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1.
This work examined preventive effects of a dietary and a medical intervention measure on postpartum (p.p.) ketogenesis in dairy cows overconditioned in late pregnancy. Sixty German Holstein cows were allocated 6 weeks antepartum (a.p.) to three high body condition score (BCS) groups (BCS 3.95 ± 0.08) and one low BCS group (LC, BCS 2.77 ± 0.14). Concentrate proportion in diet a.p. was higher (60% vs. 20%) and increase in proportion p.p. from 30% up to 50% decelerated (3 vs. 2 weeks) in high BCS groups. High BCS cows received a monensin controlled‐release capsule (CRC) (HC/MO), a blend of essential oils (HC/EO) or formed a control group (HC). Performance parameters and energy status were evaluated in three periods [day (d) ?42 until calving, one until 14 days in milk (DIM), 15 until 56 DIM]. Feed efficiency was 65% and 53% higher in HC/MO than in LC (p < 0.001) and HC groups (p = 0.002) in the second period. Milk fat content was higher in HC/EO (5.60 vs. 4.82%; p = 0.012) and milk urea higher in HC/MO (135 mg/kg) than in LC cows (107 mg/kg; p < 0.001). Increased p.p. levels of non‐esterified fatty acids in serum were found in HC (p = 0.003), HC/MO (p = 0.068) and HC/EO (p = 0.002) in comparison with LC cows. Prevalence of subclinical and clinical ketosis was 54% and 46%, respectively, in HC group. Monensin decreased the prevalence to 50% and 7% respectively. Ruminal fermentation pattern showed higher proportions of propionate (23.43 mol % and 17.75 mol %, respectively; p < 0.008) and lower acetate:propionate ratio (2.66 vs. 3.76; p < 0.001) in HC/MO than HC group. Results suggest that a monensin CRC improved energy status and feed efficiency of transition dairy cows while essential oils failed to elicit any effect.  相似文献   

2.
Coxiella burnetii (C. burnetii) is the causative agent of Q fever both in humans and animals. The objectives of this study were to investigate seropositivity and bacterial shedding in heifers and primiparous cows in an endemically infected herd and to assess the effects on post‐partum diseases, fertility and milk production. At the age of 9 months, 96 Holstein heifers were included. Sampling was performed reproduction‐orientated: at the beginning of the study, at detection of first pregnancy, 3 weeks before expected calving date (blood serum), at parturition and after 21, 42, 100 and 150 days in milk (DIM) (blood serum, vaginal swabs and milk). Serum samples were investigated by a commercial ELISA for the presence of specific antibodies and vaginal swabs and milk samples by PCR to detect C. burnetii DNA. Individual animal data (calving ease, stillbirth, retained foetal membranes, puerperal metritis, endometritis after 42 DIM, presence of corpus luteum after 42 DIM, interval calving‐first service, interval calving‐conception, number of inseminations until 150 DIM, proportion of pregnant cows until 100 and 150 DIM, proportion of pregnant cows after first service and data of the dairy herd improvement test) were documented. All heifers were seronegative at the age of 9 months and 3 weeks before the expected calving date. Subsequently, the proportion of seropositive animals and the antibody score increased significantly towards 42 and 100 DIM, respectively. Vaginal C. burnetii shedding was highest at parturition (30.9%), while the most positive milk samples were detected after 100 DIM (15.3%). Coxiella burnetii seropositivity and shedding had no impact on parameters of reproduction. However, milk fat yield was declined in puerperal vaginal shedders and cows which seroconverted during their first 42 DIM, respectively.  相似文献   

