Alley Floor Research Articles

Factors associated with lameness prevalence in lactating cows housed in freestall and compost-bedded pack dairy farms in southern Brazil

The aim of this cross-sectional study was to investigate factors associated with lameness in dairy cows on intensive farms in southern Brazil. Farms (freestall: n = 38; compost-bedded pack: n = 12) having on average 274 (range: 41–901) lactating cows were visited once in 2016 (March to October). Potential risk factors for lameness at the cow, pen and herd levels were investigated through inspection of facilities, examination of cows and the use of data collected on routine management practices. All milking cows on each farm were assessed for gait score and BCS (n = 13,716). Associations between lameness, days in milk (DIM), BCS, parity, and test-day milk yield were investigated in 16 farms with available data (n = 5,301 cows). Mixed-effects linear and logistic regressions were used to model the data. Within-herd lameness prevalence was 41.1% (range: 13.8–64.5, SD = 11.3). First- and second-lactation cows after 120 DIM and older cows after 335 DIM were more likely to be observed lame than early lactation cows. Greater parity and low BCS (≤ 2.75) were associated with increased odds of lameness. Severely lame cows had lower milk yield (on average 1.3 kg/d) than non-lame cows. Freestall dairies using mattresses as stall base had greater within-pen (95% CI: 52–69%) and herd-level (38–57%) lameness prevalence than compost-bedded farms. Higher lameness prevalence was observed on farms having slippery feed bunk alley floors (32–49%) and shortened dry periods (< 60 days: 32–42%). First-lactation pens had lower predicted within-pen lameness prevalence (0–4%) and special-needs pens higher (52–73%) compared with the prevalence observed in compost-bedded fresh-cow pens (19–41%). Freestall pens using sawdust deep-bedding had greater (46–68%) within-pen lameness prevalence, but the prevalence in barns using sand was not different from compost-bedded farms. Given the high lameness prevalence observed in this study, there is a great opportunity for implementation of lameness prevention programs. Providing walking surfaces with high traction that facilitates mobility and using soft and deep-bedded material, such as compost and sand (and avoiding the use of mattresses) may reduce lameness prevalence in the types of dairy farms visited in this study.

Robotic milking: Technology, farm design, and effects on work flow

Robotic milking reduces labor demands on dairy farms of all sizes and offers a more flexible lifestyle for farm families milking up to 250 cows. Because milking is voluntary, barn layouts that encourage low-stress access by providing adequate open space near the milking stations and escape routes for waiting cows improve milking frequency and reduce fetching. Because lame cows attend less often, preventing lameness with comfortable stalls, clean alley floors, and effective foot bathing warrants special emphasis in robotic dairies. Variable milking intervals create challenges for foot bathing, sorting and handling, and dealing with special-needs cows. Appropriate cow routing and separation options at the milking stations are needed to address these challenges and ensure that the expected labor savings are realized. Protocols and layout and gating should make it possible for a herd worker to complete all handling tasks alone. Free traffic and guided traffic systems yield similar results when excellent management is applied or when the number of cows is well below capacity. In less ideal circumstances, guided traffic and the use of commitment pens result in longer standing times and stress, particularly for lower ranking cows, and poor management with free traffic results in more labor for fetching.

Effect of alley-floor scraping frequency on Escherichia coli, Klebsiella species, environmental Streptococcus species, and coliform counts

ABSTRACT The objective of this study, conducted at the University of Kentucky Cold-stream Dairy, was to determine whether increased alley-floor scraping frequency decreased environmental mastitis-causing pathogen counts. Sixteen Holstein cows were monitored during two 3-wk treatments: removing manure from the alley floors once (1 ×) or twice daily (2 ×) by a skid steer equipped with a tire scraper. Bedding, milk, and teat-end swab samples were collected twice weekly to observe changes in streptococci, Klebsiella spp., coliform, and Escherichia coli counts and SCS. Increasing alley-floor scraping frequency to 2 × decreased all bedding pathogen counts (P = 0.01); teat-end coliform, E. coli, and streptococci counts (P

Associations of dairy cow behavior, barn hygiene, cow hygiene, and risk of elevated somatic cell count

