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.     

Effects of diets fed to dairy cows before and after calving on their plasma progesterone profiles after calving

Four weeks before their predicted mean second lactation calving date, 60 spring-calving Holstein-Friesian cows were blocked into groups of six on the basis of their predicted calving date and body condition score, and allocated at random to one of six dietary treatments in a factorial design: ad libitum grass silage, ad libitum grass silage plus barley straw or ad libitum grass silage plus 3 kg of concentrates, was offered for four weeks before the expected calving date, and after calving they were offered either 4 kg or 8 kg of concentrates plus ad libitum grass silage for eight weeks. On average, the first luteal activity occurred in all the groups at 29 days after calving. Seventeen of the cows had an atypical first plasma progesterone profile; 12 were anovulatory, three had prolonged luteal phases and two became anovulatory after having been cyclic. The cows offered grass silage only before calving had a significantly shorter mean (se) interval between calving and second luteal activity (44.9 [2.1] days), than the cows offered grass silage and straw (53.5 [1.9] days) or grass silage and concentrates (51.5 [3.2] days) (P<0.05). After calving none of the 28 cows offered grass silage and 4 kg of concentrates started cycling before day 21, whereas five of the 30 cows offered grass silage and 8 kg of concentrates cycled before day 21 (P<0.05).     

Importance of herd management in loose housing systems in the social behavior of dairy cows

In five loose housed dairy herds three different kinds of herd management were tested in two variants with respect to frequencies of agonistic social behaviour. Treatments were (1) a short (0.5 h) and a long (3 h) fixation time in the feeding rack, (2) single and group (3 animals) introduction of new heifers into the herd and (3) an open and a closed outdoor yard during nighttime. The investigated agonistic behaviour patterns were: pushing and chasing. The herds were observed in the evening after milking during one four-hour period starting one hour after opening the feeding rack when testing treatment (3) and immediately after opening the feeding rack when testing treatment (1) and (2). Statistical analysis were carried out with the Wilcoxon signed-ranks test for matched samples. Effects of fixation time differed inconsistently and were not significant. In 3 out of 5 farms the frequency of agonistic behaviour was lower, when cows were restrained 3 h in the feeding rack compared to 0.5 h. In two of these 3 herds, the animals had the possibility to drink water from bowls directly at the feeding rack, in the third herd the food was silage which has a higher water content. Therefore in these herds, the agonistic interactions at the drinking facility in the stable after opening the feeding rack was low. Contrary, in the two other herds, with dry feed (hay) and no drinking bowls at the feeding rack, frequency of agonistic behaviour was higher after the long restraint which might be due to higher competition at the drinking facilities. Agonistic interactions per cow as well as per new introduced heifer were lower (p < or = 0.05) when only a single heifer was introduced to the herd compared to the introduction of a group of 3 heifers. The frequency of agonistic social behaviour of horned dairy cows that had access to a yard at night was significantly lower compared to the situation when the yard was closed over night (p < or = 0.05). This may be due to the higher space allowances per cow but also to the additional structuring of the locomotion area.     

Some effects of feeding pasture silage as a supplement to pasture on reproductive performance in lactating dairy cows

Supplementation of a ryegrass/white clover pasture diet with pasture silage is a common management practice in New Zealand dairy herds. The effect of this supplementation on reproductive performance has not been investigated. Five herds of 20 cows were formed before calving commenced on 1 June 1992. From 5 August to 4 September, two of these herds were fed 5 kg/cow/day of pasture silage in addition to the ryegrass/white clover pasture offered to all herds. Pasture silage supplementation did not alter the intervals from calving to first ovulation, first oestrus, or to conception. However, it reduced the first service conception rate (37.5% v. 53.3%; difference +/- sed = 15.8 +/- 10.0%, for pasture and silage and pasture only cows, respectively). A positive effect on reproductive performance of pasture silage supplementation was not demonstrated in this trial.     

