Effect of restricting silage feeding prepartum on time of calving,dystocia and stillbirth in Holstein-Friesian cows

A study was carried out to investigate the effect of restricting silage feeding on time of calving and calving performance in Holstein-Friesian cows. In the treatment group (n = 1,248 cows, 12 herds) silage feeding commenced in the evening (17:00 to 20:00 h), after a period of restricted access (2 to 10 h) while in the control group ad-libitum access to silage was provided over the 24 h period (n = 1,193 cows, 12 herds). Daytime and nighttime calvings were defined as calvings occurring between the hours of 06:30 and 00:29 and between 00:30 and 06:29, respectively. Restricting access to silage resulted in less calvings at night compared to cows with ad-libitum access to silage (18 vs 22%, P < 0.05). Cows with restricted access to silage had a higher percentage of difficult calvings (11 vs 7%, P < 0.001) and stillbirths (7 vs 5%, P < 0.05) compared to cows in the control group. The percentage of calvings at night was lower (13%) when access to silage was restricted for 10 h compared to 2, 4 or 6 h (22, 18, 25%, respectively) (P < 0.001). Calf sire breed, calf gender or cow parity did not influence time of calving. In conclusion, offering silage to pregnant Holstein-Friesian cows in the evening, after a period of restricted access, reduced the incidence of nighttime calvings, but increased the incidence of dystocia and stillbirth.     

Disease frequencies in dairy cows in Sweden. II. Retained placenta

An epidemiologic study of retained placenta in dairy cows in Sweden covering 140 000 calvings is presented and various risk factors identified.

Swedish Friesian Breed (SLB) had a higher incidence than Swedish Red and White Breed (SRB). The incidence showed a linear increase with age, both when analysing the entire data set and when analysing the frequencies in cows negative for risk factors shown to increase the incidence of retained placenta, e.g., twinning, parturient paresis and dystocia. Male calves increased the risk. Loose-housed cows of both breeds had a lower incidence than tied zero-grazing cows, suggesting exercise to be a sparing factor. An increased recurrence risk ratio was found in second, third and fourth calvings for SRB and in second and third calvings for SLB.

SRB cows with a positive report of retained placenta had an increased risk of removal during the lactation. In dystocia and parturient paresis negative SLB cows, retained placenta increased the risk of removal, whereas a positive report of this disease in dystocia and/or parturient paresis positive cows did not further increase the risk removal.     

The Effect of Retained Placenta and Metritis Complex on Reproductive Performance in Dairy Cattle — A Case Control Study

A study of the computer stored records of 293 dairy cows and 652 calvings reveals the effects of retained placenta and metritis complex on reproductive performance. The overall incidence rate of retained placenta was 11.2%. Retained placenta was 4.6 times more likely to occur following twin births than following single births. Most cases of retained placenta occurred during the fall. Forty-five percent of that seasonal increase was explained by an increased number of calvings. Metritis complex was diagnosed following 54.8% of retained placenta cases. Retained placenta alone did not significantly impair reproductive performance. Metritis complex, in the presence or absence of retained placenta, caused a significant (P相似文献   

Incidence of Dystocia and Perinatal Calf Mortality Resulting from Reciprocal Crossing of Double-muscled and Normal Cattle

In order to study the incidence and causes of dystocia and perinatal calf mortality in double-muscled cattle, straight and reciprocal matings between double-muscled and normal cattle were made in three breeding seasons. A total of 348 matings resulted in 247 calvings in the four mating types. The frequency of normal calvings or calvings requiring slight assistance was higher among normal cows mated to double-muscled or normal bulls compared with that of double-muscled cows mated to double-muscled bulls (94% vs 78%, P < 0.05). In general the incidence of dystocia was higher among the double-muscled than the normal cows (19% vs 6%, P < 0.05). Calf birth weight, dam weight at calving, and condition score were not shown to contribute significantly to the differences in the frequencies of dystocia. A higher incidence of dystocia was found in the mating type which frequently gave rise to phenotypically muscular calves (DM × DM). The height, width, and area of pelvic opening were significantly smaller (P < 0.05) in the double-muscled than in the normal cows, indicating that the higher incidence of dystocia and perinatal mortality in double-muscled cattle can be attributed, at least partially, to the smaller area of pelvic opening in the double-muscled cattle.     