3.
Effect of evaporative cooling of pregnant dairy cows under heat load conditions during the dry and close-up period, on mammary gland enzymatic activity and intake of food and water, BCS, and milk performance after calving were measured in two consequent experiments. In experiment 1, 18 dry cows held in tie-stalls in a closed aerated barn under heat load conditions were used to measure the effect of evaporative cooling on the respiratory rate and body temperature, individual intake of food and water, enzymes expression level in mammary gland and adipose tissues, and BCS changes until calving. In experiment 2, two groups of 36 dry cows each, held in a commercial loose housing barn, were used to measure the effects of evaporative cooling under heat load conditions on calves' birth weight, colostrum quality and quantity, BCS changes and milk yield during 90 DIM. The non cooled (NC) cows responded to heat load by increasing their respiratory rate and daily water intake, while elevating their rectal temperature by 0.2–0.3 °C as compared with the cooled (C) cows. The external relief of heat load by the C cows in both experiments was expressed in increasing their voluntary DMI during the dry period as compared with the NC group. In experiment 2 the calves' birth weight of C cows was higher, and their colostrum quality and quantity were improved as compared with the NC group. Cooling also improved significantly BCS gain during the last 21 days until parturition, accompanied with higher cell proliferation process (based on enzymes expression at mRNA level) in the mammary gland of the C cows. Consequently, a significant increase in milk production by 5.3%, protein yield by 5.1%, ECM yield by 4.2% and FCM yield by 4.5%, was demonstrated in the C cows during 90 DIM as compared with the NC group.  相似文献   

4.
The objective of this study was to determine the effect of a monensin controlled-release capsule administered intraruminally at drying-off on body condition score (BCS) at calving, milk yield, fertility and concentration of energy-related blood metabolites in Holstein cows dried-off with low BCS (< or = 3.0, scale 1 to 5 with a 0.25 point of increment). Between July and August, 2001, 220 cows from parity 2 or more and dried-off 50-70 days before expected parturition, with a BCS < or = 3.0 were randomly assigned to either a treatment group (n=110; oral capsule of monensin releasing 335 mg/day for 95 days) or a control group (no capsule, n=110). At assignment, on day 21 before expected parturition, at calving, and at 7, 14, and 21 days in milk a blood sample was obtained from a random sub sample of 10 cows per group. Effects of monensin on serum NEFA, BHBA and glucose were measured. Milk yield, milk fat and protein content (%) at DHIA test days during the entire lactation, 305 ME milk production and reproductive responses were compared. Monensin significantly improved BCS at calving, increased milk yield at test days 4 and 8, decreased the percentage of milk protein, did not change the percentage of milk fat, and decreased NEFA and BHBA during the post-partum period.  相似文献   

5.
为了探究荷斯坦牛泌乳前期体况评分（body condition score,BCS）的影响因素及BCS对生产性能和离群寿命的影响,本研究收集江苏省某大型牛场2018年1月至2020年12月共7 811头荷斯坦牛泌乳前期BCS、生产性能测定（dairy herd improvement,DHI）结果及淘汰记录,利用多因素方差分析法在分析奶牛泌乳前期BCS变化及影响因素基础上,重点分析泌乳前期BCS及其变化对泌乳性能和离群寿命的影响,利用Cox回归对泌乳前期不同BCS的荷斯坦牛生存曲线进行绘制,并对不同BCS荷斯坦牛的淘汰原因进行卡方检验。结果表明,全群泌乳前期BCS均值为（2.95 ±0.32）。胎次、产犊季节和泌乳天数对泌乳前期BCS有极显著影响（P<0.01）,1胎牛和夏季产犊的母牛泌乳前期BCS均最高;5~30、31~60、61~100 d BCS呈显著下降。泌乳前期BCS对产奶量、乳脂率、乳蛋白率、体细胞评分等均有极显著影响（P<0.01）。产奶量和高峰奶量随BCS的增加呈极显著下降（P<0.01）。泌乳前期BCS与产奶量、高峰奶量呈极显著负相关（P<0.01）,与乳蛋白率呈极显著正相关（P<0.01）。泌乳前期BCS的变化对SCS和高峰奶量均有显著影响（P<0.05）。泌乳前期BCS对离群胎次和淘汰月龄有极显著影响（P<0.01）。生存分析表明,BCS为2.75的牛只生存概率最大。2胎和4胎母牛、冬季产犊的母牛不同BCS淘汰比例均呈极显著差异（P<0.01）;低产淘汰的牛只泌乳前期BCS淘汰分布具有极显著差异（P<0.01）。在本研究牛群中,当泌乳前期BCS为2.75时,牛只生产性能较佳且淘汰风险最低,本研究为规模化牛场荷斯坦牛泌乳前期的饲养管理提供了参考。  相似文献   