Changes in the feed intake, pH and osmolality of rumen fluid, and the position of the abomasum of eight dairy cows during a diet-induced left displacement of the abomasum

During the last six weeks of the dry period, eight Holstein-Friesian cows were fed a restricted amount of grass silage; after calving, a mixture of maize silage and concentrates was offered in a feeding regimen designed to induce a displacement of the abomasum. In the first month after calving, the cows were monitored for the following variables: feed intake and composition, milk production, the position of the abomasum, and the pH and osmolality of the rumen contents. In five of the eight cows, a left displacement of the abomasum occurred between four and 21 days after calving in the absence of other diseases. The displacement was temporary, lasting between five and 36 consecutive hours and one or two days in two of the cows (floaters), and for three or more days in the other three. Before these three cows developed the displacement, their abomasum was 4.3 to 7.9 cm higher, its contents had a higher mean osmolality (+19.2 mosmol/kg), and the ratio of roughage to concentrates in their feed was lower (-0.87) than in the three cows that did not develop clinical signs of a displaced abomasum. There were no significant differences in these variables between the floaters and the healthy cows.     

Restricting access time at pasture and time of grazing allocation for Holstein dairy cows: Ingestive behaviour,dry matter intake and milk production

The objective of this study was to assess the effects of restricting access time to pasture and time of grazing allocation on grazing behaviour, daily dry matter intake (DMI), rumen fermentation, milk production and composition in dairy cows. Twenty-one autumn-calving Holstein cows were assigned to one of the following 3 treatments: providing access to a daily strip of pasture for either 8 h between 07:00 and 15:00 h (T7–15), 4 h between 07:00 and 11:00 h (T7–11), or 4 h between 11:00 and 15:00 h (T11–15). The experimental period consisted of 3 weeks of adaptation and 6 weeks of measurements. Cows were offered a daily herbage allowance of 18 kg DM/cow to ground level, 6.1 kg DM/day of a ground sorghum grain-based supplement and 5.2 kg DM/day of maize silage. Milk yield was greater for cows with 8 h access time to the pasture (25.4 vs. 24.1 for 8 and 4 h access time, respectively). Milk yield was not different between cows that access early (T7–11) or late (T11–15) to the grazing session. Milk protein yield was greater for cows with 8 h access time (0.75 kg/d) vs. 4 h access time treatments (0.72 kg/d). Cows with late access time to grazing in the morning produce more protein (0.74 kg/d) than cows with early access to the pasture (0.70 kg/d). Duration of access had a significant effect on herbage DMI (8.3 vs. 6.6 kg/d, for 8 and 4 h access, respectively), but there was no significant effect of time of grazing allocation. Intakes of concentrate and maize silage DM did not differ between treatments.     

The incidence of cystic ovaries in dairy cattle housed in a total confinement system.

The incidence of cystic ovaries following 1830 calvings of 1061 dairy cows maintained in total confinement was evaluated. The overall incidence was 14% of lactations and 22% of cows during a three year period. Fewer primiparous than multiparous cows became cystic, 5.7% vs 18%, respectively. There was an unexplained higher incidence (18%) among calvings in 1979 than in 1980 (12%) and 1981 (13%). There were no effects due to season of calving or genetic line of cow. During the last year of the study milk production by cystic cows was significantly greater than that by non-cystic cows.     

Effect of intrauterine antibiotic treatment on reproductive performance of dairy cows following periparturient disease

