Dairy
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Item Open Access Ability of low profile cross-ventilated freestall barns to improve environmental conditions for dairy cattle(Kansas State University. Agricultural Experiment Station and Cooperative Extension Service, 2010-11-29) Smith, John F., 1962-; Harner, Joseph P.; Brouk, Michael J.; jfsmith; jharner; mbroukRecently, there has been interest in constructing mechanical ventilation with evaporative pads to improve the environmental conditions for cows during periods of heat stress. Low profile cross-ventilated freestalls with evaporative pads (LPCV) have become a popular system. The purpose of this study was to evaluate how well these LPCV systems improve the temperature-humidity index (THI) under different ambient conditions. As ambient humidity increases, ability of the LPCV to reduce THI is decreased. Producers wishing to construct LPCV barns should carefully evaluate the climate in which they want to construct LPCV structures.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 Administering a GnRH agonist (receptal) after insemination fails to improve pregnancy rates at first service(Kansas Agricultural Experiment Station, 2011-05-20) Rettmer, I.; Stewart, R.E.; Stevenson, Jeffrey S.; jssTwo experiments were performed to determine the influence of administering a highly potent agonist of gonadotropin-releasing hormone (Receptal) on various reproductive characteristics in dairy cows. In Experiment 1, lactating Holstein cows were treated with either saline (n = 51) or 8 μg of receptal (n = 50) on d 11 to 14 after estrus (d 0) and first service. Peak concentrations of LH, FSH, and progesterone, but not estradiol-17b, in blood serum were increased during 6 to 12 h after injection of Receptal. Pregnancy rates were unaffected by treatment. Concentrations of progesterone in blood serum were increased in nonpregnant and pregnant cows after injection of Receptal. Return to estrus in Receptal-treated cows increased by 2.5 ± .8 days compared to controls. The number of follicles >10 mm in diameter, assessed by transrectal ultrasonography, were reduced and follicular development was altered after Receptal. In Experiment 2, various doses of Receptal were tested in eight dairy herds, including 1,013 inseminations at first service. Cows were given a single injection of either saline or 4, 8, or 12 μg of Receptal on days 11 to 14 after first service. Pregnancy rates were not improved consistently in all herds and failed to increase across all herds. We concluded that administering a potent GnRH agonist altered number and distribution of ovarian follicles, increased cycle length, and increased concentrations of progesterone, without a consistent increase in fertility.Item Open Access Administration of GnRH at insemination in repeat breeding dairy cows: improved pregnancy rates, hormone secretion, and luteal function(Kansas Agricultural Experiment Station, 2011-08-02) Stevenson, Jeffrey S.; Mee, M. O.; Call, Edward P.; jss; epcallAdministering saline to 14 repeat breeders or 100 μg GnRH to 38 repeat breeders resulted in a greater (P=.07) proportion of pregnancies at 42 to 56 days after third service and fewer (P<.05) lost pregnancies during the 25- to 38-day period of placentation. Concentrations of LH in serum of six repeat breeders previously given 100 μg GnRH 12 hr after detected estrus (day 0) were reduced (P<.05) on days 1, 3, and 8 after estrus compared to those in six cows previously given saline at estrus. Concentrations of FSH were similar among treatment groups on days 1 and 3, but were elevated (P<.05) on day 8 in GnRHtreated cows. Furthermore, all six GnRH-treated cows had detectable FSH pulses on day 8 compared to two of six control cows. Concentrations of progesterone in serum were elevated (P<.05) on days 8 to 10 after estrus in GnRH-treated cows, and their corpora lutea obtained on day 10 after estrus and treatment contained a greater (P<.05) proportion (31 vs. 14%) of large-diameter (21 to 37 μm) luteal cells and a lesser (P<.05) proportion (69 vs. 86%) of small-diameter (10 to 17 μm) luteal cells than corpora lutea from control cows. In vitro production of progesterone in response to LH was reduced (P<.05) in luteal tissue obtained on day 10 after estrus from cows previously treated with GnRH at estrus compared to cows given only saline. It appears that pregnancy rates are improved in repeat breeders given GnRH at the time of insemination as a result of increased secretion of progesterone related to alterations in the morphology and function of the corpus luteum, as well as possible influences of FSH secretion from the pituitary gland.Item Open Access Aflatoxin in milk and dairy products(Kansas Agricultural Experiment Station, 2012-10-04) Ikins, W.G.Aflatoxins are toxic compounds that are produced by certain strains of molds, namely, Aspergillus flavus and Aspergillus parasiticus. These molds may invade stressed crops in the field or proliferate in improperly stored feed. Dairy cows are one of the many species of animals that may suffer both long-term and short-term adverse effects from consuming aflatoxin contaminated