Individual and environmental factors associated with defecation while lying down in dairy cows.

Cows typically defecate while standing. Freestalls are designed to position standing cows such that their feces fall into the alley. Cows sometimes defecate while lying down, increasing the risk that feces contaminate the stall surface. We conducted 2 studies investigating cow-level and environmental factors associated with defecating while recumbent. In experiment 1, we hypothesized that conditions making it more difficult for cows to stand up (including greater age, high body weight, pregnancy, and lameness) would increase the risk of this behavior. We followed 92 cows for 12 d, scanning stalls 5 times/d using live observation. Almost half (48%) of all cows defecated while recumbent at least once; cows that spent more time lying down and that were earlier in gestation were at highest risk. Weight, parity, age, and lameness were not associated with this behavior. In experiment 2, we tested how overstocking influenced the occurrence of defecating while recumbent. We predicted overstocking would increase the occurrence of this behavior, especially when cows were in stalls at more preferred locations. We recorded stall occupancy, displacement attempts, and defecating while recumbent in 4 groups of 36 cows tested at both 100% and 150% lying stall stocking densities for 2 nights each using a crossover design. Overstocking resulted in higher stall use and more displacements, but less lying and fewer perching events. We did not detect any relationship between use of specific stalls or competition and defecating while recumbent. Most recorded displacements were associated with perching. Increased time perching increased the likelihood of defecating while recumbent, perhaps because perching cows were less dominant or more reluctant to stand up once lying down in the stall. Overstocking did not increase defecating while recumbent, likely because cows spent less time lying down. Together, these results indicate that defecating while recumbent can be common, and points to some of the cow-level factors associated with this behavior.

Reproductive status effects of pair-housed male pigs on natural, agonistic and sexual behaviours.

Boar rearing, which avoids pain and suffering caused by surgical castration, provides better performance, a greater deposition of muscle tissue and leaner carcasses and thus has beneficial effects on both animal welfare and the product. Some countries that do not slaughter boars must consider their boar taint and aggressive and sexual behaviours. Considering that pigs are housed in large groups, which may complicate the formation of social hierarchies and increase fighting and mounting behaviours, some studies have conducted research with reduced numbers of pigs per pen, but these behaviours continued to be observed. However, a study of the reproductive status of pair-housed male pigs has yet to be reported. The aim of this study was to determine whether the reproductive status of uncastrated, immunocastrated and surgically castrated pair-housed male pigs alters their natural, agonistic and sexual behaviours. A total of 48 male pigs from Agroceres PIC™ genetics were assigned to three groups: surgically castrated (barrows), immunocastrated and uncastrated (boars). Natural, aggressive and sexual behaviours of the pigs were assessed by direct observations during four periods of 12 h each (six, five and three weeks before slaughter and the slaughter week). The pigs were housed in pairs from the growing phase until slaughter. Animal behaviour was observed from the finishing phase to slaughter. Carcass lesions were assessed according to five different classes (one: no injury; two to five: severely injured). Overall, boars spent more time lying and less time eating and drinking than barrows. In total of all the periods (48 h), boars expressed more aggressive and sexual behaviours than barrows, whereas immunocastrated pigs displayed similar behaviours to boars, before and after the second vaccine dose. No differences in carcass lesions between treatments and no prevalence of carcasses with severe injuries were observed. In conclusion, the reproductive status of pair-housed male pigs did not change the natural behaviour of boars, immunocastrated pigs or barrows. The agonistic and sexual behaviours of boars and barrows remained unchanged. When housing pigs in pairs, immunocastrated pigs presented similar agonistic and sexual behaviours to boars before and after the second immunocastration vaccine dose. The use of pair-housed uncastrated male pigs has generated welfare benefits for these animals, as the number of carcasses with injuries did not differ from barrows and immunocastrated pigs.

Dairy cow preference and usage of an alternative freestall design.

