Cubicle Refusal and Rearing Accommodation as Possible Mastitis Risk Factors in Cubicle-Housed Dairy Heifers

Fifty-nine of the 65 dairy farms with cubicle sheds in the Norwegian county of Oppland in 1990 were included in a study of rearing accommodation, cubicle refusal and mastitis incidence. The farmers recorded the favoured resting location of the individual cows and heifers throughout the final week of pregnancy as well as during calving. The observations were matched with individual records of mastitis cases during the first 30 days after calving. Mastitis incidence in the heifers was analysed by logistic regression using rearing accommodation and cubicle refusal as independent variables, controlling for herd as a clustering factor. Cubicle refusal was found in 29% of the heifers, but in only 3% of older cows. The results of the analysis indicated a tendency for cubicle refusal to be associated with an increased mastitis incidence among the heifers (OR = 2.2, c.i._95%OR = 0.9–5.4, P = 0.08). Cubicle refusal accounted for 21% (0–32%) of the mastitis cases in the study population (PAF = 0.21).     

Failure to Use Cubicles and Concentrate Dispenser by Heifers after Transfer from Rearing Accommodation to Milking Herd

Thirty-three dairy farms in the Norwegian counties of ?stfold and Akershus in which cubicle sheds had been in use for at least one year and with a herd size of less than 60 cows, were contacted and asked to participate in a study. The study focused on heifers' use of cubicles and concentrate dispenser just after being transferred from rearing accommodation to the milking herd. For each heifer, the farmer recorded cubicle use once nightly between 9 and 11 pm. The daily amount of concentrate released in the dispenser and the allotted daily ration were also recorded. The recording period was 15 consecutive days for cubicle use and 7 days for concentrate dispenser use. Cubicle refusal behaviour, i.e. lying outside the cubicles, was analysed by logistic regression using rearing accommodation of heifers, herd size, heifer age, and housing layout as independent variables, and herd as a clustering variable. On Day 2 after transfer, 34% of the heifers were showing cubicle refusal behaviour (N = 340). By Day 15 this percentage had dropped to 23. Cubicle refusal was lower throughout the whole period among heifers which used the cubicles on the 3 first days after transfer compared to those which did not. This tendency could also be detected several months later. The analysis showed cubicle refusal to be significantly associated with rearing accommodation (OR = 6.1, c.i._95%OR = 1.5–24.3, P = 0.01) and cubicle layout in the shed (OR = 0.2, c.i._95%OR = 0.0–0.7, P = 0.01). None of the tested variables were found to be significant for failure to use the concentrate dispenser, a behaviour which was less frequent than cubicle refusal. However, 8 percent of the heifers did not visit the dispenser at all throughout the 7 days of observation.     

Lameness and Claw Lesions of the Norwegian Red Dairy Cattle Housed in Free Stalls in Relation to Environment,Parity and Stage of Lactation

Approximately 88% of Norwegian dairy cattle are housed in tie stalls. Free stall housing for all dairy cattle will be implemented within 20 years. This means that the majority of existing stalls will be rebuilt in the near future. Fifty-seven free stall herds of the Norwegian Red breed were randomly selected and 1547 cows and 403 heifers were trimmed by 13 claw trimmers during the late winter and spring of 2002. The claw trimmers had been taught diagnosing and recording of claw lesions. Environment, management- and feeding routines were also recorded. Fifty-three herds had concrete slatted alleys while 4 had solid concrete. Thirty-five herds had concrete as a stall base, while 17 had rubber mats, 2 had wood and 3 had deep litter straw beds. The prevalence of lameness was 1.6% in hind claws. Models for lameness and claw lesions were designed to estimate the influence of different risk factors and to account for the cluster effects within herd and claw trimmer. Detected risk factors for lameness were: parity three and above and narrow cubicles; for heel horn erosions: lactation stage around 5–7 months after calving and solid concrete alleys; for haemorrhages of the white line: lactation stage around 3–5 months after calving and solid concrete alleys; for haemorrhages of the sole: parity one, lactation stage around 5–7 months after calving and short cubicles, for white line fissures: slatted concrete alleys; for asymmetrical claws: parities two and above and for corkscrewed claws: solid concrete alleys. The prevalence of lameness in heifers was low, however 29% had one or more claw lesions. Heifers that were housed in pens or free stalls had more heel-horn erosions, haemorrhages of the sole and white-line fissures than heifers in tie stalls. As new free stalls are being built, it is important to optimise the conditions for claw health.     

