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1.
Associations between rearing conditions and the risk of culling in dairy cows were studied by survival analysis. Data were collected from 1039 Swedish Red cows, 1029 Swedish Holsteins, and 56 cows of other milk or cross-breeds, representing all female animals born in 109 Swedish herds during 1998. Length of productive life was defined as the number of days from 1st calving to culling. The applied Weibull proportional hazards model included time-independent effects of breed, housing from 3 to 7 months of age, number of housing changes before calving, grazing before 1st calving, herd median age at 1st calving, age at 1st calving, cow housing, herd lactational incidence risk of veterinary-reported clinical mastitis, and the random effect of herd. Time-dependent effects were year, month, the interaction year by month, parity, number of breedings, pregnancy status, the interaction parity by pregnancy status, herd mean milk-production level, relative milk yield within breed-parity, and veterinary-reported clinical mastitis. The lactation was divided into six stages in which pregnancy status was assumed to be known by the farmer and culling could occur. Median productive life time in culled cows was 780 d and 14% of the records were censored due to terminated data collection. An individual calving age of 28.2–30.9 months was associated with the highest culling risk, 1.2-fold higher than calving at ≤25.3 months, whereas the risk decreased almost linearly with a higher herd median age at 1st calving. Housing in slatted pens with >7 calves from 3 to 7 months was associated with a 1.7-fold increase in risk, relative to litter pens. If a cow had changed housing system 4 times before 1st calving it increased the risk of culling 1.4 times, relative to two housing changes. These results show that rearing factors affect the productive life time of dairy cows in Swedish family operations. 相似文献
2.
An epidemiologic study of 11 653 episodes of tramped teat is presented and various risk factors identified.Swedish Red and White Breed (SRB) had a lower incidence than Swedish Friesian Breed (SLB). The incidence increased to reach a peak in the fifth (SRB) and fourth (SLB) parities. The incidence was highest in the month of calving and decreased throughout the lactation period. Dystocia and parturient paresis increased the risk of tramped teat in the month of calving in SRB cows. In SLB cows, parturient paresis increased the risk. Cows of both breeds with a positive history of tramped teat had an increased risk of recurrence in subsequent lactations. Loose-housed cows had a lower incidence than tied cows. A positive report of tramped teat increased the risk of removal, irrespective of mastitis status. 相似文献
3.
An epidemiologic study of mastisis in dairy cows in Sweden covering 137 002 calvings and subsequent lactations is presented and various risk factors identified. Swedish Friesian breed (SLB) had a higher incidence of mastisis than Swedish Red and White breed (SRB). The incidence was higher during the first part of lactation and increased with parity until the seventh lactation in SRB and the sixth lactation in SLB. Dystocia, retained placenta and parturient paresis increased the risk of mastisis during the first part of lactation in SRB, and retained placenta increased the risk of mastitis during the first part of lactation in SLB. No associations between these periparturient disorders and the occurrence of mastitis in the latter part of lactation could be found. The incidence of mastitis was increased among teat-tramp-positive cows, and a positive report of mastitis increased the risk of mastitis in subsequent calvings. The influence of environmental factors on the occurrence of mastitis was demonstrated by a higher incidence during housing as opposed to pasture, and a decreased incidence in loose-housed cows when compared to tied zero-grazing cows during the later part of lactation. During the first part of lactation, no seasonal variation could be found, and loose-housed cows had only slightly decreased incidence during this part of lactation when compared to tied zero-grazing cows. The removal rate was increased in the mastitis-positive cow population. 相似文献
4.
