Genetic analysis of group composition and relatedness in white‐headed langurs

We collected fecal samples of white‐headed langurs from 3 of the 4 remaining habitat fragments (Fa, Fb and CZ) located in southwestern Guangxi, China in Nov 2005, and used 5 microsatellite loci and the SRY gene to assess the relatedness between 46 langurs within and between groups. We observed 2 forms of group structure: one‐male/multi‐female groups (OMGs) and all‐male groups (AMGs). One AMG in Fa was composed of 2 generations, included a father, 2 sons and 1 unrelated male, and all OMGs in all 3 habitats included 1 resident male, several adult females and offspring. Of the 21 identified father‐offspring cases, the resident male fathered 20 (95%) and the non‐resident male sired 1 (5%), suggesting that adult males had overwhelming priority of access to females as the resident male in an OMG, while the non‐resident male may also have the opportunity to adopt surreptitious mating strategies.     

Observation of intra‐group and extra‐group copulation and reproductive characters in free ranging groups of western black crested gibbon (Nomascus concolor jingdongensis)

Black crested gibbons (Nomascus concolor) are 1 of only 3 gibbon species that have been observed in long‐term polygynous groups, but their mating behavior and reproductive characters have never been reported. Based on population monitoring over 7 years and direct observation for 26 months of the study groups in Wuliang Mountain, central Yunnan, we describe for the first time the copulation behavior and breeding pattern of free‐ranging western black crested gibbons. The gestation period of black crested gibbons is estimated to be between 6 and 7 months. The average breeding interval is 3.5 years, with infant independence at approximately 2.5 years. We observed 2 intra‐group copulations and 5 extra‐group copulations. Copulations were initiated when a female gave a ‘solicitation’ gesture. When a male made any mating attempt, the female might refuse it. These results demonstrate direct female mate choice. Both male and female gibbons dispersed from their natal groups and sometimes replaced paired adults in other groups. We observed no evidence of infanticide during inter‐group conflicts or after replacement of adults. Together with extra‐group copulations, these phenomena indicate a flexible social organization and complex mating system. We also observed a male‐biased sex ratio among offspring. More genetic work is necessary to describe the effects of inter‐group copulation and the genetic diversity of this population.     

Female reproductive success in a species with an age‐inversed hierarchy

In most group‐living mammals, reproductive success declines with increasing age and increases with increasing rank. Such effects have mainly been studied in matrilineal and in “age positive” hierarchies, which are stable and in which high ranking females often outperform low ranking ones. These relationships are less well‐understood in age‐inversed dominance hierarchies, in which a female's rank changes over time. We analyzed demographic data of 2 wild, unprovisioned groups of gray langurs (Semnopithecus schistaceus) near Ramnagar, Nepal covering periods of 5 years each. Female rank was unstable and age‐inversed. We measured reproductive success via birth rates (57 births), infant survival (proportion of infants surviving to 2 years) and number of offspring surviving to 2 years of age (successful births) for 3 age and 3 rank classes. We found that old females performed significantly worse than expected (birth rate P = 0.04; successful births P = 0.03). The same was true for low ranking females (P = 0.04, and P < 0.01, respectively). Infant survival was highest for young and middle‐aged as well as for high and middle ranking females. Overall, the results for these unstable hierarchies were rather similar to those for stable hierarchies of other mammals, particularly several nonhuman primates. Compared to a provisioned population of a closely related species, the wild and unprovisioned population examined (i) showed stronger age effects, while (ii) female reproductive success was equally affected by rank. Future comparative studies are needed to examine whether captive or provisioned populations deviate predictably from wild populations.     

Cognition and the brain of brood parasitic cowbirds

Cowbirds are brood parasites. Females lay their eggs in the nests of other species, which then incubate the cowbird eggs and raise the young cowbirds. Finding and returning to heterospecific nests presents cowbirds with several cognitive challenges. In some species, such as brown‐headed cowbirds (Molothrus ater), females but not males search for and remember the locations of potential host nests. We describe recent research on sex differences in cognition and the hippocampus associated with this sex difference in search for host nests. Female brown‐headed cowbirds perform better than males on some, but not all, tests of spatial memory and females show a pattern of adult hippocampal neurogenesis not found in males or in closely related non‐parasitic birds. Because of the apparent specialization of the hippocampus, brown‐headed cowbirds may be a good model in which to examine spatial information processing in the avian hippocampus and we also describe recent research on the spatial response properties of brown‐headed cowbird hippocampal neurons.     