The reaction of cows to a short-term deprivation of lying

In a herd of 20 cows in a cubicle house, lying behaviour was prevented for 3 h each morning by enclosing the animals on the slatted floor of the feeding area. Lying time of cows was recorded during the 10 h following deprivation. The 3 h of lying deprivation resulted in a recovery rate of almost 50% within the observation period. When cows were also deprived of food during the lying-deprivation period, the recovery rate of lying did not alter. However, when feeding alone was prevented, the increased feeding tendency did decrease lying time in the subsequent hour. It is concluded that cows aim to achieve a rather fixed amount of lying, and that their well-being must seriously be impaired when lying time is restricted for several hours.     

Synthetic rubber surface as an alternative to concrete to improve welfare and performance of finishing beef cattle reared on fully slatted flooring

The aim of this study was to compare a fully slatted concrete floor (concrete slatted (CS)) with the same floor on which synthetic rubber slats were placed on the concrete slats (rubber slatted (RS)) as housing solution for finishing beef cattle. The present study involved five commercial beef cattle farms in which the floor of at least three pens was kept as fully slatted, and in an equal number of pens a rubber cover was placed on the floor, tightly matching the gap profile of the concrete slats to allow the drainage of manure. A total of 326 finishing beef bulls were used (153 on CS and 173 on RS), and regardless of the floor treatment animals were housed in groups of 6 to 12 bulls/pen with a space allowance of 3.1±0.2 m²/bull. Bulls had similar initial live weights (422.3 kg on CS and 425.0 kg on RS), but bulls on RS were heavier at the end of the finishing period with a higher average daily gain than bulls kept on CS (1.53 v. 1.46 kg/day; P<0.05). The proportion of bulls treated for locomotor problems was lower in RS pens compared with CS. Rubber covering prevented the occurrence of bursitis, but it increased the odds for hoof overgrowth at end of the finishing period. Hoof overgrowth detected in vivo in bulls on RS was confirmed at the slaughterhouse by the longer dorsal wall and diagonal lengths of the hoof as well as by a more acute toe angle. Compared with bulls on CS, bulls on RS showed less inactivity and resting time, increased social interactions, decreased abnormal lying down and unsuccessful attempts to lie down, as well as shortened the time for lying down. Bulls in RS pens were dirtier compared with those in CS pens, likely due to the draining gaps being reduced to 11.6±1.2% of the total pen surface compared with the 16.9±1.7% in CS pens. This study gave further evidence about the positive effects of the RS floor on growth performance and welfare of finishing beef cattle, although compromising cleanliness and hoof overgrowth.     

Cow behaviour on a new grooved floor in comparison with a slatted floor, taking claw health and floor properties into account

The objective of this study was to compare the behaviour of cows on a grooved floor with that of cows kept on a slatted floor. The trial was carried out with two groups of 12 Holstein-Friesian cows kept in a cowshed with two symmetrical halves, identical except for the floor. One floor was grooved longitudinally to the feeding fence (width of grooves 35mm) and the other was slatted (gaps 35mm wide) perpendicular to the feeding fence. Both floors had scrapers to remove manure. After 3 weeks of being kept on these two floors, cows were switched between floors for 3 weeks. In the third week of each 3-week-period, behavioural observations of cows related to their time budget over 24h, relocation on each floor indicated by index of movement and specific behaviours (aggression, self maintenance) performed on the floors were executed. The health of claws was examined before the trial and 6 weeks later, after the trial. The grooved floor influenced the cows' daily time budget: cows kept on the grooved floor stood less (P<0.05) with four legs inside the cubicles (group 1: 36min, group 2: 39min) than cows kept on the slatted floor (group 1: 57min, group 2: 60min). Neither the specific behaviours of cows nor their movement performed on both floors were different. After switching from the grooved floor to the slatted floor, cows lay for 669min a day (in comparison to 746min a day while kept on the grooved floor, P<0.05) and they stood parallel to the feeding fence for 174min a day (in comparison to 126min a day while kept on the grooved floor, P<0.05). Given that both groups of cows on the grooved floor and the group that began on the slatted floor had a similar daily time budget, it is possible that the different time budget of the remaining group, which started off on the grooved floor, was a reaction (pleasure or disappointment) induced by returning to the familiar floor. The grooved floor was more fouled with faeces (P<0.05) than the slatted floor. The grooved floor can be evaluated as being equal to the slatted floor with a scraper in terms of the behaviour performed on it. There were hardly any slip incidents on it (during 64h of observations, two slip incidents on the grooved floor, four slip incidents on the slatted floor). However, the occurrence of stumble incidents involving the manure scraper (66 cases on the grooved floor and 48 on the slatted floor during 64h of observations) and the occurrence of foot lesions (probably of traumatic origin) suggests that the functioning of the manure scraper, which is indispensable on grooved floors, needs to be optimised.     