The occurrence of cystic ovaries in dairy cows in Sweden was investigated using data on almost 390 000 individuals. Longistic regression analysis was used to assess relationships between cystic ovaries and explanatory variables. Cows of the Swedish Red and White breed (SRB) had twice as many diagnosed cystic ovaries as did Swedish Friesians (SLB), and first-parity cows had half as many cystic ovaries as older cows. The odds for cystic ovaries increased with increasing parity for SRV cows, even after second parity, but not for SLB cows. The diagnosis appeared to be made earlier during lactation in SRB and in high-parity cows. Twin calving in the present lactation and cysts in the previous lactation increased the odds. Cows calving either during months with subsequent risk periods during pasturing or during months with increasing daylight had lower odds for cystic ovaries. The odds increased with increasing milk yield in the present lactation (estimated conditionally on yield in the previous lactation), but decreased with increasing production in the previous lactation (estimated conditionally on yield in the present lactation). In SRB cows, the odds decreased with increasing herd production level. 相似文献
5.
The effects of 15 diseases, pregnancy status and milk yield on culling were studied in 39 727 Finnish Ayrshire cows that calved in 1993 and were followed until culling or next calving. Survival analysis, using the Cox proportional hazards model, was performed with diseases, pregnancy status and milk yield as time-dependent covariates. Effects of parity, calving season and herd were also accounted for. Pregnancy status was the single most influential factor affecting culling decisions, followed by milk yield. Several diseases also had a significant effect on culling, the most influential ones being mastitis, lameness, teat injuries, and milk fever. The effects of all of these factors varied according to the stage of lactation. Milk yield had a significant effect on culling decisions, depending on the stage of lactation. At the beginning of lactation, milk production did not have any effect on culling decisions, but later on, the highest producers were at the lowest risk of being culled and the lowest producers had the highest risk. Adjusting for milk yield modified the effects of parity, most diseases and also pregnancy status on culling. Effects of parity increased after including milk yield in the model, indicating that milk yield and parity are interrelated in their effects on culling. The effects of pregnancy status also increased towards the end of lactation when milk yield was accounted for in the model. The effects of mastitis, teat injuries and lameness decreased after adjusting for milk production. These diseases lower milk yield and thus, part of their effect on culling was mediated through milk production. The effects of anestrus and ovarian cysts were mainly modified by pregnancy status, but not by milk yield. The effects of milk fever on culling increased at the beginning of lactation after including milk yield in the model. This suggests that even though cows with milk fever tend to be higher producers, it is the disease as such that triggers the culling decision early in the lactation. The changes in the effects of other diseases after adjusting for milk yield varied, depending on the disease and the stage of lactation. 相似文献
6.
The effects of 15 diseases and reproductive performance on culling were studied in 39 727 Finnish Ayrshire cows that calved in 1993 and were followed until culling or next calving. Survival analysis, using the Cox proportional hazards model, was performed with diseases and pregnancy status as time-dependent covariates. Parity, calving season and herd were included as covariates in every model. The effect of the number of inseminations was also studied. The farmer's knowledge of the cow's pregnancy status had a significant effect on culling. It varied according to the stage of lactation a cow was in; the earlier the farmer knew a cow was pregnant, the smaller was the risk of culling. If a cow had not been inseminated at all, her risk of culling was 10 times higher than if she was inseminated once. If a cow was inseminated more than once, she had a slightly lower risk of being culled than a cow inseminated only once. The effect of parity decreased when pregnancy status and number of inseminations were added to the model, indicating that part of the parity effect was accounted for by reproductive performance. Including diseases in the model with pregnancy status and the number of inseminations did not change the effects of reproductive performance on culling. Mastitis, teat injuries and lameness had the greatest effect on culling (whether adjusted for reproductive performance or not), increasing the risk of culling, followed by anestrus, ovarian cysts and milk fever. In general, the effects of diseases decreased when reproductive performance was also accounted for in the model. When pregnancy status was included in the model, the effects of anestrus and ovarian cysts became slightly more protective, but when the number of inseminations was also considered, they became non-significant at the beginning of lactation and they increased the risk of culling at the end of lactation. Sensitivity analysis, which was run to evaluate the effects of our censoring mechanism on the results, indicated that the censoring times (i.e., the time of next calving) were not fully independent of the event (culling) times; the effects of the diseases and pregnancy status at the very end of the lactation changed slightly from the original model. 相似文献
7.
