Automated detection of estrus and mastitis in dairy cows

The development and test of detection models for oestrus and mastitis in dairy cows is described in a PhD thesis that was defended in Wageningen on June 5, 2000. These models were based on sensors for milk yield, milk temperature, electrical conductivity of milk, and cow activity and concentrate intake, and on combined processing of the sensor data. The models alert farmers to cows that need attention, because of possible oestrus or mastitis. A first detection model for cows, milked twice a day, was based on time series models for the sensor variables. A time series model describes the dependence between successive observations. The parameters of the time series models were fitted on-line for each cow after each milking by means of a Kalman filter, a mathematical method to estimate the state of a system on-line. The Kalman filter gives the best estimate of the current state of a system based on all preceding observations. This model was tested for 2 years on two experimental farms, and under field conditions on four farms over several years. A second detection model, for cow milked in an automatic milking system (AMS), was based on a generalization of the first model. Two data sets (one small, one large) were used for testing. The results for oestrus detection were good for both models. The results for mastitis detection were varying (in some cases good, in other cases moderate). Fuzzy logic was used to classify mastitis and oestrus alerts with both detection models, to reduce the number of false positive alerts. Fuzzy logic makes approximate reasoning possible, where statements can be partly true or false. Input for the fuzzy logic model were alerts from the detection models and additional information. The number of false positive alerts decreased considerably, while the number of detected cases remained at the same level. These models make automated detection possible in practice.     

奶牛同期发情用药概况及进展

同期发情技术是1种以外源激素控制发情时间的新技术,通过抑制或促进黄体生长达到同期发情的目的。用于同期发情的药物可分为抑制卵泡发育、溶解黄体和促进卵泡发育排卵3类。为了取得最佳同期发情效果,常将3类药物联合应用。本文就同期发情技术中应用的药物及用药方案做了简述。     

Economic modeling of the use of gonadotropin-releasing hormone at insemination to improve fertility in dairy cows

Economic and sensitivity analysis methods were used to evaluate financial returns from use of gonadotropin-releasing hormone (GnRH) at the time of insemination to enhance fertility of dairy cows. A computer spread sheet was used to determine the best service(s) for GnRH treatment, the increase in conception rate required for economic benefit from treatment, and how profits from GnRH treatment are affected by drug cost, herd reproductive efficiency, and production costs. Financial returns increased from use of GnRH at insemination under most herd conditions. Herds with conception rates less than or equal to 45% benefited from GnRH treatment at any 1 or 2 inseminations. Herds with conception rates greater than or equal to 60% benefited from GnRH treatment only at second or later services. Selection of second and/or third insemination as the GnRH treatment service usually resulted in the greatest total return. The enhancement of fertility necessary to achieve the break-even point with GnRH treatment at third service was 2% for low- and 5% for high-conception-rate herds. Base-line herd conception rates, estrus detection efficiency, replacement costs, value of excess days not pregnant, and cost of treatment had the greatest effect on returns from treatment. Herds with high conception rates and low replacement costs were likely to realize the least benefit from GnRH treatment at insemination. On the basis of our findings, we concluded that GnRH treatment at insemination is a profitable procedure under most herd conditions. Optimal treatment regimens for specific herds may best be determined by using herd performance and management data for calculating returns.     

Technical note: use of slow-release estradiol and prostaglandin F2alpha to induce pseudopregnancy and control estrus in gilts

We determined whether a single injection of slow-release estradiol-17beta (SRE2) would induce pseudopregnancy in gilts and whether PGF2alpha would regress the corpora lutea (CL) of pseudopregnancy. Crossbred gilts (n = 40) were induced to ovulate by treatment with 400 IU of hCG + 200 IU of eCG (PG600, Intervet, Millsboro, DE) given at 180 d of age (d = 0). On d 14, gilts were injected i.m. with one of five doses (n = 8 gilts/dose) of SRE2 (0, 12.5, 25, 50, or 100 mg). Blood samples were collected before SRE2 and twice weekly until d 73 to monitor serum progesterone (P4) and estradiol (E2). On d 59, gilts received (i.m.) 10 mg of PGF2alpha (Lutalyse, Pharmacia Upjohn, Kalamazoo, MI) and were checked for estrus for 7 d. On d 62, mammary development was scored (0 = no development; 1 = some development; 2 = teat and gland development) by a neutral observer. Treatment with SRE2 increased (P < .05) peak E2 concentrations, duration of luteal function, and mammary gland score. There were no differences (chi-square, P > .05) among doses of SRE2 in the percentage of pseudopregnant gilts that showed luteolysis after PGF2alpha. We conclude that a single injection of SRE2 can induce pseudopregnancy and that the CL can be regressed with PGF2alpha, providing a simple method for controlling estrus in gilts.     