Disease frequencies in Swedish dairy cows. I. Dystocia

An epidemiologic study of dystocia incidence in Swedish dairy cows, covering approximately 140 000 calvings, is presented. Various risk factors were identified. The Swedish Friesian Breed (SLB) had a higher incidence than the Swedish Red and White Breed (SRB), and first calving number had a higher incidence than subsequent calving numbers. SLB heifers younger than 28 months when calving had a higher risk of dystocia than older heifers. SRB heifers younger than 26 months when calving had a higher risk than older heifers. An association between parturient paresis and dystocia was demonstrated. Male calves and twinning increased the risk. A reduced risk during pasture as opposed to housing for cows from tied herds was found, but no difference between incidence for cows in tied herds and cows in loose housing could be demonstrated. Previous history of dystocia increased the risk of recurrence in subsequent calvings and also the risk of being removed during lactation.     

Disease frequencies in dairy cows in Sweden. IV. ketosis

An epidemiologic study of ketosis in dairy cows in Sweden covering approximately 125 000 calvings in 1268 herds is presented and various risk factors identified.The Swedish Red and White breed (SRB) had a higher incidence of ketosis than the Swedish Friesian breed (SLB). A positive report of parturient paresis, alone or in combination with a positive report of retained placenta increased the risk of ketosis in SRB cows. Simultaneous reports of parturient paresis and retained placenta increased the risk of ketosis in SLB cows. Tied cows of both breeds with pasture had a decreased risk during the months of pasture. The incidence of ketosis decreased with herd size, and tied zero-grazing cows had a higher incidence than loose-housed cows.Cows reported positive once for ketosis had an increased risk in subsequent calvings but no increased risk of removal during lactation.     

Stillbirth parturition reduces milk production in Holstein cows

Stillbirth is defined as calf mortality shortly before, during, or shortly after parturition. Economic losses to the dairy industry in the U.S. just due to the loss of replacement heifers were estimated to be $125 million per year. Our objective in this study was to evaluate the effect of stillbirth on the dam's subsequent lactation. Data were collected from 20 farms in the U.S.A. (19 from NY, one from IN) from May 2005 until September 2006. Calving-ease scores (scale of 1-5; no problem and extreme difficulty, respectively) and stillbirths were recorded by farm personnel. We used 32,299 calvings for the final analysis where 6.5% of the calvings were stillbirths. The incidence of stillbirths for primiparous cows was 10.7% (of 11,891) and 4% (of 20,408) for multiparous cows. Stillbirth parturition significantly reduced milk production (-1.1 kg/day). The losses in milk production were evaluated in a generalized mixed linear model analysis. The daily milk production for cows with stillbirths was 34.2 kg, compared to 35.3 kg for the cows that had a live calf. Milk-production reduction was greatest early in lactation and declined afterwards. Economic losses from stillbirths include not just the lost calf, the reduced survival, and increased days open but also the decreased milk yield.     

Disease frequencies in dairy cows in Sweden. v. mastisis

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.     

Lifetime performances in Carora and Holstein cows in Venezuela

A study was conducted in the Central-western region of Venezuela to investigate the lifetime performances of 7918 Carora and 3501 Holstein cows under two different levels of management (low and high) and covering a period from 1961 to 1995. Traits analysed were: herd life, productive life, number of calvings, lifetime milk yield, days in lactation over all lactations and daily milk yield. In Carora cows born from 1961 to 1986 a decrease in herd life, productive life and number of calvings was observed, whereas cows born between 1971 and 1972 showed the lowest lifetime productive traits. Performances of Holstein cows born in the 1981–1986 period were analysed and all traits decreased during this time period. In low level herds, Holsteins remained longer (98.5 months vs. 83.3 in herd life; 69.5 vs. 54.3 months in productive life) and had higher lifetime yield (20 925 vs. 18 589 kg) than those in high level herds, but daily milk yield was lower (8.4 vs. 11.0 kg/day). All lifetime performances were higher for Carora cows under the high level management: 116.8 vs. 112.1 months of herd life, 81.8 vs. 77.1 months of productive life, 5.8 vs. 5.2 calvings, 1616 vs. 1299 days of lactation, 16 194 vs. 11 912 kg of milk over all lactations and 6.5 vs. 4.6 kg milk/day. Survival estimates for year of birth were more variable in Holsteins than in Carora cows. Management influenced survival in Holsteins only, the low level showing higher values.     