feed. In addition, dairy cows metabolize the toxin to a slightly different form, a portion of which is secreted into milk and can be consumed by humans.Item Open Access Aflatoxins: Contamination of animal feeds and food products(Kansas Agricultural Experiment Station, 2011-08-02) Phebus, Randall K.; phebusMycotoxins are toxic chemicals produced by certain species of molds during their growth on numerous substrates. Molds can invade the food and feed supply at various points throughout production, storage, processing, and distribution. Of most concern are the aflatoxins, which are highly toxic and classified as probable human carcinogens. Aflatoxins are often associated with crops that have undergone stress or feeds and foods that have been stored improperly. Tremendous economic implications are associated with regulation, testing, and loss of agricultural products from aflatoxin contamination. Dairy cattle excrete a portion of consumed aflatoxins into milk, thus, leading to a strict action level of 0.5 ppb in fluid milk. Several types of processed food products have been demonstrated to be occasionally contaminated with these toxins.Item Open Access Alfalfa hay inclusion rate in wet corn gluten feed based diets(Kansas State University. Agricultural Experiment Station and Cooperative Extension Service, 2010-11-23) Mullins, C.R.; Grigsby, K.N.; Bradford, Barry J.; bbradforIn this experiment, we evaluated the effects of varying alfalfa inclusion rate in diets containing 31% wet corn gluten feed on a dry matter basis. Eighty lactating Holstein cows were allocated into groups of 10 and assigned to 1 of 8 pens balanced for parity, stage of lactation, and milk yield. Diets were formulated to contain 0, 7, 14, or 21% alfalfa on a dry matter basis. Diets containing greater proportions of alfalfa had less corn silage and soybean meal but more corn grain. Feed intake, milk production, body weight, and body condition score were monitored, and effects of increasing alfalfa inclusion rate were assessed. As more alfalfa was included in the ration, cows consumed more feed and had a tendency to produce more solids- and energy-corrected milk. In contrast, body weight gain decreased in diets with more alfalfa. These changes in milk and body weight indicate that metabolizable energy utilization shifted from body weight gain to milk production when more alfalfa was fed. With this in mind, an economic model was constructed to determine whether the added production from including alfalfa is enough to justify incorporating it in this type of ration. The model demonstrated that, despite minor losses in productivity, decreasing alfalfa inclusion rate may improve farm profitability by reducing feed costs and expenses associated with manure handling.Item Open Access Anestrus in lactating dairy cows before ovulation synchronization(Kansas State University. Agricultural Experiment Station and Cooperative Extension Service, 2010-12-03) Cartmill, J.A.; Zarkouny, S.E.; Hensley; Stevenson, Jeffrey S.; jssThe incidence of anestrus in dairy cattle prior to first inseminations carried out after a minimum of 60 days postpartum ranged from 4 to 58% in first-lactation cows and 14 to 50% in older cows. Dairy cows with more days in milk, older than 2 years, and in better body condition (probably reflective of greater postpartum dry matter intakes) were more likely to cycle than thinner cows. Cows that were not cycling before the first week of insemination conceived at lower rates and took longer to become pregnant.Item Open Access Animal drugs and the milk supply(Kansas Agricultural Experiment Station, 2012-09-20) Wilson, R.W.The makers of the laws, rules, and regulations governing the production and processing of milk have recognized that milk is the primary diet of the very young and old. This fact mandates that it should be produced and processed in a manner to protect and maintain it in a pure, safe, and unadulterated condition. To determine adulteration of any milk product, one must first understand the legal definition of that product. In general, milk is defined as "the lacteal secretion of healthy cows that is practically free from colostrum." Anything that alters the product from the intent of this definition constitutes adulteration.Item Open Access Antibiotic versus nonantibiotic products for the treatment of Papillomatous Digital Dermatitis (hairy heel wart) in dairy cattle(Kansas State University. Agricultural Experiment Station and Cooperative Extension Service, 2010-12-01) Sargeant, J.M.; Gnad, D.P.; Isch, J.; Bathina, H.; Lising, J.; Shirley, John E.A field trial was conducted to compare oxytetracycline to three nonantibiotic therapies using bandage protocols for the treatment of hairy heel warts. Affected feet were bandaged for 4 days with either of the four products. Over a 28-day period following bandage removal, heel warts on 44 cows (11 per treatment group) were evaluated based on size, degree of pain, color, and lesion appearance. No differences were detected among treatments, suggesting that nonantibiotic therapies used in bandage protocols may be as effective as oxytetracycline.Item Open Access Application of