同期发情定时输精技术对经产奶牛繁殖力的影响

为了研究同期发情定时输精技术对牛群体繁殖力的影响,试验选取同一牛场内不同单元的经产奶牛,随机分为2个组,分别采用自然发情输精和同期发情定时输精两种方法对奶牛进行人工输精,比较两种方法对奶牛群体繁殖力的影响。研究结果显示:同期发情组和自然发情组的参配率分别为,产后54 d之前为96.3%VS 12.1%,55～90 d为64.6%VS 44.6%,91～130 d为48.1%VS 50.1%,131～170 d为39.9%VS 38.7%,180 d内的总参配率分别为249.1%VS 145.5%;相应时段的同期发情组的受胎率为39.2%、36.7%、36.5%、33.9%、92.6%,自然发情组的受胎率为44.8%、47.3%、46.2%、46.1%、 67.5%;2个组的年繁殖率分别为93.8%VS 84.6%、空怀天数为(91.6±18.3)d VS (131.7±26.8)d、配种次数分别为2.5 VS 1.8、淘汰率分别为29.1%VS 13.4%。以上结果表明,在奶牛生产中,使用同期发情定时输精技术,能显著提高牛群的繁殖力,缩短空怀时间。     

Effects of prostaglandin on the reproductive performance of dairy cows

A single injection of a synthetic analogue of prostaglandin F2 alpha (fenprostalene; Syntex) on the day of calving or between days 14 and 21 after calving did not affect the calving to first service interval, the number of services per conception or the conception rate of dairy cows. In a second trial, cows calved more than 45 days were injected once weekly with prostaglandin F2 alpha (dinoprost; Upjohn) or fenprostalene until served at the first detected oestrus. The calving to first service interval and the conception rate were not affected. Following injection of either prostaglandin, the spread in the pattern of onset of oestrus and the range in the proportion of cows (75 to 98 per cent) seen in oestrus within seven days were similar. This variation in the time of onset of oestrus after the administration of prostaglandin precludes limiting oestrus detection to four or five days per week, and is a major limitation to the use of prostaglandins in breeding programmes in dairy cows.     

Experimental use of prostaglandin F2 alpha to synchronize estrus in cattle]

Experiments were conducted for the use of prostaglandin to synchronise oestrus in dairy cows. One single dose of 5 mg F2-Alpha prostaglandin was administered via the intrauterine route. The reference values of the control groups were matched by first insemination following induced oestrus among the best of the test animals which were inseminated twice. These values reached 72 and 96 hours following application accounted for 46.7 and 50.0 per cent. The yellow body phase, a prerequisite for oestrus production by prostaglandins, had been induced in the test animals by cycle blocking, using gestagen. Possible use of the method in a bio-engineering context for large-scale oestrus synchronisation in cows is discussed.     

Histology of the oviduct epithelium of dairy cows after estrus synchronization with cloprostenol

After fading away of the effect of cloprostenol contained in the Oestrophan inj. Spofa preparation, the qualitative and quantitative changes in the epithelium of oviduct ampulla and isthmus of dairy cows were studied. Three dairy cows in the fourth to fifth day after heat were used as control, three cows with the rectally palpated active corpus luteum were given 0.5 mg cloprostenol i. m. On the eighth day after treatment, samples were taken from ampulla and isthmus by means of necropsy. After histological treatment, the samples were evaluated microscopically. Histological staining with hematoxylin-eosine, PAS reaction and PAS reaction with nucleus staining with Harris hematoxylin were used to describe the occurrence of the so-called pale cells. In accordance with the literary data, these cells are believed to be intraepithelial lymphocytes, the function of which will have to be further researched and determined objectively. On the eighth day after cloprostenol administration or on the fourth to fifth day after ovulation in the ipsilateral ovary, a significant decrease in epithelium thickness close to infundibulum and in the depth of ampulla (P less than 0.001) was observed. The changes in the contralateral left side were not significant. After cloprostenol application, the multiplication of nail-like cells in the right-side oviduct ampulla was statistically significant (P less than 0.05).     