Changes in embryo production results and ovarian recrudescence during the acclimatisation to the semiarid tropics of embryo donor Holstein-Friesian cows raised in a temperate climate

Pregnant Holstein-Friesian (HF) heifers were transported from central Europe (defined as temperate conditions) to north-eastern Brazil (defined as tropical, semiarid conditions). They were kept in open-sided pens with a hard floor, a roof for shade and sprinkled with water for 10 min every hour if ambient temperature exceeded 30 degrees C. Their diet was balanced to meet nutritional requirements and they were fed twice daily. Control animals were randomly chosen first and second lactation animals located on a farm 25 km away and receiving similar management. Imported animals were superovulated in 1996 (n=63) and 1997 (n=96), compared to 38 and 45 cows in the control herd. The variates recorded were: the interval post-partum to first oestrus; changes in ovarian size and activity; responses to superovulation; and, embryo quality.The average daily milk yields of the imported cows were 20.0 and 23.3 l in 1996 and 1997, respectively compared to 22.1 l throughout the experiment for cows in the control herd.The post-partum anoestrus interval in the imported cows were 112.1+/-30.5 days in 1996 compared to 55.0+/-18.0, 48.2+/-12.0 and 42.6+/-10.7 days in 1997 for control cows. The size and functionality of the ovaries was lowest for the imported animals in 1996 but did not differ between other group-year combinations. These animals also had a lower superovulatory response in 1996 than control cows in terms of the number of ovulations (6.4+/-4.3 versus 13.6+/-5.9, P<0.05) and good quality embryos (1.2+/-0.9 versus 4.4+/-2.1, P<0.05). The two groups of cows did not differ in respect of these characters in the second year of the study.The imported cows had lower reproductive efficiency and responses to superovulation in their first year in their new environment. A period of approximately 1.5 years is required for full adaptation.     

Mountain pasturing of rearing stock reduces the culling risk as dairy cows

Alpine transhumance or droving livestock to mountainous areas during summer months is highly relevant for Austrian agriculture but also for other countries in Alpine regions. Access of rearing stock to mountain pastures is often claimed to be beneficial with respect to health and longevity, but the robust evidence is scarce. Therefore, its effect was tested by including it in the routine genetic evaluation data set for longevity. Alpine transhumance records from 2004 to 2013 were used. After several plausibility checks and restriction to animals with sire and dam known, records of 871 287 dual-purpose Fleckvieh cows sired by 9953 bulls were available. Data were analysed by means of survival analysis accounting for the time-dependent fixed effects of region-year-season, relative performance within herd, change of herd size, and Alpine pasturing of cows, the fixed effects age at first calving and Alpine pasturing of rearing stock, the random time-dependent effect of herd-year and the random genetic effects of sire and maternal grandsire. Fleckvieh cows that had access to Alpine pasture during their rearing period at least once for a minimum of 60 days had functional longevity that was nearly 2 months prolonged compared with cows that had always stayed on the farms as calves or heifers. In a more detailed analysis, the lowest relative culling risk among the significant estimates was observed for cows that had been Alpine pastured in years 1 and 3; it was about 15% below that of cows that never had access to mountain grazing. Evidence for the beneficial effect of Alpine pasturing of rearing stock on the animals’ later fitness, indicated by longevity, could thus be provided.     