Poor dairy cow hygiene has been consistently associated with elevated somatic cell count (SCC) and the risk of subclinical mastitis. The objective of this study was to determine the associations between dairy cow standing and lying behavior, barn hygiene, cow hygiene, and the risk of experiencing elevated SCC. Lactating Holstein dairy cows (n=69; 86±51 DIM; parity: 2.0±1.2; means ± SD), kept in 1 of 2 groups, were monitored over a 4-mo period. Each group contained 61±1 (mean ± SD) cows over the study period; complete data were obtained from 37 and 32 animals within each respective group. Cows were housed in a sand-bedded, freestall barn with 2 symmetrical pens, each with a free cow traffic automatic milking system. To vary barn hygiene, in 4 consecutive 28-d periods, alley manure scrapers in each of the 2 pens were randomly assigned to frequencies of operation of 3, 6, 12, and 24 times per day. During the last 7dof each period, cow hygiene (upper leg/flank, lower legs, and udder; scale of 1 = very clean to 4 = very dirty) and stall hygiene (number of 0.15×0.15-m squares contaminated with manure in a 1.20×1.65-m grid) were recorded. Standing and lying behavior of the cows were collected during those days using data loggers. Individual-cow SCC was recorded at the beginning and end of each 28-d period. Elevated SCC was used as an indicator of subclinical mastitis; incidence of elevated SCC was defined as having a SCC >200,000 cells/mL at the end of each 28-d period, when SCC was <100,000 cells/mL at the beginning of the period. Less frequent scraping of the barn alleys was associated with cows having poorer hygiene. Poor udder hygiene was associated with poor stall hygiene. Longer lying duration was associated with poor hygiene of the upper legs/flank and udder. Greater premilking standing duration was associated with poor udder hygiene and decreased frequency of lying bouts was associated with poor hygiene of the lower legs. Higher milk yield was associated with poor hygiene of the udder and lower legs; multiparous cows had poorer hygiene of the upper legs/flank and udder. Over the study period, 24 new cases of elevated SCC were detected. No associations existed for the risk of experiencing an elevated SCC with alley scraping frequency or cow behavior patterns. However, increased odds of occurrence of elevated SCC were noted for cows of lower milk yield as well as for multiparous cows. In summary, these results show that cow hygiene is affected by the standing and lying behavior of cows and by the cleanliness of the cow’s environment. These findings emphasize the need for cows to be provided clean standing and lying environments. The results also show that frequent cleaning of barn alley floors will help improve cow hygiene.

Locomotion score and claw disorders in Norwegian dairy cows, assessed by claw trimmers

This cross-sectional study was part of a large project on free-stall housing. The aim was to assess the use of locomotion score (LocS) performed by 15 professional claw trimmers and the relation to claw disorders at claw trimming, to see if LocS recordings could be used to screen herds for claw problems. The claw trimmers scored locomotion, trimmed and recorded claw disorders in 2569 cows in 61 dairy herds. The relation between LocS and hind-claw disorders was identified by three multivariable models with binomial outcomes; model 1: LocS>1 vs. LocS=1, model 2: LocS>2 vs. ≤2 and model 3: LocS>3 vs. ≤3. Input variables were different claw disorders, type of alley floor, days in milk and parity. Significant claw disorders from separate models were put into the same model. Herd and claw trimmer were included in the model as random effects. The results were as follows: there were more heel-horn erosions in cows with LocS>1 vs. cows with LocS=1 with OR=1.6 (1.4/1.9) and in cows with LocS>2 vs. cows with LocS≤2 with OR=1.6 (1.2/2.2). There were more sole ulcers in cows with LocS>1 vs. cows with LocS=1 with OR=1.8 (0.9/3.4), in cows with LocS>2 vs. cows with LocS≤2 with OR=3.3 (1.8/5.9) and LocS>3 vs. LocS≤3 with OR=3.1 (1.5/6.3). There were more separations (white line fissure and/or double sole in cows with LocS>1 vs. cows with LocS=1 with OR=1.7 1.4/2.2), in cows with LocS>2 vs. cows with LocS≤2 with OR=2.1 (1.3/3.4) and LocS >3 vs. LocS≤3 with OR=3.1 (1.8/5.2). There were more corkscrewed claws in cows with LocS>2 vs. cows with LocS≤2 with OR=1.8 (1.0/3.2).

