Ecological niche of the Asiatic Cheetah (Acinonyx jubatus venaticus) in the arid environment of Iran (Mammalia: Felidae)

The Asiatic Cheetah, Acinonyx jubatus venaticus, is a species of global conservation concern and a small population occurs in Iran in fragmented habitats located in the central parts of the country with a continental, arid climate. Naybandan Wildlife Refuge (NWR) holds the largest population in Iran. To understand better the factors which determine the occurrence of cheetahs in these areas, we applied an Ecological Niche Factor Analysis (ENFA) to assess the relationship between occurrences of cheetahs across the NWR and topographic, biological, and anthropogenic factors. ENFA analysis results suggested that cheetahs have a tendency to inhabit areas different from the mean conditions of the study area and live in a narrow set of conditions. They prefer mountainous habitats far from flat areas, habitats near to water resources, and habitats with high prey densities. 13% of the NWR can be classified as suitable habitat for the cheetah, indicating a high conservation value of this reserve for the species.     

Dietary Factors Associated with Faecal Consistency and Other Indicators of Gastrointestinal Health in the Captive Cheetah (Acinonyx jubatus)

Gastrointestinal diseases pose significant risks to captive cheetah survival and welfare. Multiple factors are thought to be associated with these diseases, but to date a comprehensive epidemiological survey of disease risk factors has not been conducted. A survey of diet and health parameters was completed for 184 captive cheetahs in 86 international facilities. Comparisons were made among dietary factors with respect to disease status and observed faecal consistency, incidence of vomiting and diarrhoea in the past 4 weeks. Extremely dry faeces were most common in cheetahs fed carcasses, but was still of low incidence (15%). Contrastingly, cheetahs fed commercially prepared diets had the highest prevalence of liquid faeces “always” or “often” (9%). Cheetahs fed raw meat diets had the highest prevalence of soft faeces with no shape (22%), as well as of firm and dry faeces (40%). No broad category of diet exerted any influence on the health parameters investigated. However, feeding of ribs at least once per week reduced the odds of diarrhoea (P = 0.020) and feeding of long bones (limbs) at least once per week was associated with a lower odds of vomiting (P = 0.008). Cheetahs fed muscle meat at least once per week had reduced odds of suffering from chronic gastritis (P = 0.005) or non-specific gastrointestinal disease (P < 0.001). The only factor identified as increasing the odds of chronic gastritis was feeding of horse “often” or “always” (P = 0.023). The findings of the current study build on existing empirical research to support a recommendation towards a greater inclusion of skeletal components. Current husbandry guidelines advocating the use of supplemented raw meat diets are likewise supported, but the use of horse meat, as well as commercially prepared diets for captive cheetahs, warrants caution until further research is conducted.     

Consequences of a low litter birth weight phenotype for postnatal lean growth performance and neonatal testicular morphology in the pig

The consequences of a low litter average birth weight phenotype for postnatal growth performance and carcass quality of all progeny, and testicular development in male offspring, were investigated. Using data from 25 sows with one, and 223 sows with two consecutive farrowing events, individual birth weight (BW) was measured and each litter between 9 and 16 total pigs born was classified as low (LBW), medium (MBW) or high (HBW) birth weight: low and high BW being defined as >1 standard deviation below or above, respectively, the population mean for each litter size. Litter average BW was repeatable within sows. At castration, testicular tissue was collected from 40 male pigs in LBW and HBW litters with individual BW close to their litter average BW and used for histomorphometric analysis. LBW piglets had a lower absolute number of germ cells, Sertoli cells and Leydig cells in their testes and a higher brain : testis weight ratio than HBW piglets. Overall, LBW litters had lower placental weight and higher brain : liver, brain : intestine and brain : Semitendinosus muscle weight ratios than MBW and HBW litters. In the nursery and grow–finish (GF) phase, pigs were kept in pens by BW classification (9 HBW, 17 MBW and 10 LBW pens) with 13 males and 13 females per pen. Average daily gain tended to be lower in LBW than HBW litters in lactation (P = 0.06) and throughout the nursery and GF phases (P < 0.01), resulting in an increasing difference in body weight between LBW, MBW and HBW litters (P < 0.05). Average daily feed intake was lower (P < 0.001) in LBW than HBW litters in the nursery and GF phases. Feed utilization efficiency (feed/gain) was similar for LBW and HBW litters in the nursery, but was lower (P < 0.001) in HBW than LBW litters in the GF phase. By design, slaughter weight was similar between BW classifications; however, LBW litters needed 9 more days to reach the same slaughter weight than HBW litters (P < 0.001). BW classification did not affect carcass composition traits. In conclusion, LBW litters showed benchmarks of intrauterine growth retardation, LBW had a negative impact on testicular development and germ and somatic cell populations, and was associated with decreased postnatal growth during all phases of production; however, no measurable effect on carcass composition traits was established.     

