Determining suitable dimensions for dairy goat feeding places by evaluating body posture and feeding reach.

Confined goats spend a substantial part of the day feeding. A poorly designed feeding place increases the risk of feeding in nonphysiological body postures, and even injury. Scientifically validated information on suitable dimensions of feeding places for loose-housed goats is almost absent from the literature. The aim of the present study was, therefore, to determine feeding place dimensions that would allow goats to feed in a species-appropriate, relaxed body posture. A total of 27 goats with a height at the withers of 62 to 80 cm were included in the study. Goats were tested individually in an experimental feeding stall that allowed the height difference between the feed table, the standing area of the forelegs, and a feeding area step (difference in height between forelegs and hind legs) to be varied. The goats accessed the feed table via a palisade feeding barrier. The feed table was equipped with recesses at varying distances to the feeding barrier (5-55 cm in 5-cm steps) at angles of 30°, 60°, 90°, 120°, or 150° (feeding angle), which were filled with the goats' preferred food. In 18 trials, balanced for order across animals, each animal underwent all possible combinations of feeding area step (3 levels: 0, 10, and 20 cm) and of difference in height between feed table and standing area of forelegs (6 levels: 0, 5, 10, 15, 20, and 25 cm). The minimum and maximum reach at which the animals could reach feed on the table with a relaxed body posture was determined for each combination. Statistical analysis was performed using mixed-effects models. The animals were able to feed with a relaxed posture when the feed table was at least 10 cm higher than the standing height of the goats' forelegs. Larger goats achieved smaller minimum reaches and minimum reach increased if the goats' head and neck were angled. Maximum reach increased with increasing height at withers and height of the feed table. The presence of a feeding area step had no influence on minimum and maximum reach. Based on these results, the goats' feeding place can be designed to ensure that the animals are able to reach all of the feed in the manger or on the feed table with a relaxed posture, thus avoiding injuries and nonphysiological stress on joints and hooves. A feeding area step up to a maximum of 20 cm need not be taken into account in terms of feeding reach. However, the feed table must be raised at least 10 cm above the standing area to allow the goats to feed in a species-appropriate, relaxed posture.

The Role of Egg Production in the Etiology of Keel Bone Damage in Laying Hens.

Keel bone fractures and deviations belong to the most severe animal welfare problems in laying hens and are influenced by several factors such as husbandry system and genetic background. It is likely that egg production also influences keel bone health due to the high demand of calcium for the eggshell, which is, in part, taken from the skeleton. The high estrogen plasma concentration, which is linked to the high laying performance, may also affect the keel bone as sexual steroids have been shown to influence bone health. The aim of this study was to investigate the relationship between egg production, genetically determined high laying performance, estradiol-17ß concentration, and keel bone characteristics. Two hundred hens of two layer lines differing in laying performance (WLA: high performing; G11: low performing) were divided into four treatment groups: Group S received an implant containing a GnRH agonist that suppressed egg production, group E received an implant containing the sexual steroid estradiol-17ß, group SE received both implants, and group C were kept as control hens. Between the 12th and the 62nd weeks of age, the keel bone of all hens was radiographed and estradiol-17ß plasma concentration was assessed at regular intervals. Non-egg laying hens showed a lower risk of keel bone fracture and a higher radiographic density compared to egg laying hens. Exogenous estradiol-17ß was associated with a moderately higher risk of fracture within egg laying but with a lower risk of fracture and a higher radiographic density within non-egg laying hens. The high performing layer line WLA showed a significantly higher fracture risk but also a higher radiographic density compared to the low performing layer line G11. In contrast, neither the risk nor the severity of deviations were unambiguously influenced by egg production or layer line. We assume that within a layer line, there is a strong association between egg production and keel bone fractures, and, possibly, bone mineral density, but not between egg production and deviations. Moreover, our results confirm that genetic background influences fracture prevalence and indicate that the selection for high laying performance may negatively influence keel bone health.