6.
The objectives of this study were to examine the effect of parity and days in milk (DIM) on dry matter intake (DMI) and actual milk yield (MYAct) of grazing spring calving dairy cows in early lactation (< 100 DIM) and to develop equations to predict DMI and milk yield for grass based systems of milk production. A dataset containing 335 observations from 134 Holstein Friesian dairy cows was assembled from two early lactation grazing studies. Observations were available for primiparous (n = 130) and multiparous (n = 205) cows during periods of DMI measurement using the n-alkane technique. Animal performance was divided into two classes of DIM: less than 50 DIM (< 50 DIM) or between 51 and 100 DIM (> 50 DIM). Parity and DIM had a significant effect on grass DMI (GDMI), total DMI (TDMI), MYAct and milk composition. TDMI increased with parity and DIM and ranged from 13.4 kg/cow per day (primiparous animals, < 50 DIM) to 20.1 kg/cow per day (multiparous animals, > 50 DIM). Actual MY increased with parity and decreased with DIM (range: 24.1 kg/cow per day (primiparous animals, > 50 DIM) to 33.0 kg/cow per day (multiparous animals, < 50 DIM)). Multiparous cows had greater bodyweight (BW) and lower BCS than primiparous cows. In the early lactation period a number of variables had a significant effect on GDMI, TDMI and milk yield. These predictor variables included BW, BCS, potential milk yield (MYPot), DIM, daily herbage allowance (DHA; > 4 cm), concentrate level and parity. The equations accounted for 79%, 83% and 86% of the variation in GDMI, TDMI and milk yield, respectively. Actual milk yield was always below the MYPot of the cows, the mean difference was 5.8 kg/cow per day. As DHA and concentrate level increased, the difference between MYAct and MYPot reduced. This study supports the concept that immediately post-calving offering a grass based diet with a medium level of concentrate supplementation is sufficient to support high milk production in grazing dairy cows.  相似文献   

7.
The aim of the current study was to evaluate the effects of high carbohydrate or fat diets, fed for 15 days at the end of breeding season, on leptin, GH and LH secretions in prepubertal fat‐tailed Tuj lambs. For that purpose, 9‐month‐old ram‐lambs were divided into three groups as control group (fed with basal ration, n = 4), high carbohydrate (HC) group, basal ration plus barley, n = 4), or high fat (HF) group (basal ration plus by‐pass fat, n = 4). For the measurement of leptin and GH, blood plasma samples were collected on days 1, 4, 9 and 14 of the experiment. For the measurement of LH pulse frequency, serial blood samples were collected every 15 min for 6 h on day 14. Lambs were weighed and body condition scored (BCS) on days 1 and 15. Body weight and BCS increased towards the end of the study (p < 0.05). The BCS was higher in high energy groups at the end of the experiment (p < 0.05). Diet affected plasma leptin concentrations (p = 0.002) but time did not. The GH concentrations were not affected by diet or time. The LH pulse frequency appeared to be higher in HC and HF groups but there were no statistical difference between the groups. There was a significant positive relationship between overall BCS and corresponding leptin concentrations (R2 = 0.263; p = 0.010) and between LH pulse frequency and leptin concentrations (R2 = 0.594; p = 0.003). In conclusion, the present study suggests that rather than type of energy, amount of energy intake and body energy reserves are much important regulators of plasma leptin concentrations and LH pulse frequency in fat‐tailed Tuj lambs.  相似文献   

8.
The objective was to evaluate the effect of body condition score (BCS) at 30 days before calving (−30 days) induced by a differential nutritional management, parity and week of lactation (WOL) on milk yield and composition, and milk casein and fatty acid composition. Primiparous and multiparous Holstein cows with high BCS (PH, n = 13; MH, n = 9) and low BCS (PL, n = 9; ML = 8) under grazing conditions were sampled at WOL 2 and 8 (before and after peak of lactation). Milk yield was greater in multiparous than in primiparous cows and tended to decrease from WOL 2 to 8 only in ML cows. Milk protein, fat and casein yields were greater in multiparous than in primiparous cows and decreased from WOL 2 to 8. Milk casein concentration in milk protein was greater in MH cows than in ML, PH and PL cows at WOL 2. Milk κ‐casein was greater, and β‐casein was less in multiparous than in primiparous cows. As lactation progressed, proportion of casein fractions were not altered. Only κ‐casein fraction was affected by BCS at −30 days as PL showed a higher concentration than PH. The de novo (4:0–15:1) and mixed‐origin fatty acids (16:0–16:1) in milk fat increased, whereas preformed fatty acids (≥17:0) decreased from WOL 2 to 8. Saturated (SAT) fatty acids tended to be greater and monounsaturated fatty acids (MUFA) were less in multiparous than in primiparous cows. High‐BCS cows had greater concentrations of polyunsaturated (PUFA), conjugated linoleic acid (CLA) as well as n‐6 and n‐3 fatty acids in milk fat than low‐BCS cows. The results indicate that casein and fatty acid fractions in milk were affected by parity and may be modified by a differential nutritional management during the pre‐calving period (BCS at −30 days) in cows under grazing conditions.  相似文献   

