The value of specific pathogen-free rhesus monkey breeding colonies for AIDS research.
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Animals↗
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Use of Freund's adjuvant arthritis test in anti-flammatory drug screening in the rat: value of animal selection and preparation at the breeding center.
The Freund's adjuvant technic, using killed Mycobacterium butyricum suspended in mineral oil, is a refined tool for anti-inflammatory drug evaluation. Its use has long been reserved for testing and not for screening due to technical problems in the preparation of valid animal models. After reviewing the methodology, the authors demonstrated that the availability of arthritic rats from a modern breeding center (Charles River France, SA, Elbeuf, France) make the procedure applicable to drug screening. This has both practical and economic advantages. The animals can be used as test organisms for drug evaluation 14 da after treatment. Three criteria for measuring the effectiveness of anti-arthritic drugs have been established: an arithritic index determined by examination of the 4 paws; changes in the erythrocyte sedimentation rate; and changes in levels of plasma fibrinogen. The curative activity of test substances can be evaluated by a single series of measurements of these 3 criteria after 14 da of treatment. This test was compared with 2 others; edema of the paw induced by the subcutaneous injection of kaolin or carrageenan, and was found to be superior.
Animals↗
[Levels of luteinizing hormone in sheep of various breeds].
Determined were the LH values in the course of the sexual cycle which ranged within limits of 1 ng ml-1, with a peak of 60 to 250 ng ml-1 on the day of oestrus. By leaving the lambs with their mothers, the normal cycle is stopped, conclusive differences in the rest levels of LH were found out in the Finnish sheep breed, in Romanov sheep, and in the mutton Merino breed. After ovariectomy there occurred an increase of LH in sheep of the Tsigai breed to 6 ng ml-1 and in sheep of the mutton Merino breed to 18 to 22 ng ml-1.
Animals↗
Associations of scrotal circumference with semen traits in young beef bulls.
Associations of percent live sperm, sperm number, sperm concentration, sperm motility, and potential breeding efficiency score with scrotal circumference were studied using data from the records of 465 Polled Hereford and 264 Simmental bulls. Data were subdivided by breed and within breed into three groups according to scrotal circumference (SC) size. Group I bulls had SC measurements <32 cm. Group II included bulls with SC measurements between 32 cm and the mean measurement of the breed (i.e., 35 cm for Polled Hereford and 38 cm for Simmentals). Group III was comprised of bulls with SC values above their respective breed averages. Age and body weight differences were also evaluated in the three groups. Average age differences among bulls in the three groups differed by not more than nine days in the two breeds. Average body weight differences among the three groups were statistically significant (P<0.05) with the maximum difference between any two groups within breed being 80 pounds. Average differences in percent live sperm and sperm number were greater (P<0.05) in Groups II and III than in Group I. For sperm concentration ratings, sperm motility ratings and potential breeding efficiency score, and for both breeds, Group I had a significantly lower (P<0.05) number of bulls classified satisfactory and a significantly greater (P<0.05) number of bulls classified unsatisfactory than did groups II and III.
Journal Article↗
Two-dimensional and M-mode echocardiographic measurements of cardiac dimensions in healthy standardbred trotters.
The aim of the study was to establish normal echocardiographic values of healthy Standardbred trotters not published previously. Twenty-three clinically normal horses weighing between 350 and 490 kg were examined in the same manner: first a thorough physical and then detailed echocardiographic examination were performed. Standardised two-dimensional (2D) and guided M-mode echocardiographic imaging techniques were used to measure interventricular septal thickness (IVS), left ventricular internal diameter (LVID), left ventricular wall thickness (LVW), left atrial internal diameter (LAID) in end-systole (s) and end-diastole (d) and aortic diameter (AOD) in end-diastole. Mean, range and standard deviation of the different parameters were calculated. The mean values (in centimetres) were as follow (2D/M-mode): IVSs: 4.6/4.7; IVSd: 3.1/3.0; LVIDs: 7.0/7.0; LVIDd: 10.7/10.7; LVWs: 3.9/3.9; LVWd: 2.7/2.7; LAIDs: 10.4/-; LAIDd: 11.3/-; AODd: 7.2/-. Results of two-dimensional and M-mode measurements were compared to each other and to normal values obtained from other breeds.
Animals↗
[Some reproductive characteristics of the Peulh ewe from Niger].
The duration of the oestrous cycle, oestrous, pregnancy and post-partum anoestrus, as well as the kinetics of plasma progesterone and prolactin levels during each of those periods, were studied in ewes of a tropical breed without wool. The value of the parameters and the profiles of the two hormones were comparable to those of other European and tropical breeds, suggesting that the Sahelian climate has little to do with the sexual endocrinology of the sheep.