Radiographic examination of keel bone damage in living laying hens of different strains kept in two housing systems.

A high prevalence of deviations and fractures of the keel bone is a widespread welfare problem in laying hens. The aim of this study was to experimentally investigate this multifactorial problem throughout the laying period and to compare the prevalence and severity in different layer lines and different housing systems. High performing white (WLA) and brown (BLA) pure bred layer lines and low performing white (R11, G11) and brown layer lines (L68) were kept in both single cages and a floor housing system. A total of 97 hens (19 or 20 from each line, respectively) were repeatedly radiographed in the 35th, 51st and 72nd week of age. Fracture prevalence increased with age (p<0.001). The proportion of deviated keel bone area increased only for caged BLA, WLA and R11 hens (p<0.05) and was significantly higher for caged WLA and R11 hens compared to floor-housed WLA and R11 hens in the 72nd week of age (p<0.05). In the 72nd week of age hens in the floor housing system showed significantly more fractures than hens kept in cages (p<0.05). Prevalence of keel bone deviations was significantly higher in the white layer line R11 but significantly lower in the white layer line G11 compared to both brown layer lines and WLA (p<0.05). Brown layers showed significantly more fractures than white layers (p<0.05) in the 51st and 72nd week of age. Within the brown layers there was a significantly lower prevalence of deviations (p<0.05) and fractures (p<0.05) in the low performing (L68) compared to the high performing line (BLA). Our results show a different development of keel bone damage in caged compared to floor-housed hens under experimental conditions. Additionally, they indicate genetic effects on keel bone damage.

Influence of a Sustained Release Deslorelin Acetate Implant on Reproductive Physiology and Associated Traits in Laying Hens.

The aim of this study was to develop an animal model with non-laying hens which would allow for investigation of the relationship between egg production and common diseases in hens. A total of 40 Lohmann Selected Leghorn hens were kept for 20 weeks in a floor housing system in two groups: group "Adult" (21 weeks of age) and group "Juvenile" (14 weeks of age). In each group, 10 hens were administered a 4.7 mg sustained release deslorelin acetate implant subcutaneously; in group "Adult" after, in group "Juvenile" before the onset of lay. In both groups, the remaining hens served as control hens. An examination of each hen was performed weekly, including ultrasonography to check for ovarian follicles, analysis of estradiol-17ß plasma concentration, and assessment of comb size. Digital radiographs of the keel bone were taken in experimental weeks 7 and 15. No follicles were detected on the ovary of treated hens for a certain time period which varied between individuals (between 8 weeks and until the end of the experiment). Estradiol-17ß concentrations were significantly higher in control hens. The comb was significantly smaller in treated hens. A lower prevalence of keel bone damage (group "Adult") and foot pad dermatitis (FPD) (both groups) was found in treated compared to control hens. These results show that a model with laying and non-laying hens can be achieved by administering a deslorelin acetate implant. Furthermore, they indicate a relationship between egg production and keel bone damage as well as FPD.

Regular Exposure to Cowbells Affects the Behavioral Reactivity to a Noise Stimulus in Dairy Cows.