Serving capacity — A measure of the serving efficiency of bulls during pasture mating

The aim of the study was to determine whether the serving capacity of a bull, the number of services it achieved during a pasture mating period, was related to the proportion of oestrous cows in its herd it served. Twelve groups of 3 to 10 bulls were mated with spayed, oestrous heifers at a bull: cow ratio of 1 to 5 for a 7.5 hour period. The serving capacity of a group of bulls was highly correlated with the proportion of oestrous heifers the group of bulls served (r = 0.94), and the proportion of oestrous heifers the bulls served 2⁺ times (r = 0.98). The high correlations occurred because each bull, whatever its serving capacity (range 0 to 15 services), rarely served the same heifer twice. The correlation coefficient between the number of services a bull achieved and the number of heifers it served was 0.96 (n = 54). It was concluded that the serving capacity of a bull is an accurate measure of serving efficiency during pasture mating.     

The effect of long or chopped straw on pig behaviour

In the EU, pigs must have permanent access to manipulable materials such as straw, rope, wood, etc. Long straw can fulfil this function, but can increase labour requirements for cleaning pens, and result in problems with blocked slatted floors and slurry systems. Chopped straw might be more practical, but what is the effect on pigs’ behaviour of using chopped straw instead of long straw? Commercial pigs in 1/3 slatted, 2/3 solid pens of 15 pigs were provided with either 100 g/pig per day of long straw (20 pens) or of chopped straw (19 pens). Behavioural observations were made of three focal pigs per pen (one from each of small, medium and large weight tertiles) for one full day between 0600 and 2300 h at each of ~40 and ~80 kg. The time spent rooting/investigating overall (709 s/pig per hour at 40 kg to 533 s/pig per hour at 80 kg), or directed to the straw/solid floor (497 s/pig per hour at 40 kg to 343 s/pig per hour at 80 kg), was not affected by straw length but reduced with age. Time spent investigating other pigs (83 s/pig per hour at 40 kg), the slatted floor (57 s/pig per hour) or pen fixtures (21 s/pig per hour) was not affected by age or straw length. Aggressive behaviour was infrequent, but lasted about twice as long in pens with chopped straw (2.3 s/pig per hour at 40 kg) compared with pens with long straw (1.0 s/pig per hour at 40 kg, P=0.060). There were no significant effects of straw length on tail or ear lesions, but shoulders were significantly more likely to have minor scratches with chopped straw (P=0.031), which may reflect the higher levels of aggression. Smaller pigs showed more rooting/investigatory behaviour, and in particular directed towards the straw/solid floor and the slatted floor than their larger pen-mates. Females exhibited more straw and pen fixture-directed behaviour than males. There were no effects of pig size or sex on behaviour directed towards other pigs. In summary, pigs spent similar amounts of time interacting with straw/solid floor when long and chopped straw were provided, and most aspects of pig-directed behaviour and injuries were not affected by straw length. There was an increase in pigs with minor shoulder lesions with chopped straw, perhaps because of increased aggression. The use of chopped straw as an enrichment material for pigs warrants further investigation in larger and more detailed studies.     

Influence of a raised slatted area in front of the nest on leg health,mating behaviour and floor eggs in broiler breeders

European farms for broiler breeders often have raised slatted areas in front of the nests, but in other regions of the world no raised slatted areas are provided. This study aimed to investigate the effects of a raised slatted area on leg health, mating behaviour and floor laying behaviour. Ten groups of 33 broiler breeder hens and three males were housed in two pen types: with or without a raised slatted area in front of the nests. Each pen had one plastic and one wooden nest. Between 25 and 31 weeks of age, ten marked hens per pen were weighed and assessed weekly on foot pad dermatitis, hock burn and wounds. At the end of week 31, animals were euthanized and bone strength of the tibia and humerus of these individuals was assessed. At 24, 27 and 30 weeks of age, mating behaviour was observed for an hour per pen, noting both numbers of successful and unsuccessful copulations. The number of eggs laid in the nests and on the floor was recorded daily between 20 and 31 weeks of age. Foot pad dermatitis scores were affected by age, but not by pen type. Generally, there were only minor issues with foot pad dermatitis (scores < 11 on a 0–100 scale), probably due to the young age of the hens. Body weight was not affected by pen type, while the prevalence of hock burns was too low to analyse and no difference in bone strength was found for the tibia and the humerus. Overall, mating behaviour was less frequent in pens with raised slats than in pens without raised slats (29 ± 2 vs 35 ± 3 times/h) and more frequent at 27 weeks of age than at 24 and 30 weeks of age (38 ± 1 vs 31 ± 4 and 27 ± 2 times/h). The pens with raised slats had a lower percentage of floor eggs than pens without raised slats (11.2 ± 0.4 vs 19.3 ± 0.5%). The wooden nest was preferred over the plastic nest as on average 63% of the eggs were laid in the wooden nest. This study shows that providing raised slats decreases mating behaviour and percentage of floor eggs, although its effects on leg health remain inconclusive.     