Prostaglandin treatment and subsequent cystic ovarian disease in Holstein cows

Using computerized herd health data, a prospective cohort study was devised to determine whether cows treated with prostaglandins had a higher incidence of cystic ovarian disease than comparable cows not treated. Of 744 cows selected as having diseases for which prostaglandin administration may be indicated, 240 received prostaglandin. Sixteen cows had cystic ovarian disease following prostaglandin administration. Chi-square analysis showed no association (P greater than 0.10) between cystic ovarian disease and the use of prostaglandin. Incidence of cystic ovarian disease within 150 days of calving in clinically normal cows was compared with that of cows with reproductive disorders. Cows with reproductive disorders had a significantly (P less than 0.01) higher incidence of cystic ovarian disease.     

Disease incidence in dairy herds in the southern highlands district of New South Wales, Australia

The purpose of this study was to determine clinical disease incidence in eight non-seasonally calving, pasture-fed dairy herds in the southern highlands district of New South Wales. This was a longitudinal population study. The study included all cows that calved between January 1994 and December 1995 and consisted of 2111 lactation records from 1430 cows. The incidence of the more common diseases were: calving-associated disorders, 18.0 cases per 100 calvings (95% CI 16.4-19.8 cases per 100 calvings); metabolic disorders, 5.5 cases per 100 cow-yr at risk (95% CI 4.5-6.6 cases per 100 cow-yr at risk); reproductive-tract disorders, 22.3 cases per 100 cow-yr at risk (95% CI 19.2-25.8 cases per 100 cow-yr at risk); udder disorders, 17.6 cases per 100 cow-yr at risk (95% CI 15.9-19.5 cow-yr at risk) and lameness, 3.7 cases per 100 cow-yr at risk (95% CI 2.9-4.7 cow-yr at risk). In agreement with dairy-cow disease-incidence studies conducted elsewhere, disorders of the reproductive-tract and udder were the most frequent clinical conditions encountered. These findings confirm that dairy herd-health programs should emphasise the control of these two groups of disorders.     

奶牛卵巢囊肿分布调查及形成原因分析

为了探讨北京市规模化奶牛场奶牛卵巢囊肿的发病情况、致病因素及形成机制,本研究采用直肠检查及B超诊断,结合奶牛的胎次、分娩季节及血清生化指标、激素水平等分析了奶牛卵巢囊肿的分布情况、影响因素及形成原因。结果表明,卵巢囊肿在所试奶牛场的发病率为10.73%,不同胎次奶牛卵巢囊肿发病率不同;在所有卵巢囊肿奶牛中,夏季分娩奶牛（51.06%）明显高于春季（8.51%）和冬季（17.02%）;胰岛素、胰岛素样生长因子1（IGF-1）及雌二醇（E₂）等与奶牛卵巢囊肿的发生密切相关,其中患有卵巢囊肿奶牛血清胰岛素和IGF-1的平均浓度均显著低于正常奶牛血清值（P < 0.05）,而血清E₂的平均浓度却显著高于正常奶牛血清值（P < 0.05）。该研究结果为奶牛场奶牛卵巢囊肿的预防和治疗提供了可靠的依据。     

Investigation on the Distribution and Analysis on Formation Cause of Cystic Ovarian Disease in Dairy Cows

In order to explore the incidence,pathogenic factors and the formation mechanism of cystic ovarian disease (COD) in Beijing scale dairy farm,we used the rectal examination and ultrasound diagnosis,combined with the dairy parity,calving season and serum biochemical indices and hormone levels to investigate the distribution,influencing factors and formation cause of cow ovarian cysts.The results showed that the incidence of cystic ovarian disease (COD) was 10.73% in the testing dairy herds and the incidence of COD was associated with the parities.The incidence rate of ovarian cyst in the cows calving in the summer (51.06%) was higher than those calving in the spring (8.51%) and winter (17.02%).Insulin,IGF-1 and E₂ were closely related with the formation of the cow ovarian cyst.The average concentrations of serum insulin and IGF-1 in cows with ovarian cysts were significantly lower than those of normal cows(P < 0.05),but the average concentration of serum E₂ was significantly higher than that of normal cows(P < 0.05).This study provided reliable basis for the prevention and treatment of cow ovarian cyst.     