In alpine regions, cows are often equipped with bells during pasture season to ensure that farmers can locate them. Constant exposure to the chime of a bell may affect cows' acoustic perception in general. The aim of this study is to test whether routine bell exposure affects the reactivity to a noise stimulus and might be associated with hearing impairment in cows. For the assessment, behavioral and cardiac indicators were used as indirect measures of hearing capacity. Cows that were either used to wearing a bell or not were exposed to a playback of low and high amplitude (=varying loudness). In addition, we tested whether wearing earplugs, mimicking hearing impairment, reduced the cows' reactivity toward the playback. On 24 farms, half of them routinely using cowbells, 96 Brown Swiss cows were tested in a 2 × 2 factorial cross-over design (65 or 85 dB, without or with earplugs) in a balanced order. The effects of bell experience, amplitude, and earplugs on the latency to the first behavioral and cardiac response to a 5-s playback were analyzed using linear mixed-effects models, considering dependencies within the data set. Cows reacted faster without earplugs and when they were exposed to 85 dB compared with 65 dB. The proportion of cows leaving the feeding rack after onset of the playback was reduced by bell experience and earplugs and was increased when exposed to 85 dB compared with 65 dB. Exposure without earplugs to 85 dB but not to 65 dB increased heart rate. Heart rate and heart rate variability indicated increased sympathetic activation during the exposure to 85 dB compared with 65 dB. In general, behavioral and cardiac indicators did not indicate severe hearing impairment due to routine bell exposure. The 85-dB stimulus increased arousal and avoidance compared with the 65-dB stimulus, with bell experience and earplugs leading to a general decrease in avoidance of the stimulus. This may reflect an altered acoustic perception of the playback stimulus in dairy cows that are routinely exposed to bells.

Space Allowance of the Littered Area Affects Lying Behavior in Group-Housed Horses.

Horses can sleep while standing; however, recumbency is required for rapid eye movement (REM) sleep and therefore essential. Previous research indicated a minimal duration of recumbency of 30 min per 24 h to perform a minimal duration of REM sleep. For group-housed horses, suitable lying area represents a potentially limited resource. In Switzerland, minimal dimensions for the space allowance of the littered area are therefore legally required. To assess the effect of different space allowances of the littered area on lying behavior, 38 horses in 8 groups were exposed to 4 treatments for 11 days each; T0: no litter provided, T0.5: 0.5× minimal dimensions, T1: minimal dimensions, and T1.5: 1.5× minimal dimensions. Non-littered areas were covered with hard rubber mats. Lying behavior was observed during the last 72 h of each treatment. The total number of lying bouts per 24 h was similar in treatments providing litter, whereas in treatment T0, recumbency occurred only rarely (F1,93 = 14.74, p = 0.0002) with the majority of horses lying down for less than 30 min per 24 h ([Formula: see text], p = 0.0006). Overall, the total duration of recumbency per 24 h increased with increasing dimensions of the littered area, whereby the effect attenuated between treatment T1 and T1.5 in high-ranking horses but continued in low-ranking horses (F1,91 = 3.22, p = 0.076). Furthermore, low-ranking horses showed considerably more forcedly terminated lying bouts in treatments T0.5 and T1, but were similar to high-ranking horses in T1.5 (F1,76 = 8.43, p = 0.005). Nonetheless, a number of individuals showed durations of recumbency of less than 30 min per 24 h even in treatment T1.5. The lying behavior was dependent on the availability of a soft and deformable surface for recumbency. A beneficial effect of enlarged dimensions of the littered area was shown by increased durations of recumbency and decreased proportion of forcedly terminated lying bouts in low-ranking horses. Taking this into account, it became evident that the minimal dimensions for the littered area as implemented in the Swiss animal welfare legislation do not ensure undisturbed lying behavior for all members of a given group.

Are Eyes a Mirror of the Soul? What Eye Wrinkles Reveal about a Horse's Emotional State.

Finding valid indicators of emotional states is one of the biggest challenges in animal welfare science. Here, we investigated in horses whether variation in the expression of eye wrinkles caused by contraction of the inner eyebrow raiser reflects emotional valence. By confronting horses with positive and negative conditions, we aimed to induce positive and negative emotional states, hypothesising that positive emotions would reduce whereas negative emotions would increase eye wrinkle expression. Sixteen horses were individually exposed in a balanced order to two positive (grooming, food anticipation) and two negative conditions (food competition, waving a plastic bag). Each condition lasted for 60 seconds and was preceded by a 60 second control phase. Throughout both phases, pictures of the eyes were taken, and for each horse four pictures per condition and phase were randomly selected. Pictures were scored in random order and by two experimenters blind to condition and phase for six outcome measures: qualitative impression, eyelid shape, markedness of the wrinkles, presence of eye white, number of wrinkles, and the angle between the line through the eyeball and the highest wrinkle. The angle decreased during grooming and increased during food competition compared to control phases, whereas the two phases did not differ during food anticipation and the plastic bag condition. No effects on the other outcome measures were detected. Taken together, we have defined a set of measures to assess eye wrinkle expression reliably, of which one measure was affected by the conditions the horses were exposed to. Variation in eye wrinkle expression might provide valuable information on horse welfare but further validation of specific measures across different conditions is needed.