Habitat use and locomotion of the François' langur (Trachypithecus francoisi) in limestone habitats of Nonggang,China

We collected data on habitat use and locomotion of the François' langur (Trachypithecus francoisi) between August 2003 and July 2004 at Nonggang Nature Reserve, China. A total of 739 h of behavioral data were collected during this study. We tested 2 predictions: (1) that the langurs may have special patterns of habitat use and locomotion adaptive to the limestone habitat, and (2) the langurs may exhibit different patterns of habitat use and locomotion among different zones of limestone hill. Our results indicated that François– langurs spent more time in the low‐risk, relatively food‐poor cliff–hilltop areas. When young leaves and fruit were scarce in the dry season, the langurs increased their time in the high‐risk, food‐rich valley basin. François– langurs were semi‐terrestrial, and leaping and climbing were their main locomotor modes. These behavioral patterns are considered to be related to characteristics of topography and vegetation in limestone habitat, such as large areas of cliff and discontinuous canopy. Our results also supported Prediction 2. The langurs confined locomotion to the main canopy and frequently adopted leaping while traveling in the hillside and valley basin. While traveling in cliff–hilltop areas, they tended to stay in the lower stratus (≤5 m) or move on the ground, and walking and climbing were their dominant traveling modes.     

Secretory Patterns of Prolactin in Dogs: Circannual and Ultradian Rhythms

The objectives of the present study were to characterize in dogs circannual and ultradian prolactin (PRL) secretory patterns and also to compare gender differences in the ultradian period of study in the Southern hemisphere. Blood samples were collected at 15‐min intervals for 2.5 h from seven male and seven female dogs and a single monthly sampling, over a 1‐year time span, from six male dogs for the ultradian and circannual studies, respectively. Plasma PRL was measured by a homologous enzyme immunometric assay. The ultradian study evidenced PRL elevations suggesting pulsatile secretion in both genders. Significantly higher mean smoothed baseline (ng / ml [7.02 ± 1.2 vs 1.23 ± 1.0, p < 0.01]) and AUC (ng/ml * 2.5 h [25.2 ± 3.8 vs 4.4 ± 3.8, p < 0.01]) were found in females when compared with males. In the circannual study, plasma PRL concentrations did not statistically differ among the months of the year. When grouped together the 3 months with a longer daylight had significantly higher PRL concentrations than the 3 months with the shortest (2.31 ± 0.37 vs 0.96 ± 0.37, p < 0.01). The correlation between length of daylight and PRL concentrations was 0.24, p < 0.05. It is concluded that PRL does have a circannual rhythmicity and that there are ultradian gender‐related differences in the period under study in these groups of dogs. This study also demonstrates plasma PRL elevations suggesting pulsatile secretion in male dogs.     

Annual survival and site fidelity of free‐ranging white‐tailed deer (Odocoileus virginianus): comparative demography before (1983–1992) and after (1993–2005) spatial confinement

Survival and movement are important demographic variables influencing the dynamics of large herbivores with implications for management and evolution of life‐history strategies. Management practices such as spatial confinement and harvest regulation attempt to control survival and movement for the sustainability of harvested deer populations, but a paucity of long‐term data exists on these management practices. We examined annual survival and site fidelity of free‐ranging white‐tailed deer (Odocoileus virginianus) over 10 years (1983–1992) to compare demographic parameters after spatial confinement (1993–2005). We used capture records (n = 174; 104 females, 70 males), marked deer recaptures (n = 42), and dead recoveries (n = 68) to estimate sex‐specific, age‐specific and time‐specific parameters. We found that annual female survival was 50% from 1983–1987 during a period of intense harvest, but increased to 93.7% after intense harvesting was eliminated. Prior to spatial confinement, annual survival of marked male deer averaged 36.7%–42.5%. After spatial confinement, annual survival increased on average for males (58%–99%) and females (77%–98%). Females showed high levels of site fidelity (>99%) prior to spatial confinement, whereas males showed much less site fidelity (≤4.5% for the 2 top‐ranking models). During spatial confinement, the semi‐impermeable fence effectively increased site fidelity of males (≥56%). These results stem from long‐term study (23 years) of a large herbivore experiencing changes to life‐history, resulting from changes in management that were applied to the population and aimed at altering population demographics, for sustainability of a harvestable population of deer.     

