Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “ARTIODACTYLA”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,009 records · Page 56Linked to original sources
PubMed1977

Effect of lipid solvents on cutaneous moisture loss.

Application of various lipid solvents and dimethyl sulphoxide to the skin of cattle, sheep, eland and African buffalo exposed to an air temperature of 20 degrees C caused an increase in cutaneous moisture loss. The effect did not occur after exposure to an air temperature of 40 degrees C or after adrenaline administration. Blockage of sweating by either bethanidine or phenoxybenzamine did not affect the response. Camel, donkey, dog and man showed no increase in cutaneous moisture loss after lipid solvent application to the skin. It is concluded that lipid solvents directly stimulate the secretory cells of the sweat glands of members of the family Bovidae and that this is not due to the release of transmitter substance nor to stimulation of adrenergic receptors, but is due to direct stimulation of the sweat glands themselves.

Animals↗
PubMed1983

Decline with age in the rate of reduction of progesterone to 20 alpha-hydroxypregn-4-en-3-one in the blood of perinatal ruminants.

The activity of the enzyme 20 alpha-hydroxysteroid dehydrogenase present in erythrocytes of foetal and new-born ruminants has been determined by incubating 0.1 ml blood with 0.16 mumol [4-14C]-progesterone for 15 min at 39 degrees C in a final volume of 2 ml buffered saline. It was found that the activity, measured as mumol 20 alpha-hydroxypregn-4-en-3-one produced from progesterone per millilitre of erythrocytes per hour, declined from levels at birth as high as 1.50 mumol for sheep, 0.50 mumol for goats and 0.43 mumol for cattle to levels of around 0.11, 0.08 and 0.04 mumol respectively by 30-60 days of age. This decline in activity was also apparent in blood taken from sheep foetuses in which longitudinal studies were possible and appeared to have begun prior to 35 days before term. The highest activity obtained was 2.59 mumol for foetal sheep blood taken at 115 days of gestation. It is suggested that the observed decline in 20 alpha-hydroxysteroid dehydrogenase activity is a function of the replacement of foetal erythrocytes with adult-type erythrocytes which begins around 120 days of gestational age and that the role of the enzyme is to maintain an appropriate progestational environment within the foetoplacental unit.

20-Hydroxysteroid Dehydrogenases↗
PubMed1974

Two types of molecular evolution. Evidence from studies of interspecific hybridization.

To assess the significance of macromolecular sequence differences among species, we compared the serum albumins of 81 pairs of vertebrate species capable of producing viable hybrids. Micro-complement fixation experiments showed that the average difference between the albumins within such pairs was only 3 immunological distance units for placental mammals (31 pairs), but 36 units for frogs (50 pairs). Albumin immunological distance is strongly correlated with other measures of genetic distance, including those made with DNA annealing techniques. It therefore seems likely that mammalian species pairs capable of hybridization are far more similar at the macromolecular sequence level than is the case for most hybridizable frogs. We think the most likely explanation for the marked molecular restriction on hybridization among mammals is that the ratio of regulatory evolution to protein evolution is higher for mammals than for frogs. Mammals may have experienced unusually rapid regulatory evolution; indeed, this could be the factor responsible for their unusually rapid anatomical evolution.

Amino Acid Sequence↗
PubMed1985

Kinetics of redox-linked proton pumping activity of native and subunit III-depleted cytochrome c oxidase: a stopped-flow investigation.

The kinetics of oxidation of reduced cytochrome c by cytochrome c oxidase reconstituted into unilamellar vesicles (COV) has been followed by stopped-flow method in the time range 3 msec-1 sec. In the presence of valinomycin, the oxidation of cytochrome c is linked to proton ejection in the external medium, with an apparent stoichiometry (H+/e-) of 0.93 +/- 0.22, under conditions in which the enzyme is in the more active "pulsed" state (i.e., having undergone oxidation-reduction cycles). The time course of reaction indicates that the conformational change(s) involved in coupling the redox reaction to proton translocation is fast. Similar experiments carried out with cytochrome c oxidase depleted of subunit III show that proton-pumping is maintained, although with a lower efficiency (H+/e- = 0.5). The number of protons ejected per electron appears to be correlated to the value of the respiratory control ratio; although this result is partly due to an increase in the rate of diffusion back into the vesicles, a relationship between the respiratory control ratio and the efficiency of the proton pump may be inferred, suggesting a control of the H+/e-ratio.

Animals↗
PubMed1991

Synonymous nucleotide substitution rates in mammalian genes: implications for the molecular clock and the relationship of mammalian orders.

Synonymous substitution rates have been estimated for 58 genes compared among primates, artiodactyls, and rodents. Although silent sites might be expected to be neutral, there is substantial rate variation among genes within each lineage. Some of the rate variation is associated with G + C content: genes with intermediate G + C values have the highest rates. Nevertheless, considerable heterogeneity remains after correcting for G + C content. Synonymous substitution rates also vary among lineages, but the relative rates of genes are well conserved in different lineages. Certain genes have also been sequenced in a fourth order (lagomorph or carnivore), and these data have been used to investigate mammalian phylogeny. Data on lagomorphs are consistent with a star phylogeny, but there is evidence that carnivores and artiodactyls are sister groups. Genes sequenced in both rat and mouse suggest that the increased substitution rate in rodents has occurred since the rat/mouse divergence.

