Effects of immunocastration and supplementary feeding level on the performance and blood biochemical markers of farmed yearling fallow deer (Dama dama).

In cervids, blood biochemical markers may reflect changes in various physiological and environmental factors, especially in response to changes in metabolism following nutrient supplementation or the manipulation of hormone production. Decreasing androgen production through immunocastration (IC) to ease the husbandry of male animals is currently a more ethically acceptable method than physical castration, but its commercial use is unexplored in fallow deer. Forty yearlings male fallow deer were grouped into four treatment combinations: IC on high (200 g commercial pellets + 600 g concentrate mixture of 90% oats and 10% wheat grains) or low (100 g commercial pellets + 300 g concentrate mixture of 90% oats and 10% wheat grains) level of feed supplementation, or noncastrated bucks on a high or low level of feed supplementation. Immunocastrated animals were vaccinated at the start of the study (Week 1) and again during Week 3 of the study. Diet affected all body growth parameters (slaughter weight, daily gain, carcass weight, dressing percentage and body condition score). Fallow deer from all treatments showed increasing concentrations of fat and energy blood biochemical markers over the study period, including plasma glucose (GLU) and triglyceride (TRIG), and decreased cholesterol (CHOL) and lipase (LIPA) concentrations. The higher level of supplementary feeding decreased plasma albumin (ALB) and creatinine (CREA), and increased globulin (GLOB) concentrations. On the other hand, IC and lower-level supplementation reduced growth performance. Overall, IC may be an interesting tool for welfare management of yearling stags for slaughter; however, the advantage appears to only be in well-fed animals, as low-level of feeding can further reduce growth performance in immunocastrated animals. Further studies should evaluate the carcass performance of animals under similar treatment conditions to ascertain the effects on muscle and fat yields.

To beat or not to beat: Behavioral plasticity during the antler growth period affects cortisol but not testosterone concentrations in red deer (Cervus elaphus) males.

Out of rut, male red deer (Cervus elaphus) associate themselves in bachelor groups where animals compete for rank position via agonistic interactions. In a previous study on red deer, males were recognized either as "Non-Fighters" (NF, low frequency of attacks) or "Fighters" (F, high frequency of attacks). This study, therefore, aims to verify the consistency of the inter-individual differences in fighting attitude across different social contexts and investigate whether they could be considered an individual characteristic. Behavioral consistency was presumed across three different sampling seasons, assuming that NF would have lower cortisol (C) and testosterone (T) concentrations than the F males. In 2015 the males were kept in one large group and labelled NF and F. In 2016, the herd was divided into two subgroups ("NF" and "F") based on the frequency of attacks. Finally, in 2017, the males were divided into two randomly composed subgroups. Data about agonistic behavior and concentration of C and T were collected during each season. In 2015 the individuals differed only for the fighting attitude. After the division, the frequency of the attacks always increased, being consistently lower in NF than in F. Unexpectedly, a slight increase in the concentration of C was detected in the NF in 2016, compared to the F who experienced no difference neither in 2015 nor 2017. No significant differences were found in T. We concluded that, even though the males had shown behavioral plasticity, their diversified interaction-prone attitude had been maintained despite the modifications of the social environment.

The bony horncore of the common eland (Taurotragus oryx): composition and mechanical properties of a spiral fighting structure.

