Dairy Day, 1987
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Item Open Access Cow-side milk progesterone testing(Kansas Agricultural Experiment Station, 2012-09-20) Call, Edward P.; Stevenson, Jeffrey S.; jssCow-side milk progesterone tests are effective in determining the presence of an active corpus luteum (CL) on the ovary. The test is best used as an adjunct to the Preventive Herd Health Program (PHHP) as a means of identifying cows that have not yet been detected in heat and are candidates for synchronization with prostaglandin (PGF). Several test kits are on the market, and all involve similar chemical principles. However, each test has its own protocol, so read and follow directions EXACTLY. A “control” or “sample” must be run with each test for comparison.Item Open Access Update on gonadotropin-releasing hormone treatments for repeat breeders(Kansas Agricultural Experiment Station, 2012-09-20) Stevenson, Jeffrey S.; jssIn three of six studies involving over 1,650 cows, treatment of lactating dairy cows with 100 µg GnRH (2 cc Cystorelin®) at the time of third or fourth insemination improved conception rates by 12 percentage points. When all six studies are considered, rates improved by 10 percentage points. These data provide strong evidence for continued use of GnRH at the time of insemination for repeat breeders.Item Open Access Update on heat detection aids(Kansas Agricultural Experiment Station, 2012-09-20) Stevenson, Jeffrey S.; Call, Edward P.; jssPoor heat detection is a major cause of reproductive failure in most dairy herds. About one-half of the heat periods are undetected, resulting in prolonged calving intervals. In many cases, the problem is serious enough that some producers have compromised their breeding goals by utilizing natural mating exclusively or maintaining clean-up bulls. The result of these compromises means loss in genetic superiority of future replacement heifers and the potential for serious injury or death of farm help or family.Item Open Access Early lactation somatic cell count should be low(Kansas Agricultural Experiment Station, 2012-09-20) Dunham, James R.Cows and heifers in milk for fewer than 50 days, as shown on the DHIA Somatic Cell Count report, should have a lower average Somatic Cell Count than cows in milk for more than 300 days, if the dry cow mastitis treatment and management programs are effective. The DHIA Somatic Cell Count (SCC) average for a dairy herd is a good evaluation of a mastitis control program. Since leucocytes migrate to the mammary system during periods of subclinical mastitis, the SCC average indicates the amount of subclinical mastitis in a herd. A realistic goal for a herd average SCC is less than 200,000. In many herds with average SCC over 400,000, the average SCC of early lactation cows is higher than that of late lactation cows. This indicates a problem during the dry period, either dry cows are not being cured of mastitis or they are becoming re-infected with mastitis during the dry period.Item Open Access USDA-DHIA Sire Summaries-AI Advantage(Kansas Agricultural Experiment Station, 2012-09-20) Call, Edward P.USDA-DHIA Sire Summaries are published semiannually and provide the dairy industry with an accurate evaluation of the transmitting ability of bulls for milk and milk components. Genetic potential is established at the time of conception. Therefore, current service sires represent the primary means of improving the genetic base of the future herd. Based upon first evaluation of daughters of AI and non-AI bulls, the data clearly indicate the genetic superiority of bulls selected by the AI industry. Dairy producers are strongly urged to select service sires from the Active AI bull listings.Item Open Access Relative feeding value of three forage-based diets for Holstein heifers(Kansas Agricultural Experiment Station, 2012-09-20) Shirley, John E.; Morrill, J.L.; Carinder, W.H.Soybeans interseeded with grain sorghum and harvested as a mixed forage silage crop can be used successfully as a feed for growing dairy heifers. However, daily gain is greater when grain sorghum silage plus alfalfa hay or prairie hay supplemented with milo grain and soybean meal is fed.Replacement heifer programs should be cost effective but yield a heifer large enough to be bred to calve by 24 months of age and with a well developed mammary gland relatively free of internal fat. A daily gain of 1.6 to 1.8 lbs appears to be optimum to achieve the desired bodyweight to be bred by 14 months of age. Feed cost to achieve the above physical goals often accounts for 60% of the total cost in a replacement heifer program. Forage may constitute the majority of a heifer's dry matter intake during the growing phase, if it supplies adequate energy, protein, mineral, and vitamins. Grain sorghum silage and prairie hay are abundant feed sources in Kansas and are frequently used in the diets of replacement heifers. However, grain