Possible causes and treatment strategies for the estrus and ovulation disorders in dairy cows

The reproductive performance of dairy cows has declined, along with an increase in their milk yield. First-service conception rates in lactating dairy cows are often lower than 50%. The precise detection of estrus is an important factor in the reproductive management of dairy cows for successful fertilization and pregnancy. However, estrus expression has been decreasing in modern dairy cows, affecting the detection rate of estrus. In addition to estrus, a high incidence of ovulation disorders affects the fertility of dairy cows. To address these problems, it is necessary to understand the changes in the endocrine functions that underlie estrus and ovulation disorders, and to develop effective treatment strategies. Recent studies have revealed that neurokinin B and neurokinin 3 receptor signaling play important roles in the regulation of the secretion of gonadotropin-releasing and luteinizing hormones, suggesting a potential clinical avenue for the stimulation of gonadal function. In this review, I have discussed the problems in estrus and ovulation disorders in modern dairy cows as well as the possible applications of neurokinin 3 receptor agonists in the treatment of these disorders.     

Reproductive efficiency of three estrus synchronization schemes comprising fixed-time insemination in dairy cows

The objective of this field trial was to compare the odds of pregnancy at 25 days (P25) and at 60 days (P60), of embryonic death (ED) between 25 and 60 days, and of non-pregnant cows returning to heat 20-25 days after artificial insemination (AI). Three fixed-time insemination protocols involving combined administration of either double gonadotrophin-releasing hormone (GnRH) and prostaglandins (A) or GnRH, human chorionic gonadotrophin (hCG) and prostaglandins (B), or double treatment with prostaglandins (C) were used. Cows included in the trial were selected from five herds, comprising a total of 735 (herd size range 85-250, median 120) Holstein dairy cows. Animals used for the study were multiparous, 4-7 years of age, had expressed at least one overt postpartum heat, were between 60 and 120 days of lactation and had at least one palpable corpus luteum and no gross morphological anomalies of their reproductive tracts. They were randomly allocated to receive treatment A (n = 89), B (n = 93), or C (n = 65). Pregnancy of cows not observed in heat 18-24 days post AI was diagnosed by transrectal ultrasonography at 25-30 days and confirmed by rectal palpation at 60-75 days post AI. Those that were detected in heat in the normal period post AI were re-inseminated. No differences were detected among the three treatment groups concerning the odds of P25 (P = 0.5), P60 (P = 0.2) and ED (P = 0.13). In contrast, non-pregnant cows that were administered treatment A were less likely to exhibit estrous signs in the normal period post AI than those administered treatments B (P = 0.02) or C (P = 0.005).     

Use of prostaglandin F2 alpha in the treatment of unobserved estrus in lactating dairy cattle

A field trial was conducted to evaluate the use of prostaglandin F2 alpha (PGF2 alpha) (lutalyse)a in lactating dairy cattle with unobserved estrus in the presence of a functional corpus luteum (CL) and clinically normal reproductive tract. Seventy-three Holstein and 9 Jersey cows, weighing between 340.0 and 772.7 kg, were allotted to treatment and control groups. All treated cows were inseminated within 80 hours after treatment as assigned by this trial. Control cows were inseminated at the first observed estrus. Of the treated cows, 50% showed estrus within 80 hours after treatment. In this trial, 96% of the treated cows and 92% of the control cows were determined to have at least 1 functional CL on the day of treatment. For the treatment group and the control group, mean serum progesterone concentrations were 4.1 ng and 3.5 ng (P less than 0.2, by Student's t test), respectively, on day of treatment and were 0.4 ng and 5.0 ng (P less than 0.005, by Student' t test) on day 5 after treatment. Pregnancy rates were 57% for treated and 47% for control cows (P = 0.5, by X2). Days from treatment to first-observed estrus, treatment to first service, and treatment to conception were significantly reduced in the treatment group compared with these criteria for the control group (P less than 0.05, 0.005, and 0.01 respectively). It was concluded that induction of luteolysis with PGF2 alpha in lactating dairy cattle with unobserved estrus and a palpable functional CL will be an effective addition to reproductive health programs.     