AIMS: To quantify the effect of treating lactating dairy cows that had histories of periparturient disorders or disease with a single intrauterine infusion of 0.5 g cephapirin, 3-6 weeks prior to the start of the seasonal breeding period. METHODS: Cows (n=690) from spring-calving dairy herds (n=22) were enrolled in a prospective case-control study if they had a history of dystocia, a dead calf at calving or within 24 h of calving, retained foetal membranes (RFM), metabolic disease, twins or a vulval discharge 13 days postpartum. Cows were blocked by age, periparturient condition and calving date, and randomly assigned to be either treated with 0.5 g of cephapirin by intrauterine infusion, or left as untreated controls. Treatment occurred 24-42 days before the planned start of mating (PSM) within each herd. In addition, the reproductive tracts of 91 cows from 4 herds were examined using a vaginal speculum and rectal palpation and cervical-os discharge was scored on a scale from 0 (nil) to 3 (purulent). RESULTS: Overall, more treated cows were retained in the trial herds until pregnancy testing than control cows (p0.05). Average 28-day submission rate was higher (93.1% vs 87.1%; p0.05) and PSM-to-first-service interval was shorter (9+/-1 vs 11+/-1 days; p0.05) in treated than control cows. The percentage of cows not pregnant at the end of the mating period was not affected by treatment overall. However, amongst cows diagnosed with RFM, a dead calf, or vulval discharge, pregnancy rates 28 and 56 days after PSM were higher for treated than control cows (p0.05). Cows with a purulent cervical-os discharge had lower 28-day submission rates (p0.01), lower 28-day pregnancy rates (p0.05) and higher non-pregnant rates at the end of mating than cows with nil or mucoid cervical-os discharges. CONCLUSIONS: Intrauterine treatment with 0.5 g cephapirin improved reproductive performance of dairy cattle, especially those that had a history of RFM, a calf dead at calving or within 24 h of calving, or a vulval discharge.     

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.     

Management of calving in Norwegian cubicle-housed dairy herds.

Sixty of the 65 dairy farms with cubicle houses in the Norwegian county of Oppland were included in a field study of the management of calving in 1990. The farmers recorded the location of the cow when giving birth, farmer presence and whether assistance was given during calving, occurrence of suckling, and time after birth when cow and calf were separated. Such data were recorded for a total of 1125 calvings. About 10% occurred on pasture, while 78% of the remaining calvings took place in the cubicle-equipped section. Thirteen percent calved in a calving pen, the remaining cows being tethered at the time of calving. Thirty-two percent of the calvings took place in houses lacking a calving pen altogether. Farmers were present during 41% of the calvings. Suckling most frequently occurred after pasture calvings, and was least frequent after calvings within the cubicle-equipped section of the cowhouse. Injuries to the calf caused by trampling or contact with fittings etc. were rare, and no more common in association with calving in the cubicle-equipped section than with calving taking place with the cow isolated from the rest of the herd. All calves were removed from their dams within 24 h after birth.     

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.     

Effects of periparturient events on subsequent culling and fertility in eight UK dairy herds

The occurrence of five periparturient events and their effects on subsequent culling and fertility was recorded in eight herds in the UK. Combining data from all 2105 calvings, the proportion affected by assisted calving, dead calf, retained fetal membranes (RFM), milk fever or twins was 5.9, 8.2, 5.3, 5.0 or 3.3 per cent, respectively. Compared with unaffected herdmates, cows with an assisted calving or a dead calf had higher early (but not late) culling rates, (assisted calving: 8.8 per cent being culled before 100 days after calving compared with 5.7 per cent; P=0.05; dead calf: 12.2 per cent culled compared with 5.3 per cent; P=0.001). Compared with unaffected animals, cows with milk fever were four times more likely to be culled before 100 days after calving (16.2 per cent compared with 5.3 per cent; P=0.001), whereas those with RFM were twice as likely to be culled between 100 and 200 days (14.3 per cent compared with 7.6 per cent; P=0.003), and both groups were twice as likely to not be pregnant by 200 days. Cows with RFM or milk fever also had markedly reduced subsequent fertility: both conditions extended calving to pregnancy intervals (by 20 days; P=0.001, or by 13 days; P=0.03, respectively), lowered 100-day in-calf rates (by 24.5 per cent; P=0.001, or by 17.8 per cent; P=0.008, respectively) and lowered 200-day in-calf rates (by 20 per cent; P=0.001, or by 15 per cent; P=0.002, respectively). The birth of twins had no effect on subsequent culling or fertility.     