Neonatal survival of Steller sea lions (Eumetopias jubatus)

Neonatal survival of Steller sea lions ( Eumetopias jubatus ) are often considered inconsequential to their population dynamics. However, observations of dead animals on rookeries and in surrounding waters suggest that early mortality is not uncommon. This study used the natural markings of adult females in a mark and resighting framework to estimate the apparent survival (φ) of pups with the Cormack–Jolly–Seber model at two sites on Lowrie Island, Alaska from birth to 3 wk old. Estimates varied greatly by site and year; 2002 Area 5:     (95% CI: 0.199, 0.684; n = 21), 2002 Area 1:     (0.437, 0.916; n = 21), 2003 Area 5:     (0.414, 0.738; n = 56), and 2003 Area 1:     (0.695, 0.997; n = 32). The mean estimate across the four area × year combinations was     (0.569, 0.772). Survival was lowest on the first day of life and then leveled off at a higher rate. None of the four environmental covariates we considered (swell height, interaction of tide and swell heights, density, or birth date) were significantly related to neonatal survival. Our results suggest that estimates of first-year survival that do not account for mortality prior to dispersal from the natal rookery may significantly overestimate survival rate.     

Blood platelets of the cheetah (Acinonyx jubatus)

The blood platelet count and platelet morphology of 22 adult cheetahs was investigated. The platelet counts of the animals displayed a normal distribution, with a mean count of 344×10⁹/l and a mean platelet volume of 11 fl. Morphological and ultrastructural features of the cheetah platelets revealed the typical platelet morphology of anuclear cells, with granules scattered throughout the cytoplasm. The characteristic surface canalicular system and microtubules were present. True cross‐sections of the platelets had a mean area of 2.146 µm², circumference of 6.805 µm, and mean minimum and maximum projections of 1.000 µm and 2.933 µm, respectively. Zoo Biol 23:263–271, 2004. © 2004 Wiley‐Liss, Inc.     

Effect of average litter weight in pigs on growth performance,carcass characteristics and meat quality of the offspring as depending on birth weight

Offspring born from normal litter size (10 to 15 piglets) but classified as having lower than average birth weight (average of the sow herd used: 1.46 ± 0.2 kg; mean ± s.d.) carry at birth negative phenotypic traits normally associated with intrauterine growth restriction, such as brain-sparing and impaired myofiber hyperplasia. The objective of the study was to assess long-term effects of intrauterine crowding by comparing postnatal performance, carcass characteristics and pork quality of offspring born from litters with higher (>1.7 kg) or lower (<1.3 kg) than average litter birth weight. From a population of multiparous Swiss Large White sows (parity 2 to 6), 16 litters with high (H = 1.75 kg) or low (L = 1.26 kg) average litter birth weight were selected. At farrowing, two female pigs and two castrated pigs were chosen from each litter: from the H-litters those with the intermediate (H_I = 1.79 kg) and lowest (H_L = 1.40 kg) birth weight, and from L-litters those with the highest (L_H = 1.49 kg) and intermediate (L_I = 1.26 kg) birth weight. Average birth weight of the selected H_I and L_I piglets differed (P < 0.05), whereas birth weight of the H_L- and L_H-piglets were similar (P > 0.05). These pigs were fattened in group pen and slaughtered at 165 days of age. Pre-weaning performance of the litters and growth performance, carcass and meat quality traits of the selected pigs were assessed. Number of stillborn and pig mortality were greater (P < 0.05) in L- than in H-litters. Consequently, fewer (P < 0.05) piglets were weaned and average litter weaning weight decreased by 38% (P < 0.05). The selected pigs of the L-litters displayed catch-up growth during the starter and grower–finisher periods, leading to similar (P > 0.05) slaughter weight at 165 days of age. However, H_L-gilts were more feed efficient and had leaner carcasses than H_I-, L_H- and L_I-pigs (birth weight class × gender interaction P < 0.05). Meat quality traits were mostly similar between groups. The marked between-litter birth weight variation observed in normal size litters had therefore no evident negative impact on growth potential and quality of pigs from the lower birth weight group.     