Animals↗
Growth, puberty, and carcass characteristics of Brahman-, Senepol-, and Tuli-sired F1 Angus bulls.
Postweaning growth, sexual development, libido, and carcass data were collected from two consecutive calf crops using 31 Brahman x Angus (B x A), 41 Senepol x Angus (S x A), and 38 Tuli x Angus (T x A) F1 bulls. Following weaning (by mid-September) and preconditioning, at the start of the study (late September) bulls were fed concentrate (three times each week at a rate equivalent to 4.5 kg/d) on bahiagrass pasture for approximately 250 d. At the start of the study and at 28-d intervals, BW, hip height, and scrotal circumference (SC) were measured. Concurrently at 28-d intervals, when the SC of a bull was > or = 23 cm, semen collection was attempted using electroejaculation. Ejaculates were evaluated for presence of first spermatozoa (FS), 50 x 10(6) sperm with at least 10% motility (PU), and 500 x 10(6) sperm with at least 50% motility (PP). After all bulls reached PP they were subjected to two libido tests. Carcass data were collected on all bulls (n = 110) and Warner-Bratzler shear (WBS) force values were assessed on a subset (n = 80). For both years, B x A bulls were heavier (P < 0.05) and taller (P < 0.05) than S x A and T x A bulls at the start and end of the study. However, breed type did not influence (P > 0.10) gain in BW or hip height during the study. Scrotal circumference of T x A bulls was larger (P < 0.05) than that of B x A or S x A bulls at the start of the study, but there was no effect (P > 0.10) of breed type by the end of the study. At PU and PP, B x A bulls were older (P < 0.05), heavier (P < 0.05), and taller (P < 0.05) and had larger (P < 0.05) SC than S x A and T x A bulls. Tuli x Angus bulls were younger (P < 0.05) than S x A bulls at PU and PP but had similar SC. Libido scores tended (P < 0.10) to be lower for B x A than for S x A and T x A bulls. Breed type affected (P < 0.05) carcass traits; B x A bulls had the heaviest (P < 0.05) hot carcass weight, greatest (P < 0.05) dressing percentage, larger (P < 0.05) longissimus muscle area than S x A bulls, and higher (P < 0.05) USDA yield grade than T x A bulls but greatest (P < 0.05) WBS force values. Breed type did not affect (P > 0.10) USDA quality grade. In conclusion, tropically adapted F1 bulls produced from Senepol (Bos taurus) and Tuli (Sanga) sires bred to Angus cows in Florida had lighter BW, shorter hip heights, and smaller carcasses than those from Brahman sires but reached puberty earlier and had higher libido scores and lower WBS force values.
Adaptation, Physiological↗
The effect of selective breeding on the development of coronary atherosclerosis in WHHL rabbits. An animal model for familial hypercholesterolemia.
To increase the incidence of coronary atherosclerosis in Watanabe heritable hyperlipidemic (WHHL) rabbits, an animal model for familial hypercholesterolemia, selective breeding has been carried out. The results obtained are as follows: The incidence of coronary atherosclerosis before selective breeding was 21.8%, whereas that after the breeding was 58.9% (average values for rabbits between 4 and 12 months old), showing that the incidence of coronary atherosclerosis can be increased by an appropriate breeding technique. With respect to the relationships between parents and offspring, if parents had coronary atherosclerosis, then the incidence of the disease in the offspring was 83.3%; therefore the disease was strongly heritable. The mean total cholesterol (TC) and triglyceride (TG) levels of the colony before selective breeding were 579 +/- 163 mg/dl and 471 +/- 144 mg/dl, respectively, while those after the breeding were 665 +/- 151 mg/dl and 603 +/- 178 mg/dl; serum lipid levels increased in parallel with incidence of coronary atherosclerosis. The earliest development of coronary atherosclerosis in the colony after selective breeding was found in 4-month-old rabbits and the whole colony suffered from the disease at 18 months of age.
Animal Husbandry↗
Species-area relation for birds of the Solomon Archipelago.
Accurate values of number of breeding bird species have been obtained for 50 islands of the Solomon Archipelago. From information about species altitudinal distributions on each island, the values are apportioned into number of montane species (S(mt)) and of species present at sea-level (S(low)). S(low) increases linearly with the logarithm of island area A over a million-fold range of areas (correlation coefficient 0.99) and with a comparatively low slope, while the log S-log A relation is markedly curved. With increasing isolation of an archipelago, the species-area relation decreases in slope and may shift in form from a power function to an exponential. Comparison of Pacific archipelagoes at different distances from the colonization source of New Guinea shows that the decrease in slope is due to increasing intra-archipelago immigration rates, arising from overrepresentation of the most vagile inter-archipelago immigrants in more distant archipelagoes. When colonists are sorted into sets correlated with their dispersal abilities, the slope of the species-area relation for the most vagile set is close to zero, but for the least vagile set is close to the value predicted by Preston for "isolated universes."
