H were less than that of 10L. These data indicate that soaking can be used in combination with tunnel ventilation and evaporative pads to reduce heat stress.Item Open Access Serving temperature effects on milk flavor, milk aftertaste, and volatile-compound quantification in nonfat and whole milk(Kansas State University. Agricultural Experiment Station and Cooperative Extension Service, 2010-12-01) Francis, L.L.; Kong, S.H.; Chambers, Delores H.; Jeon, I.J.; Simmons, S.R.; Schmidt, Karen A.; kschmidtMany people seem to prefer to drink milk when it is cold. Research describing flavor and aftertaste of milk, and then correlating these traits with their chemical composition, has not previously been done. The objectives of this study were to describe milk flavor and aftertaste by using a descriptive sensory panel and to quantify the headspace volatiles of nonfat and whole milk as a function of serving temperature. Headspace volatile compounds of milk samples served at 40°F and 60°F were quantified by using solid-phase microextraction (SPME) analysis, with a 75-μm Carboxen- PDMS fiber, sampling milk at 140oF for 30 minutes, and then analyzing by gas chromatography, flame ion detection (GCFID) for quantification. Descriptive-panel results indicated that serving temperature did not affect the milk flavor. Nonfat milk flavor and texture were rated to have greater sour aromatics, and to be slightly chalky, flat, and bitter, but less sweet, than whole milk. Characterization of milk aftertaste at 15 seconds after swallowing indicated that nonfat milk had very slight sour and cooked attributes. Characterization of milk aftertaste at 90 seconds after swallowing indicated that nonfat milk had very slight cooked attributes and was less sweet than whole milk. Serving temperature did not affect concentrations of volatile compounds, but nonfat milk had a greater concentration of hexanal and lesser (P < 0.05) concentrations of benzaldehyde, ethyl caproate, heptanal, 2-heptanone, and nonanal than whole milk did. These data provide evidence that fat contributes to the “flavor” and aftertaste attributes of milk more than serving temperature does.Item Open Access Performanceof lactating dairy cows fed yeast and fibrolytic enzymes(Kansas State University. Agricultural Experiment Station and Cooperative Extension Service, 2010-12-01) Titgemeyer, Evan C.; Johnson, B.J.; Shirley, John E.; etitgemeWe evaluated the effect of supplementing typical dairy diets with yeast and fibrolytic enzymes on dairy cow performance. Twentyfour Holstein cows were used to evaluate the effects of yeast (Procreatin-7, a live culture of Saccharomyces cerevisiae) and various amounts of FP800 (a fibrolytic enzyme mixture) on lactation performance. Treatments were arranged in a 4 × 2 factorial design consisting of 8 treatments: 0, 5, 10, or 15 g of FP800 per day and 0 or 5 g of Procreatin-7 per day. Design and conduct of the experiment allowed at least 10 observations in each of the 8 treatment combinations. Within each 28- day period, the first 2 weeks were used for adaptation to treatment and the next 2 weeks were used for measuring feed intake and milk production. Diets were fed individually to each cow twice daily. The diet contained 22% ground corn, 20% corn silage, 20% wet corn gluten feed, 17% alfalfa, 8% whole cottonseed, and 8% expeller soybean meal. Dietary protein was 19% of dry matter. Treatments were top-dressed to the diets. Cows were milked twice daily. Dry matter intake averaged 64.6 lb/day, milk production averaged 96.8 lb/day, and efficiency of milk production averaged 1.50 lb milk/lb dry matter intake. Dry matter intake, milk production, milk efficiency, and production of all milk components were not changed by addition of either fibrolytic enzymes or yeast. Percentages of fat, protein, and solids-not-fat (SNF) in milk were also not affected by treatment. The results demonstrated no production responses to the addition of fibrolytic enzymes or yeast to the diets of lactating cows under our experimental conditions.Item Open Access Beta-cyclodextrin complexing to reduce antibiotic residue in milk(Kansas State University. Agricultural Experiment Station and Cooperative Extension Service, 2010-12-01) Banala, S.; Brouk, Michael J.; Simmons, S.R.; Schmidt, Karen A.; mbrouk; kschmidtVarious percentages (1.2% to 13%) of β- cyclodextrin (β–CD) were added to water or pasteurized whole milk to study β-CD crystallization patterns. Influential factors such as crystallization time (4 to 12 h), crystallization temperature (45º vs. 72ºF), and centrifugation speed (25 to 3000 × g) were investigated. Optimized crystallization conditions were verified in antibiotic-tainted raw milk samples via the enzyme-linked receptor-binding assay and by solids partitioning. In water, β-CD precipitate increased significantly as β-CD concentration and crystallization time increased, but was independent of the centrifugation speed. In pasteurized whole milk, precipitate increased as β-CD concentration, crystallization time, and centrifugation speed increased. The best β-CD precipitation conditions in milk were designated as: 9.1% β-CD concentration (w/w), 4 hour crystallization time, 45ºF, and centrifugation at 25 × g for 10 minutes. Eleven cows were treated with cephapirin sodium or cephapirin benzathine. Milk was obtained 12 h later and treated with β-CD. As β- CD concentrations increased, precipitates increased, and the corresponding supernatants showed reduced concentrations of antibiotics when tested by enzyme-linked receptorbinding assay. Results indicated that β-CD may have the potential to reduce the residues of cephapirin sodium or cephapirin benzathine in antibiotic-tainted raw milk.Item Open Access Accelerated growth programs for dairy calves(Kansas State University. Agricultural Experiment Station and Cooperative Extension Service, 2010-12-01) Brouk, Michael J.; mbroukAccelerated-growth feeding programs are the newest buzz word in calf rearing. Accelerated programs require a milk replacer containing more crude protein and less fat content than traditional milk replacers. These programs are generally phase-feeding programs that increase the amount of milk replacer as the calf advances in age. In addition, changes