Habituating to handling: Factors affecting preorbital gland opening in red deer calves

The preorbital gland plays not only an olfactory role in cervids but also a visual one. Opening this gland is an easy way for the calf to communicate with the mother, indicating hunger/satiety, stress, pain, fear, or excitement. This information can be also useful for farm operators to assess how fast the calves habituate to handling routines and to detect those calves that do not habituate and may suffer chronic stress in the future. Thirty-one calves were subjected to 2 consecutive experiments to clarify if observing preorbital gland opening is related to habituation to handling in red deer calves (Cervus elaphus). Calves were born in 3 different paddocks, handled as newborns (Exp. 1), and then subjected to the same routine handling but with different periodicity: every 1, 2, or 3 wk (Exp. 2). In Exp. 1, preorbital gland opening was recorded in newborns during an initial handling (including weighing, ear tagging, and sex determination). Preorbital gland opening occurred in 93% of calves during this procedure and was not affected by sex, time since birth, or birth weight. Experiment 2 consisted of measuring preorbital opening during the same routine handling (weighing, blood sampling, and rump touching to assess body condition) when calves were 1, 3, and 5 mo old. Binary logistic regression showed that gland opening was associated with habituation to handling, since at 1 and 3 mo the probability of opening the gland decreased with the number of handlings that a calf experienced before (P = 0.008 and P = 0.028, respectively). However, there were no further changes in preorbital gland opening rate in the 5-mo-old calves (P = 0.182). The significant influence of the number of previous handlings on the probability of opening the preorbital gland was confirmed through generalized linear model with repeated measures (P = 0.007). Preorbital gland opening decreased along the phases of the study. Nevertheless, we found a significant trend in individuals to keep similar opening patterns (intraclass correlation coefficient = 0.807, P < 0.001), which suggests that the more stressed individuals can be detected with this method. Therefore, we conclude that preorbital gland opening during routine handlings is related to the number of previous handlings, and thus it can be used as an indicator of lack of habituation to handling in farmed cervids.This study was supported by projects AGL2012-38898 (Ministry of Economy and Competitiveness, Spain), MZERO0714‏ (Ministry of Agriculture, Czech Republic), CIGA20145001 (Czech University of Life Sciences, Czech Republic), and IGA no. 20145026 (Faculty of Tropical AgriSciences, Czech Republic).Peer Reviewe

Variation of mating systems of introduced sika deer

Le système d'appariement de Cerfs Sika (Cervus nippon) introduits dans la forêt de Manetin (220 km2), République tchèque, a été étudié de 1989 à 1993. Le Sika était strictement nocturne en raison des pressions de chasse et des dérangements continus par l'homme dans la journée. Les activités de rut ont été suivies par triangulation des cris des mâles en divers sites, ainsi que par comptage au phare des cerfs dans les zones ouvertes. Durant toutes les saisons, les activités vocales ne furent pas réparties uniformément sur la zone d'étude, étant généralement concentrées dans des champs proches de la forêt. En 1989, un lek fut constitué. Par la suite, il éclata en arènes dispersées. Ces arènes furent occupées par intermittence et étaient localisées tant dans les pâturages ouverts qu'en forêt mature et à l'interface de ces deux types d'habitat

Benefits for Dominant Red Deer Hinds under a Competitive Feeding System: Food Access Behavior, Diet and Nutrient Selection