Fertility control of Rattus nitidus using quinestrol: effects on reproductive organs and social behavior

Fertility control has been identified by studies in the laboratory and the field as a more appropriate and long‐term control strategy for rodent pests than lethal control. In this study, we investigated the effects of quinestrol on mass of reproductive organs and on social behaviors in female and male Himalayan field rats (Rattus nitidus). A total of 16 adult females and 16 adult males were randomly assigned to 4 groups. One male and one female group were fed rice with 0.005% quinestrol by weight for 7 days, and another 2 groups were fed rice only. After 7 days, rats were assigned to 10 min dyadic encounters between groups, and investigation, aggression, defense and attack latency were quantified. All animals were killed on day 10, and reproductive organs were dissected and weighed. Dyadic encounter data showed that there were obvious changes in social behaviors of quinestrol‐treated rats. Quinestrol significantly inhibited the investigative behavior of quinestrol‐treated males toward control females in Rattus nitidus, but seldom affected investigation between control males and quinestrol‐treated females. Aggression of control females toward quinestrol‐treated males was higher than that of quinestrol‐treated females, and defense of quinestrol‐treated males toward control females was more remarkable than that of control males. Quinestrol remarkably decreased wet masses of epididymis and spermotophore in males and ovaries in females, but had no effect on wet masses of testes and uteri after quinestrol treatment. These results indicate that the anti‐fertility effects of quinestrol on R. nitidus are attributed to not only suppressing reproductive organs but also impacting social behaviors associated with territory defense and mate choice.     

Sex‐specific participation in inter‐group conflicts within a multilevel society: the first evidence at the individual level

Inter‐group conflicts are common among many group‐living animals and involve potentially complex motivations and interactions. Mammals living in multilevel societies offer a good opportunity to study inter‐group conflicts. This study is the first to explore the function of sex‐specific participation during inter‐group conflicts within a multilevel society at the individual level. The Sichuan snub‐nosed monkey (Rhinopithecus roxellana) is an endangered seasonal breeding species living in a multilevel society. From Sep 2007 to May 2008 we recorded 290 inter‐group conflicts of a free‐ranging provisioned band of R. roxellana in the Qinling Mountains of China to investigate the function of individual aggression during inter‐group encounters. Our findings show that adult males were the main participants in inter‐group conflicts, while females took part in them only occasionally. The male participation rate during the mating season, when adult females were estrous, was significantly higher than that during the non‐mating season. Furthermore, males directed their aggression to other males, and directed more intense aggression towards bachelor males than towards other resident males. For both sexes, the participation rate as initiators was higher in the winter than that in the spring; and there was a significant positive correlation between group size and the participation rate as initiators. Our results suggest that inter‐group aggression in Sichuan snub‐nosed monkeys is linked to both mate defense and resource defense.     

Acute hepatic necrosis and death in a subadult southern white rhinoceros (Ceratotherium simum) associated with exposure to sterigmatocystin in forage contaminated with Aspergillus nidulans

A young male southern white rhinoceros (Ceratotherium simum), which was resident in a zoo as part of a multi‐rhinoceros group, died suddenly. Necropsy and histopathological findings supported a diagnosis of death from acute hepatic necrosis. The microscopic distribution of liver lesions was suggestive of hepatotoxicosis. Further investigation revealed potential exposure to a mycotoxin, sterigmatocystin, present in spoiled lucerne hay contaminated with Aspergillus nidulans. It was concluded that mycotoxicosis was the likely cause of the hepatic necrosis and death in this animal.     

The effect of fertility control on the transmission of bovine tuberculosis in wild brushtail possums

AIM: To determine the effect of fertility control on the rate of transmission of bovine tuberculosis (Tb), caused by Mycobacterium bovis, in brushtail possums (Trichosurus vulpecula).