in the calf starter are necessary to achieve optimal performance. These programs increase weight gain during the liquid-feeding period and may positively impact calf health. Changes in the composition and amount of milk replacer used increase the cost of the accelerated program, compared with that of conventional programs. Gains achieved from an accelerated-growth program during the first few weeks of life are quickly lost if aggressive feeding and management programs are not followed through after weaning. Acceleratedgrowth calf programs are part of the total heifer rearing program to improve overall lactation efficiency by reaching optimal growth and age-at-first-breeding targets for dairy operations.Item Open Access Reduced age at first calving: effects on lifetime production, longevity, and profitability(Kansas State University. Agricultural Experiment Station and Cooperative Extension Service, 2010-12-01) Meyer, M. J.; Everett, R.W.; Van Amburgh, M.E.The primary advantages of reducing age at first calving (AFC) include reducing rearing costs as well as reducing time in which the heifer is only a capital drain on farm resources. The primary disadvantage of reducing AFC is that it is frequently associated with a reduction in first-lactation milk yield. Despite this reduction in first-lactation milk yield, production per year of herd life is typically increased by reduced AFC. Furthermore, although the first lactation yield may be influenced by AFC, future lactations are decidedly not. In addition, stayability and health of cows are not influenced by reduced AFC as long as heifers freshen at an adequate weight. Most analyses indicate that the financial advantage afforded from heifers that freshen at a low AFC seems to at the least offset any milk lost during the first lactation. Furthermore, when the time value of money is considered in this analysis, a reduced AFC (~22 months) seems likely to represent a more fiscally sound management decision. When applying these ideas on the farm, a properly managed feeding and breeding program should permit a firstlactation cow to weigh ~1,210 lb after freshening at 22 months of age. The National Research Council recommends a postpartum weight equal to 82% of her mature body weight. This can be achieved with a maximal prepubertal average daily gain (ADG) of 2 lb/day when a traditional preweaning program is employed or 1.8 lb/day when an intensified preweaning program is employed. Because of the well defined link between inadequate body weight at calving and increased mortality and morbidity in first-lactation cows, achieving this target post-calving body weight is of critical importance.Item Open Access Johne's Disease: where do we go from here?(Kansas State University. Agricultural Experiment Station and Cooperative Extension Service, 2010-12-01) Hollis, Larry C.; lhollisJohne’s disease was characterized as a significant disease in cattle before the start of the 20th century. The disease causes a chronic wasting away and non-responsive diarrhea, coupled with a long incubation period and difficulty in diagnosis until late in the course of disease. As a result, it has become a costly aggravation to dairy producers over the years. Of even greater concern, however, is the more recent incrimination of the causative agent, Mycobacterium avium subspecies pseudotuberculosis (MAP), as a possible cause of Crohn’s disease in humans. Because MAP is present in milk of cows with advanced Johne’s disease, and occasionally survives pasteurization, the dairy industry must work proactively to control this disease and reduce the potential for any associated human health risks.Item Open Access Effect of a new teat dip on somatic cell count, incidence of Mastitis, and milk production in a commercial dairy(Kansas State University. Agricultural Experiment Station and Cooperative Extension Service, 2010-12-01) Shirley, John E.; Miller, W.F.; Rottinghaus, J.; Titgemeyer, Evan C.; etitgemeFive hundred and thirty Holstein cows located in a commercial dairy herd near Birdseye, Indiana, were used to evaluate an iodophor (0.50% iodine) teat dip containing a new conditioner. The new teat dip (Dinerin) was evaluated against a common commercial teat dip (WestAgro Iodozyne pre-dip and West- Agro Blockade post dip). The study was conducted February 17 through June 25, 2004. Cows treated with Dinerin teat dip had lower somatic cell counts and produced more milk than those treated with the WestAgro products.Item Open Access Quantification of volatile flavor compounds in off-flavor and commercial reduced-fat milk samples(Kansas State University. Agricultural Experiment Station and Cooperative Extension Service, 2010-12-01) Francis, L.L.; Lee, J.; Chambers, Delores H.; Jeon, I.J.; Simmons, S.R.; Schmidt, Karen A.; kschmidtVarious chemical compounds contribute to the naturally pleasant flavor of milk. Over time, however, and with unwanted chemical reactions, loss of flavor is inevitable. This study was conducted to identify and quantify volatile flavor compounds associated with off-flavored and commercial reduced-fat milk products. Fresh milk was used for the preparation of altered milk samples having off-flavors such as “light-oxidized” and “high-acid.” Milk lacking freshness (i.e., milk produced two weeks before sampling and maintained at 40oF in the dark) also was compared with fresh unaltered milk and two commercial milk samples. For headspace analysis, milk samples were subjected to SPME-GC for volatile compound identification. In addition, the composition and aerobic and coliform microbial counts for all milk samples were analyzed. The milk samples did not differ in the concentrations of volatile flavor constituents. When comparing “light-oxidized” milk samples (200 lx exposure for 1 or 3 hr), 2-butanone and pentanal concentrations tended to increase as light exposure time increased. All milk samples had similar fat and total solids contents. “High-acid” milk had a greater total aerobic microbe count than the other milk samples. Fresh milk had a greater octanal concentration than the offflavored reduced-fat milk samples did. This might indicate that octanal is an important contributor to fresh milk flavor and deserves further study.