An empirical analysis of the cost of rearing dairy heifers from birth to first calving and the time taken to repay these costs

Rearing quality dairy heifers is essential to maintain herds by replacing culled cows. Information on the key factors influencing the cost of rearing under different management systems is, however, limited and many farmers are unaware of their true costs. This study determined the cost of rearing heifers from birth to first calving in Great Britain including the cost of mortality, investigated the main factors influencing these costs across differing farming systems and estimated how long it took heifers to repay the cost of rearing on individual farms. Primary data on heifer management from birth to calving was collected through a survey of 101 dairy farms during 2013. Univariate followed by multivariable linear regression was used to analyse the influence of farm factors and key rearing events on costs. An Excel spreadsheet model was developed to determine the time it took for heifers to repay the rearing cost. The mean±SD ages at weaning, conception and calving were 62±13, 509±60 and 784±60 days. The mean total cost of rearing was £1819±387/heifer with a mean daily cost of £2.31±0.41. This included the opportunity cost of the heifer and the mean cost of mortality, which ranged from £103.49 to £146.19/surviving heifer. The multivariable model predicted an increase in mean cost of rearing of £2.87 for each extra day of age at first calving and a decrease in mean cost of £6.06 for each percentile increase in time spent at grass. The model also predicted a decrease in the mean cost of rearing in autumn and spring calving herds of £273.20 and £288.56, respectively, compared with that in all-year-round calving herds. Farms with herd sizes⩾100 had lower mean costs of between £301.75 and £407.83 compared with farms with <100 milking cows. The mean gross margin per heifer was £441.66±304.56 (range £367.63 to £1120.08), with 11 farms experiencing negative gross margins. Most farms repaid the cost of heifer rearing in the first two lactations (range 1 to 6 lactations) with a mean time from first calving until breaking even of 530±293 days. The results of the economic analysis suggest that management decisions on key reproduction events and grazing policy significantly influence the cost of rearing and the time it takes for heifers to start making a profit for the farm.     

Comparison of reproductive performance by artificial insemination versus natural service sires in California dairies

This study compared the calving to conception intervals for cows in AI pens with cows exposed to natural service sires, controlling for milk production, mastitis occurrence, parity and calving month effects. Records from 10 western United States dairy herds (mean herd size = 2058 cows) were evaluated retrospectively over an 18-month period. Eight bull breeding analysis cohorts were created (the first cohort 0-50 days in milk and the remaining cohorts at 25 days in milk intervals through 226 days). The cohorts contained non-pregnant cows that were first moved into bullpens during the described cohort period. Equal numbers of non-pregnant cows only exposed to AI during the cohort period were randomly selected from the pool of eligible non-pregnant cows. An AI cow was used only once in the data analysis, but was included in a bull breeding cohort at a later date if she remained non-pregnant and was transferred to a bullpen. Univariate and multivariate survival analysis was used to compare the calving to conception intervals. Cows in AI groups had higher hazard rates for pregnancy across all cohorts. Parity and milk production were significantly associated with risk for pregnancy. In herds that practice a mixture of AI and bull breeding, overall herd reproductive performance might be improved by allowing cows more opportunities at AI prior to moving them into clean-up bullpens.     