the progesterone (CIDR) insert in artificial insemination programs of dairy cattle(Kansas State University. Agricultural Experiment Station and Cooperative Extension Service, 2010-11-29) Stevenson, Jeffrey S.; jssUse of progesterone inserts (controlled interval drug release, CIDR) offers another option for synchronizing estrus and ovulation in replacement heifers and lactating dairy cows. Results indicate that heifers may be inseminated after detected estrus, at a fixed time (timed AI), or a combination of both. Conception rates exceed 50% in both scenarios. Practical applications of the CIDR in lactating cows have been used to resynchronize the return estrus of previously inseminated cows and as part of first-service AI-breeding protocols. Use for resynchronization has no drawbacks in previously inseminated cows, but may increase embryo survival during the first 30- to 60-days of pregnancy. No increase in the heat-detection rates of open cows is generally achieved, and no differences in return conception rates are observed between treated and control cows. First-service applications of the progesterone insert have resulted in some positive and some negative effects on timed AI (TAI) conception rates. More research is warranted to determine if an identifiable subpopulation of cows can benefit from exposure of the progesterone insert before first AI.Item Open Access Assessment of mastitic infection in bovine milk using ATP bioluminescence(Kansas Agricultural Experiment Station and Cooperative Extension Service., 2011-05-04) Meyer, M. J.; Sukup, D.; Schmidt, Karen A.; Shirley, John E.; kschmidt; jshirleyFew choices exist for a mobile, rapid, and nonsubjective assessment of mastitic infection in bovine milk. This project evaluated the effectiveness of using the Biotrace® raw milk quality ATP bioluminescence assay to serve this role. Milk samples with various somatic cell counts (13,000 - 2,500,000) and signs of mastitic infection were obtained from the Kansas State University Dairy Teaching and Research Center. Within 24 hr, raw milk samples were evaluated for microbial numbers and relative light units (RLU). The printed test procedure was modified to evaluate accurately clinical mastitic milk samples. As somatic cell count increased in raw milk, the RLU value increased. In addition, RLU values differentiated among milk samples with various levels of mastitic infection (none, subclinical, and clinical). Repeatability of the ATP bio-luminescence method was very good (CV = 4.76%). These results suggest that the Biotrace® raw milk quality test kit can served effectively as a nonsubjective, rapid assay to determine the degree of mastitic infection in bovine milk.Item Open Access Association of cow and quarter-level factors at a dry off and new intramammary infections in the dry period(Kansas State University. Agricultural Experiment Station and Cooperative Extension Service, 2010-11-29) Dingwell, R.T.; Leslie, K.E.; Sargeant, J.M.; Schukken, Y.H.; Timms, L.L.; Shirley, John E.Data from 300 cows and 1,178 quarters were analyzed to determine factors associated with new intramammary infections (IMI). Teatends that were cracked and teats that did not close during the dry period were 1.7 and 1.8 times more likely to develop new IMI, respectively. The level of milk production on the last day of lactation significantly influenced new IMI and teat canal closure. More (P<0.05) cows (36%) producing $21 kg of milk developed new IMI than cows (18%) producing less. When milk production was 21 kg or higher, teat canals were 1.8 times more likely to remain open.Item Open Access ATP bioluminescence can evaluate cleaning and sanitizing effectiveness in the milking parlor(Kansas Agricultural Experiment Station and Cooperative Extension Service, 2011-07-22) Meyer, M. J.; Schmidt, Karen A.; kschmidtFour areas of the milking parlor were evaluated for effective cleaning and sanitation using total aerobic counts (standard plate count) and ATP bioluminescence (ATPB) techniques. Whereas the plate counts only monitor bacterial numbers, the ATPB results (reported as relative light units, RLU) also indicate residual soil or food residue on the surface. Results showed little correlation between the RLU values and the aerobic plate count data; however, the ATP bioluminescence system is a fast (<2 min) and simple method that evaluates the effectiveness of cleaning and sanitation procedures employed.Item Open Access Automated activity monitoring of estrus and time of ovulation(Kansas Agricultural Experiment Station and Cooperative Extension Service, 2014-03-26) Stevenson, Jeffrey S.; jssDetection of estrus can be facilitated by use of automated activity monitors that measure physical activity. Increased physical activity is largely correlated with estrus. Our objective was to determine when ovulation occurs relative to increased physical activity so we could recommend optimal timing of insemination to maximize conception rates in lactating dairy cows. Cows (n = 65) were fitted with pressure-sensitive rump-mounted transmitters (HeatWatch; HW) that are activated by a mounting herdmate to indicate standing estrus. The same cows