Management practices associated with udder health of first-parity dairy cows in early lactation

This study aimed at investigating associations between management routines including feeding, housing, and milking around calving, and udder health of first-parity cows in early lactation in Swedish large, high producing, low bulk-milk somatic cell count (SCC) dairy herds housed in free stalls. Seventy-two dairy herds participated and data concerning 1189 first-parity cows calving during the study period (October 2005-January 2006) was collected. Multivariable regression analysis were performed with three different outcomes; within-herd number of first-parity cows veterinary treated for clinical mastitis at days -10 to 60 after calving, within-herd number of first-parity cows with a SCC> or =200,000cells/mL at first test-day, and SCC of first-parity cows at first test-day. Cow factors significantly associated with good udder health of first-parity cows (few cases of clinical mastitis and or low SCC) were being of the Swedish Red breed, having a high milk yield at first test-day, and a milk-urea > or =5mmol/L at first test-day. Herd factors significantly associated with good udder health were having mattresses as flooring in the cubicles in the lactating cow housing, and to house the first-parity cows in tie stalls 1 month before calving. Cow factors significantly associated with poor udder health of first-parity cows were having a milk-urea <4mmol/L at first test-day. Herd factors significantly associated with poor udder health of first-parity cows were feeding first-parity cows sugar-beet pulp or corn silage, and to give silage from a different batch to pregnant heifers than to lactating cows. Moreover, to have sawdust or shavings in the calving pen, to be moved from the calving pen > or =2 days after calving, to milk first-parity cows at the calving site instead of in the parlor, and to rinse, clean or disinfect milking units before a first-parity cow was milked were also significantly associated with poor udder health of first-parity cows. The results indicate that different control measures must be taken depending on the nature of the udder health problem.     

Frequency of ovarian follicular cysts, reasons for culling, and fertility in Holstein-Friesian cows given gonadotropin-releasing hormone at two weeks after parturition.

Holstein-Friesian cows (n=204) were given saline solution or 200 microgram of gonadotropin-releasing hormone (GnRH) by intramuscular injection at 8 to 23 days after parturition. Of cows culled, fewer GnRH-treated cows were culled for infertility, compared with number of cows given saline solution (26 vs 57%; P less than 0.05). Frequency of ovarian follicular cysts was reduced from 15.2% in controls to 5.7% for cows given GnRH (P less than 0.01). The interval to 1st insemination, interval to conception, and inseminations per conception did not differ among saline solution or GnRH-treated cows which remained in the herds. These data provide evidence for reduction in infertility and reproductive disorders in early postpartum dairy cows given GnRH as a prophylactic.     

Effect of twin birth calvings on milk production, reproductive performance, and survival of lactating cows

OBJECTIVE: To evaluate effect of twin birth calvings on milk production, reproductive performance, and survival of lactating cows. DESIGN: Retrospective observational cohort study. ANIMALS: 33,868 cows from 20 farms. PROCEDURES: Data on age at calving for primiparous cows and mature equivalent milk yield for multiparous cows, assistance at calving, stillbirths, twin births, gestation duration, pregnancy at the end of the data collection period, and culling-death for all cows were extracted from farm computer records and used for statistical analysis. RESULTS: Prevalence of twin parturitions was 1.3% (159/12,050) and 6.5% (1,410/21,818) for primiparous and multiparous cows, respectively. Primiparous and multiparous cows with singletons produced more milk than cows with live twins or at least 1 dead twin (primiparous, 33.1 vs 31.9 vs 31.2; multiparous, 36.5 vs 35.7 vs 35.0). Multiparous cows with dead twins produced less milk than cows with live twins. Compared with dams with singleton birth, cows with twins were 0.78 times as likely to conceive and 1.42 times as likely to die or be culled. Cows with dead twins also had increased time to conception, compared with live twins. CONCLUSIONS AND CLINICAL RELEVANCE: Twin birth was associated with decreased survival, milk production, and reproductive performance. Having at least 1 dead twin was even more detrimental than having live twins and resulted in decreased milk production and reproductive performance of lactating cows.     