METHODS: At two study sites with a history of Tb infection in the resident possum population, a sample of adult male and female possums (n=50), determined by palpation to be Tb-free, was surgically sterilised by gonadectomy. A sample of untreated Tb-free male and female possums (n=54) served as controls. Each study site was trapped every 2 months over a 3-year period, and the Tb status of the individuals in the trial assessed. At the conclusion of the trial, all remaining experimental individuals were killed, necropsied and examined for characteristic lesions typical of Tb. The rate of transmission of Tb infection was estimated using the incidence of tuberculous cases in the experimental animals and comparing it between sites, sex and sterilisation treatment.

RESULTS: Sterilisation by gonadectomy resulted in a reduction in the rate of transmission of Tb in male possums by 53%, but a corresponding increase in sterilised females for reasons that are still unclear. However, this interaction was statistically weak (p=0.10). When the sexes were combined, there was no overall effect of sterilisation on the rate of transmission of Tb (p=0.43). Sterility treatment notwithstanding, there was a highly significant difference in the rate of transmission between the sexes (p=0.01), being almost one order of magnitude higher in untreated males compared with untreated females.

CONCLUSIONS: Although lacking strong statistical support, these results suggest that fertility control that targets endocrine control of fertility may provide some additional benefits for disease control over that achieved by reductions in population density, by reducing the rate of transmission of M. bovis in male possums. However, additional studies are needed to confirm the validity of these results. The large difference in the rate of transmission of M. bovis in untreated males compared with untreated females suggests that transmission of Tb among males may be an important driver of the dynamics of Tb infection in possums.     

Sex Steroid Levels in XY Males and Sex‐Reversed XX Males,of Rainbow Trout (Oncorhynchus mykiss), During the Reproductive Cycle

In this study, the annual cycle of the gonadal steroids testosterone (T), 11‐ketotestosterone (11‐KT), 17β‐oestradiol (E2) and 17α, 20β‐dihydroxy‐4‐pregnen‐3‐one (DHP) was determined using radioimmunoassay and then compared, for XY males (n = 35) and sex‐reversed XX males (n = 27) rainbow trout, to establish possible endocrinology differences. Both in XY males and sex‐reversed XX males, significant correlation was shown between body weight and T (r = 0.5046 and 0.34078, respectively; p < 0.0001) or KT (r = 0.52494 and 0.43545, respectively; p < 0.0001) concentrations. Plasma androgen levels in XY and sex‐reversed XX males were similar and showed an intense seasonal variation. The highest levels for T and 11‐KT were detected from December to April with a peak in January (51.67 ± 5.11 and 61.95 ± 4.25 ng/ml, for XY males and 57.1 ± 5.82 and 59.27 ± 4.84 ng/ml, respectively, for XX males). In addition, there was a positive correlation (p < 0.0001) between T and 11‐KT levels for XY males (r = 0.7533) and sex‐reversed XX males (r = 0.6019). Concentrations of DHP in XY males also showed seasonal variation with a peak in February (25.18 ± 12.99 ng/ml). However, DHP levels in sex‐reversed XX males were undetectable (<0.1 ng/ml) over the year. Levels of E2 were undetectable through the year in both groups of trout. In conclusion, the androgenic and oestrogenic profiles of sex‐reversed XX males were similar to those observed in XY males. The only difference in the annual gonadal steroid cycle between XY and sex‐reversed XX males was in the DHP profile.     

Some special contributions in research by the Veterinary School

Extract

The Veterinary School is divided into three major departments. These are Physiology and Anatomy, headed by Professor R. E. Munford. Veterinary Clinical Sciences, headed by Professor E. D. Fielden and Veterinary Pathology and Public Health headed by Professor B. W. Manktelow. Heads of Departments are largely responsible for academic leadership and administration of research within the groups of disciplines resident in their departments.     