Horns are permanent structures projecting from the head of bovids, consisting of a bony horncore covered with a layer of skin and then a sheath of keratinous material showing variability of growth intensity based on nutrition. From the point of view of the horn's mechanical properties, the keratin sheath has been widely studied, but only a few studies have considered the complete structure of the horn and fewer studies have focused on the bony horncore and its characteristics. The latter showed the important role of the bony core, when cranial appendages are subject to mechanical stress (as happens during fighting). The mechanical properties of bone material, along with its mineral profile, are also important, because they can show effects of different factors, such as nutrition and mineral deficiencies in diet. For this reason, eight horncores of captive common eland male were sampled at four positions along the vertical axis of the horn. The main aim was to study variation in mechanical properties and the mineral content along the vertical axis of the horncores. We further analysed whether the spiral bony ridge present on eland horncores differs in any of the studied properties from adjacent parts of the horncore. In other antelopes, spiral ridges on the horns have been proposed to increase grip during wrestling between males. Cross-sections of the horncores were performed at four positions along the longitudinal axis and, for each position, two bone bars were extracted to be tested in impact and bending. Moreover, in the first sampling position (the closest position to the base) two bars were extracted from the spiralled bony area. The resulting fragments were used to measure ash content, bone density and mineral content. Results showed that horn bone decreased along the vertical axis, in ash (-36%), density (-32%), and in impact work 'U' (marginally significant but large effect: -48%). The concentration of several minerals decreased significantly (Mg, Cr, Mn and Tl by -33%, -25%, -31%, -43%, respectively) between the basal and the uppermost sampling site. The bone tissue of the horncore spiral compared with non-spiral bone of the same position showed a lower ash content (53% vs. 57%), Mg and Mn; in addition to showing approximately half values in work to peak force 'W', bending strength 'BS' and 'U', but not in Young's modulus of elasticity 'E'. In conclusion, similarly to the results in a totally different fighting bony structure, the antlers, the horncore of eland shows advantageous parameters in bone tissue of the base in respect to the tip, with higher values for mechanical properties, density and mineral profile. Moreover, the spiral bone tissue showed lower material mechanical properties. Probably the spiral tissue of the horn may have a role in deflecting potential cross-sectional fractures during wrestling. In addition, it may serve to improve the grip during wrestling, and we propose that it may also prevent risk of rotation of sheath with respect to internal bone not only in this, but also in other straight bovid horns.

Effect of species-specific differences in chromosome morphology on chromatin compaction and the frequency and distribution of RAD51 and MLH1 foci in two bovid species: cattle (Bos taurus) and the common eland (Taurotragus oryx).

Meiotic recombination between homologous chromosomes is crucial for their correct segregation into gametes and for generating diversity. We compared the frequency and distribution of MLH1 foci and RAD51 foci, synaptonemal complex (SC) length and DNA loop size in two related Bovidae species that share chromosome arm homology but show an extreme difference in their diploid chromosome number: cattle (Bos taurus, 2n = 60) and the common eland (Taurotragus oryx, 2nmale = 31). Compared to cattle, significantly fewer MLH1 foci per cell were observed in the common eland, which can be attributed to the lower number of initial double-strand breaks (DSBs) detected as RAD51 foci in leptonema. Despite the significantly shorter total autosomal SC length and longer DNA loop size of the common eland bi-armed chromosomes compared to those of bovine acrocentrics, the overall crossover density in the common eland was still lower than in cattle, probably due to the reduction in the number of MLH1 foci in the proximal regions of the bi-armed chromosomes. The formation of centric fusions during karyotype evolution of the common eland accompanied by meiotic chromatin compaction has greater implications in the reduction in the number of DSBs in leptonema than in the decrease of MLH1 foci number in pachynema.

Seroprevalence of Neospora caninum and Toxoplasma gondii in exotic ruminants and camelids in the Czech Republic.

Neospora caninum and Toxoplasma gondii are the protozoan parasites with definitive hosts from order Carnivora. Due to vertical transmission, both parasites can cause abortions and neonatal mortality that lead to significant productive and economic losses in the domestic ruminants. The aim of this study was to describe N. caninum and T. gondii seroprevalence in the group of frequently farmed captive exotic ruminants (n = 184) including Bovidae (barbary sheep, bezoar goat, common eland, American bison, water buffalo, and yak) and Camelidae (bactrian camel, guanaco, llama, and alpaca). Antibodies were tested by indirect fluorescent antibody test (IFAT) and enzyme-linked immunosorbent assay (ELISA). Higher prevalence of T. gondii antibodies (31% in IFAT and 52% in ELISA) was detected compared to N. caninum (24% in IFAT and 17% in cELISA). Mixed infection was found in 18 (10%) and 22 (12%) animals by IFAT and ELISA, respectively. Higher seroprevalence of both N. caninum and T. gondii was found in Camelidae compared to Bovidae. To author knowledge, this is the first detection of T. gondii and N. caninum antibodies in common elands and bezoar goats.

Quality attributes and composition of meat from red deer (Cervus elaphus), fallow deer (Dama dama) and Aberdeen Angus and Holstein cattle (Bos taurus).