The aims of this follow-up study were: (a) to evaluate the role of ECT technology as a risk factor for several diseases; and (b) to determine if the effects of these diseases on cows' reproductive performance and as risk factors for culling are influenced by exposure to ECTs. Diseases considered were retained placenta, metritis, ketosis, cystic ovaries, silent heat, milk fever, clinical mastitis, and foot and leg problems. We used historical and contemporary controls (with control herds selected to match the experimental herds for size and location). Data consisted of 10264 Swedish Red and White (SRB) and 5461 Swedish Friesian (SLB) lactation records in 150 herds of which 33 used cow-trainers. Logistic regression was used to estimate the effects of parity and exposure to electric cow-trainers on the risks of diseases and the effects of diseases and exposure to electric cow-trainers on risk of culling. The least-squares procedure was used to estimate the effects of diseases on reproductive performance. The dominant effects associated with use of electric cow-trainers were an increased risk for silent heat, clinical mastitis, ketosis and culling relative to cows in herds not using cow-trainers. Diseases had negative effects on reproductive performance and the effects were larger for cows in herds using cow-trainers. In herds using electric cow-trainers, the largest increase in the interval from first service to conception (58 days) was caused by the occurrences of silent heat, cystic ovaries and the combination of two or more diseases. Retained placenta, metritis, cystic ovaries, clinical mastitis and a combination of two or more diseases increased the risk of culling about two times relative to healthy primiparous cows with the increase being greater for cows in herds using cow-trainers. Silent heat did not increase risk of culling in control groups, but was the largest risk factor for culling in the exposed group. We concluded that exposure to electric cow-trainers increased the incidence risk of silent heat, clinical mastitis, and ketosis and changed silent heat from a neutral disease with respect to culling to a major risk factor. Finally, exposure to cow-trainers increased the general negative effect of diseases on the cows' reproductive performance and risk for culling. 相似文献
8.
The study describes the profiles of culled cows in order to assess the possible contribution to economic losses due to health disorders. Data regarding dates of birth, final calving and culling, parity at culling, milk yield at the two first test-days of the final lactation and reason(s) for culling were collected in a 5-year survey, carried out from 1989 to 1994 in 84 commercial Holstein farms in western France. Polytomous logistic regression was used to assess the relationship between parity, calving-to-culling interval, milk yield and eight groups of primary culling reasons (i.e. udder disorders; infertility or reproductive disorders; lameness or foot/leg defects; emergency culling reasons; other health disorders; low milk yield; sales for dairy purpose; and other voluntary culling reasons). Out of a total of 5133 culled cows, the proportions of culls, for each of these groups of reasons, were 12.4, 28.4, 2.7, 3.9, 4.6, 16.7, 5.9, and 25.4%, respectively. Cows culled for udder disorders left the herd earlier in lactation and were more frequently at parities 4–6 than cows culled for voluntary reasons. In contrast, cows culled for infertility were younger and culled later within lactation. They were also higher yielding cows than those culled for other reasons. Cows culled for lameness were similar to those of the voluntarily culling group. Cows culled for emergency reasons were more frequently younger cows in early lactation. Cows culled for other health disorders left the herd early in lactation, but at a higher parity than the voluntarily culled cows. These results suggest that most of the culls related to health could be contributing to economic loss. However, special priority should be given to reduce culling for reproductive problems, which is the most costly exit reason. 相似文献
9.
The impact of ten diseases of dairy cattle on milk production, calving interval and culling were studied in a university operated dairy herd. Cows with clinical mastitis, ketosis or displaced abomasum had lowered milk production. Cows with metritis, retained placenta, cystic graafian follicles or ovarian hypofunction had longer calving intervals. Cows with clinical mastitis, metritis, pneumonia or retained placenta had increased risks of culling.The relationship between disease and culling was based on the medical history of culled and nonculled cows using a case control approach. Therefore, it is likely that in many cases, the association between disease and culling is due to the impact of that disease on productivity. 相似文献
10.