Sex and age differences in meat composition of Yeso sika deer (Cervus nippon yesoensis) reared for a short period after capture in the wild

Yeso sika deer captured in winter around Lake Akan in Hokkaido were reared for 8–10 months at Tokyo University of Agriculture in Abashiri. Six 1‐year‐old females and males and six 2‐year‐old or older (adult) females and males were slaughtered and their carcasses were processed. The chemical composition, mineral contents and fatty acid composition of the loin were measured. No marked influence of gender or age was noted in the chemical composition of loin. In the mineral contents, significant differences were noted. The potassium and sulfur contents were lower and the sodium content was higher in adult deer meat (P < 0.05, respectively) and the potassium content was higher in male deer meat (P < 0.05). Arsenic, cadmium or lead were not detected. In the unsaturated fatty acid, a significant interaction was detected (P < 0.05), and it was high in 1‐year‐old female deer meat and low in 1‐year‐old male deer meat. Significant gender or age differences were noted only in the mineral contents in the loin of deer reared for a short period after capture.     

Reproduction and Development of the Released Przewalski’s Horses (Equus przewalskii) in Xinjiang,China

In China, the first Przewalski’s horse (Equus przewalskii) group was released in Kalamaili Ungulate Protected Area in Xinjiang, in August 2001. The objective of this study was to investigate reproduction and development of released Przewalski’s horses in Xinjiang, China from 2002 to 2006. Twenty-four descendants were naturally born, average reproduction rate was 38.7%, and average survival rate of foals was 69.1% in this interim. Frequent alternation of the leading stallion and infertility in female horses due to environmental factors were main causes for the low reproduction rate. The infant mortality rate of released Przewalski’s horses was 25.0%, and 83.3% of death in infants was due to the leading stallion infanticide. The released Przewalski’s horses exhibited seasonal breeding, 70.8% of infants were born in May and June. The fertility rates were 8.3% in April and 37.5% in May, which were lower compared to those of the captive Przewalski’s horse groups (18.3% and 44.3%, respectively). Furthermore, the fertility rate in June was 33.3% and higher than the captive groups (18.3%). These findings showed that the breeding peak of the released Przewalski’s horse groups was later than the captive groups, and suggested that the altered survival environment and food supplies were the main reasons contributing to the delayed breeding peak.     

Estimation of phenotypic and genetic parameters for weight gain and weight at fixed ages in the double-muscled Belgian Blue Beef breed using field records

In the double‐muscled Belgian Blue beef (DM‐BBB) breed, selection focuses on muscular conformation and not on weight gain and higher weight. There are very few studies on growth in the DM‐BBB using field records. Therefore, farms have no available useful figures on weight at fixed ages and weight gain for the DM‐BBB. This study describes and evaluates live weights of DM‐BBB animals. All the data were gathered on farms in Belgium. It was found that a male DM‐BBB weighs an average of 51 kg at birth, 98 kg at 3 months, 242 kg at 7 months, 430 kg at 13 months and 627 kg at 20 months. Between the age of 7 and 20 months, weight gain is more than 1200 g a day. Females weigh 47 kg at birth, 96 kg at 3 months, 189 kg at 7 months and 332 kg at 13 months. For males, estimates of heritability for weights at 7, 13 and 20 months were between 0.21 and 0.36. The heritability for weight gain between 13 and 20 months was 0.13. This demonstrates that it is possible to select for higher weights and for increased growth between 13 and 20 months. Animals having high weights at a young age (7 and 13 months) tend to have also high weight at slaughtering age (20 months; r_g between 0.81 and 0.98), but no additional growth between 13 and 20 months (r_g between −0.09 and 0.00). High weight at 20 months is partially due to growth between 13 and 20 months (r_g = 0.49).     

Social relationships and dispersal patterns in a clan of spotted hyaenas Crocuta crocuta in the Kruger National Park

Membership, social relationships and dispersal were recorded for all members of one clan of spotted hyaenas, Crocuta crocuta, in the Kruger National Park over a period of 27 months. The clan comprised females, cubs, and three social classes of males: resident natal males, peripheral immigrant males and central immigrant males. Although a linear dominance hierarchy was recorded under all circumstances, it was most strongly expressed at food. Females were philopatric and maintained a network of amicable relationships with each other and their offspring. Social dominance assured them priority of access to carcasses, so that they obtained a high proportion of meat. Males left their natal clans and attempted to join neighbouring clans, where they were initially treated as territorial intruders, but could eventually gain membership albeit with low social status, lowest feeding priority at carcasses and precarious social relationships. An immigrant male that maintained close attendance on females became a central immigrant and gained unrivalled breeding status. The segregation of a clan into co-operative relatives and subordinate immigrants assures an optimal distribution of resources.     