Context Specificity of the ANS Stress Response during Two Regrouping Experiments in Goats.

The aim of this study was to analyze whether the activity of the autonomic nervous system (ANS) differs between two regrouping procedures in goats, which would indicate stimulus specificity of these stressors. Applying two regrouping procedures, we evaluated heart rate and heart rate variability (RMSSD, SDNN, and RMSSD/SDNN). The two regrouping procedures were (1) introduction of individual goats into established groups ("introduction experiment") and (2) temporary separation and subsequent reintegration of individuals from/into their group with two levels of contact during separation ("separation experiment"). In the "introduction experiment," the heart rate of introduced goats while lying decreased continuously from an average 78 to 68 beats/min from before the introduction to the last day of the introduction period. Inversely, RMSSD increased continuously from 41 to 62 ms, which, on its own, would indicate an adaptation to the situation. During the "separation experiment," heart rate while lying was higher when goats were separated in the "acoustic contact treatment" (82 beats/min on average) compared with the "restricted physical contact treatment" (75 beats/min on average). This difference reflected a higher level of arousal during the "acoustic contact treatment." However, heart rate activity did not allow detecting effects of separation or reintegration. Even though it can be assumed that both the separation and introduction of goats are stressful for goats, the ANS reactions observed in this study differed between the two management procedures indicating that the ANS activation was specific to each situation. In addition, we discuss the ANS results in context with earlier findings of variables of the hypothalamic pituitary adrenal (HPA) axis (fecal cortisol metabolites) and behavior (lying and feeding). As correspondence between ANS, HPA, and behavioral reactions was limited both within and across experiments, the results of this study underline the concept that stress response patterns are context specific.

Do bells affect behaviour and heart rate variability in grazing dairy cows?

In alpine regions cows are often equipped with bells. The present study investigated the impact of wearing a bell on behaviour and heart rate variability in dairy cows. Nineteen non-lactating Brown-Swiss cows with bell experience were assigned to three different treatments. For 3 days each, cows were equipped with no bell (control), with a bell with inactivated clapper (silent bell) or with a functional bell (functional bell). The bells weighed 5.5 kg and had frequencies between 532 Hz and 2.8 kHz and amplitudes between 90 and 113 dB at a distance of 20 cm. Data were collected on either the first and third or on all 3 days of each treatment. Whereas duration of rumination was reduced with a functional bell and a silent bell compared with no bell, feeding duration was reduced with a silent bell and was intermediate with a functional bell. Head movements were reduced when wearing a silent bell compared with no bell and tended to be reduced when wearing a functional compared to no bell. With a functional bell, lying duration was reduced by almost 4 hours on the third day of treatment compared with the first day with a functional bell and compared with no bell or a silent bell. All additional behavioural measures are consistent with the hypothesis of a restriction in the behaviour of the cows wearing bells, although this pattern did not reach significance. There was no treatment effect on heart rate variability, suggesting that the bells did not affect vago-sympathetic balance. An effect of experimental day was found for only 1 out of 10 behavioural parameters, as shown by a decrease in lying with a functional bell on day 3. The results indicate behavioural changes in the cows wearing a bell over 3 days, without indication of habituation to the bell. Altogether, the behavioural changes suggest that the behaviour of the cows was disturbed by wearing a bell. If long-lasting, these effects may have implications for animal welfare.