Influence of sward height, daily timing of concentrate supplementation, and restricted time for grazing on forage utilization by lactating beef cows

To establish the effect of sward height, concentrate feeding time, and restricted time for grazing on forage utilization by grazing cattle, 32 crossbred beef (24 Angus and eight Hereford) cows (632 kg BW) and calves (104 kg BW) were grouped by weight and calving date. They were assigned randomly to two sward height treatments (4 to 8 or 8 to 12 cm), replicated four times. The herbage comprised mainly Kentucky bluegrass, orchardgrass, some forbs, and white clover. The cows were restricted to 12 h/d grazing (0700 to 1900) or unrestricted to 24 h/d grazing and fed a concentrate supplement (4.1 kg DM.cow(-1).d(-1), approximately 0.65% of BW or 33% of total DMI) either at 0700 or 1800. The experiment was repeated over three 15-d periods in May, June/July, and August 2000. The herbage on high sward height pasture was higher (P = 0.06) in NDF and ADF and lower (P < 0.01) in CP than low sward height herbage. For cows restricted to 12 h/d grazing, supplementing at 0700 as opposed 1800 resulted in greater (P = 0.04) forage DMI (8.6 vs. 8.1 kg/d), whereas cows that were unrestricted showed little change (8.2 kg/d at 0700 vs. 8.4 kg/d at 1800). Supplementing at 1800 as opposed to 0700 resulted in greater (P = 0.03) herbage DM digestibility (67.7 vs. 64.5%) for cows on high sward height, whereas cows on low sward height exhibited minimal differences (65.4% at 1800 vs. 66.3% at 0700). Cows restricted to 12 h/d grazing and supplemented at 0700 as opposed to 1800 resulted in greater (P = 0.06) digestible DMI (5.0 vs. 4.7 kg/d), whereas unrestricted cows exhibited the opposite response (4.6 kg/d digestible DMI at 0700 vs. 4.9 kg/d at 1800). Supplementing at 1800 as opposed to 0700 increased the time spent grazing to a greater (P = 0.09) extent for restricted than for unrestricted cows. When forage availability or grazing time was limiting (due to a low forage allowance and restricted access to forage, respectively) supplementing concentrates at 0700 resulted in greater forage utilization and intake rate because of increased forage DMI, DM digestibility, and digestible DMI. However, when forage or grazing time was not limiting, supplementing concentrates at 1800 resulted in greater forage utilization because of increased forage DM digestibility.     

Reproductive efficiency and calf survival in Ontario beef cow-calf herds: a cross-sectional mail survey.

A survey of the efficiency of production of Ontario beef cow-calf herds was conducted using a stratified systematic random sample of Ontario producers. In general, about 87% of females exposed to breeding produced a live calf and 6% of these died before reaching four weeks of age. The herd to herd variation in these rates was quite large, the coefficient of variation being about 17%. The stillbirth rate was 1.7% and the abortion rate 1.2%. In general, herds in northern Ontario and herds whose owners kept breeding and calving records, had reduced livebirth rates, the latter probably reflecting accuracy of data. Herds with a restricted (less than three months) breeding season had increased livebirth rates. Herds using injectable vitamins ADE, and prophylactic antibiotics, had increased neonatal losses. Herds with a restricted calving season (less than or equal to 3 months) and/or feeding free choice salt to cows had decreased neonatal losses. Herdsize and calf mortality rate were directly related, but this did not appear to be due to increased density of cows at calving time. In herds, where calving occurred during the spring, using scour vaccines in calves was associated with increased calf mortality.     