Involvement of Plasma Progesterone, Oestradiol-17β and Cortisol in Ovulatory Response to Gonadotropin-releasing Hormone in Dairy Cows with Cystic Follicles

The aim of the present study was to examine the plasma concentrations of progesterone, oestradiol-17beta and cortisol in the cows with cystic follicle and to examine its relationship with the ovulatory response to gonadotropin-releasing hormone (GnRH). Eighty-five post-partum Holstein-Friesian cows with cystic follicles regardless of the presence of corpus luteum were studied. Follicular size, presence of corpus luteum and occurrence of ovulation were checked by palpation per rectum. Blood collection and palpation per rectum were conducted on days 0, 7 and 14. Gonadotropin-releasing hormone was administered at day 7. Plasma concentrations of progesterone, oestradiol-17beta and cortisol were determined. Progesterone concentrations of <3.2, 3.2-4.8 and >4.8 nmol/l were defined as low, intermediate and high, respectively. Sixty-three (74.1%) of 85 cows showed low (<3.2 nmol/l =1 ng/ml) progesterone concentrations on day 0. Only 40 (47.1%) of them showed low-low pattern of progesterone at days 0 and 7. In 27 (31.8%) of them, progesterone concentration had increased by day 14. Of 22 cows having high progesterone concentration (>/=4.8 nmol/l) on day 0, corpus luteum was not detected in 18 cows (21.2%). Only in 10 cows, cystic follicle disappeared after GnRH administration. However, only one of 27 cows in which progesterone pattern was low-low-high at days 0, 7 and 14 experienced ovulation of the cystic follicle. Significantly lower oestradiol-17beta concentration was found on day 7 in cows showing a low-low-low pattern than a low-low-high pattern of progesterone (43.0 +/- 4.6 vs 55.8 +/- 2.8 pmol/l, p < 0.05). There was no significant difference in cortisol concentration on any days (days 0, 7 and 14) between cows showing a low-low-low and low-low-high pattern of progesterone. These results suggest that approximately one-fifth of cows diagnosed to have ovarian cysts possess luteal cysts and that a high oestradiol-17beta concentration at the time of GnRH administration is involved in the subsequent ovulation of the follicle, although ovulated follicle may not be cystic.     

Turnover of Dominant Follicles prior to First Ovulation and Subsequent Fertility in Postpartum Dairy Cows

Contents: The ovaries of 64 multiparous Holstein cows were scanned twice weekly by ultrasonographyfrom Day 6 postpartum until 60 days or return to normal estrous cycle, and turnover of dominant follicles in relation to subsequent fertility were determined. The mean (SD) number of days from parturition to detection of the first postpartum dominant follicle (10 mm) was 9.0 0.5, which was predominantly located in the ovary contralateral to previous pregnancy in 54/64 cows. The first postpartum dominant follicle ovulated in 34 cows, failed to ovulate in 18, became cystic in 10, and only 2 were diagnosed as ovarian quiescent which delayed the detection of dominant follicles until days 25 and 30 postpartum. Number of dominant follicles in cows with anovulated first dominant follicle was 2.8. 1.1 prior to first ovulation (range 2–5). Growth and regression of cystic follicles were observed 24 times in 6110 cows, and a total of 20 cystic follicles persisted 32.7 9.0 days (range 18–58 days) except one which persisted for 124 days. Conception rate was 89.5% and postpartum interval to conception within 180 d after calving was 96.7 days in cows detected with less than 3 dominant follicles before first ovulation compared with those of 42.9% and 141 days in cows detected with more than 4 dominant follicles. It is concluded that the number of dominant follicles detected prior to first ovulation varied from I to 5, which positively correlated with ovulation intervals, while only those cows which first ovulated less than 3 dominant follicles resulted in reasonable reproductive performance.     