Social dominance is widely known to facilitate access to food resources in many animal species such as deer. However, research has paid little attention to dominance in ad libitum access to food because it was thought not to result in any benefit for dominant individuals. In this study we assessed if, even under ad libitum conditions, social rank may allow dominant hinds to consume the preferred components of food. Forty-four red deer hinds (Cervus elaphus) were allowed to consume ad libitum meal consisting of pellets of sunflower, lucerne and orange, and seeds of cereals, corn, cotton, and carob tree. The meal was placed only in one feeder, which reduced accessibility to a few individuals simultaneously. During seven days, feeding behavior (order of access, time to first feeding bout, total time spent feeding, and time per feeding bout) were assessed during the first hour. The relative abundance of each meal component was assessed at times 0, 1 and 5 h, as well as its nutritional composition. Social rank was positively related to the amount of time spent feeding during the 1st h (P = 0.048). Selection indices were positively correlated with energy (P = 0.018 during the 1st h and P = 0.047 from 1st to 5th) and fat (only during the 1st h; P = 0.036), but also negatively with certain minerals. Thus, dominant hinds could select high energy meal components for longer time under an ad libitum but restricted food access setting. Selection indices showed a higher selectivity when food availability was higher (1st hour respect to 1st to 5th). Finally, high and low ranking hinds had longer time per feeding bout than mid ones (P = 0.011), suggesting complex behavioral feeding tactics of low ranking social ungulates

Influence of the energy on the observed standarized selection ratios during first feeding hour (<i>B_i^0–1</i>; black triangles and solid line; <i>R</i> = 0.79) and first to fifth (<i>B_i^1–5</i>; hollow triangles and dashed line; <i>R</i> = 0.68).

<p>Note the different slopes, which indicate a lower selectivity in the second period when the amount of food available was lower.</p

One-way Pearson correlations among social rank and food access behavioral indices (<i>T/n</i> = mean time per feeding bout; <i>FFB</i> = time to first feeding bout; <i>AO</i> = order of access to the feeder; <i>TFB</i> = total number of feeding bouts; <i>FT</i> = time spent feeding during the first hour; <i>N</i> = 44).

*, and ***<p>indicate significance at 0.05, and 0.001 level.</p

Meal components (mean ±SE) and selection indices during the 1^st feeding hour.

<p>A high <i>ŵ</i> (greater than 1) or <i>B</i> (greater than 1/7 = 1.43) indicates food items selected positively. A low <i>ŵ</i> (lower than 1) or <i>B</i> (lower than 1.43) indicates food items selected negatively.</p>† and **<p>respectively indicate if selection was significant at 0.1 and 0.01 level.</p

Experimental design for the ‘Restricted food access’ experiment.

<p>Only 6 hinds at most are allowed to feed at once. Location of video cameras and their visual field is shown.</p

Nutritive and mineral mean (±SE) contents of offered wholemeal feed, and food remaining after red deer hinds fed for 1 and 5 hours.

<p>The experiment was repeated for 7 days, and paired t-tests show differences between initial and 1^st hour food remaining, and between 1^st to 5^th.</p>†, *, **, and ***<p>respectively indicate significant differences at 0.1, 0.05, 0.01, and 0.001 level.</p><p>Only significant values in paired t-tests are shown.</p

Plotting of <i>T/n</i> (mean time per feeding bout, log- transformed to achieve normality) <i>vs.</i> normalized social rank (<i>ArcsenSqrt</i> of hierarchical social rank; Côté 2000), with linear (solid line; <i>R</i> = 0.11; <i>P</i> = 0.230) and quadratic (dashed line; <i>R</i> = 0.44, <i>P</i> = 0.011) adjusting.

<p>Plotting of <i>T/n</i> (mean time per feeding bout, log- transformed to achieve normality) <i>vs.</i> normalized social rank (<i>ArcsenSqrt</i> of hierarchical social rank; Côté 2000), with linear (solid line; <i>R</i> = 0.11; <i>P</i> = 0.230) and quadratic (dashed line; <i>R</i> = 0.44, <i>P</i> = 0.011) adjusting.</p

Meal components (mean ±SE) and selection indices from 1^st to 5^th hours.

<p>A high <i>ŵ</i> (greater than 1) or <i>B</i> (greater than 1/7 = 1.43) indicates food items selected positively. A low <i>ŵ</i> (lower than 1) or <i>B</i> (lower than 1.43) indicates food items selected negatively. Any food item was significantly selected.</p