试验通过收集出生、产犊和离群的记录,探究宁夏地区荷斯坦牛成母牛的淘汰情况,分析影响该地区奶牛长寿性的因素。对15 523头荷斯坦牛的生产寿命、在群寿命和利用胎次进行描述性统计,分析淘汰时的胎次、季节和泌乳阶段的分布情况;计算生产寿命、在群寿命和利用胎次之间的表型相关,利用固定模型分析场-出生年、出生季节、牧场规模、淘汰原因和头胎产犊月龄对长寿性的影响。结果显示,宁夏地区荷斯坦牛的平均利用胎次为2.36胎,平均生产寿命为736.59 d。荷斯坦牛成母牛在产后第1个月内的淘汰风险最高,随着泌乳阶段的延长,成母牛在每个胎次内的淘汰风险均逐渐降低;随着淘汰胎次的增加,奶牛淘汰更加集中发生在产后泌乳早期;生产寿命、在群寿命和利用胎次之间存在较高的表型相关（均>0.9）,场-出生年、出生季节、牧场规模、淘汰原因和头胎产犊月龄对长寿性有显著影响（ P<0.05）,春季出生和22月龄头胎产犊的奶牛长寿性表现更好。本研究初步揭示了宁夏地区荷斯坦牛成母牛的淘汰规律和长寿性的影响因素,为宁夏地区牛群选育成母牛长寿性状奠定了基础。 相似文献
11.
试验通过收集出生、产犊和离群的记录,探究宁夏地区荷斯坦牛成母牛的淘汰情况,分析影响该地区奶牛长寿性的因素。对15523头荷斯坦牛的生产寿命、在群寿命和利用胎次进行描述性统计,分析淘汰时的胎次、季节和泌乳阶段的分布情况;计算生产寿命、在群寿命和利用胎次之间的表型相关,利用固定模型分析场-出生年、出生季节、牧场规模、淘汰原因和头胎产犊月龄对长寿性的影响。结果显示,宁夏地区荷斯坦牛的平均利用胎次为2.36胎,平均生产寿命为736.59 d。荷斯坦牛成母牛在产后第1个月内的淘汰风险最高,随着泌乳阶段的延长,成母牛在每个胎次内的淘汰风险均逐渐降低;随着淘汰胎次的增加,奶牛淘汰更加集中发生在产后泌乳早期;生产寿命、在群寿命和利用胎次之间存在较高的表型相关(均>0.9),场-出生年、出生季节、牧场规模、淘汰原因和头胎产犊月龄对长寿性有显著影响(P<0.05),春季出生和22月龄头胎产犊的奶牛长寿性表现更好。本研究初步揭示了宁夏地区荷斯坦牛成母牛的淘汰规律和长寿性的影响因素,为宁夏地区牛群选育成母牛长寿性状奠定了基础。 相似文献
12.
The levels of oestrone sulphate in plasma of pregnant cows was followed from 30 days of pregnancy until parturition. The Swedish Jersey Breed (SJB) showed significantly lower levels of oestrone sulphate between 101 and 200 days of pregnancy than either the Swedish Red and White (SRB) or the Swedish Lowland Breed (SLB). No significant difference was noted between SRB and SLB. On days 141-160 of gestation the oestrone sulphate values were still below the 10 nmol/l level for the SJB while they were above this level for the SRB and the SLB, and the difference was significant. In the SJB, levels above 10 nmol/l were reached on days 161-180 of gestation. In the second part of this study the levels of oestrone sulphate were measured around parturition in SRB cows. At parturition, the levels of oestrone sulphate rose to peak values of 79.9 +/- 5.2 nmol/l and then decreased to 6.6 +/- 0.5 nmol/l on the day after calving. In one cow peak values of 66.0 nmol/l were reached 2 days prior to parturition, and subsequently dropped to 7.0 nmol/l at parturition. This cow had retained foetal membranes. A possible relationship between low oestrone sulphate levels prior to parturition and retained foetal membranes is discussed. 相似文献
13.