BACKGROUND: The consumption of venison from deer species has increased in recent years owing to presumably positive health effects. Therefore a comparison was made of the physical characteristics, chemical composition and sensory attributes of meat obtained from red deer, fallow deer and Aberdeen Angus and Holstein cattle raised under conditions typical for commercial farming practice and slaughtered at similar ages. RESULTS: Venison had one-quarter the crude fat content, lower total collagen and a higher proportion of heat-soluble collagen. It was darker and less yellow than beef. Deer species provided meat with higher polyunsaturated/saturated fatty acid ratio and lower atherogenic index. In addition, the venison of red deer contained five times as much n-3 polyunsaturated fatty acids as the beef. Steaks prepared from venison were scored higher than beef for flavour and aroma intensity; they were also tenderer and more easily chewable. CONCLUSION: Compared with beef, venison from two widely farmed deer species was superior in nutrient composition, thus offering potential benefits for human consumption, and it received higher scores for most of the sensory attributes examined.

Horn size is linked to Sertoli cell efficiency and sperm size homogeneity during sexual development in common eland (Taurotragus oryx).

Background: In polygynous species, the development of secondary sexual characters is usually decisive for male reproductive success. However, our understanding about the links between the growth of these traits and reproductive efficiency is still elusive. Most research efforts in this topic have been also focused on adult males, although the development of some secondary sexual characters, like bovid horns, typically starts after birth, continues during the puberty and in some species, such as the common eland, slows or even stops during adulthood. In this study, we investigated the relationships between horn size and testicular function during sexual development in common elands using a comprehensive approach that considers both spermatogenic and sperm parameters. Methods: Twenty-two non-sexually mature common elands were used for the present study. Horn size, body mass, testes mass, and gonadosomatic index were assessed. Spermatogenic activity was determined by cytological and histological analyses. Sperm concentration, morphology, morphometry, and intramale variation in sperm size were evaluated on epididymal sperm samples. Cluster analysis was performed to explore the influence of age on relationships between horn size and reproductive function. Results: We found that bigger horns are associated with increased Sertoli cell efficiency and reduced intramale variation in sperm size. Both parameters were not related to one another while they have shown to be associated with enhanced sperm quality in ungulates. Moreover, horn size was positively linked to the testis mass, sperm concentration, and testicular investment in the seminiferous epithelium. Spiral length and basal circumference were the horn traits most strongly correlated with spermatogenic and sperm parameters as well as those responsible for the sexual dimorphism in this species. Cluster analysis rendered two groups: the first one including males ≤30 months old, while the second one those >30 months old. Horn development and reproductive function were still correlated within age groups, with the strongest relationship found between horn size and sperm size homogeneity in males >30 months old. Conclusion: Taken together, our results indicate that horn size can be regarded as a good index of male reproductive potential during sexual development and provide insights into the role of secondary sexual characters in sexual selection dynamics.

Reproductive tract morphology and symmetry of farmed common eland (Tragelaphus oryx) bulls, and their relationship with secondary sexual traits and social rank.

Common eland bulls are important game ranching animals in southern Africa, for tourism, breeding/live sales, trophy hunting, and game meat production. Interest has grown in their production potential, intensifying animal husbandry and breeding approaches. However, little scientific information is available regarding the intensive management of this species, including information regarding scientifically based selection criteria for breeding bulls. Often, simple phenotypic traits are utilised unless high-value game animals are being bred, with horn and body size often being the only traits considered for breeding bulls. This study provides basic information about the reproductive tract morphology, symmetry, and their relationships with secondary sexual traits, social rank, and temperament in common eland. Six eland males (2-2.5 years old; 203 ± 20 kg) were utilised for the study. Social rank, body weight and body condition score, temperament score, and horn size were determined before the animals were culled, and their reproductive tracts were collected for morphometric and histological evaluation. Results indicate relatively low asymmetry in bilateral reproductive tract components. Individual traits of eland bulls such as age, body weight, and social rank correlated the development of some testicular morphologies and thus may possibly be used in zoos, game ranching, and commercial production for the selection of breeding males, but not temperament and horn length, which should be carefully evaluated. Whilst this study provides baseline information from a limited sample size, further studies should incorporate the assessment of testicular hemodynamics, as well as the effects of factors such as season and androgen secretion patterns over a wider age range of common eland males and populations to provide further information for the management practices of breeding common eland bulls.