Effects of feeding pistachio by‐products silage on growth performance,serum metabolites and urine characteristics in Holstein male calves

This study investigated physiological effects of pistachio by‐products silage (PBPS) substituted in Holstein male calves diets and its effects on the growth performance. Twenty‐four Holstein male calves (4–5 months of age and 155.6 ± 13.5 kg BW) were randomly assigned to one of four experimental diets (n = 6); contained 0%, 6%, 12% and 18% of PBPS (DM basis) respectively. During a 6‐month experiment, dry matter intake (DMI) and weight gain were recorded and blood and urine samples were collected at different times. Results showed that mean DMI was not affected by different levels of PBPS in diets. But the calves fed 6% PBPS had the highest average daily gain (p < 0.05) and the lowest feed conversion ratio (p < 0.05). The calves fed 12% and 18% PBPS had lower albumin, white blood cell, haemoglobin and packed cell volume (p < 0.05) than those fed other diets. However, other serum metabolites, complete blood count (CBC), insulin and liver enzymes were not affected by the experimental diets. The long‐term feeding of PBPS at different levels had no significant effect (p > 0.05) on pH, specific gravity, the number of white and red blood cells and epithelial cells count in urine. The animals did not show any symptom of illness or toxicity during the experimental period and all of the blood and urine parameters were in a normal range. It was concluded that substitution of PBPS up to 18% of the total diet that provide up to 18.2 g/kg DM total tannin had no adverse effects for Holstein male calves.     

A newly‐found pattern of social relationships among adults within one‐male units of golden snub‐nosed monkeys (Rhinopithecus roxenalla) in the Qinling Mountains,China

Group living provides various advantages to individuals in regards to protection avoidance, intergroup competition, productive success and social information. Stable one‐male units (OMUs) consist of relationships between the adult females and the resident male as well as the relationships among adult females. Based on continuous observation of a reproductive group of golden snub‐nosed monkeys (Rhinopithecus roxellana) in the Qinling Mountains, we analyzed the relationships among adult individual dyads within 4 OMUs. The results indicated that in golden snub‐nosed monkey societies, females not only had no strong tendency to build a relationship with the resident male in the OMU but also had no strong tendency to build relationships with other females in the OMU. In comparison with hamadryas (Papio hamadryas) and gelada baboons (Theropithecus gelada), the relationships within golden snub‐nosed monkeys OMUs showed neither the star‐shaped pattern observed in hamadryas baboons nor the net‐shaped pattern observed in gelada baboons. We concluded that the relationships within golden snub‐nosed monkey OMUs indicated a third pattern in nonhuman primate societies. Future research is required to determine the potential mechanisms for such a pattern.     

Metastatic diagnosis of canine sternal lymph nodes using computed tomography characteristics: A retrospective cross‐sectional study

The accurate evaluation of sternal lymph nodes (StLNs) is critical for the staging of canine thoraco‐abdominal tumours. Computed tomography (CT) provides a non‐invasive means of assessing StLNs, but its diagnostic accuracy for identifying metastases is unclear. In this retrospective cross‐sectional study, we assessed the diagnostic power of various CT measurements. Fifty‐seven dogs that underwent concurrent CT and cytological examination of the StLNs were enrolled retrospectively. The size, shape, X‐ray attenuation and uniformity of the StLNs were assessed. The dogs were divided into metastasis‐negative (n = 21) and metastasis‐positive (n = 36) groups. Logistic regression analysis showed that the size (StLN‐to‐second sternebra ratio [ratio‐size]) and precontrast attenuation were significantly different between groups. Combining these parameters achieved a specificity and positive predictive value of 100% (cut‐off values: 1.0, 37.5 Hounsfield units, respectively). This suggests that the combination of ratio‐size and precontrast attenuation is effective for differentiating metastasis to the StLNs on CT.