Freestall housing for dairy cows was created to reduce the amount of bedding and labor needed to keep stalls clean. However, some aspects of stall design may restrict stall usage by cows. The aim of this study was to assess dairy cow preference and usage of a conventional stall (with a neck rail and metal stall dividers) and an alternative stall design with no neck rail or stall dividers other than a wooden board protruding slightly (8cm) above the lying surface. In the no-choice phase of the study, 48 cows were randomly assigned to 8 groups (of 6 cows each); groups were alternately allocated to the 2 treatments. Each group was observed for 7 d on one treatment and then switched to the alternate treatment for 7 d. For the choice phase (also 7 d), groups in adjacent pens were merged (to form 4 groups, each with 12 cows) and cows had free access to both treatments within the merged pen. In the no-choice phase, cows spent more time standing with 4 hooves in the alternative versus conventional freestall (0.60±0.06 vs. 0.05±0.06h/d), but stall designs had no effect on time spent lying down (13.2±0.4 vs. 12.9±0.4h/d). In the choice phase, cows spent more time lying down in the conventional freestall (9.4±0.8 vs. 4.1±0.8h/d) and more time standing with all 4 hooves in the alternative stall (0.24±0.03 vs. 0.02±0.03h/d). These results illustrate how different stall design features can affect different types of stall use; the more open design facilitated standing fully in the stall, but the protruding partitions likely made the stall less suitable for lying.

Sampling behavior of dairy cattle: effects of variation in dietary energy density on behavior at the feed bunk.

Factors affecting sampling behavior of cattle are poorly understood. The objectives of this study were to measure the effects of variation in feed quality on the feeding behavior of Holstein dairy heifers. Thirty-two heifers were housed in 4 groups of 8. Each group pen had 8 distinct feeding stations. The total mixed ration (TMR) provided was low energy (TMR-L), moderate energy (TMR-M), or high energy (TMR-H). During trial 1 (d 1 to 8), heifers were offered a uniform baseline diet (TMR-M in all 8 feeding stations) interspaced with 2 uniform test diets on d 3 and 6 (TMR-L or TMR-H in all 8 feeding stations). During trial 2 (d 9 to 17) heifers were offered a nonuniform baseline diet (7 feeding stations with TMR-L and 1 feeding station with TMR-H) interspaced with 3 uniform test diets on d 11, 14, and 17 (TMR-L, TMR-M, or TMR-H in all 8 feeding stations). Heifers were observed in pairs (n=16) for 15 min following delivery of fresh feed. Relative to the uniform baseline period of trial 1, 31% fewer switches occurred between feeding stations when offered TMR-H and 51% more switches when offered TMR-L. Relative to the nonuniform baseline of trial 2, 49% fewer, 27% fewer, and 25% more switches occurred during the TMR-H, TMR-M, and TMR-L treatments, respectively. In general, when heifers were offered a diet that was lower in energy density than that previously experienced, they spent less time at each feeding station and when offered a higher energy diet, heifers spent more time at each feeding station. The greater the contrast in energy density between the test and baseline diets, the greater the change in the behavioral response. Competitive interactions at the feed bunk were most frequent when TMR quality varied among the 8 feeding stations; during the nonuniform baseline period of trial 2, the number of competitive interactions was over 3.5 times higher than during all uniform dietary treatments. In summary, dairy heifers sample feed quality by changing feeding locations at the feed bunk and this sampling behavior is affected by variation in diet quality along the feed bunk and across days.

Short communication: effects of bedding quality on the lying behavior of dairy calves.

The lying behavior of adult cattle is strongly affected by characteristics of the lying surface, but no previous work has assessed the effects of lying surface for dairy calves. We evaluated how the lying behavior of dairy calves changed when calves were provided sawdust-bedded versus concrete lying surfaces, and in response to variation in dryness of the sawdust bedding. Five Holstein calves, approximately 2-wk old, were individually housed in pens with half of the lying surface bedded with kiln-dried sawdust [90% dry matter (DM)] and the other half with wet bedding varying in DM at 4 levels (74, 59, 41, and 29%) or bare concrete. All calves were tested on all 5 treatments, with treatment order assigned using a 5 × 5 Latin square. Total lying time averaged 17.2 ± 0.1 h/d and did not vary with treatment, but time lying on the wet bedding decreased from 5.3 ± 1.1 h/d at 74% DM to almost zero at 29%. Lying times on the side of the pen with dry bedding varied from 12.2 ± 1.2 h/d (when the wet bedding was 74% DM) to 16.8 ± 1.2 h/d (at 29% DM). Standing times were higher on the dry than the wet bedding (2.6 vs. 1.7 ± 0.1 h/d) but did not change across the range of bedding DM tested on the wet side. No calves ever lay down on the bare concrete. In conclusion, dairy calves showed clear preference for drier sawdust bedding and aversion to concrete lying surfaces, indicating that access to soft and dry bedding is important for growing calves.