Influence of management factors on pregnancy attrition in dairy cattle

The present study was conducted to determine the influence of management factors on pregnancy attrition in dairy cattle. Data from 3162 diagnosed pregnancies in parous cows and 1050 in heifers at 9 commercial dairy herds in northeastern Spain were used. Pregnancy diagnosis by palpation per rectum was performed from 30 to 70 d post insemination. Pregnancy attrition was registered when pregnancy diagnosis resulted negative in a second palpation carried out between 120 and 150 d following insemination. Overall proportion of pregnancy losses was 7.9% (9.6% in parous cows and 2.8% in heifers). Data analysis was performed by multiple logistic regression methods. For all animals, effect of time of pregnancy diagnosis was shown (Odds ratio = 0.97 for 1 d increase; P = 0.0042). Conceptus loss in heifers was lower than in parous cows (Odds ratio = 0.28; P = 0.0001), and a higher proportion of pregnancy attritions was detected in animals inseminated in spring, summer and winter, compared to those inseminated in autumn (P < 0.04). Herd effect on pregnancy attrition was also significant. Similar results were observed in the subanalysis for parous cows and, furthermore, no effect of lactation number and of interval from previous calving to pregnancy was shown in this group. In heifers, no effect of time of pregnancy diagnosis and of insemination season on pregnancy attrition was shown, and only a herd effect was observed. Our data suggest that the influence of parity status (heifer vs cow) could affect the proportion of pregnancy attrition rather than early diagnosis, and, in pregnant cows, adaptation to seasonal changes associated with temperature decreases seem more efficient.     

Early pregnancy diagnosis by transrectal ultrasonography in dairy cattle

The objective of the present study was to determine differences in time of detection of pregnancy between heifers and cows and the interval after insemination at which the maximum sensitivity and negative predictive value of transrectal ultrasonography were obtained. One-thousand-four-hundred transrectal ultrasonographies (TRUS-1; 1,079 in cows and 321 in heifers) were performed using a 5-MHz linear-array transducer. The cattle were randomly assigned to have TRUS performed once between days 24 and 30 (estrus=day 0) in cows or between days 21 and 27 in heifers. Every TRUS diagnosis was subsequently compared with a second TRUS diagnosis (TRUS-2), performed 3-8 days later, after day 30 (range 31-38) for cows and after day 27 (range 28-35) for heifers. The sensitivity and specificity between cows and heifers for the common days of TRUS (from 24 to 27) were compared. In cows, sensitivity increased gradually from 74.5% at day 24 to 100% at day 29 (P<0.01). Specificity increased from days 24-25 and reached a plateau of 96.6% on day 26 (P<0.01). In heifers, sensitivity increased from 50% at day 21 to 100% at day 26 (P<0.01). Specificity increased from 87.5% at day 21 and remained steady at 94% starting on day 23 (P>0.05). The sensitivity for cows and heifers was 89.2 and 96.8%, respectively (P<0.05) and the specificity was 93.0 and 93.4% (P>0.05). In this study, heifers were diagnosed pregnant earlier than cows, and the maximum sensitivity and negative predictive value were obtained 3 days earlier in heifers than cows (days 26 and 29, respectively).     