9.
The objective was to evaluate the effect of cow genetic group, nutritional level and their interaction on some economically important traits of dual-purpose herds managed under field conditions. Nine herds were monitored during a production cycle in Yucatan, Mexico. Herds were grouped into four nutritional levels (NL) based on the metabolizable energy (ME) apparently available on pasture, nutritional management, and milk production. Cows were classified into three genetic groups (GG): low (≤25%), middle (25–75%) and high (≥75%) graded for Bos taurus inheritance. Total milk sold (TMS), days in milk (DIM), TMS adjusted to DIM within each NL (TMSA), body condition score (BCS) at calving, changes of BCS during lactation (CBCS), calf weaning weight (WW), age at weaning (AW), kg of calf weaned per cow (KWC) and calf mortality were studied. The statistical model included the fixed effects of NL, GG, month of calving (MC), parity number (PN) and BCS at calving and GG × NL interaction. The effects of NL, GG, MC, PN and GG × NL were significant (p < 0.05) for TMS, KWC. As expected, TMS increased with NL from 562.4 ± 106 kg for NL1 to 2366.3 ± 100.1 kg for NL4. KWC was greatest for NL2 (138.6 kg) followed by NL1 (135 kg); the lowest KWC corresponded to NL4 (96.0 kg) (p < 0.05). TMS values for the middle (1727 ± 94.7 kg) and the high graded GG (1603.5 ± 83.5 kg) were twice those for the low graded GG cows (828.5 ± 95 kg) (p < 0.05). KWC was also higher for the middle graded group (152.8 kg) than for the low or (104 kg) or the high graded GG (118 kg) (p < 0.05). With better nutrition cows of all GG improved their milk performance but not the calf traits. CBCS was negative for all GG. The highest BCS lost was for cows in NL1 and NL2 and for cows in the high graded GG (p < 0.05).  相似文献   

10.
Pregnancy rate, calving interval, weaning weight, birth weight and quarterly body condition score (BCS) were collected on fall calving multiparous English crossbred cattle (ages 3 to 10) from 1994 to 2001 to evaluate the critical time of cow condition measurements that predict production. The study was initiated with 260 cows. Replacement animals entered the study at first calving (2 years of age), with 45, 54, 27, 68, 54, and 45 animals added in years two through seven, respectively. Body condition score was measured in association with calving, breeding, weaning, and midway between weaning and calving (August). Regression of the logit of the probability of pregnancy (Y) showed that pregnancy outcome was quadratically related to BCS at breeding (P < 0.0001, Y = − 4.81X2 − 0.52X − 4.339) and linearly related to BCS at calving (P = 0.009, Y = 0.32X + 4.17), but was not associated with either the pre- or postpartum change in condition (P > 0.05). Calving interval varied cubically with BCS at calving and quadratically with BCS at breeding (P < 0.0001 and P = 0.002, respectively). The largest decreases in calving interval were associated with increases in body condition score at calving from 3.5 to 4.5 and from 7 to 8. Calf weight at 205 days was related to both the BCS at breeding and the change in BCS from breeding to weaning (P = 0.01 and P = 0.004). Calf weight at 205 days was also associated with BCS at weaning (P = 0.0003). Cows with either low or high BCS at weaning tended to wean lighter calves than cows with moderate condition (4.5 and 5.5). Moreover, BCS at weaning (≈ 6 months prior to calving) was related to birth weight (P = 0.01). Dams with a BCS at weaning of 7 birthed heavier calves than dams with low (3 to 4) or high (8.5) BCS. The relationship of BCS at breeding with pregnancy rate, calving interval, and weaning weight suggests that maintenance of adequate BCS immediately before, during, and after the breeding season may be most critical to sustaining adequate reproductive performance and calf gains in animals subject to the seasonal forage production associated with a Mediterranean climate.  相似文献   