sorghum is relatively low in protein, deficient in calcium, low in potassium, and potentially adequate in energy for growing heifers diets, whereas prairie hay is adequate in potassium, low in calcium and phosphorus, marginal in protein, and low in energy. Soybeans are well adapted to Kansas conditions and offer a forage that is abundant in protein, calcium, and potassium but relatively low in energy and phosphorus. Silage composed of a mixture of soybeans and grain sorghum should provide sufficient protein, energy, calcium, phosphorus, and potassium to meet the needs of growing dairy heifers. This trial was designed to ascertain the value of soybean-grain sorghum silage relative to sorghum silage or prairie hay as a feed for growing dairy heifers.Item Open Access Glucose. starch, and dextrin utilization in the small intestine of steers(Kansas Agricultural Experiment Station, 2012-09-20) Kreikmeier, K.K.; Harmon, D.L.; Avery, T.B.; Brandt, Robert T., Jr.Holstein steers (775 lbs) were surgically fitted with abomasal and ileal cannulae, portal and mesenteric venous catheters, and an elevated carotid artery. These steers were used to study starch digestion in the small intestine. Glucose, corn starch, and corn dextrin were infused into the abomasum at various levels and ileal digesta samples were collected. Disappearance of carbohydrate (CHO) in the small intestine was determined using Cr:EDTA as an indigestible marker. Blood samples were collected from the portal vein and carotid artery during carbohydrate infusion. Blood flow was determined, and net glucose absorption across the small intestine was calculated. Glucose infusions resulted in higher arterial glucose concentrations and increased net glucose absorption than either starch or dextrin infusions. Increasing infusion rates above 20 g/h for both starch and dextrin resulted in no further increases in net glucose absorption. Even though the enzymatic processes for starch and dextrin hydrolysis became saturated at a low infusion rate, the amount of starch and dextrin disappearing in the small intestine increased with higher infusion rates. This was accompanied by an increased volatile fatty acid (VFA) concentration in the ileal fluid with starch and dextrin infusions, but not when glucose was infused. Data from these experiments support two concepts: (1) microbial fermentation is involved in small-intestinal starch appearance and (2) starch and dextrin hydrolysis in the small intestine of steers is more rate limiting than glucose absorptive capacity.Item Open Access Rumensin for the lactating dairy cow(Kansas Agricultural Experiment Station, 2012-09-20) Kube, J.C.; Frey, R.A.; Shirley, John E.Two Holstein cows were fed Rumensin for 12 weeks, beginning approximately 90 days postpartum. Milk production increased 7%, whereas percentage fat in milk decreased 10.3%. Percentage protein in milk increased 9.6% in the early stages and decreased 10.2% in the late stages of the study. Daily fat yield did not change, whereas protein yield increased in the early stages, but did not change in later stages. Fat corrected milk (FCM) did not change with treatment, but dry matter intake (DMI) tended to increase when Rumensin was fed. Acetate concentration did not change whereas propionate concentration increased, causing a significant decrease in ruminal acetate:propionate ratio. Rumen pH showed a nonsignificant numerical increase.Item Open Access Evaluation of a calf starter supplement(Kansas Agricultural Experiment Station, 2012-09-20) Morrill, J.L.; Reddy, P.G.An experimental calf starter made from a pelleted commercial type supplement and feeds readily available on the farm was compared to a conventional pelleted calf starter in an attempt to demonstrate an economical alternative to commercial calf starter. Calves fed the experimental starter consumed as much starter and gained as much weight as calves fed the conventional starter, thus demonstrating a potential for savings on feed cost. The project is continuing in an attempt to improve the starter composition.Item Open Access Effect of ruminal protozoa on performance of early-weaned calves(Kansas Agricultural Experiment Station, 2012-09-20) Anderson, K.L.; Nagaraja, Tiruvoor G.; Morrill, J.L.; Reddy, P.G.; Avery, T.B.; Anderson, N.V.; tnagarajTwenty newborn bull calves assigned to two groups, protozoa-free or protozoa-inoculated, were used to determine the effects of ruminal protozoa on performance of early weaned calves. Calves in the protozoa group were inoculated via stomach tube with a suspension of ruminal protozoa at weekly intervals until a viable population was established. Calves were evaluated weekly for weight gain and feed intake. Feed intake and weight gain were not significantly different between the groups but tended to be higher in protozoa-inoculated than protozoa-free calves.Item Open Access Use of extruded soy flour in milk replacers for