also were fitted with neck-mounted activity monitors (Select Detect; SD). Additional cows (n = 68) were fitted with only the activity monitor. Beginning approximately 14.5 hours after the individual activity monitor on a cow reached a set threshold, transrectal ultrasonography was used to identify the ovarian preovulatory follicle. Repeated ovarian scans were performed every 3 hours until ovulation occurred or 36 hours after threshold was reached. Although average intervals to ovulation actually differed (P < 0.05) by only 1.5 h (27.2 ± 0.6 h for HW vs. 25.7 ± 0.4 h for SD), deviations between onsets differed by 2.0 ± 0.4 h (increased activity preceded time of standing to be mounted). Increased physical activity tended to increase before the first standing event and endured longer than the duration of estrus measured by HW. We concluded that the activity monitor was a reliable tool to detect estrus, and ovulation occurred at similar intervals from increased activity as from the first standing event associated with estrus.Item Open Access Availability of calcium in dairy and other human foods(Kansas Agricultural Experiment Station, 2012-10-04) Jeon, I.J.In 1985 the annual sales of dairy products on the average grew 3.3%, and is expected to grow 6.4% in 1986, according to the U.S. Department of Commerce. This positive growth was attributed in part to increased consumer awareness on the reported role of calcium in combating hypertension (high blood pressure) and osteoporosis (a brittle bone disease common in older women). A recent report suggested that many consumers are seeing the publicity that many cases of hypertension may be the result of too little calcium intake, not too much sodium. Consumers are also well aware that a calcium-deficient diet can result in the development of osteoporosis, a progressive loss of bone mass that leaves the skeleton fragile and vulnerable to fractures. The gradual loss in bone mass begins in the mid-30's but the damage is not apparent until at least 20 years later, when a significant amount of loss has occurred.Item Open Access Bacterial degardation of milk components is affected by storage temperature and time(Kansas State University. Agricultural Experiment Station and Cooperative Extension Service, 2010-12-10) Zimmerman, S.; Jeon, I.J.; McVay, L.; Ferdinand, E.; Sukup, D.; Shirley, John E.; Schmidt, Karen A.; jshirley; kschmidtRaw milk is an excellent medium for bacterial growth. The objective of this study was to evaluate the number of microbes and component degradation in raw milk. Milk fat content did not affect bacteria counts. As storage temperature or time increased, greater numbers of bacteria were present. In this study, milk protein was degraded preferentially over lactose or milk fat. As the milk storage temperature increased from 39 to 45°F, protein degradation became more pronounced. Milk fat remained relatively stable, though some degradation products were observed, especially after 4 days of storage at 39°F. Both milk fat and protein degradation can produce small, volatile compounds that negatively affect the flavor and odor of milk. Thus, to maintain high quality fluid milk in the market, milk must be available to the consumer soon after its processing.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 Bioavailability of alfalfa calcium(Kansas Agricultural Experiment Station, 2012-10-04) Harbers, L.H.; Ward, G.M.; Dayton, A.D.The availability of oxalate and non-oxalate calcium in alfalfa was determined using a chick assay. Oxalate-bound calcium was found to contribute only 16% as much influence as nonoxalate calcium. The nonoxalate calcium in alfalfa was 18% more available than calcium carbonate (precipitated chalk).Item Open Access Bioavailability of lysine from hydroxymethyl lysine(Kansas Agricultural Experiment Station and Cooperative Extension Service, 2012-09-07) Elwakeel, E.A.; Titgemeyer, Evan C.; Brake, D.W.; Nour, A.M.; Nassar, M.E.; Faris, Brian R.; etitgeme; brfarisTwelve mature sheep were used as a ruminant model to estimate the bioavailability of lysine in hydroxymethyl lysine (HML) compared with a commercial product of rumen-protected lysine (RPL; LysiPEARL, Kemin Industries, Inc.) with known availability. The sheep were fed a diet with a forage to concentrate ratio similar to that of dairy diets. Following a control period in which plasma lysine was measured when sheep received no supplemental lysine, the sheep were provided 2 of 4 treatments during periods 2 and 3; treatments included RPL to provide 3 or 6 g/day of available lysine (actual amounts of product provided were based on the manufacturer’s data related to ruminal escape and intestinal availability) and 3 or 6 g/day of lysine provided as HML. Blood samples were collected at the end of each feeding period at 3 hours after feeding. Both HML and RPL significantly increased plasma lysine concentrations. By comparison with plasma lysine concentrations when known amounts of bioavailable lysine were provided as RPL, the bioavailability of lysine in HML was estimated to be 94%. Results indicate that HML may be an effective means of supplementing lysine to dairy cattle.