11.
This study aimed to assess the effect of ketone body status early postpartum on time empty in 74 multiparous dairy cows under field conditions. Animals were equally distributed across eight farms and were controlled by the same herd‐fertility‐monitoring programme. Cows were visited twice antepartum and six times postpartum at weekly intervals between 0530 and 0830 a.m. On these occasions, body condition scores and milk yields were measured, blood and milk samples were taken, cows were gynaecologically examined, and parameters of reproduction were recorded. Cows with a time empty of less or more than 80 days were classified as early and late conceiving cows (EC and LC, respectively). A time empty of 80 days results in calving‐to‐calving intervals of 1 year and classification based on this threshold value resulted in groups of equal size and equal distribution of EC and LC within farms. Ketone bodies measured were β‐hydroxybutyrate in blood and acetoacetate and acetone in blood and milk. Blood and milk ketone body concentrations, as well as the ratios of acetoacetate and acetone to β‐hydroxybutyrate, over the first 6 weeks postpartum were higher in LC than in EC, whereas plasma glucose and non‐esterified fatty acids and milk fat, protein and urea concentrations did not exhibit clear differences between groups. Ketone body concentrations were as good predictors of time empty as ketone body ratios and might have practical impact in herd‐fertility‐monitoring programmes.  相似文献   

12.
The aim of this work was to compare energy and lipid metabolism during the peripartum period between Modenese (MO) and Italian Friesian (IF) cows. The study was carried out on 33 pluriparous pregnant cows, 19 IF and 14 MO, reared together in the same herd and kept under equal conditions of management and nutrition. Blood was sampled from jugular vein starting 4 week before expected calving date until 4 week post‐calving, once weekly. Plasma was analysed for glucose, NEFA, BHBA, triglycerides and cholesterol concentrations. Body condition score (BCS) was assessed weekly after blood sampling. Data from antepartum (a.p.) and post‐partum (p.p.) periods were separately analysed as repeated measures by a linear mixed models with the effect of breed, time and their interaction as main factors and random cow within breed. The energy status differed between the two breeds during the peripartum period. We observed higher BCS a.p. and p.p. and lower BCS variations p.p. in MO compared to IF group. Modenese cows showed lower glucose and cholesterol concentrations (p < 0.001), but higher NEFA values, NEFA to cholesterol and NEFA to albumin ratios (p < 0.001) during a.p.; on the contrary, IF cows had higher (p < 0.05) cholesterol, NEFA, BHBA levels and NEFA to albumin ratio than MO ones during p.p. The differences observed between the two breeds suggest how MO cows are subjected to lipid mobilization during late gestation; on the contrary, IF cows are predisposed to mobilize their lipid reserves at the beginning of lactation to support high production. The results indicate a diverse ability to cope with metabolic stress and suggest the hypothesis that the differences in concentrations of plasma parameters and their variation amplitude around the calving period might depend on the different genetic merit for milk production between the two breeds.  相似文献   

13.
ABSTRACT

Aims: To assess the change in body condition score (BCS) during the early and late dry periods and its association with postpartum diseases and milk yield in grazing dairy cows from central Argentina.

Methods: BCS assessments during the dry period, and cow health and milk production records up to 90 days in milk (DIM), were collated for cows from 28 farms at monthly visits between 2007 and 2008. Cows were categorised into four groups; those in Group 1 (n=7,067) maintained or gained BCS during the early and late dry periods; Group 2 (n=2,615) maintained or gained BCS during the early dry period and lost BCS during the late dry period; Group 3 (n=1,989) lost BCS during the early dry period and maintained or gained BCS during the late dry period; and Group 4 (n=5,144) lost BCS during the early and late dry periods.