Journal Article↗
Influence of estrogen-treated females on sexual behavior and male testosterone levels of a social group of rhesus monkeys during the nonbreeding season.
The effect of the sequential estradiol benzoate treatment of each of 6 ovariectomized (OVX) females on a social group of rhesus monkeys was examined during the period from May to August. The group was housed outdoors and was composed of 7 adult males and 5 intact females, in addition to the 6 OVX animals. Social behavior was observed and male testosterone levels were monitored before, during and after estrogen treatment of the OVX females. Behavior of an unmanipulated group was also examined, and no sexual behavior occurred in this control group from May through August. In contrast, the sexual behavior of both males and gonadally intact females of the experimental group increased when estrogen-treated females were present. Sexual behavior remained elevated after the estrogen-treated females had been removed and continued so into the breeding season. The sexual behavior of the untreated females was displayed in cycles about 26 days in length. Male testosterone levels increased to values typical of the breeding season. Aggressive and submissive behavior also increased during the treatment. These results confirm previous findings about the influence of estrogen-treated females on male sexual behavior, and present the first direct evidence of increased testosterone levels in this situation. In addition, the data suggest that the presence of estrogen-treated females can induce sexual behavior in the other females of the same social group.
Agonistic Behavior↗
A bioeconomic model for comparing beef cattle genotypes at their optimal economic slaughter end point.
A bioeconomic model of a feedlot was developed for the comparison of beef cattle genotypes under specified management and marketing conditions. The optimization behavior of commercial feedlot managers is incorporated into the model using optimum economic rotation theory. The days spent in the feedlot (rotation) by a group of animals are derived using this theory so as to maximize an objective function. Differences among breeds in the present value of profits from a single rotation, expressed per animal, represent the expected price premium paid for a feeder animal of a particular breed. Feed requirements and growth rates for a genotype are predicted over time for a specified diet from estimated mature size. Estimates of carcass fatness over time as a function of the energy content of the diet and estimates of dressing percentage over time are used for each genotype. A base model is described that incorporates biological parameters estimated for 11 breeds from a major breed comparison experiment and uses prices of inputs and outputs for Ontario feedlots. Sensitivity of the model to these biological and economic assumptions is shown. When breeds are compared at constant days fed, weight, or fat depth slaughter points, rankings are inconsistent, relative to those when each breed is slaughtered at its optimal economic point. The model can be used to establish appropriate slaughter end points for comparing beef cattle breeds and crosses and to evaluate breeding objectives for feedlot traits in genetic improvement programs.
Agriculture↗
[Methemoglobin level in the blood of agricultural animals and poultry].
Studies were carried out with all kinds of farm animals and birds with regard to the quantitative determination of methemoglobin in their blood in connection of seasonal changes. Blood was immediately treated upon sampling. Methemoglobin determination was carried out spectrophotometrically. Evaluated was also the percent of nitrates in the rations of the animals and birds. It was found that during the winter the amound of methemoglobin in the blood of both animals and birds varied from 0.25 to 4.4 of the total amount of methemoglobin. Its percent content during the summer varied from 0.25 to 4.17 with animals, and from 9.5 to 15.7 with birds of the total amount of methemoglobin. The amount of blood methemoglobin was found to correlate directly with the percent of nitrates in the ration. Except for birds, the seasons had no effect on the values of methemoglobin. The breed, weight, age, and physiologic status (pregnancy, barrenness) did not either affect the amount of methemoglobin. There were individual variations of the methemoglobin values with animals of one and the same species.
Animal Feed↗
Identification of quantitative phenotypes in backcross and intercross offspring.
The computer program SKUMIX was used to analyze the values of quantitative traits in controlled breeding experiments using inbred rat strains. The SKUMIX program iterated parameters were used to determine the number of expected phenotypes, the values of means and their ratios in the progeny. The computer computed parameters were identical with the results calculated using the real values. The SKUMIX program may be valuable to analyze quantitative data obtained from intercross and backcross breeding experiments yielding overlapping values that cannot be individually assigned to a particular phenotype.
Animals↗
Predicting the annual effective size of livestock populations.
