Effects of temperament during handling and social rank on the blood biochemical parameters of common eland (Taurotragus oryx).

Large herbivores are subject to handling and social stress in captivity. These may affect blood biochemical values, which motivated this research. Twelve healthy common eland (Taurotragus oryx) were monitored for 12 months. The animals were handled monthly, and blood samples were collected. Samples from every second month were analysed for 14 blood biochemical parameters. Temperament throughout the handling, as the summation of various behavioural responses, was calculated as a proxy of the stress generated during handling. Social behaviour was recorded each month, and the agonistic interactions were used to calculate the social rank, which was considered a proxy of social stress. Generalised Linear Mixed Models were designed to test the effects of temperament and social rank on the blood biochemical parameters while keeping sex, age, body condition, and body weight as covariates. The results show that the temperament during handling influences blood levels of albumin, alkaline phosphate, blood urea nitrogen, glucose, total bilirubin, and total protein; however, social rank has little influence, affecting just albumin. The ranges observed in the values of these biochemical parameters were still within their reference intervals, implying the absence of pathology or physiological problems during the study. The results suggest that blood biochemical values of physically restrained common eland should be carefully interpreted, even in animals already habituated to routine handling. On the contrary, social rank has low effects on the blood biochemical parameters.

Differential effects of ruminally protected amino acids on fattening of fallow deer in two culling periods.

A well-balanced amino acid profile in the feedstuffs for livestock is essential to support adequate growth. This is well studied for monogastric species but still not well understood for ruminants and especially for the most unconventional species, like cervids. This study investigated the influence of ruminally protected lysine (Lys) and methionine (Met) supplementation during the fattening period, as well as two slaughter seasons (late autumn (LA) v. late winter (LW)), on the growth, carcass traits, body condition and blood plasma metabolites of fallow deer (Dama dama). Forty-five yearlings of fallow deer bucks were allocated into three groups, balanced by weight (40.2 ± 2.7 kg). The deer were pasture-fed and supplemented with barley, free-choice mineral premix, silage during the winter period, and varying levels of ruminally protected Lys and Met: no amino acids (Control), 9 g/day of Lys, and 9 g/day of Lys plus 3 g/day of Met (Lys+Met). Animals were slaughtered in two separate seasons, LA (six animals per group), and LW (nine animals per group). Animals culled in LA had higher average daily weight gain than LW (P = 0.002), due to the reduced growth during winter typical for seasonal cervids in temperate zone, mediated by the photoperiod. Dressing percentage was significantly higher in LW and in the Lys+Met group (P = 0.002). Body condition score (P = 0.024), kidney fat index (KFI) (P = 0.005), and internal fat (P < 0.001) increased significantly with Lys+Met supplementation. During LW, KFI (P = 0.004) and kidney fat (P = 0.001) were also significantly higher than in LA. Blood creatinine concentration increased significantly for deer receiving Lys (P = 0.002) and Lys+Met (P < 0.001). Also, triglycerides level increased in Lys group (P < 0.001). These findings highlight the effects of Lys and Met supplementation on the growth and internal fat storage for winter survival, suggesting a different use of the supplemented resource according to the season. Also, the observed effects on protein and fat metabolism of fallow deer may influence the production of farmed animals, and offer interesting insights about the physiology of the species.

Effects of age, sex, lactation and social dominance on faecal egg count patterns of gastrointestinal nematodes in farmed eland (Taurotragus oryx).

The eland is a large African antelope that can be bred in a temperate climate, under similar conditions and production systems as cattle. However, knowledge of parasites in farmed elands outside the area of their native habitat is still limited, and information concerning factors that influence these parasites is lacking. Therefore, faecal samples from an entire herd of elands, including calves and adult females and males, were examined monthly over a one year period. Almost 84% of the animals were found to be positive for gastrointestinal nematodes. Strongyle-type eggs were most frequently detected (prevalence 75%), followed by Capillaria sp., Nematodirus sp. and Trichuris sp. eggs. Following culturing eggs to infective larvae, Teladorsagia sp., Trichostrongylus sp., Nematodirus sp., Cooperia sp. and Oesophagostomum sp. were identified. Following necropsy of two calves that died during the study one abomasal nematode (Teladorsagia circumcincta), five small intestinal nematode species (Nematodirus helvetianus, N. spathiger, Cooperia oncophora, C. curticei and Capillaria bovis) and two large intestinal nematodes (Oesophagostomum venulosum and Trichuris ovis) were recovered. From these findings, it is evident that the eland harbours nematodes that are typical for domestic cattle and small ruminants. Morphological and morphometric analyses of recovered nematodes revealed that these parasites do not require any special morphological adaptation to establish infection in elands. The faecal output of strongyle-type and Nematodirus sp. eggs was seasonal, with the highest egg production taking place during spring and summer. Calves had higher faecal egg counts (for all the monitored nematode species) than adults did. Lactation in females was significantly (P<0.0001) associated with higher strongyle nematode egg shedding. Social dominance also affected faecal egg count patterns. The lower the hierarchical position among adults (regardless of sex), the higher the risk of nematode infection. This effect was evident for strongyles (P<0.0001) and Capillaria sp. nematodes (P=0.0065). The results of our study suggest that control measures applicable in domestic cattle and small ruminants might be similarly applicable for controlling gastrointestinal nematode infections in captive farmed elands.

Pre-orbital gland opening in farmed red deer (Cervus elaphus) during stressful handling.

Stressful manipulation by humans has been previously shown to result in opening the pre-orbital gland of the newborn red deer. We hypothesized that exposure of red deer to stressful handling would result in opening the pre-orbital gland. Further, we tested the potential factors associated with pre-orbital opening, including season, sex, age and struggling behavior. Pre-orbital gland status was observed in 76 red deer (48 males, 28 females) during 281 handling events with the animal isolated and fixed in a mechanical restraint cradle (crush) within 3 consecutive years. The deer age ranged from 1 to 5 yr in males, and from 1 to 11 yr in females at the beginning of observations. The proportion of handling events with an open gland was considerably greater during than before handling (27.76 vs. 0%, respectively, P < 0.001). The deer that struggled or stiffened revealed 2-fold greater incidence of pre-orbital opening (P < 0.01), regardless of sex. Thus, pre-orbital opening seemed to accompany the behaviors that have been found to be related to acute stress. The probability that the animal opens its pre-orbitals during handling sharply increased at the beginning of the rut (mating season, P < 0.01). Deer that threatened the handler (10% out of 215 observations) opened their pre-orbitals 30 times more often than nonthreatening ones. These effects indicate that other motivations are likely involved in the opening of pre-orbitals, in addition to the perception of a stressful event. Incidence of pre-orbital opening decreased with age in both sexes (P < 0.05) across 3 consecutive yr of observations, which suggests habituation to repeated handling. Sex of the animal did not influence the probability of pre-orbital opening. We found significant variability in pre-orbital opening across the individuals (P < 0.001). In conclusion, we confirmed an association between opening of the pre-orbital gland and stressful handling in sub-adult and adult red deer, although repeated human handling did not elicit such incidence of pre-orbital opening as found in newborn red deer calves. Our results support multifactorial origins of pre-orbital opening and prompt the necessity of further research to distinguish between different motivations that might have been involved in opening of pre-orbitals.