Effects of breeding season length and calving season on range beef cow productivity

A 5-yr study was conducted beginning in 1983 with 460 cows to evaluate the effects of three breeding seasons (30, 45, and 70 d in length) and two times of spring calving, March (early) and April (late), on cattle production under Nebraska Sandhills range conditions. Criteria evaluated included pregnancy and weaning percentages, calving date and distribution, cow weights and body condition at four intervals, calf birth and weaning weights, and cow productivity. The 30-d breeding season included a 10-d estrus synchronization and AI period; in the other breeding seasons only natural breeding was used. The same sires were used over the entire study period. Percentage of cows pregnant and percentage of calves weaned were lower (P less than .01) for cows bred for 30 d than for cows bred for 45 or 70 d. Average calving dates were similar among the breeding groups within the early and late calving herds. Pregnancy rates from AI were higher (P less than .01) for the cows calving in April (64%) than for the cows calving in March (41%). Cows calving in April lost less weight between precalving and prebreeding and were heavier (P less than .05) at prebreeding time than the cows calving in March. Calf weaning weights were not different (P greater than .10) among any of the breeding season groups or between the two calving herds when calves were weaned at a similar age. Cow productivity (calf weaning weight per breeding female) was highest (P less than .05) for the cows bred for 70 d (186 kg), intermediate for the cows bred for 45 d (172 kg), and lowest for cows bred for 30 d (162 kg).(ABSTRACT TRUNCATED AT 250 WORDS)     

Size and management effects on reproduction in first-, second- and third-parity beef cows

The effects of size, management and size x management interactions on reproduction in beef cattle were determined by using 3,126 breeding and calving records from 1980 to 1985. Cows were from three synthetic lines that differed in mature size (small, medium and large). The lines differed also in the percentages of Jersey, Angus and Simmental. Each line was replicated in two herds. One herd (Rhodes) followed a spring calving schedule and weaned calves at about 180 d of age. The other herd (McNay) calved cows in the fall and weaned calves early at about 45 d of age. Cycling rate, conception rate, abortion rate and calving rate were each evaluated for first-, second- and third-parity dams. An important interaction (P less than .05) was found between lines and management in heifers. Cycling rate and calving percentage were almost identical for all three lines in the Rhodes herd, but small heifers in the McNay herd had about 20% higher cycling (83.8 vs 63.1%) and calving rates (73.8 vs 53.0%) than large heifers. Line x management interactions were not significant in second- and third-parity dams, but line did remain a significant source of variation in calving rate. Calving rates in second-parity dams were 85.0, 78.1 and 70.7% for small, medium and large cows, respectively. In third-parity dams, small cows had a higher calving rate (P less than .05) than either medium or large cows (80.9 vs 66.1 or 68.7%, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of restricted suckling on milk yield,composition and flow,udder health,and postpartum anoestrus in grazing Holstein cows

The effect of restricted suckling on milk yield and composition, udder health, and postpartum anoestrus in dairy cows in pasture-based systems, was studied in 32 Holstein multiparous cows and their calves. At calving, each cow–calf pair was randomly assigned to one of two treatments: restricted suckling (RS) of the cows by her own or another calf, twice daily for 30 min or artificial rearing (AR) of the calves with milk obtained from the bulk tank, offered twice a day in buckets. Treatments were applied until week 8 after calving. The diet of the cows consisted of direct grazing in improved pastures, corn silage and a commercial concentrate which was offered at milking. Milk production and composition, udder health, body condition score of the cows, body weight and milk intake of the calves were measured weekly, and the first postpartum ovulation was determined three times a week by ovarian ultrasonography. Cows with RS management had a lower machine-milked milk yield (17.9 vs. 24.8 kg/d), a lower fat percentage (3.21 vs. 4.11%) and 4% fat-corrected milk yield (16.2 vs. 25.7 kg/d), and also a lower average milk flow (1.35 vs. 1.76 kg/min) than cows in the AR treatment. There was no effect of treatment on milk protein percentage or udder health as measured by milk electrical conductivity. The interval from calving to first postpartum ovulation was shorter in the AR cows than in the RS cows (18.5 vs. 21.8 days). The RS calves consumed more milk (7.2 vs. 5.4 kg/d), gained more body weight (0.813 vs. 0.656 kg/d), and had a higher body weight at weaning (84.3 vs. 73.3 kg) than AR calves. Restricted suckling of grazing dairy cows had a negative effect on machine-milked milk yield, fat percentage and 4% fat-corrected milk yield, but had no effect on udder health or on improved weight gain and body weight at weaning of the calves.