Effects of flooring and restricted freestall access on behavior and claw health of dairy heifers

Claw health, locomotion, feed intake, milk yield, body weight, activity, and lying and standing behavior of dairy heifers were monitored in a single dairy herd during the first 3 mo after calving. During the first 8 wk after calving, 2 treatments were applied: restricted freestall access by closing the stalls between 2300h and 0500h (yes or no) and alley flooring (concrete or rubber topped slatted floors). Apart from treatments, housing was identical. The animals were kept in small groups (n=4 to 6) in adjacent barn pens. Thereafter, the animals were kept in 1 group in a freestall section with concrete slatted floor and unrestricted access to the stalls for 5 wk. All animals were fed the same partial mixed ration. We hypothesized that (1) hard flooring causes high mechanical load of the claws and (2) restricted freestall access causes prolonged standing bouts and reinforced effects of hard flooring on claws. The heifers had only minor claw lesions before first calving, and the prevalence and severity of sole hemorrhages increased during the first 3 mo after calving (from 0.24±0.08 to 1.18±0.14 and from 0.04±0.01 to 0.24±0.02, respectively), particularly in the outer hind claws. Animals kept on rubber alley flooring had lower average hemorrhage scores in wk 9 (0.13±0.03 vs. 0.21±0.03) and wk 14 (0.20±0.03 vs. 0.27±0.03) after calving, had a slower feed intake (3.05±0.14 vs. 3.46±0.14 g/s) and spent more time feeding (7.3±0.3 vs. 6.6±0.3 min/h) than animals kept on hard concrete alley floors. Restricted freestall access resulted in fewer standing bouts per day (14.4±1.0 vs. 17.9±1.0) and more strides per hour (99.8±5.4 vs. 87.2±5.4) without changing overall standing time (15.0±0.3 vs. 14.7±0.3 h/d) and did not affect the occurrence of sole hemorrhages. The animals with no overnight freestall access spent more time standing (55.9±0.9 vs. 35.8±0.9 min/h) and feeding (7.8±0.3 vs. 4.3±0.3 min/h) between 2300 and 0500h and less during the rest of the 24-h period (31.3±0.8 vs. 37.0±0.8 min/h and 6.8±0.3 vs. 7.6±0.3 min/h). Thus, the animals adapted to restricted freestall access, that caused increased overnight standing, by additional lying down during the day and used part of the extra standing time at night for feeding. The restrictions probably had only a minor effect on the mechanical load of their claws. Therefore, the first part of the hypothesis was confirmed and the second part was rejected.

Effects of two trimming methods of dairy cattle on concrete or rubber-covered slatted floors

This study monitored claw health, claw conformation, locomotion, activity, and step traits of cows from a single dairy herd that were trimmed according to the standard Dutch method or with an alternative “concave” trimming method. Half of the cows were kept in a stall section with concrete slatted floors in the alleys. The other cows were kept in a pen within the same housing with an identical concrete slatted floor in the alleys, but with a rubber top layer. All experimental cows were kept in the same environment for at least 3 mo before and after trimming. It was hypothesized that trimming for more-concave soles (i.e., with 3 to 5mm of sole dug out under the claw bone) was preferred to the standard Dutch trimming with flat sole surfaces for cows kept in stalls with soft alley floors. None of the claw health or locomotion traits differed for the trimming methods. No interactions were found between flooring and trimming method. Floor effects were significant for several traits. Cows on the rubber-topped floors had significantly fewer sole hemorrhages (prevalence of 22 vs. 48% in mo 3) and larger claws (claw length 76.1±5.0 vs. 72.5±4.9mm; heel height 49.3±6.3 vs. 46.0±6.4mm; claw diagonal 129±6.4 vs. 125±6.9mm), spent more time standing in the alleys (55.4±2.8 vs. 49.6±2.8%), and had higher activity (61.0±3.7 vs. 53.0±3.7 steps/h). This suggests greater claw comfort on rubber flooring compared with concrete flooring. Kinetic patterns during claw-floor contact while walking were similar for all treatments. During the double-support (stance) phase, claw-floor contact area increased to a maximum in the first 30% of double-support phase time, remained more or less stable until 80% of double-support phase time, and sharply decreased as the animal pushed off as shown by the change in center of pressure. A gradual change of center of pressure in the medial direction during double-support phase time was shown. The research hypothesis was rejected, but soft alley floors had subtle beneficial effects.