Extrinsic factors significantly affect patterns of disease in free-ranging and captive cheetah (Acinonyx jubatus) populations

The cheetah (Acinonyx jubatus) has been considered a paradigm for disease vulnerability due to loss of genetic diversity. This species monomorphism has been suspected to be the basis for their general poor health and dwindling populations in captivity. North American and South African captive populations have high prevalences of hepatic veno-occlusive disease, glomerulosclerosis, gastritis, and systemic amyloidosis, diseases that are rare in other species. Unusually severe inflammatory reactions to common infectious agents have also been documented in captive cheetahs. The current study compared disease prevalences in free-ranging Namibian cheetahs with those in two captive populations of similar ages. The occurrence of diseases in the free-ranging population was determined from 49 necropsies and 27 gastric biopsies obtained between 1986 and 2003 and compared with prevalences in 147 North American and 80 South African captive cheetahs. Except for two cheetahs, the free-ranging population was in robust health with only mild lesions present, in contrast with significantly higher prevalences in the captive populations. Despite widespread heavy Helicobacter colonization in wild cheetahs, only 3% of the free-ranging population had moderate to severe gastritis, in contrast with 64% of captive cheetahs. No severe inflammatory reactions to viral infections were detected in the free-ranging animals. Because free-ranging Namibian cheetahs are as genetically impoverished as captive cheetahs, these findings caution against attributing loss of fitness solely to genetic factors and attest to the fundamental importance of extrinsic factors in wildlife health.     

Nutritional insult and recovery in the neonatal rat cerebellum: Insulin-like growth factors (IGFs) and their binding proteins (IGFBPs)

Alterations in growth caused by neonatal malnutrition may be mediated in part by changes in insulin-like growth factor (IGF) and IGF binding protein (IGFBP) expression. Since the neonatal rat cerebellum undergoes a transient, proliferative growth phase in the first two weeks of life, this structure was used to determine whether alterations in circulating and tissue IGFs and IGFBPs may mediate effects of impaired nutrition on the developing central nervous system. Gravid rats were placed on a 4% (protein-calorie deprived, D) or 20% (control, C) protein diets one day prior to delivery and allowed to nurse their pups postpartum. Pups nursing from D mothers received a limited volume of milk and were calorically deprived. Some litters of D pups were foster fed by C mothers from day 8 to day 13 to constitute a recovery group (R). Cerebellar weight, protein, and DNA content in D pups were less than C, p<0.001. In R pups, DNA and protein returned to C levels by day 13. Between days 6 and 13, serum IGF-I levels rose from 158±18 to 210±18 ng/ml in C but remained low in D (47±6 ng/ml and 25±3 ng/ml), respectively. In R pups, serum IGF-I partially recovered during this time, and increased from 49±5 to 110±7 ng/ml. In cerebellar extracts, IGF-I levels in both C and D were lower at 13 days than at 6 days, p<0.05 and p<0.005, respectively. IGF-I levels in C were similar at day 9 and day 11 and were consistently higher than D (11.84±0.83 vs 8.56±0.92 ng/g, p<0.02 C vs D). In R, IGF-I was reduced on day 11, but was similar to C on day 13. Serum IGF-II in D was lower than C, p<0.01, and did not increase in the R group. Cerebellar IGF-II was virtually undetectable in either group. Immunoprecipitation and ligand blotting studies of serum demonstrated that circulating levels of 32–34 K IGFBPs were increased 3–4 fold in D vs C, reflecting high levels of IGFBP-1 and/or-2, while levels of 24 K IGFBP-4 were lower in D vs C. By contrast, immunoprecipitation and ligand blotting of cerebellar extracts detected IGFBP-2 and-4, but did not detect IGFBP-1. Further, tissue levels of IGFBP-2 were not increased in D vs C, and levels of IGFBP-4 also were not markedly affected by nutritional deprivation. These results suggest that alterations in tissue content and the availability of IGF-I only modestly contributed to the effects of impaired nutrition in the developing central nervous system.     

Effects of dietary enrichment with a marine oil-based n-3 LCPUFA supplement in sows with predicted birth weight phenotypes on birth litter quality and growth performance to weaning