Introducing heifers to freestall housing.

Little work to date has assessed how dairy cattle respond when first introduced to freestall housing. In this study we carried out 2 experiments. The aim of experiment 1 was to assess the behavioral responses of naïve heifers to pens fitted with freestalls. Holstein heifers (n=7 groups, each containing 3 heifers, 3 mo of age), with no previous experience with freestalls, were initially housed on a sawdust bedded pack and fed through a fixed feed barrier for at least 6 wk and then moved to a freestall pen fitted with a head-locking feed barrier. When kept on the bedded pack, the heifers' lying time averaged 14.2 h/d. On the day heifers were moved to the freestall pen, lying times declined by 2.9 h, but recovered on the following days. The time spent lying down on the barn floor (i.e., outside the lying area) increased by 2.5 h on the day heifers were introduced to freestalls and remained higher during subsequent days. Heifers spent 46 min/d less time feeding on the day they were switched to the head-locking barrier, but recovered on the following days. In experiment 2 we assessed the behavioral responses of naïve heifers introduced to pens fitted with freestalls with or without a neck rail. Holstein heifers (n=12 groups, each containing 2 heifers, 3 mo of age), with no previous experience with freestalls, were initially housed on a sawdust bedded pack and then moved to a freestall pen with or without neck rails. Heifers spent 4.2 h/d less time lying down in the 24 h following introduction into the freestall pen; the neck rail treatment had no effect on lying time but heifers spent more time standing with just their front 2 hooves in the stall when a neck rail was in the stall. In summary, lying and feeding behavior of naïve heifers is altered following introduction to new housing.

Cow preference and usage of free stalls compared with an open pack area.

Free-stall housing systems are designed to provide a comfortable and hygienic lying area, but some aspects of stall design may restrict usage by cows. The aim of this study was to compare free-stall housing with a comparable lying area (open pack) without stall partitions. We predicted that cows would spend more time lying down and standing in the bedded area when provided access to an open pack than when in free stalls. We also predicted that cows would spend less time standing outside of the lying area and less time perching with the front 2 hooves in the lying area when using the open pack. Groups (n = 8) of 12 cows each were provided access to either the open pack or stalls. After a 7-d adaptation period, each group was tested sequentially in the 2 treatments for 3 d each. This no-choice phase was followed by an 8-d choice phase during which cows had simultaneous access to both treatments. During the no-choice phase, cows spent more time lying down (13.03 +/- 0.24 vs. 12.48 +/- 0.24 h/d) and standing with all 4 hooves in the bedded area (0.96 +/- 0.12 vs. 0.41 +/- 0.12 h/d) of the open pack than in the stalls. During the choice phase, cows spent more time lying down (7.20 +/- 0.29 vs. 5.86 +/- 0.29 h/d) and standing with all 4 hooves in the bedded area (0.58 +/- 0.07 vs. 0.12 +/- 0.07 h/d) of the open pack than in the stalls. In both the no-choice (1.66 +/- 0.24 vs. 0.55 +/- 0.24 h/d) and choice (0.55 +/- 0.07 vs. 0.29 +/- 0.07 h/d) phases, cows spent more time standing with just 2 hooves in the stalls than in the open pack. In conclusion, cows spent more time lying and standing with all 4 hooves in the bedded open pack than in the stalls. Additionally, cows spent more time standing in the alley and standing with just the front 2 hooves on the bedding in the stalls than in the bedded open pack; increased standing time on wet concrete is a known risk factor for lameness.

Neck-rail position in the free stall affects standing behavior and udder and stall cleanliness.