泌乳早期发情和乏情奶牛机体代谢和生殖机能的变化

在某一集约化牛场,随机选取奶牛30头,在奶牛产后发情期(50～90 d)内根据奶牛是否发情将奶牛分为发情组和乏情组。通过对试验奶牛血液生化指标(Glu、BHBA、NEFA)、内分泌指标(FSH、LH、LP、E2、P4)等进行调查和检测。结果显示:当奶牛发情时,机体血浆Glu、FSH、LH、E2和LP浓度高,血浆NEFA、P4浓度低,但乏情时正好相反。当奶牛发情时,血浆leptin与LH、E2呈显著正相关,与P4呈显著负相关,但乏情奶牛未呈现相关性。这些结果提示奶牛乏情与机体能量代谢状况和Ins、Gn、E2、P4、Lp分泌少有关。能量平衡能促进奶牛产后发情,与机体高水平血糖、Lp、FSH、LH、E2和低水平P4、NEFA有关。LP是奶牛泌乳早期发情的一个重要调控因子,在奶牛产后能量平衡、生产性能和繁殖性能之间起到一个平衡纽带的作用。     

Failure of a single postpartum prostaglandin treatment to improve the reproductive performance of dairy cows

A study was conducted to evaluate the effects of postpartum prostaglandin treatment on reproduction in 3 seasonal calving dairy herds. Recently calved lactating dairy cows were paired on herd, age, calving date and previous production index. One cow in each of the 196 pairs received a single intramuscular injection of 25 mg of the prostaglandin analogue, dinoprost, between 14 and 28 days after calving. Subsequent reproduction was monitored. Within each herd and overall, there was no significant effect of treatment on the intervals from calving to first service, mating start date to first service, calving to conception, mating start date to conception and first service to conception. Treatment also had no significant effect on 21-day submission and pregnancy rates, on the proportion of each group not pregnant at the end of mating, and on first service pregnancy rates. Responses to treatment did not vary between cows calving within 50 days of mating start date and earlier calving cows or between cows aged less than 5 years and older cows.     

Synchronization of estrus in postpartum beef cows with melengestrol acetate and prostaglandin F2 alpha

At the beginning of the breeding season, most beef herds consist of a population of cyclic and anestrous postpartum cows. To be most effective and economical, an estrous synchronization method for postpartum beef cows must be capable of synchronizing estrus in cyclic cows and inducing estrus in anestrous cows. In the first of two experiments, the combination of melengestrol acetate (MGA) fed for 9 d and prostaglandin F2 alpha (PGF2 alpha) administered on the last day of MGA feeding synchronized estrus in cyclic cows (94%) and induced estrus in anestrous cows (66%) as effectively as combining PGF2 alpha with a progestin implant (97 and 75%, respectively). In the second experiment, MGA treatment was necessary for 7 d prior to administering PGF2 alpha to maximize the expression of estrus in cyclic and anestrous cows. In both experiments the proportion of cows exhibiting a synchronized estrus and the pregnancy rates tended to be higher for cows that were cyclic prior to treatment. However, the MGA-PGF2 alpha treatments consistently induced estrus in more than 50% of the anestrous cows and approximately one-third of the cows that were anestrous prior to treatment conceived during the synchronized breeding period. The MGA-PGF2 alpha treatment was 33 to 46% less expensive than a comparable estrous synchronization method that is approved by the U.S. Food and Drug Administration. If feeding MGA and administering PGF2 alpha is approved, it may be the treatment of choice for synchronizing estrus in cyclic cows and inducing estrus in anestrous cows when supplemental feeding is feasible.     

Synchronization of estrus with melengestrol acetate and prostaglandin F2 alpha in beef and dairy heifers