The Effect of Sex on the Chemical and Mineral Composition of the Meat, Bone and Liver of Giraffe (Giraffa giraffa angolensis).

Consumers tend to buy meat based on visual physical characteristics, which are affected by the chemical composition of the meat, and there is very little known about the chemical composition of the meat of giraffe. This study therefore aims to broaden the knowledge base on the chemical composition of giraffe meat, rib bone and liver. Eight different muscles from 15 giraffes were analyzed to determine the chemical composition, yielding an average moisture of 77.2 ± 0.09 g/100 g meat, an average protein of 20.8 ± 0.09 g/100 g meat, an average intramuscular fat (IMF) of 1.4 ± 0.03 g/100 g meat and an average ash of 1.1 ± 0.01 g/100 g meat. There was a significant interaction between sex and muscle for the moisture, protein and ash contents, while only muscle had an effect on the fat content. The mineral content of the bone, liver and Longissimus thoracis et lumborum muscle was also analyzed, and bone was found to be a rich source of calcium (highest concentration), whilst the liver had the highest concentration of iron. The chemical composition of the giraffe meat was such that it could be classified as lean meat.

Ivermectin decreases parasite load, testosterone, and potentially antler length in a group of captive red deer males (Cervus elaphus).

Secondary sex traits (SSTs) can favour males in intra-sexual competition, allowing females to reliably assess their quality. They can also be connected to other aspects of fitness, such as resistance to parasites and pathogens, as parasites have negative effects on the development of SSTs. Antlers are one of the most recognizable examples of SSTs whose development is regulated by testosterone and reflects the actual condition of the bearer. Elevated testosterone can exaggerate the size of SSTs while impairing the function of the immune system ("The Immunocompetence Handicap Hypothesis") posing a trade-off between antler development and immune function. In this study, we experimentally manipulated the parasite load in captive red deer (Cervus elaphus) males with Ivermectin during antler development for two consecutive years. Expecting an inverse proportionality between parasite load and antler size, we hypothesized the treated deer to have larger antlers than the untreated ones. Our results showed that, following the immunocompetence handicap hypothesis, parasite load was positively associated with testosterone levels. However, the application of Ivermectin suppressed the parasite load of the treated animals but did not lead to the development of larger antlers. Instead, it significantly suppressed the concentration of testosterone in the treated animals, whilst the animals that had higher testosterone also had the highest parasite load. Our findings show that Ivermectin can potentially decrease the levels of testosterone and, consequently, antler size. These findings have important implications for the management of captive populations, especially in contexts where the development of large trophies is desired.

Consumer acceptance and quality of game meat "droëwors" sausages with different levels of added fat.

Droëwors (dried sausage) is a unique dried meat product from South Africa, which is not smoked, fermented, nor is nitrite used in its production. The objective of the study was to compare the quality parameters and consumer acceptance of common eland meat droëwors with different quantities of added beef fat. Three treatments containing either 10, 15, or 20% (by weight) added beef fat were compared regarding chemical composition, fatty acid profiles, and sensory properties. Increasing the amount of fat in the dried product resulted in a significant decrease in the protein and ash percentages. The sausages with 10% added fat had the most favourable fatty acid profile in terms of nutritional value. Several differences were found in the sensory profiles of the products evaluated by the trained sensory panel; in particular, the evaluation scores for texture improved with increasing fat content. No differences were found between the products by the untrained consumer panel for appearance and taste. When the dataset was analysed according to gender, it was found that women evaluated the 10% fat samples more favourably. This is in line with their stated preference for low-fat meat products. For these reasons, the production of sausages with the lowest fat content can be recommended as they best meet consumer expectations.

The effects of challenge or social buffering on cortisol, testosterone, and antler growth in captive red deer (Cervus elaphus) males.

We equipped 17 captive red deer males (Cervus elaphus) with GPS collars to measure inter-individual distances throughout the 5-months of the antler growth period. We expected some individuals to associate regularly with others while others would not. We predicted that males aggregating with others within a socially stable environment (Associates) would benefit from a form of "social buffering" and would likely have lowered cortisol (C) and testosterone (T) concentrations. Males only irregularly joining social groupings would experience elevated levels of aggression; according to the "Challenge hypothesis", their T and C concentrations should increase. Interacting with a higher proportion of Associates did indeed reduce C concentrations. Conversely, avoiding Associates and challenging other males stimulated the T secretion. Admittedly, males avoiding regular proximity to others tended to develop the largest antlers. They probably benefited from frequent successful agonistic threats to conspecifics, resulting in elevated T concentrations. Regular association with tolerant, conspecifics and "social buffering" did not seem sufficient for producing larger antlers despite reducing C concentrations. Alternative social strategies were adopted within the same group of individuals and showed how the trade-off between these strategies could have an essential impact on C and T concentrations.