Data from an observational study, carried out during a 4.5 year period (1986–1990), were used to quantify the effects of health disorders on the risk of culling. The study population consisted of 47 commercial Holstein dairy herds from western France, comprising 4123 cows. Logistic regression was used to assess the relationships between health disorders and early and late culling. Fourteen main health disorders with clinical signs and one subclinical disease were studied: abortion, periparturient accident, calving provided with assistance, digestive disorders, ketosis, locomotor disorders, mastitis, metritis, milk fever, cystic ovaries, respiratory disorders, retained placenta, teat injuries, non-traumatic udder disorders and status with respect to milk somatic cell count. Adjustments were made for year, month of calving, parity, breeding value for milk, best of the two first milk production records and reproductive performance. The possible effects of interactions among variables were also studied. The herd effect was taken into account using random effect models. Non-traumatic udder disorders, teat injuries, milk fever and the occurrence of both ketosis and assistance at calving were significantly associated with an increased risk of being early culled (odds ratios (OR) ranging from 1.6 to 10.3). Early and late abortion, late metritis, poor peproductive performance, retained placenta, non-traumatic udder disorders within 45 days post-partum and mastitis occurring in the first 3 months of the lactation were positively associated with a late culling (OR ranging from 1.2 to 6.6). Cows with lower breeding value for milk and higher parities were high risk groups for culling. A lower level of milk production and occurrence of both reproductive disorders and poor reproductive performance were risk factors for late culling. 相似文献
15.
The association between sole ulcer found at routine claw trimming 2–6 months after calving and reproductive, health and productive traits in the same lactation, was investigated in an observational study of 2368 dairy cows in 102 Swedish herds. The data were analysed by mixed multivariable linear-, logistic- and Poisson-regression modelling at the cow level, accounting for clustering within herd. Associations were found between sole ulcer and first-service conception risk in the first study year (OR 0.59), calving interval (2% longer), treatment for anoestrus (OR 1.61), and 305-day milk yield (479 kg ECM higher). No associations could be shown between sole ulcer and first-service conception risk in the second study year, the number of services per conception, clinical mastitis, high milk somatic-cell counts or culling. 相似文献
16.
The effects of calving intervals of 12 and 15 months on milk yield and milk composition were studied in 105 Swedish Red and White (SRB) and 46 Swedish Holstein (SLB) cows with 280 initiated lactations and 165 completed lactations (followed by another calving). The cows were divided into two groups, one early inseminated and the other late inseminated. The cows in the early group were inseminated at first oestrus 50 days after calving, aiming at a conventional 12-month calving interval, and the second group 140 days after calving, aiming at an extended calving interval of 15 months. Effects were studied by mixed-model analysis. Compared with the 12-month groups, total milk yield increased by 15-16% in the extended calving interval groups of both breeds, while fat, protein and lactose contents were slightly lower. The duration of lactation was 55-60 days longer in the 15-month than in the 12-month groups of both breeds. Given the possibility of a longer lactation, primiparous cows generally maintained their production longer than multiparous cows. SLB cows, especially those with a high peak yield, maintained their production longer than SRB cows. Average milk production per day within a calving interval tended to be slightly lower (2-5%) in both breeds when the interval was extended, owing to longer periods with low production and longer dry periods. 相似文献
17.