Results: Cows in Group 1 had reduced odds of having retained fetal membranes (RFM), metritis, and clinical mastitis up to 90 DIM than cows in Group 2 (p<0.001), but the odds of disease were similar to cows in Group 3. The odds of having RFM or clinical mastitis tended to be lower in cows in Group 1 than cows in Group 4 (p=0.08). The odds of cows being culled or dying during the first 90 DIM were lower for cows in Group 1 than for those in Groups 2, 3, and 4 (p≤0.05). Mean accumulated milk yield up to 90 DIM was higher in cows in Group 1 than Group 2 and Group 4 (p<0.001), but was similar to that of cows in Group 3 (p=0.28).

Conclusions and clinical relevance: Cows that lost BCS during the late dry period had increased odds of being diagnosed with several postpartum diseases and had decreased milk yield compared to cows that maintained or gained BCS during the entire dry period. Loss of BCS during any stage of the dry period was also associated with increased incidence of culling or death during the first 90 DIM. These results should raise awareness among dairy cattle producers of the importance of properly managing cow body condition during the dry period, especially during the late dry period.  相似文献   

14.
The purpose of this study was to estimate the prevalence of Subclinical ketosis (SCK) between 4 and 19 days in milk (DIM) in a grazing production system and investigate the importance of potential risk factors for SCK. This cross‐sectional study was conducted in dairy cows (n = 107), which had more of two parities. The concentration of β‐hydroxybutyric (BHB) in blood was quantified through a hand‐held meter. Potential risk factors evaluated were calving interval (CI), milk yield in previous lactation, metritis, dystocia, calf sex (male), parity (≤3 vs. ≥4) and pre‐partum body condition score (BCS ≤ 3.5 vs. ≥3.75). Prevalence of SCK was 10.3% (95% CI 4.7–15) between 4 and 19 DIM. Risk factors identified were the occurrence of both metritis and pre‐partum BCS ≥ 3.75. Cows with metritis had 4.9 (95% CI 1.17–20.98) times more risk of developing SCK than cows without metritis. And the cows with pre‐partum BCS ≥ 3.75 had 5.25 (95% CI 1.32–21.11) times more risk of developing SCK than cows with pre‐partum BCS ≤ 3.5. Metritis could induce a lower feed intake and promote the development of SCK. High pre‐partum BCS could induce a greater mobilization of body reserves altering liver function and aggravating post‐partum NEB. The results are indicative of the expected prevalence of SCK in grazing production system. Factors associated could help to identify cattle at risk of SCK and improve the management of strategies to limit the effects.  相似文献   

15.
AIMS: To determine the effectiveness of intra-rumenal controlled release capsules (CRC) containing 32?g of monensin administered pre-calving to reduce the cumulative incidence of subclinical ketosis (SCK) in mainly pasture-fed dairy cows.

METHODS: Cows (n=837) due to calve in the first 6 weeks of the spring calving period were enrolled from four commercial herds in the Waikato region of New Zealand in a blinded, randomised, negative-controlled field trial. Three weeks before the start of the calving period cows were randomly allocated to receive either no treatment (control) or a single CRC containing monensin and then blood sampled on two occasions, 7 days apart within 12 days following calving for measurement of concentrations of beta hydroxybutyrate (BHBA) in blood. Cows were diagnosed with SCK if the concentration of BHBA in blood in either of these samples was ≥1.2?mmol/L.

RESULTS: Fewer treated cows were diagnosed with SCK within 12 days post-calving than control cows (144/340 (42.4%) vs. 192/336 (57.1%); p<0.001). There was no interaction between treatment group and age, breed or herd of origin. From the final multivariable model it was estimated that treatment with CRC containing monensin reduced the absolute cumulative incidence of SCK by 17.9 (95% CI=9.2–25.8)% compared to no treatment.

CONCLUSIONS: Treatment with a CRC containing monensin >10 days prior to calving reduced the cumulative incidence of SCK of pasture-based dairy cows in commercial dairy herds within 12 days post-calving.