The effects of a marine oil-based n-3 long-chain polyunsaturated fatty acid (mLCPUFA) supplement fed to the sow from weaning, through the rebreeding period, during gestation and until end of lactation on litter characteristics from birth until weaning were studied in sows with known litter birth weight phenotypes. It was hypothesized that low birth weight (LBW) litters would benefit more from mLCPUFA supplementation than high birth weight litters. A total of 163 sows (mean parity=4.9±0.9) were rebred after weaning. Sows were pair-matched by parity and litter average birth weight of the previous three litters. Within pairs, sows were allocated to be fed either standard corn/soyabean meal-based gestation and lactation diets (CON), or the same diets enriched with 0.5% of the mLCPUFA supplement at the expense of corn. Each litter between 9 and 16 total pigs born was classified as LBW or medium/high average birth weight (MHBW) litter and there was a significant correlation (P<0.001) between litter average birth weight of the current and previous litters within sows (r=0.49). Sow serum was harvested at day 113 of gestation for determination of immunoglobulin G (IgG) concentrations. The number of pigs born total and alive were lower (P=0.01) in mLCPUFA than CON sows, whereas the number of stillborn and mummified pigs were similar between treatments. Number of stillborns (trend) and mummies (P<0.01) were higher in LBW than MHBW litters. Tissue weights and brain : tissue weight ratios were similar between treatments, but LBW litters had decreased tissue weights and increased brain : tissue weight ratios compared with MHBW litters. Placental weight was lower (P=0.01) in LBW than MHBW litters, but was not different between treatments. Average and total litter weight at day 1 was similar between treatments. mLCPUFA increased weaning weight (P=0.08) and average daily gain (P<0.05) in MHBW litters, but not in LBW litters. Pre-weaning mortality was similar between treatments, but was higher (P<0.01) in LBW than MHBW litters. IgG concentration in sow serum was similar between treatments and litter birth weight categories. In conclusion, litter birth weight phenotype was repeatable within sows and LBW litters showed the benchmarks of intra-uterine growth retardation (lower placental weight and brain sparing effects). As maternal mLCPUFA supplementation decreased litter size overall, only improved litter growth rate until weaning in MHBW litters, and did not affect pre-weaning mortality, maternal mLCPUFA supplementation was not an effective strategy in our study for mitigating negative effects of a LBW litter phenotype.     

Diurnal patterns of stem extension growth in peach (Prunus persica): Temperature and fluctuations in water status determine growth rate

Field measurements of stem extension growth rate in peach ( Prunus persica [L.] Batsch) exhibited a consistent diurnal pattern. Stem extension rate was lowest in the early morning and increased throughout the day. In the late afternoon, 2–3-fold increases in extension rate occurred and were sustained for 2 to 4 h. After this growth surge, rates precipitously declined and remained low during the night. The temperature response of stem growth rate at constant water potential was determined using potted trees in a dark growth chamber. Under such conditions, stem growth rate was strongly dependent on air temperature. In the field, the observed stem growth rate deviated from that predicted on the basis of temperature. These deviations were proportional to the rate of change in stem water potential. A model was constructed to predict diurnal patterns of stem extension rate using temperature and water potential data. The model was tested using data from undisturbed trees and from trees in which water potential was artificially manipulated. Growth patterns predicted by the model were in general agreement with observed rates.     

Ultrasonographic and laparoscopic evaluation of the reproductive tract in older captive female cheetahs (Acinonyx jubatus)

The study uniquely described the clinical value of transabdominal ultrasonography for monitoring features characterizing the estrous cycle in female cheetahs (Acinonyx jubatus). The reproductive tracts of 21 female, nulliparous, and relatively aged (median: 11 and interquartile range: 9.25–14 years) captive cheetahs resident on two sites in Namibia were assessed by transabdominal ultrasound. Subsequently, the ovarian findings on ultrasound were compared with direct visualization while performing laparoscopic sterilization. A combination of these observations supported by concurrent sampling for vaginal cytology and serum progesterone concentrations defined the estrous status of individual animals. At one site, six cheetahs had been implanted with the GnRH agonist, deslorelin as a contraceptive at least once within the preceding 11 years. On ultrasound, 31 uterine horns and 35 ovaries with discernible structures on 28 (86%) were visualized in the 21 cheetahs. The uterine body was difficult to visualize because of its intrapelvic location. Eleven of 19 uteri (58%) visualized showed endometrial edema suggestive of estrogenization. The uteri of four cheetahs (19%) showed evidence of mild cystic endometrial hyperplasia. Paraovarian cysts were seen on ultrasound (n = 21) and laparoscopy (n = 26) in 16 (76.2%) and 18 (85.7%) cheetahs, respectively. Ovarian volumes obtained from ultrasonographically determined dimensions predicted cyclic activity. Laparoscopy showed that 19 ovaries had discernible follicular structures. In the study population, 10 (47.6%) cheetahs were in proestrus or estrus; none in the luteal phase; and 11 (52.4%) in anestrus. Transabdominal ultrasound, in combination with serum progesterone concentrations and vaginal cytology, was used with acceptable accuracy to assess cyclic ovarian activity in captive cheetahs. A considerable proportion of this aged population showed ovarian activity and the prevalence of paraovarian cysts was notable. A history of prior deslorelin treatment was not associated with either reproductive activity or uterine pathology.     

