Daytime shelter use of individually kept horses during Swedish summer.

In Sweden, no provision for summer shelter to protect horses from heat and insects is required, although access to shelter for horses kept outdoors 24 h during winter is a requirement. This study investigated horses' daytime shelter-seeking behavior in relation to weather conditions and insect activity during a 2-wk period in summer. Eight Warmblood riding horses had access to 2 shelters of different design to test which shelter design is preferred by horses. Furthermore, rectal and skin temperatures and insect-defensive behavior were measured to test whether horses would benefit from the provision of shade. The horses were kept alone in paddocks for 4 d. During 2 d, horses had access to 2 shelters: 1) open shelter with roof and uncovered sides and 2) closed shelter with roof, wind nets on 2 sides, and opaque plastic opposite the entrance. Weather conditions (ambient temperature, relative humidity, solar radiation, wind speed) were recorded every 10 min. The number of insects (flies, mosquitos) was counted from insect traps placed in each shelter and outside. Behavior (shelter use, insect-defensive behavior, locomotion, grazing) was recorded at 5-min intervals between 0900 to 1200 h and 1300 to 1600 h and rectal and skin temperatures were measured at 0800 h, 1200 h, and 1600 h. Data were analyzed with PROC MIXED and GLIMMIX procedure for Generalized Linear Mixed Models. Ambient temperature ranged from 16 to 25°C (average temperature humidity index 65.7 ± 1.4). Five horses preferred the closed shelter and were observed inside up to 2.5 h continuously. Greater wind speed decreased the likelihood of observing horses inside the shelter ( < 0.001), as did lower numbers of flies ( < 0.001). The insect-defensive behaviors, skin shiver and ear flick, were performed less frequently when horses were using the closed shelter ( < 0.001), indicating that they were less disturbed by insects. Thirty-minute shelter use had no effect on rectal and skin temperatures ( > 0.05). Results showed that horses made use of shelters during the summer even when weather conditions were moderate. A shelter with roof and covers on 3 sides was preferred over a shelter with roof only and can reduce insect-defensive behavior.

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 2 h 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 +/- 2.4 g 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.

Effect of different flooring systems on weight and pressure distribution on claws of dairy cows.

Weight and pressure distribution on the claw were studied in Swedish Holsteins housed in different flooring systems. A total of 127 cows housed in different sections of the experimental barn were used. Each section had different flooring in the walking and standing areas. There were rubber mats or abrasive mastic asphalt flooring on the alleys or a low-abrasive slatted concrete floor. Some sections had feed-stalls equipped with rubber mats; other sections did not. The vertical ground reaction force, contact area, and average contact pressure were determined on the left hind foot using the I-Scan system and analyzed with the F-scan system. These determinations were made in each of the following 3 zones of the claw: bulb, wall, and sole. Most of the weight on claws exposed to concrete floors was carried by the bulb (37.4 +/- 3.5 and 18.3 +/- 2.9% of weight exerted on the foot in the lateral and medial claw, respectively) and the wall zone (20.0 +/- 2.6 and 13.4 +/- 2.4% on lateral and medial claw, respectively). The weight and pressure distribution in cows kept on sections with rubber covered alleys but passing daily over the asphalt floor on their way to the milking parlor did not differ in any zones, except for lateral bulbs, compared with those exposed to slatted concrete alone. Still, the weight bearing of the sole zone in cows kept on rubber mats without access to asphalt was less than that of cows kept on concrete slatted floors (5.1 +/- 0.7 vs. 12.7 +/- 1.1% and 1.1 +/- 0.5 vs. 8.7 +/- 0.7% in lateral and medial claws, respectively). In cows kept on asphalt flooring without feed-stalls, most weight was exerted to the sole zone (36.2 +/- 2.9 and 22.2 +/- 1.8% in lateral and medial claws, respectively). Feed-stalls in combination with asphalt flooring yielded a decreased total contact area (30.1 +/- 1.2 cm(2)) compared with asphalt floors without feed-stalls (35.7 +/- 1.2 cm(2)). The largest total contact area was obtained on the asphalt floor without feed-stalls, resulting in a lower contact pressure (39.8 +/- 2.3 N/cm(2)) than in claws exposed to concrete (66.0 +/- 2.7 N/ cm(2)) or rubber mats (56.7 +/- 1.7 N/cm(2)). In conclusion, housing with abrasive floors resulted in claws with increased contact area at the sole surface and therefore, decreased contact pressure, but reduced the weight-bearing role of the strongest part of the claw capsule, the claw wall.