Short Communication: Effect of Alley Floor Cleanliness on Free-Stall and Udder Hygiene

The objective was to evaluate the effect of alley floor cleanliness on the hygiene of the free-stalls and udder and teats of cows. Mechanical scrapers were used on rubber-slatted floors to improve the cleanliness of the alley floor. Two sections containing 21 cows each were evaluated once weekly for a period of 3 wk. One section had scrapers on the rubber-slatted floor in the alleys and the other section did not. The scrapers ran 12 and 7 times/d in the free-stall alley and feed alley, respectively. Manure accumulation in the alleys at approximately 2h after the scrapers had run was less in the section with the scraper than in that without the scraper. Differences between sections with and without scrapers were found in the sites close to the wall in the feed alley, and immediately behind the free-stalls in the free-stall alley. In the section without scrapers, manure accumulation was greater in the free-stall alley than in the feed alley. Manure contamination of the area in the free-stalls where the udder normally comes in contact with the free-stall floor was significantly reduced from 29.1 to 17.9±2.4g of dry matter when the alley floor was kept clean by the use of scrapers. The hygiene scores of the dirtiness of udders were reduced from 25.8±1.7 to 18.9±1.6, and those of the teats from 37.9±2.3 to 24.2±2.3 in the section with scrapers and cleaner alley floor compared with the section without scrapers. The scrapers greatly improved the hygiene on the rubber-slatted alley floor. The cleaner alley floor had a positive effect on the cleanliness of the free-stalls and the udder and teats of the cows.

Accurate visual guidance despite severe neglect

Unilateral inactivation of the superior colliculus causes profound neglect. In cats, this neglect has been studied previously using tasks that require gaze orientation to, or detection of, a stimulus appearing somewhere in the visual field of an attentive animal. We investigated how neglect affects a completely different kind of task, visually guided foot placement while walking across a cluttered surface. We made muscimol injections into one superior colliculus, and performed perimetry to gauge the extent of the cat's neglect. Cats then walked repeatedly through a cluttered test alley. Most of the time, their gaze was deviated towards the side of the injection, so that they saw the alley floor ahead of them in their neglected hemifield. Surprisingly, they accurately avoided stepping on the densely scattered objects, just as they normally do. We surmise that cats process 'neglected' visual stimuli to guide foot placement even when they are unable to consciously perceive these stimuli.

Transections involving the direct subiculum-anterior thalamic fibers: Effects on cue utilization in the straight alley

The effect of transecting fornix fibers bound for the anterior thalamic nuclei on the ability of rats to respond to changes in reward magnitude, tactile stimuli, and aversive olfactory cues was assessed. Animals with this damage failed to respond differentially to upshifts and downshifts in reward magnitude maintaining maximal running speeds throughout testing. Passive avoidance and extinction deficits also were exhibited by transected animals. However, these same animals were capable of responding to changes in the tactile stimuli of the alley floor. In all tests the performance of transected animals was different from that of controls only in the early parts of the alley. These results extend the similarities between the behavioral effects of hippocampal lesions and those that follow transections involving the fornix—thalamic fibers traveling in the postcommissural fornix.

Changes in spontaneous, odor modulated and shock induced behavior patterns following discrete olfactory system lesions