CLINICAL RELEVANCE: Administration pre-calving of an intra-rumenal bolus containing monensin can be considered as one of a range of management options for the control of SCK in early lactation.  相似文献   

16.
Recently, it has been demonstrated that administration of equine chorionic gonadotropin (eCG) in the postpartum period in dairy cows can enhance follicle growth, reduce the interval from calving to first ovulation and increase plasma estradiol concentrations, and, thus, could enhance reproductive performance in a dairy herd when administered on day 6 postpartum. The aim of this study was to investigate the effects of a single dose of eCG between days 9 and 15 postpartum on parameters of reproductive performance in dairy cows. German Holstein cows (n = 1937; primiparous cows: n = 748; pluriparous cows: n = 1189) in a commercial dairy farm were randomly assigned to three experimental groups. Animals within the group eCG received a single dose of 600 IU eCG intramuscularly (i.m.) between days 9 and 15 postpartum followed by an i.m. administration of 500 μg cloprostenol after 14 days. Those of treatment group PG received cloprostenol only between days 23 and 29 postpartum. Cows of the control group remained untreated. Starting on day 49 postpartum, cows were subjected to a Presynch‐Ovsynch protocol and inseminated artificially. The impact of application time (days postpartum) of eCG on the intervals calving to first service and calving to conception was statistically not significant. Outcomes of reproductive performance (i.e. first service conception rate, proportion of pregnant cows until 100 and 150 days in milk [DIM], number of inseminations until 150 DIM, calving to first service interval and calving to conception interval) did not differ significantly between treatment group eCG and group PG compared to control group. Regarding postpartum eCG administration, significant interactions between treatment and parity, season, milk yield, and early puerperal disorders, respectively, could not be shown. In conclusion, an eCG treatment of dairy cows between days 9 and 15 postpartum to increase reproductive performance cannot be recommended under the given circumstances.  相似文献   

17.
This study evaluated the supplementation effects of three herbal plants (thyme [THY], eucalyptus [EUC] and celery [CEL]), a commercial phytogenic additive ?containing essential oils (PFA‐EO, Digestarom® P.E.P.) and monensin (MON) in calf starter on performance, rumen fermentation and blood metabolites during pre‐ (days 3–55) and post‐weaning (days 56–70). Sixty‐six Holstein dairy calves (3 days of age, 41.2 ± 3 kg of BW) were allocated to one of six starters supplemented with: (i) no additives (CON), (ii) MON (30 mg/kg), (iii) THY (23 g/kg), (iv) CEL (23 g/kg), (v) EUC (23 g/kg) and (vi) PFA‐EO (3 g/kg). All the calves were offered starters ad libitum plus 6 L of whole milk daily. Starter intake tended to be the highest in calves fed PFA‐EO and THY; intermediate in calves fed CON, MON and EUC; and the lowest in those fed CEL. Average daily gain (ADG) and feed efficiency (FE) remained unaffected by dietary treatments during the pre‐weaning. During the post‐weaning period, ADG and FE ?were greatest in calves fed EUC followed by those fed CON, MON, PFA‐EO and THY, and then in those fed CEL. No differences were observed among the treatments in skeletal growth, faecal score, rumen pH or ammonia‐N concentration. Compared to calves fed CON and MON, those fed the herbal plants or PFA‐EO tended to recorded higher molar proportions of acetate and butyrate, and the acetate: propionate ratio. Blood malondialdehyde level did not differ among treatments, but calves on CON had the highest glucose concentration, and those fed PFA‐EO recorded the highest value for β‐hydroxyl butyrate on day 70. In conclusion, the results indicate that the three herbs and PFA‐EO are capable of modulating some of the rumen fermentation parameters and blood metabolites as well as eucalyptus could potentially be a better alternative to monensin for improving post‐weaning performance.  相似文献   