Effect of various degrees of dystocia in dairy cattle on calf viability, milk production, fertility and culling

The objective of this study was to analyse the effect of dystocia on calf viability, milk production, fertility and culling under field (farm) conditions in a retrospective case-control study. A total of 253 calvings that were attended by a veterinarian were classified into three categories: mild dystocia (MD), severe dystocia (SD) and caesarean section (CS). For every case of dystocia, a control was chosen from the same farm and matched for calving month, breed and parity. Cases and controls were compared concerning calf viability, milk production, fertility and culling. The proportion of stillbirths was significantly higher in cows with dystocia compared with their controls. However, the difference was lower in CS cows than in the other two groups. MD had no significant effects on milk production, fertility and culling. There were no obvious effects of SD on monthly test day milk production, while CS cows produced significantly less milk than their controls. Compared with controls, less SD (50.0% versus 61.6%) and CS cows (48.6% versus 70.3%) conceived until 200 days in milk and more CS cows (31.1% versus 16.2%) were culled in the same time interval. These data demonstrate the scope of economic and animal welfare opportunities associated with the reduction of dystocia by management and breeding.     

Incidence of infertility in dairy cows

The incidence of anoestrus, suboestrus, delayed ovulation, cystic ovaries, repeat breeder cows, endometritis and other forms of infertility was studied in 283 herds over a period of eight years (2,304 cases). The total incidence of infertility (0.111 cases per cow per year) varied significantly from year to year. The peak of the seasonal variation occurred in December-April and did not correspond with the seasonal variation in calving. Both the size of herd and the type of housing affected the incidence of infertility, but the differences were great in respect of the various diagnoses. The incidence of ketosis by herd correlated significantly with the incidence of infertility by herd.     

Environmental and managerial determinants of somatic cell counts and clinical mastitis incidence in Ohio dairy herds

A stratified-random sample of 48 Ohio dairy herds participated in a 1-year disease monitoring survey to study herd management and environmental conditions affecting udder infection and clinical mastitis incidence. The mean monthly bulk-tank somatic cell count was used as an indicator of overall udder infection. Clinical incidence was determined by monthly on-farm interviews with the dairy producers. Management and environmental conditions were assessed by direct observation as well as by personal interview of dairy managers. The final multivariable analysis-of-variance model of log bulk-tank somatic cell count had an R² value of 0.43. Lower log bulk-tank somatic cell count was found in herds with hired milkers, a clean and dry cow exercise area, clean teats following milking and fewer milking cows. The number of months spent on pasture was also significant. The final model for clinical mastitis incidence had an R² value of 0.38. Less clinical mastitis was found on farms where straw bedding was used, pre-dip was not used, where there were fewer cows, fewer person-hours per cow were spent milking cows, a greater percentage of calvings occurred in the designated calving facility, and cows spent fewer months per year on pasture. Other potentially important disease determinants could not be included in the final models because of limited sample size relative to the model degrees of freedom (six each).     

Demographic dynamics and off-take of cattle herds in southern Mali

The herds of 95 families were monitored for 1 year in eight villages in the cotton-growing region of southern Mali. In 2006–2007, reproduction performances were average, with 0.54 calvings/year per cow, and mortality was low. Herd numerical productivity is not very high, less than 0.13/year, because of the high proportion of males kept for animal draught. Depending on the herd size, the behaviour of the families differs, in terms of off-take and in-take of animals. Families that only have one or two draught animals seek to increase their animal draught capacity, with a negative net off-take (−0.13/year). Families with two to three cows have a very low net off-take (0.02/year), with culling of adult animals compensated by purchase. They therefore capitalised this year, with an annual herd growth of 8%. Families with a very large herd (20 to 50 cows) take off more of their stock, with a net off-take of 0.08/year (very few animal purchases) and make a stock growth of 5%. And finally, families with an average-sized herd (6 to 19 cows) take off the whole of the year’s production, with a net off-take of 0.11/year and a nil stock growth rate. The use of a demographic model made it possible to measure the sensitivity of the productivity rate to the different demographic parameters.