Effects of cubicle characteristics on animal welfare indicators in dairy cattle

Cubicle characteristics such as cubicle dimensions or management factors such as cow-to-cubicle ratio could affect health and behaviour of dairy cows. The objective of this study was to estimate effects of cubicle characteristics on animal welfare indicators in dairy cattle. A total of 64 loose housing farms in Germany were assessed once during the winter housing period by one experienced assessor. Nearly 15% of the dairy cows had access to pasture during summer months for <6 h/day, whereas 85% were zero-grazing farms. Selected animal welfare indicators (duration of the lying down process, collisions of cows with cubicles, cows lying outside cubicles, cow cleanliness, integument alterations, lameness and subclinical mastitis incidence) of the Welfare Quality® protocol and cubicle characteristics such as cow-to-cubicle ratio and cubicle dimensions were recorded. Data were statistically analysed using a multiple linear regression approach. Pasture access and cubicle type were considered as potential influencing factors. Wider cubicles positively affected the proportion of dairy cows with dirty flanks (−18.5% per 10 cm increase) but increased the number of cows with severe integument alterations (+8.9% per 10 cm increase). Larger lying areas reduced the percentage of cows with dirty udders (−2.9% per 10 cm² increase). Longer distances from neck rail to curb were associated with higher prevalence of cows with dirty flanks (+3.1% per 10 cm increase) and subclinical mastitis incidence (+1.2% per 10 cm increase). With increasing neck rail height, the duration of the lying down process (−0.1 s per 10% increase), the percentages of cows with dirty legs (−8.4% per 10 cm increase), dirty udders (−7.0% per 10 cm increase) and severe lameness (−3.0% per 10 cm increase) decreased. Compared with rubber mat-equipped cubicles, deep-bedded cubicles showed a reduction in the lying down duration (−0.8 s), percentages of cows with dirty legs (−34.2%), dirty udders (−30.5%) and lesions and swellings (−13.1%). Compared with farms that did not provide any summer grazing, pasture access was associated with an increase of cows with severe lameness (+5.6%). Contrastingly, the number of cows with subclinical mastitis incidence was lower when cows had access to pasture in summer (−5.4%). Findings of the present study indicate several associations between cubicle characteristics and animal welfare in dairy cattle. Bedding type was found as the most influencing factor in terms of health and behaviour. Results of this study are valuable for farmers to identify the optimal cubicle design and improve the animal welfare level.     

Evaluation of intrauterine antibiotic treatment of clinical metritis and retained fetal membranes in dairy cows

Retained fetal membranes (RFM) and clinical metritis (CM) are frequently diagnosed disease conditions in dairy cows and considered of major economic impact due to negative effect on reproduction and milk production. The objective of this study was to evaluate the efficacy of i.u. tetracycline for the treatment of RFM and CM in dairy cows. Affected cows were randomly assigned to two groups; treatment group animals received i.u. 5 g chlortetracycline twice weekly for 2 wks, and no treatment group.A total of 1416 cows and 804 heifers in 5 herds calved during the study period. CM was diagnosed in 18.6% (inter farm range; 15.2–23.5%) and 30% (19.4–42.3%) of cows and heifers, respectively. RFM was diagnosed in 13.1% (9.4–18.1%) and 9.2% (3.6–13.8%) of cows and heifers, respectively. Conception rates after first insemination were 38.3%, 42.5% and 18% in normal, treated and non-treated CM cows, respectively. Numbers of days open were 140.5, 136.2 and 165.5 in normal, treated and non-treated CM cows, respectively. Based on 305-d corrected milk yield, cows and heifers affected by RFM and CM produced 300–500 kg less milk compared with their normal herd mates. Cows treated for CM produced 654 kg more milk per 305-d corrected lactation compared to non-treated control cows. Treatment of RFM had no effect on reproductive performance or milk production. In conclusion, i.u. chlortetracycline treatment was proven to prevent the detrimental effect of CM on reproductive performance in heifers and cows and on milk production in cows only.     

Differences between single and paired heifers in residency in functional areas, length of travel path, and area used throughout days 1–6 after integration into a free stall dairy herd

The integration of heifers into free stall dairy herds is a frequent management procedure, but little systematic research has been conducted on its effect on cow behavior. Previous studies mainly focused on aggressive interactions, but it is also of interest how integration affects the spatial distribution of both the cows in the herd and the integrated heifers. In the present study we integrated a single and a pair of heifers on each of six Swiss working farms in a balanced order. Using an automatic tracking system, we recorded the positions of all the cows and of the integrated heifers at 1 min intervals for six continuous 24 h periods. From these data we calculated the proportion of time the animals spent in the activity area, at the feed rack and in the lying cubicles, their average path length and the area of the barn that they used. We then compared the behavior of the integrated heifers with that of the cows in the introductory weeks. We also compared the behavior of the cows recorded in the control weeks directly preceding the integration and in the introductory weeks. For evaluation we used linear mixed-effects models. Singly integrated heifers spent a higher proportion of time in the activity area (0.29 vs. 0.14; P < 0.001) and a lower proportion of time in the lying area (0.40 vs. 0.53; interaction with day, P = 0.011) than the cows, whereas the heifers of the pairs mainly spent a lower proportion of time in the feeding area than the cows (0.23 vs. 0.32; interaction with day, P = 0.044). Average path length was longer for the integrated heifers soon after introduction but approached the values of the cows later on (interaction with day, P = 0.012). The total barn area used by a given animal was largest in the cows and was reduced in heifers integrated singly or in pairs (cows: 341/373 m², pairs: 306 m², single heifer: 333 m²; P = 0.055). Cows were little influenced in their space use by the integration of a single or pair of heifers. In summary, the behavior of the singly integrated heifers differed more markedly from that of the cows than the behavior of the heifers introduced in pairs during the introductory week. We would therefore recommend integrating pairs rather than single heifers into herds of dehorned dairy cows to ease their integration.     