18.
The effects of body condition score (BCS) change and status ante‐ and postpartum (pp) on health and reproductive performance in 234 German Holstein cows from eight dairy farms were evaluated. BCS was determined from 6 weeks antepartum until 20 weeks pp in 2‐week intervals. Three and 5 weeks pp progesterone concentrations in blood serum were determined to detect the presence of luteal tissue as an indicator of cyclicity. The incidence of various diseases, percent cycling cows, reproductive measures and culling rate were assessed. Data were subjected to logistic regression to account for possible herd and lactation number effects. Cows with a low BCS status (<3.0) at calving and during early lactation (4–10 weeks pp) were at a higher risk of suffering from lameness (OR 2.9–9.4), not being cycling at 3 and/or 5 weeks pp (OR 2.24–3.99) and being culled (OR 2.56–2.79) than cows in better body condition (≥3.0) In addition, cows with a low BCS status at parturition were at a higher risk of developing endometritis (OR 2.95) and becoming pregnant later than 105 days pp (OR 5.92) than cows with a BCS ≥ 3.0. At 10 weeks pp, the risk of dystocia (OR 4.10) or retained placenta (OR 2.78) at the preceding calving and not being pregnant at 200 days pp (OR 2.42) was higher in cows with a BCS < 3.0 than with a BCS ≥ 3.0. Cows with no BCS loss antepartum were more likely to have an interval from calving to first artificial insemination of <80 days and <105 days open, to be cycling at 3 and 5 weeks pp and to be pregnant at 200 days pp than cows with a BCS loss of >0.25 (OR 2.44–6.67). Furthermore, cows with no BCS loss from calving to 4 weeks pp had a lower risk of suffering from displaced abomasum than cows with a slight or a severe BCS loss (OR 0.09–0.07 respectively). In conclusion, our results suggest that body condition loss during the antepartal period affected BCS status at parturition and to a certain extent during lactation which was linked to a higher incidence of reproductive disorders and lameness, a higher culling rate and lower reproductive performance.  相似文献   

19.
The aim of this study was to evaluate the behaviour of adenosine deaminase (ADA) activity, as well as its participation in the immunomodulation of pregnant cows. Thus, sixteen cows were divided into two groups (A and B): the group A was composed by cows not pregnant (n = 8), while the group B was composed by pregnant cows (n = 8). Serum levels of interleukin‐10 (IL‐10), IL‐6, tumour necrosis factor alpha (TNF‐α), reactive oxygen species (ROS) and C‐reactive protein (CRP), as well as ADA and glutathione S‐transferase (GST) activities, were measured on five sampling times (3, 5, 7 and 8 months of gestation, and soon after calving). Serum ADA activity was similar throughout the experiment in the cows belonging to the group A, but its activity increased during the experiment in cows from the group B, that is it was lower in the third and fifth months of pregnancy, and higher on months 7, 8 and after calving when compared to the group A. TNF‐α and IL‐6 serum levels were lower in pregnant cows compared to non‐pregnant animals; however, they significantly increased after calving. Serum levels of IL‐10 increased after 8 months of gestation, but it reduced after calving when compared to the group A, while CRP increased on month 8 of gestation and after calving compared to the group A. Pregnant cows showed lower serum ROS levels on months 3, 5 and 7 of gestation, and higher levels at the post‐partum. Serum GST activity was higher on month 5 of gestation in pregnant cows, but it was lower on months 7, 8 and in the post‐partum compared to the group A. Based on these evidence, we concluded that ADA activity and the others mediators or inflammatory modulators have important role in the maintenance of cow′s gestation due to their immunomodulatory effects.  相似文献   

20.
The relations between body condition score (BCS), milk yield, serum insulin-like growth factor-I (IGF-I) profile, and luteal activity were investigated in postpartum dairy cows. Seventy-one healthy high-producing multiparous Holstein cows were subjected to transrectal ultrasound scanning twice weekly from the first to the eighth week postpartum. Blood samples were collected twice weekly to measure serum progesterone (P4) and every 2 weeks to detect serum IGF-I concentrations. BCS was monitored weekly after calving. Cows with serum P4 concentrations ≥1 ng/ml on at least two consecutive samplings were considered to have commenced luteal activity. Commencement of luteal activity (C-LA) was observed earlier than 45 days postpartum in 71.8% of cows while 28.2% showed C-LA later than 45 days. Prolonged luteal phase was the most common abnormal pattern of luteal activity observed. Cows with a C-LA earlier than 45 days postpartum had higher (P ≤ 0.05) mean serum concentrations of IGF-I than those with later C-LA. In addition, cows which showed C-LA earlier than 45 days postpartum had more optimal productive indices including shorter calving to conception interval and calving to first service interval (P ≤ 0.05), and fewer services per conception (P = 0.07). C-LA was significantly later in cows that lost more than 0.5 BCS units within 3 weeks postpartum than in those that lost less than 0.5 units BCS during the same interval (P = 0.02). We conclude that high-producing dairy cows with higher postpartum serum IGF-I concentrations have earlier commencement and normal luteal activity, and better reproductive performance. Severity and duration of BCS loss adversely affect commencement of luteal activity.  相似文献   

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