The importance of udder and teat conformation for teat seeking by the newborn calf.

Because antibody levels in colostrum and the efficiency of the intestinal absorption of these antibodies decrease with time after birth, late sucking inadequate passive immunity. The influence of the conformation and the size of the udder and teats of the dam on the teat-seeking behavior of newborn calves with respect to the time they first suckle was studied in 42 cow-calf pairs housed in individual calving pens. A smaller distance from udder to floor (e.g., low slung udders) led to increase in the time spent teat seeking; it also had a significant effect of the time of the first suckle. The variation in the distance from udder to floor accounted for 24 and 15% of the variations in rank order of the calves with respect to duration of active teat seeking before first suckling and to the time to first suckle, respectively. The results of this study showed that calves born to cows or heifers with low slung udders cannot be expected to obtain colostrum soon enough by natural suckling. They should either be helped to suckle or be hand fed to ensure that they receive a good and adequate passive immunity.

Cow-calf behaviour in relation to first suckling.

For the newborn calf, the length of time between birth and when (and if) it manages to obtain its first suckle plays an important role in the acquisition of passive immunity. In a study of 21 pairs of dairy cows and their calves, loose housed in individual calving boxes, the calves suckled for the first time at a median of four hours, nine minutes after birth. Nineteen suckled within 12 hours, with a range between 50 minutes and 11 hours, 44 minutes. Calves that were active early usually suckled early. However, irrespective of the start of a calf's activities, long pauses while teat seeking played a decisive role in the time of the first suckling. Factors which affected the periodicity and length of these pauses would therefore greatly influence the time of the first suckling.

Milk intake before first colostrum in newborn dairy calves. Effect on intestinal transmission of macromolecules.

The aim of this experiment was to investigate if ingestion of non-colostrum milk before first colostrum by calves impaired intestinal transmission of macromolecules from colostrum fed to calves 8, 16, and 24 h later. This design reflects the situation when calves are born in housing systems where the cow and her newborn calf are not separated from the herd, which gives the calf opportunity to suckle cows other than the mother. Two groups of eight calves each were fed pooled colostrum three times at 8, 16, and 24 h of age. One of the groups were fed non-colostrum milk 30 min after birth. Marker molecules were used to estimate absorption from each colostrum feeding. Blood samples were taken 8 h after each feeding and at 1 wk of age. At no time was there any significant difference between the plasma IgG means of the two groups. There was no difference in transmission of the marker molecules. It was concluded that early ingestion of non-colostrum milk before first colostrum does not change intestinal permeability to colostral macromolecules.

Intestinal transmission of macromolecules in newborn dairy calves of different ages at first feeding.

Four groups of eight newborn calves were used to study the intestinal transmission of colostral immunoglobulin from the intestinal lumen to the blood circulation. The first feed was given one, eight, 16 or 24 hours after birth. Thereafter, three feeds were given with eight hour intervals. All feeds were from the same pool of colostrum and the amount fed each time corresponded to 3 per cent of the calves birthweight. To estimate the transmission of macromolecules in each feed four different macromolecules were used as markers. For the first feed, the marker was bovine IgG, in the second FITC-dextran, in the third ovalbumin and in the fourth human serum albumin. Blood samples were taken eight hours after each feed and at one week old. There were no differences in transmission for the first feed although the calves varied in age between one and 24 hours, but in the second, third and fourth feeds the calves that received a first feed at one hour old, transmitted significantly more of the marker molecules than did the other three groups. The substantial transmission of macromolecules at the first feed in all four groups indicates that a base level of transmission capacity is maintained during the first 24 hours or longer and that, under certain conditions, acceptable passive immunisation is possible in calves given their first colostrum as late as 24 hours after birth.