Animals↗
PubMed1975

Nutritional studies on East African herbivores. 1. Digestibilities of dry matter , crude fibre and crude protein in antelope, cattle and sheep.

1. A series of digestibility trials was done using four animals of each of the following species: Friesian cattle (Bos taurus), Boran zebu cattle (Bos indicus), Corriedale sheep, fat-tailed sheep, eland (Taurotragus oryx Pallas), Coke's hartebeest (Alcelaphus buselaphus cokei Günther), Thomson's gazelle (Gazella thomsonii Günther) and bush duiker (Sylvicapra grimmia L.). 2. Two batches of pelleted food were prepared from ground maize cobs, cassava, whs (A-E) were prepared containing 65 (A)-135 (E) g crude protein (nitrogen times 6-25)/kg dry matter. The crude-fibre contents of all the diets were similar (120-138 g/kg dry matter). 3. The animals were given the high-protein diet (E), then given diets with decreasing protein contents finishing with the low-protein (A). The antelope and half the sheep were given diets from the first batch of pelleted food, the other four sheep and all the cattle were given diets from the second batch of food. 4. In sheep, there were significant differences in digestibility between the two batches of food. 5. There were no significant differences in the over-all mean digestibilities of all diets when given to cattle (both species) and sheep. However, with diet E, dry-matter digestibility was higher in sheep than in cattle (P smaller than 0-05): the reverse was true with diet A (P smaller than 0-001). Crude-fibre and crude-protein digestibilities followed a similar pattern. The differences between Corriedale and fat-tailed sheep were not significant. The only significant difference between the two species of cattle was the higher digestibility of crude protein in Borans given diet E (P smaller than 0-05). 6. The over-all mean digestibility of the dry matter was higher (P smaller than 0-001) in hartebeest and duiker than in sheep; in Thomson's gazelle (P smaller than 0-01) and eland (P smaller than 0-001) it was lower than in sheep. The values for crude-fibre digestibilities varied in a similar way. 7. The mean apparent digestibility of crude protein was higher (P smaller than 0-001) in eland, hartebeest and duiker than in sheep and gazelle. 8. The results are discussed in relation to the feeding habits and digestive physiology of the various species.

Africa, Eastern↗
PubMed1975

Nutritional studies on East African herbivores. 2. Losses of nitrogen in the faeces.

1. A series of nitrogen-balance trials was done using groups of four animals of various species of wild and domesticated ruminants using pelleted diets (Arman & Hopcraft, 1975). 2. Various herbivores were given grass or grass hays, legumes, herbs and shrubs. Food and faecal samples were analysed for N. 3. With the pelleted diets, the N content of the faecal dry matter (DM) was low for eland (Taurotragus oryx Pallas), high for sheep and cattle (Bos taurus and Bos indicus) and intermediate for the three small antelope species (hartebeest (Alcelaphus buselaphus cokei Günther), Thomson's gazelle (Gazella thomsonii Günther) and duiker (Sylvicapra grimmia L.)). With the natural doffers, similar relationships were found, together with variations associated with the type of diet. 4. Three forms of equation were used to express the relationship between faecal N and food N. One of the forms, the linear regression of g faecal N/kg DM intake v. g food N/kg DM intake, fitted the results less well than did the other two and was not used to estimate metabolic faecal N(MFN) losses9 5. MFN was calculated by extrapolation of linear regressions of g faecal N/kg faecal DM v. g N intake/kg faecal DM for the pelleted diets. The range of values was (g N/kg faecal DM): Friesians 7-6, eland 8-1, zebu cattle 11-0 and small antelope and sheep 11-5-12-69 There were significant differences (P smaller than 0-001) between species in slopes and intercepts. 6. MFN was calculated from linear regressions of g faecal N/kg faecal DM v. g food N/kg food DM for all diets. This method gave the best fit for the pelleted diets. Values for these diets were (g N/kg faecal DM): eland 8-3, cattle and sheep 9-3-11-0 and small antelope 11-6-12-3. Species differences were significant (P smaller than 0-001). With grasses, values ranged from 5-9 for non-ruminants (rabbit (domesticated), warthog (Phacohoerus aethiopicus Pallas) and hippopotamus (Hippopotamus amphibius L.)) plus eland and wildebeest (Connochaetes taurinus Burchell), to 8-4 for for the other ruminants (sheep, goat, hartebeest, gazelle, duiker, buffalo (Syncerus caffer Sparrman)), kob (Adenota kob thomasi Sclater), reedbuck (Redunca redunca Pallas) and topi (Damalisucs korrigum Ogilby). For ruminants (sheep, hartebeest, duiker and kob), excluding eland, given legumes the value was 8-6, and for sheep and duiker given herbs the value was 14-7. With shrubs, faecal-N losses were variable and sometimes high. 7. With the pelleted diets, true digestibilities of crude protein (N times 6-25) varied from 0-84 to 0-91. 8. The results are discussed in relation to the digestive physiology and feeding habits of the various species, and there is an examination of the feasibility of using linear regressions of crude protein in the diet v. N in the faecal DM for evaluating the quality of the diets selected by free-ranging East African herbivores.

Animal Feed↗