During 3 consecutive calving seasons, calving performance, placental characteristics and endocrine profiles of total 98 pregnancies of late pregnant Swedish Red and White (SRB) and Swedish Holstein (SLB) dairy heifers and cows, were investigated. Ninety-four singleton pregnancies and 4 sets of twins were recorded. In animals with singleton pregnancy, 8 stillbirths, 7 weak calves, 3 premature parturitions and 1 abortion were registered. In the SLB heifers, 19% of stillbirth (5/26) were observed, while 5% (2/42) were noted for the SRB heifers. One stillborn calf derived from the SRB cows and none was found from the SLB cows. In the heifers and cows delivering a normal living calf with unassisted parturition, the placentome thickness monitored by ultrasonography was constant towards the end of pregnancy. The numbers of foetal cotyledons varied individually between animals but in total, fewer cotyledons were found in the foetal membranes of the SRB animals than in the SLB animals (69 +/- 19) vs. (88 +/- 29) (p < 0.05). No morphological and numerical differences of the placentome thickness in animals delivering a stillborn or weak calf, compared to animals delivering a normal living calf, could be observed. In animals with unassisted parturition and without birth complications, the levels of progesterone (P4), PGF2alpha metabolite (PG-metabolite), cortisol, oestrone sulphate (E1SO4) and pregnancy associated glycoproteins (PAGs) were not different by breeds and parities. In animals carrying stillbirth, higher levels of E1SO4 were found in 3 SRB animals and 1 SLB heifer, whereas lower levels of E1SO4 were recorded in 3 SLB heifers during the last week of pregnancy, compared to the profiles found in animals with unassisted parturition. Additionally, the levels of PAGs remained low and constant in 1 SRB cow (delivering a stillborn calf), 1 SRB heifer (giving birth prematurely), 4 animals (carrying twins) and 1 aborting SRB cow. Our results show a very high rate of stillbirth in especially SLB heifers and deviating profiles of E1SO4 and PAGs in animals with impaired parturition were recorded. 相似文献
18.
The use of the calving index as a measure of herd fertility ignores the proportion of the herd that is culled, generally for failing to conceive. It is more important to consider the total cost of long calving intervals, high culling rate and even low pregnancy rates in an integrated index that reflects inefficient management, than to have to cope with balancing a number of separate physical indicators. In a study of 91 herds containing 14,524 cows a full range of physical indices was examined. The average herd calving interval was 380.3 days, with a culling rate of 23.1 per cent. Of the cows calving, 76.9 per cent recalved, a figure which when adjusted for the calving interval (CIA calving rate) became 73.8 per cent. In quartiles split on the basis of CIA calving rate, the top quartile achieved 82 per cent with a calving index of 375.2, and a culling rate of 16.7 per cent. These standards were achieved by serving 91.9 per cent of the cows after calving, at an interval to first service of 67.2 days. The submission rate for artificial insemination in the first 24 days after the earliest service date was 57.5 per cent and the overall pregnancy rate was 51.2 per cent. As a result 92.1 per cent of the cows served, and 85.3 per cent of those which calved, conceived again, with an average of 1.9 services per conception. Assessing fertility on a financial basis, with costs attributed to calving interval, culling rate and pregnancy rate to give a fertility index, the average herd was losing pounds 62/cow/year, compared with target levels.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
19.
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
20.
The effects of grazing during summer and possible interaction effects between breed and management system on milk production and postpartum reproductive performance were studied in 93 Swedish Red and White (SRB), Swedish Holstein (SLB) and Swedish Jersey (SJB) cows with 214 initiated lactations. The cows were divided into two groups: zero-grazing with tiestalls, or grazing during summer. Effects were studied by mixed-model analysis. The results indicated that grazing (rather than zero-grazing) can reduce the milk yield in the following lactation in SLB cows, whereas it had little effect on the production of SRB cows. Grazing SJB cows produced more milk, but with a significantly lower fat content. Grazing before or during the postpartum period stimulated reproductive performance, indicating a higher conception rate in all breeds and a 13-27-day shorter interval from calving to conception in the SRB and SLB cows, whereas in the limited number of SJB cows, the trend was the converse. 相似文献
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