Regional variation in the cheetah (Acinonyx jubatus) revisited: Morphology of wild and captive populations

The cheetah (Acinonyx jubatus) is listed as a vulnerable species by the International union for the conservation of nature (IUCN), including two critically endangered subspecies, the Saharan cheetah, and the Iranian cheetah, so it is imperative that we understand variation in cheetah morphology to make good decisions regarding the conservation of this species. Here, we aim to determine whether northeastern African cheetahs have smaller body sizes than southern African cheetahs. This study also adds to our knowledge of cheetah morphology from two cheetah populations that do not yet have comprehensive published data: Kenya, and northeastern Africa, including captive individuals. We calculated means and standard deviations on cranial and body measurements of live or in few cases, freshly dead, cheetahs from the aforementioned populations, plus previously published data on Namibian and Botswanan cheetahs and compared them to one another using multivariate analysis of variance. Results show that northeastern African cheetahs have smaller body sizes than southern and eastern African populations. We also found that captive cheetahs retain the morphological characteristics of their ancestral population- captive cheetahs from southern Africa have similar body sizes to wild southern African cheetahs and larger body sizes than captives from northeastern Africa. Other analyses regarding cheetah growth agree with previous studies on Namibian and Botswanan cheetah populations rates. As such, this study can serve as a baseline for the care of captive cheetah populations to maintain healthy weights and body proportions.     

Pattern of growth in weight of alate and apterous nymphs of the English grain aphid, Sitobion avenae

Daily increase in fresh weight was recorded for apterous and alate nymphs of S. avenae at 20°C. Comparison with a control group indicated that daily disturbance and weighing of nymphs did not affect significantly their growth, developmental time or survival. The increase in fresh weight of apterous and alate virginoparae at 20°C was best described by logistic equations. Alate virginoparae were significantly heavier than apterous virginoparae at birth and throughout most of their nymphal life, but they experienced a weight loss at the final ecdysis. The relative growth rate did not remain constant, but declined during development. The decline is associated with a decline in honeydew production per unit body weight. The implications of an inconstant relative growth rate and the marked loss in weight at the adult moult in alates are discussed.

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Résumé L'enregistrement de l'augmentation quotidienne du poids frais à 20°C des larves ailées et aptères de S. avenae a montré que des perturbations quotidiennes n'affectent pas significativement la croissance, la durée du développement et la survie. Les équations logistiques décrivent plus exactement l'augmentation de poids frais des aptères et des ailés virginipares à 20°C. Les virginipares ailés étaient significativement plus lourds que les virginipares aptères à la naissance et pendant la plus grande partie de la vie larvaire, mais présentaient une perte de poids à la mue finale. Le taux de croissance relative ne restait pas constant, mais diminuait au cours du développement. La diminution était associée à une diminution de la production de miellat par unité de poids du corps. La discussion porte sur les conséquences de la variation de l'augmentation du poids relatif et de la perte marquée de poids à la mue imaginale.

     

Embryonic growth rate and birth weight of the offspring of apterous and alate aphids: a cost of dispersal

Apterous and alate Sitobion avenae (Fab.) were dissected from the third instar onwards and the size and degree of development of their largest embryos recorded. From at least the third instar apterae had larger and more well developed embryos than alatae. Embryos in both morphs showed an exponential increase in volume with time during their mothers' nymphal development, but those in apterous mothers grew faster. Although alatae had a longer pre-reproductive development than apterae, it was not long enough to compensate for the lower embryo growth rates in alatae and as a consequence they initially produced smaller and fewer offspring than apterae. After 4 days of reproduction apterous and alate mothers produced similar sized offspring and at the same rate. The total fecundity of apterae was greater than that of alatae.

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Résumé La taille et l'état de développement des plus gros embryons de Sitobion avenae Fab ont été examinés par dissection d'ailés et aptères à partir du troisième stade. La taille des embryons des 2 morphes augmente pendant le développement larvaire des mères, mais ceux des mères aptères grossissent plus vite. Bien que la période précédant la reproduction des alates soit plus longue chez les ailés que chez les aptères, les embryons des ailés sont néanmoins incapables de l'emporter en taille sur les aptères, et les ailés produisent initialement moins de pucerons et plus petits que les aptères. Après 4 jours de reproduction, les mères ailées et aptères produisent des pucerons de même taille au même rythme. La fécondité totale des aptères est supérieure à celle des ailés; la différence est liée à la biologie des 2 morphes.