Effects of Immunocastration and Amino Acid Supplementation on Yearling Fallow Deer (Dama dama) Testes Development.

Forty-four fallow deer bucks (10 months old; 22.9 ± 2.4 kg) were utilized to investigate the effects of immunocastration and amino acid supplementation on testes development. Immunocastrated bucks were administered Improvac® at weeks 1, 8, and 20 of this study (control group: intact males). Starting at week 8, half of each sex received rumen-protected lysine and methionine (3:1) supplementation. At slaughter (week 37/39), body size, internal fat deposits, antler size parameters, testes weight, testes surface color, cauda epididymal sperm viability and morphology, and seminiferous tubule circumference and epithelium thickness were determined. Animals with larger body sizes, greater forequarter development, and antler growth also had greater testes development. Whilst the result of immunocastration on testes size is unexpected, testes tissue showed impaired development (atrophied seminiferous tubules), decreased sperm viability, and normal morphology. Testes tissue from immunocastrated deer was less red, possibly indicating reduced blood supply. Conversely, amino acid supplementation increased testes' redness and sperm viability, and intact males fed amino acids showed the greatest seminiferous tubule development. Thus, immunocastration may be a welfare-friendly alternative for venison production. Whilst the results support findings from the literature that testes size is not a reliable indicator of immunocastration success, this warrants further investigation in deer over different physiological development stages.

Newly described anatomical opening on forelimb tendon in the artiodactyls and its relation to knee clicks.

To understand which morphological/anatomical parts may be responsible in artiodactyl ungulates for the clicking sound made when moving, this research focuses on the forelimb tendon apparatus where an undescribed opening in the fibrous cuff (manica flexoria), called hereafter for its shape as an "oval window" in the manica flexoria (OWMF), was detected. This oval window was found in 24 of the 25 species of four families (Camelidae, Giraffidae, Cervidae, and Bovidae) evaluated; the exception being in Bos taurus taurus (Domestic cattle). The length and width of the OWMF enabled correct species discrimination between the majority of species, but remained conservative intraspecifically, as it did not differ between the left and right side of the forelimb, third and fourth digits, or between sexes. When evaluating the shape of OWMF in individual species, and measuring its length and width, 18 out of the 24 species investigated had this window as an oval shape, the remaining 25% of species exhibited more oval-oblong shapes with either proximal or distal asymmetry. The function of the OWMF in the thoracic autopodium of most ruminant even-toed ungulates is not yet fully understood. Its most likely function is to help balance the pressure inside the ligament cuff and reduce the friction of the touching surfaces of the muscle tendons-thus facilitating the movement of the digits when walking. None of the absolute or relative OWMF parameters fit exclusively with the occurrence and distribution of knee-clicks produced by some bovids and cervids during movement, so the mechanism responsible for this sound remains cryptic from the present anatomical perspective.

Physical meat quality characteristics of Angolan giraffe (Giraffa giraffa angolensis) as affected by sex and muscle.

Giraffe numbers grow exponentially when farmed, necessitating periodic culling. This study quantified the effect of sex and muscle on the physical quality characteristics of eight giraffe muscles. The Warner-Bratzler shear force (WBSF) was the only parameter to be affected by an interaction between sex and muscle (P < 0.001), although the interaction for the CIE L* values tended towards significance (P = 0.054). Cooking loss (male = 41.6 ± 0.35%; female = 40.7 ± 0.33%; P = 0.024) and CIE L* values (male = 38.8 ± 0.23; female = 37.3 ± 0.27; P = 0.039) were both affected by sex. Muscle had an effect on all physical parameters. The ultimate pH of all muscles was 5.5-5.9; the average WBSF of <43 N for all muscles indicates giraffe meat in this study is tender. This study shows that yield and physical characteristics of giraffe meat are favourable, and the results may be useful for the marketing of giraffe meat.