Beef (n = 783) and dairy (n = 209) heifers at 14 locations were used to evaluate the efficacy of feeding melengestrol acetate (MGA; .5 mg/d) for 7 d followed by an i.m. injection of 25 mg prostaglandin F2 alpha (PGF) on the last day of MGA feeding (MGA + PGF) to synchronize estrus. Untreated heifers (C) and heifers injected once i.m. with PGF served as contemporary controls. Heifers were observed for estrual behavior for a minimum of 38 d starting on the 2nd d of MGA feeding. Heifers in estrus from d 1 through d 60 after PGF injection were artificially inseminated (AI) or bred to bulls (d 30 to 60 post PGF only). During the 7-d MGA feeding period fewer (P less than .01) MGA + PGF (1.5%) than C (20.6%) or PGF (18.1%) heifers were observed in estrus. Percent of heifers in estrus d 1 to 6 post PGF was different among groups (P less than .05; 30.5, 52.8, 72.3 for C, PGF and MGA + PGF, respectively). More (P less than .01) MGA-fed (92%) than non-MGA-fed (C and PGF combined) heifers (85.4%) were observed in estrus during d 1 to 24. Conception rate (CR) during d 1 to d 6 was not different (P = .19) between C (58.9%) and MGA + PGF (51.2%) heifers; CR was lower (P = .01) for MGA + PGF than for PGF (68.3%) heifers.(ABSTRACT TRUNCATED AT 250 WORDS)     

Comparison of effects of GnRH and prostaglandin in combination, and prostaglandin on conception rates and time to conception in dairy cows

OBJECTIVE: To assess the effectiveness of a gonadotrophin-releasing hormone (GnRH) / prostaglandin program (GnRH-PG-GnRH, Ovsynch) on conception rates and time to conception of lactating dairy cows compared with a PG program (double prostaglandin injection). DESIGN: A randomised multi-centre cohort study was conducted with 778 cows from nine dairy herds. Cows at different stages of lactation were randomly assigned, after matching for days open at the time of treatment, to either the PG or Ovsynch program. PROCEDURE: Cows on the PG program received two intramuscular injections of prostaglandin (2 mL, Prosolvin) 11 days apart. The Ovsynch program consisted of two intramuscular injections of GnRH (1 mL, Fertagyl) 9 days apart, separated by one injection of prostaglandin 40 h before the second GnRH injection. Milk samples were taken at the time of artificial insemination and assayed for progesterone by radioimmunoassay. RESULTS: The Ovsynch program was not significantly different to PG in achieving conception, with overall conception rates of 37.6% and 41.4%, respectively, for each program. There was, however, a significant interaction between the effects of parity and treatment (P = 0.03), because conception rates were higher in older cows (parity 5 or more) on the PG program than for older cows on the Ovsynch program. There was no significant effect of treatment (P > 0.5) on time to conception after treatment, but older cows were slower to conceive (P < 0.0001). Conception rates differed (P < 0.0001) among herds. CONCLUSION: The median days to conception for both groups was 22 and mean days from treatment to conception were 36.3 +/- 3.3 and 31.6 +/- 2.7 for the Ovsynch and PG programs respectively, indicating that reproductive performance of cows was not significantly different with Ovsynch program or PG program. There appears to be a need to evaluate causes of reproductive failure in older cows.     

Synchronization of estrus in dairy goats treated with prostaglandin F at various stages of the estrous cycle.

Dairy goats were given IM injections of 125 micrograms of cloprostenol sodium on day 6 of the estrous cycle (prostaglandin F [PGF] 6, n = 22) or day 12 of the estrous cycle (PGF 12, n = 26). Mean +/- SE hours from injection to onset of behavioral estrus and proportion of goats responding were 46 +/- 4.2 (range, 12 to 88 hours) and 95% and 48 +/- 2.9 (range, 34 to 68 hours) and 100% for groups PGF 6 and PGF 12, respectively. There was no significant difference between the groups in mean time to onset of estrus, but variances about the means were different. Of the does in groups PGF 6 and PGF 12, 67 and 85%, respectively, had signs of onset of estrus between 36 and 60 hours after administration of PGF. Mean (+/- SE) hours from injection to time of peak concentrations of luteinizing hormone (LH) were 62 +/- 3.1 and 64 +/- 2.1 for groups PGF 6 and PGF 12, respectively. Of the does in groups PGF 6 and PGF 12, 86 and 100%, respectively, had LH peaks. Of the does in groups PGF 6 and PGF 12, 68 and 77%, respectively, had peak concentrations of LH between 48 and 72 hours after administration of PGF. All does in groups PGF 6 and PGF 12 had concentrations of progesterone greater than or equal to 1.0 ng/ml on the day of administration of PGF. Concentrations decreased to less than 1.0 ng/ml by 48 hours after injection in all does except 1 in group PGF 6.(ABSTRACT TRUNCATED AT 250 WORDS)