This study tested the effect of neck-rail position on stall usage and udder and stall cleanliness. Thirty Holstein lactating cows were tested in groups of 6. Each group was tested with each of 5 neck-rail positions (130, 145, 160, 175, and 190 cm from the rear curb, at a constant height of 125 cm above the bedded surface) for 1 wk, with the order of testing allocated in a 5 x 5 Latin square. When the neck rail was positioned further from the rear curb, cows spent less time standing with their front 2 hooves in the stall (2.2 +/- 0.26 h/d at 130 cm vs. 1.7 +/- 0.27 h/d at 190 cm, mean +/- SE) and more time standing with all 4 hooves in the stall (0.0 +/- 0.02 h/d at 130 cm vs. 0.6 +/- 0.07 h/d at 190 cm). These effects of neck-rail position tended to be more marked for smaller cows, perhaps because the standing behavior of larger cows was restricted even in the 190-cm treatment. Cows were more likely to defecate and urinate in the stalls when the neck rail was positioned further from the rear curb. Cows using these stalls tended to have dirtier udders and these stalls required more cleaning time (0.4 +/- 0.16 min/d at the 130-cm position vs. 1.6 +/- 0.35 min/d at the 190-cm position). In summary, positioning the neck rail further from the curb increased the time that cows spent standing fully in the stall. This change in standing behavior is likely beneficial for hoof health, but reduced udder and stall cleanliness.

Effects of bedding quality on lying behavior of dairy cows.

Cows prefer to spend more time lying down in free stalls with more bedding, but no research to date has addressed the effects of bedding quality. Bedding in stalls often becomes wet either from exposure to the elements or from feces and urine. The aim of this study was to test the effect of wet bedding on stall preference and use. Four groups of 6 nonlactating Holstein cows were housed in free stalls bedded daily with approximately 0.1 m of fresh sawdust. Following a 5-d adaptation period, each group of cows was tested sequentially with access to stalls with either dry or wet sawdust bedding (86.4 +/- 2.1 vs. 26.5 +/- 2.1% dry matter), each for 2 d. These no-choice phases were followed by a 2-d free-choice phase during which cows had simultaneous access to stalls containing either wet or dry bedding. Stall usage was assessed by using 24-h video recordings scanned at 10-min intervals, and responses were analyzed by using a mixed model, with group (n = 4) as the observational unit. The minimum and maximum environmental temperatures during the experiment were 3.4 +/- 2.2 and 6.8 +/- 2.5 degrees C, respectively. When cows had access only to stalls with wet bedding, they spent 8.8 +/- 0.8 h/d lying down, which increased to 13.8 +/- 0.8 h/d when stalls with dry bedding were provided. Cows spent more time standing with their front 2 hooves in the stall when provided with wet vs. dry bedding (92 +/- 10 vs. 32 +/- 10 min/d). During the free-choice phase, all cows spent more time lying down in the dry stalls, spending 12.5 +/- 0.3 h/d in the dry stalls vs. 0.9 +/- 0.3 h/ d in stalls with wet bedding. In conclusion, dairy cows show a clear preference for a dry lying surface, and they spend much more time standing outside the stall when only wet bedding is available.

Overstocking reduces lying time in dairy cows.

Our objective was to understand the effect of overstocking on the lying and standing behavior of dairy cattle. We manipulated freestall availability by providing 12, 11, 10, 9, or 8 freestalls to 12 cows (n = 4 groups, 12 cows/group), thus creating stocking levels of 100, 109, 120, 133, and 150%, respectively. Treatments were applied for a week at a time in a switchback design. Each group returned to the 100% stocking level after exposure to the other treatments. In addition to lying and standing behavior, we measured each cow's ability to displace others from the freestall to understand the interaction between social status and response to overstocking. When groups of cows had fewer stalls available, they spent less time lying down. There was no effect of overstocking on time spent standing with only the front legs in the stall. Instead, cows compensated for the reduced lying times by spending more time outside of the stall. When fewer stalls were available, animals were more likely to be displaced from stalls. The cow's ability to displace others from the stalls, however, did not explain the magnitude of their reduction in lying time when provided with fewer freestalls. Due to increased competition for stalls, cows lay down sooner at 150% than at the 100% level. Stall use was more uniform across time and across stalls within the pen when fewer freestalls were available. In conclusion, when cows had access to fewer freestalls, there was increased competition for stalls, increased time standing outside the stalls, and reduced lying time.