Carcass and Offal Yields of Farmed Common Eland (Taurotragus oryx) Males, as Affected by Age and Immunocastration.

This study investigated the effects of immunocastration and slaughter age on the carcass yield performance of intensively farmed common eland males. Eighteen male eland (five immunocastrated juveniles, three intact juveniles, five immunocastrated sub-adults, and five intact sub-adults) were finished for four months, after which their carcass, offal, primal cut, and individual muscle yields were determined. Juveniles were ~6 months of age at the start of the experiment, while sub-adults were ~1.5 years old. Primal cuts were dissected to determine the percentage yields of meat, bones (with tendons), separable fat, and trimmings. Immunocastration had no effect on offal or carcass yields. While sub-adults had increased individual muscle yields, juveniles had greater proportionate yields of primal cuts and a greater total high-value: low-value meat ratio. Whilst slaughtering younger male eland could provide additional economic advantages, this should be considered being against changing marketing trends.

Borrelia spirochetes in European exotic farm animals.

Ticks transmit a broad spectrum of pathogens, threatening both animal and human health. Tick survival and proliferation are strongly dependent on host selection and suitability. The hard tick Ixodes ricinus, which is widespread throughout most of Europe, is a host generalist capable of feeding on many different vertebrate species. Pasture-kept exotic farm animals may be at a high risk for tick and tick-borne pathogens infestations but research characterizing this is currently lacking. This study focused on the detection of Borrelia spirochetes (including Borrelia miyamotoi) in exotic farm animals. Using nested-PCR with Borrelia-specific primers, 121 serum samples from 54 exotic farm animals of several species bred in four different farms in Bohemia and Moravia (Czechia) were tested. Positive samples were sequenced for the identification of Borrelia species. The prevalence of Borrelia DNA in the samples ranged from 13 to 67%, depending on the sampling site. The sequencing results confirmed the DNA presence of multiple spirochete species from the Borrelia burgdorferi sensu lato complex. Only one sample from an ostrich (Struthio camelus) was found to be positive for Borrelia myiamotoi. The results show that exotic farm animals can serve as hosts for hard ticks and can be infected by Borrelia spirochetes, transmitted by hard ticks. Therefore, these animals could play a relevant role in maintaining Borrelia spirochetes in nature.

Ante-and post-mortem strategies to improve the meat quality of high-value muscles harvested from farmed male common eland (Taurotragus oryx).

The effects of immunocastration, pelvic suspension and wet ageing on the meat quality of the longissimus lumborum et thoracis (LTL) and biceps femoris (BF) muscles of male common eland were evaluated. Ten subadult males were either immunocastrated (n = 5) or remained intact (n = 5) throughout a four-month growth trial, after which their carcass sides were randomly allocated to either pelvic- or Achilles-suspension. The LTL and BF were further aged for 14 days, measuring changes in the physical quality weekly. The sensory quality of the LTL and BF were determined after ageing (8/9 days, respectively). Immunocastration had minimal effects on the meat quality of male eland, but pelvic suspension decreased the shear force. All muscles reached minimum shear force after seven days of ageing, and the panellists ranked the pelvic-suspended muscles higher for tenderness traits. Incorporating pelvic suspension and wet ageing into the commercial processing of eland carcasses should be considered to improve overall meat quality.

The Effect of Barley and Lysine Supplementation on the longissimus lumborum Meat Quality of Pasture-Raised Fallow Deer (Dama dama).

The chemical characteristics (proximate composition, amino acids, and fatty acids) and sensory quality of the longissimus lumborum (LL) muscle of 45 farmed male fallow deer were investigated. The animals were divided into three separate groups (n = 15 per treatment): pasture-fed (P), pasture-fed and supplemented with barley (B), and pasture-fed and supplemented with barley and lysine (BL). Differences were observed in LL moisture and the intramuscular fat contents, the latter being almost two-fold greater in the meat of B and BL groups compared to P. The concentrations of histidine, leucine, alanine, glutamic acid and glycine in the raw meat were higher in the BL group compared to the P group. Higher contents of n-3 polyunsaturated fatty acids (PUFAs), and consequently lower n-3 ratios, were found in the P group, compared to the BL group. The grilled meat samples from the P group scored higher than the other groups for grassy flavour, and lower for liver flavour.