calves(Kansas Agricultural Experiment Station, 2012-09-20) Dawson, D.P.; Morrill, J.L.; Reddy, P.G.; Behnke, Keith C.Oil-extracted, desolveritized soy flour without additional heat treatment was used to prepare protein supplements for calf milk replacers by extrusion processing. Various combinations of temperature, moisture, calcium concentration, sulfur, and acid were used to prepare 32 different products. These products were tested for trypsin inhibitor and antigenic activity and the most promising one was chosen for further testing. This product alone or with supplementary amino acids or amino acids and citric acid was used to provide 70% of the protein in experimental milk replacers. These replacers were compared to an all-milk replacer, using growth and metabolic responses of young Holstein bull calves. The extruded soy protein was inferior to milk protein but calf performance was sufficient to indicate a potential for this kind of product in areas where milk products are prohibitively expensive. Amino acid supplementation of this soy product was not beneficial. Acidification had some benefit in the young (<3 week old) calf, but was not beneficial later.Item Open Access Effect of supplemental potassium and buffer in starters for early-weaned calves(Kansas Agricultural Experiment Station, 2012-09-20) Flynn, P.; Morrill, J.L.; Reddy, P.G.; Higgins, James J.Sixty Holstein heifers were used from birth to 8 weeks of age to study the effect of amount of potassium (K) in the diet and of adding a buffer to the starter. Starters were formulated with and without 1% trona, a natural ore buffer, at K concentrations of .9, 1.25, and 1.5% of the dry matter. To supply adequate fiber, yet allow formulation of the starter containing .9% K, 20% prairie hay was included. All calves were fed milk and a prestarter, using an early weaning procedure. Growth and feed consumption data and evaluation of health and metabolic activity were used as response criteria. Overall, calves fed 1.25% K consumed the same amount, whether fed buffered or nonbuffered starter. At other K levels, calves fed nonbuffered starters consumed more. Growth of calves fed buffered starter with 1.5% K was depressed. Metabolic data supported the conclusion that this buffer was not beneficial with this type of starter. Increasing the amount of K did not significantly increase calf response, but there was a trend for gains to increase as K increased to 1.25% in both buffered and nonbuffered starters. Since these calves were not heat stressed, opportunity for maximum benefit from added K did not exist.Item Open Access Performance of early weaned calves fed lasalocid(Kansas Agricultural Experiment Station, 2012-09-20) Anderson, K.L.; Nagaraja, Tiruvoor G.; Morrill, J.L.; Reddy, P.G.; Avery, T.B.; Anderson, N.V.; tnagarajTwenty-two newborn, bull calves were used to determine the effects of lasalocid on growth and feed intake of early-weaned calves from week 1 to 12. Calves were assigned to lasalocid or control groups on day 3. Lasalocid-fed group received lasalocid in milk from day 4 to 7 and in milk and pre-starter from days 7 to 14 and in starter feed from weeks 2 to 12. Lasalocid-fed calves had a significantly higher feed consumption and greater weight gain than calves that did not receive lasalocid. The difference became apparent only after 6 wk of age. Lasalocid appears to be a beneficial feed additive for newborn calves.Item Open Access Further studies utilizing hormones to alter estrous cycles and fertility(Kansas Agricultural Experiment Station, 2012-09-20) Stevenson, Jeffrey S.; Stewart, R.E.; Call, Edward P.; jssIn one large dairy herd, we examined the reproductive performance of 943 cows following early postpartum hormonal therapy utilizing gonadotropin-releasing hormone (GnRH or Cystorelin®) and prostaglandin F2-alpha (PGF). None of our hormonal treatments improved reproductive efficiency in this herd, whereas earlier studies at the KSU Dairy Teaching and Research Center had proved beneficial. However, cows given PGF to induce estrus at the beginning of the breeding period had similar reproductive performance to control cows, suggesting a potential use for one injection of PGF to allow the breeding of more cows by a target date after calving (e.g., by 65 days).Item Open Access Influence of prebreeding progesterone plus prostaglandin F2-alpha on estrus and fertility in lactating dairy cows(Kansas Agricultural Experiment Station, 2012-09-20) Mee, M.O.; Stewart, R.E.; Stevenson, Jeffrey S.; Call, Edward P.; jssProgesterone administered before breeding may increase estrous expression and subsequent fertility in lactating dairy cows. Holstein cows (n=302) were assigned randomly at calving to three groups. Cows received no treatment (controls), one injection of prostaglandin F 2-alpha (PGF), or progesterone plus one injection of PGF (PRID + PGF). The average interval to estrus was 5 days shorter in PRID + PGF cows compared to cows given only PGF. In addition, more cows were observed in estrus 2 to 5 days after treatment in the PRID + PGF group compared to the PGF group. Average days from calving to conception were reduced in PRID + PGF cows by 15 to 20 days compared to control and PGF cows. We concluded that prebeeding progesterone in combination with PGF appears to enhance fertility.Item Open Access Gonadotropin-releasing hormone improves conception rates of repeat-breeders with previous reproductive disorders(Kansas Agricultural Experiment Station, 2012-09-20) Stevenson, Jeffrey S.; Call, Edward P.; jssAn experiment examining the benefit of treating repeat-breeders with 100 µg GnRH (Cystorelin ®) at the time of third or fourth insemination was conducted in 513 dairy cows of which 93 (abnormal cows) had been diagnosed previously (during the 60 to 90 days postpartum) as having reproductive disorders, including retained placenta, uterine infections, prolonged anestrus, and cystic ovaries. Treatment with GnRH improved conception in normal and abnormal repeat-breeding cows by 13 percentage points or 42%.Item Open Access Concentrations of progesterone and conception rates in Holstein heifers after hCG administration during the first 3 weeks after estrus(Kansas Agricultural Experiment Station, 2012-09-20) Stewart, R.E.; Mee, M.O.; Stevenson, Jeffrey S.; jssWe conducted two experiments to determine the effects of administering human chorionic gonadotropin (hCG) on day 4 or on days 15, 16, and 17 after estrus on conception rates and progesterone secretion by the corpus luteum in Holstein heifers. In the first experiment, 60 heifers received hCG or saline on day 4 after estrus and AI. Conception rates were similar between groups. Concentrations of progesterone were increased in treated pregnant and nonpregnant heifers 7 and 14 days after treatment compared with pregnant and nonpregnant controls. In the second experiment, 62 heifers received hCG or saline on days 15, 16, and 17 after estrus and AI. Conception rates again were similar between groups. Concentrations of progesterone were higher in treated pregnant heifers on days 16, 17, and 21 after estrus and in treated nonpregnant heifers on days 17 and 21 compared with pregnant and nonpregnant controls. We conclude that stimulation of the newly formed or mature corpus luteum by hCG increased production of progesterone without affecting conception rates.Item Open Access Effect of production on reproduction(Kansas Agricultural Experiment Station, 2012-09-20) Call, Edward P.The genetic antagonsim that exists between production and reproduction is overcome by sound management practices. Kansas Holstein herds were ranked by quartile and analyzed by comparing various reproductive traits. Higher producing herds suffered less reproductive loss based upon the factors considered. The most significant differences concerned the average days dry, average days open on cows not yet serviced, percent of cows open more than 120 days since fresh, and average age at first calving. An adequate record system will identify potential reproductive problems, and a sound Preventive Herd Health Program (PHHP) will minimize actual losses from disease and cows not yet bred. All herds, regardless of production level, would benefit by calving heifers at 24 mo.Item Open Access Feeding and managing early lactation cows(Kansas Agricultural Experiment Station, 2012-09-20) Dunham, James R.Feeding and managing dairy cows during the prepartum and early lactation periods have more effect on total lactation yields than all other factors. It is during this time that the pattern of milk production is established for the entire lactation. The full production potential of high producing cows cannot be realized unless these periods are given special consideration.Item Open Access Periparturient disorders in dairy cows(Kansas Agricultural Experiment Station, 2012-09-20) Stevenson, Jeffrey S.; jssThe economic climate in the dairy industry requires producers to operate efficiently to remain competitive. Attention to details and understanding of reproduction, metabolism, digestive functions, milk secretion, and all aspects of husbandry are essential. To be successful, producers must minimize reproductive failure because reproductive performance affects the quantity of milk produced per cow per day of herd life, the number of potential replacements needed to maintain a constant herd size, and the longevity of the cow in the herd. In practice, this translates into well-designed programs of herd health, milking, feeding, and reproductive management that minimize involuntary culling of. problem cows by maintaining healthy, profitable cows. The purpose of this review is to focus on the interrrelationships of various periparturient disorders in dairy cows and highlight their collective impact on reproductive performance, milk yield, and predisposition to other diseases.