Three groups of male hooded rats were preoperatively matched and then sham operated (SHAM), bilaterally lateral olfactory tract lesioned or anterior olfactory nucleus/anterior commissure lesioned. In one experiment, spontaneous behavior patterns emitted in an exploration field containing different odors were quantified during satiated and food deprived conditions. In other experiments, flinch and jump thresholds to electric shock and running patterns in an appetitively motivated straight alley experiment were measured. All lesioned animals were hyperactive and typically froze and groomed less than SHAMs while sniffing and rearing patterns differentiated the lesioned and SHAM groups in several ways. All animals had similar flinch and jump thresholds and also emitted similar types of responses to electric shock. In the straight alley, odors from normal and stressed rats had little effect on the running time of the experimental animals while a faint cat odor strongly inhibited SHAM running behavior. Responses to a novel chemical odor (trimethylpentane) and to changes in the alley floor or electric shock applied to the floor were minimal in all animals. The results were discussed against a background of other olfactory system lesions and some evidence separating the effects of olfactory cues from nonolfactory lesion effects was presented. Finally, problems associated with tests for olfactory discrimination were discussed. A need for more rigorous and specific discrimination tests in behavioral studies involving anosmia was emphasized.

IV. Regional studies. Hudson Geotraverse: geology of the Mid-Atlantic Ridge at 45° N/ Petrology of submarine volcanics from the NE Pacific

A strip across the Crest Mountains and High-Fractured Plateau of the Mid-Atlantic Ridge has been surveyed systematically between latitudes 45 and 46° N. Continuous bathymetric, magnetic and gravimetric data have been obtained. Seismic refraction experiments have revealed a complex structure lineated parallel to the axis of the Ridge. Seismic reflexion studies have revealed a picture of the sediment cover, and have shown the possible existence of block faulting of the underlying rocks, with faults alined both parallel and at right angles to the axis of the Ridge. The major rock types found in 46 dredge stations can be grouped as follows: (1) Ubiquitous basalts and tuffs (ranging from theoleiites to alkali basalts, with a few ferro-basalts and high-Al basalts). Basalts rich in resorbed high-calcic plagioclase xenocrysts are common; these occur both on the slopes of shield volcanoes and in the deepest hole of the Median Valley. A nearby fault scarp yielded coarse-grained gabbros. (2) Serpentinized mafic and ultramafic rocks are not restricted to elongated, presumably blockfaulted seamounts, but are also common on the slopes of what had been interpreted on morphological grounds as shield volcanoes; they are absent, however, on the Median alley floor and its immediate scarp slopes. The pre-serpentinization rock types include dunites, harzburgites, gabbros, troctolitic gabbros and amphibolitic peridotites showing crude cumulate textures. (3) The lower parts of the steep inner walls of the Median Valley have yielded metabasalts and metadiabases showing alteration within the greenschist facies of etamorphism, whilst still retaining original igneous characteristics. (4) Restricted to the fault scarps of elongated seamounts further removed from the Median Valley are higher grade metamorphic rocks of the almandine amphibolite facies of metamorphism. These rocks have lost all igneous textures and exhibit a strong gneissic fabric. (5) Three localities yielded dioritic rocks in association with serpentinized ultramafics. The diorites vary in character from hornblende-rich quartz diorites to more siliceous, almost hornblende-free trondhjemites. The latter show considerable albitization. The whole suite of rocks shows great affinities with similar suites found as late stage intrusives in alpine-type ultramafic complexes. About 23% of the specimens collected included gneissic, granitic and sedimentary rock types of erratic origin, ice rafted into the area in the Pleistocene. A study of their distribution indicates that there are no erratics in the Median Valley, that they are scarce on the mountain ranges immediately flanking the Valley, but beyond these areas they are abundant and are randomly distributed over the whole area. Such a distribution may be a result of ocean-floor spreading, indicating that the Median Valley is younger than the last ice age, or that extrusions subsequent to the last ice age have engulfed any erratics present in the Median Valley. The thickness of manganese coating on extrusive rocks and their K/Ar and fission track ages increase systematically with distance on either side of the axis of the M.A.R., strongly supporting the ocean-floor spreading hypothesis. The ages and coatings both show a marked change in their rate of increase beyond a distance of 50 to 60 km on either side of the axis. The position at which this occurs coincides with the thickening in these areas of sediments found in the inter-volcanic valleys, and the morphological changes between the Crest Mountains and the High-Fractured Plateau. The combined data strongly suggest that there was either a quiescent period sometime in the Pliocene during which ocean-floor spreading was inactive, or that the rate of spreading had accelerated during the Pliocene from less than 1 cm a -1 to a computed 2.5 cm a -1 in Pleistocene times.