Effect of Ractopamine HCl Supplementation on Fecal Shedding of Escherichia coli O157:H7 and Salmonella in Feedlot Cattle

The effects of the β-agonist ractopamine, recently approved for use in feedlot cattle to improve carcass quality and performance, on fecal shedding Escherichia coli O157:H7 and Salmonella in feedlot cattle was examined. In the first study, 20 feedlot steers and heifers were randomly assigned to receive ractopamine or no ractopamine (control) by way of oral bolus for 28 days. Fecal samples were collected daily, and shedding of E. coli O157:H7 determined. When examined during the entire 28-day experimental period, ractopamine decreased (P = 0.0006) the percentage of cattle shedding E. coli O157:H7 (58% vs. 42% for control and ractopamine treatments, respectively). A second study was conducted in a commercial feedlot facility in the southwestern United States. Eighteen pens of cross-bred beef heifers (approximately 100 head/pen and 9 pens/treatment) were randomly assigned to receive either 0 (control) or 200 mg ractopamine/head·d^–1. Fresh fecal samples (30/pen) were collected off the pen floor before ractopamine supplementation and again after approximately 28 days of ractopamine supplementation (within a few days of slaughter); the samples were cultured for E. coli O157:H7 and Salmonella. The percentage of animals shedding E. coli O157:H7 was decreased when data were pooled across replicates (P = 0.05) in ractopamine-treated cattle compared with controls. The percentage of animals shedding Salmonella tended to be higher (P = 0.08) with the ractopamine treatment when data were pooled across replicates. Although further research is required to confirm these results, the potential food safety implications of this research are intriguing. Mention of trade name, proprietary product, or specific equipment does not constitute a guarantee or warranty by the United States Drug Administration and does not imply its approval to the exclusion of other products that may be suitable.     

Effect of time at pasture combined with restricted indoor feeding on production and behaviour in dairy cows

Extremely high nutrient loads have been reported in grazed grassland regimes compared with cutting regimes in some dairy systems that include the use of supplemental feeding. The aim of this study was, therefore, to investigate the effects on productivity and behaviour of high-yielding dairy cows with limited access to indoor feed and restriction in the time at pasture in a continuous stocking system. During a 6-week period from the start of the grazing season 2005, an experiment was conducted with the aim of investigating the effect of restrictive indoor feeding combined with limiting the time at pasture on the productivity and behaviour of high-yielding dairy cows (31.0 ± 5.4 kg energy-corrected milk) in a system based on continuous stocking. The herd was split into three groups allocated to three treatments consisting of 4, 6.5 and 9 h at pasture, respectively. Each group of cows grazed in separate paddocks with three replicates and was separately housed in a cubicle system with slatted floor during the rest of the day. All cows were fed the same amount of supplement, adjusted daily to meet the ad libitum indoor intake of the cows at pasture for nine hours. The herbage allowance was 1650 kg dry matter (DM) per ha, and the intake of supplemental feed was 9.1 kg DM per cow daily. The limitation of the time at pasture to 4 h in combination with restrictive indoor feeding reduced the daily milk, fat and protein yield and live weight compared with 9 h of access to pasture. The proportion of time during which the cows were grazing while at pasture increased from 0.64 to 0.86 and the estimated herbage intake per h at pasture decreased from 2547 g DM to1398 g DM, when time at pasture changed from 4 to 9 h. It can be concluded, that in systems with a high herbage allowance, the cow was able to compensate for 0.8 of the reduction in time at pasture by increasing the proportion of time spent grazing and presumably also both the bite rate and mass, although the latter two have not been directly confirmed in the present study.