Effective population size (Ne) is an important parameter determining the genetic structure of small populations. In natural populations, the number of adults (N) is usually known and Ne can be estimated on the basis of an assumed ratio Ne/N, usually found to be close to 0.5. In farm animal populations, apart from using pedigrees or genetic marker information, Ne can be estimated from the number N of breeding animals, and a value of 1 is commonly assumed for the ratio Ne/N. The purpose of this paper is to show the relation between effective population size and breeding herd size in livestock species. With overlapping generations, Ne can be predicted knowing the number of individuals entering the population per generation and the variance of family size, the latter being directly related to the survival pattern (or replacement policy) in the breeding herd. Assuming an ideal survivorship leading to a geometric age distribution, it can be shown that the number of breeding animals tends to overestimate effective size, particularly in early-maturing species. The ratio of annual effective size to the number of breeding animals is shown to be equal to [1 + (a- 1)(1 - s)]2/(1 - s2), where a is the age at first offspring and s is the survival rate (including culling) of the parents between successive births. This expression shows to what extent inbreeding may be determined by demography or culling policy independently of the actual herd size. In many situations a fast replacement or an early culling will increase annual effective size. Consequences for the management of small populations are discussed.
Animals↗
[Control of Aedes aegypti in Martinique. Contribution of entomology studies].
The dengue prevention activities in Martinique are based on: Entomological surveillance (including the use of insecticide in all parts of the Island). Epidemiological (clinical, serological and virological) surveillance. Health Education (radio, TV, exhibitions, talks in primaries and secondaries schools, in associations,...). The main breeding sites of Aedes aegypti are maintained by human practices: flowers vases, containers, used tyres, waste... The role of those human practices in the standing of Aedes aegypti populations at high level in Martinique have lead us to emphasize entomological observations and Health education. The calculation of classical Breteau Index abstracts the nature and the productivity of the breeding sites (f.e.: no difference between a flower vase and a drum). In operational way, we have introduced a new approach for calculating the Breteau index value which includes the breeding sites nature and productivity. This approach permit us to adapt the Health education message in each geographical sector.
Aedes↗
Crossbreeding of exotic and indigenous cattle in Nigeria--haematological correlates.
The blood values of the German Brown, N'Dama and their three-quarter, half and quarter hybrids were studied to ascertain if and how some haematological parameters changed with crossbreeding. It was found that the red blood cell (RBC) and white blood cell (WBC) count and packed cell volume percentage (PCV) were significantly higher (P less than 0.01) in the N'Dama than in the German Brown; the crosses had values which were intermediate as compared to the two parent breeds. Generally, the changes in the mean blood values paralleled changes in the expected genotypes resulting from crossbreeding of the two parent breeds. The tendency of the blood values to change in direct proportion to the degree of N'Dama contribution was strongest for the WBC, followed by the PCV and RBC, respectively. A small random sample for leucocyte differential count did not reveal any differences amongst the genotypic groups.
Animals↗
Blood profile of pigeons (Columba livia) during growth and breeding.
Changes in the blood profile of domestic pigeons (Columba livia) were studied during growth and breeding cycle. Counts of erythrocytes and leucocytes, and values of mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), blood volume, plasma volume (BV), width of erythrocytes, and length, width and volume of erythrocyte nuclei of squabs almost reached adult values by the 4th week of age. During courtship and mating, while the level of plasma glucose increased, those of albumin, potassium, cholesterol, calcium and uric acid decreased. At nest-building, plasma albumin and plasma calcium increased significantly. The initial phase of incubation showed an elevation in plasma calcium and a decline in cholesterol and sodium, whereas mid-phase of incubation indicated a marked rise in cholesterol and uric acid. Terminal phase of incubation had significantly low plasma protein level. During feeding and brooding period, a significant rise in sodium, protein and glucose levels and a fall in calcium were observed. Following egg-laying, there was a significant rise in calcium and a drop in protein, haemoglobin, cholesterol, sodium and MCH values. Concomitant with the phenomenal rate of growth of squabs, their haematological indices neared adult values by the 4th week of age and during breeding activity significant changes in blood values occurred.
Age Factors↗
Estimating genetic differences in natural resistance in Rhön and Merinoland sheep following experimental Haemonchus contortus infection.
Genetic parameters of natural resistance were estimated in Rhön and Merinoland (German Merino) sheep following experimental infection with Haemonchus contortus. A total of 133 Rhön and 244 Merinoland lambs descending from 5 and 6 rams, respectively, were evaluated. Each helminth-naive lamb was orally infected with 5000 infective third-stage larvae (L(3)) of the nematode H. contortus at 12 weeks of age. Faecal egg counts (FEC) and haematocrit values were measured in all lambs at 16 and 20 weeks of age. Seventy-nine Merinoland and 29 Rhön male lambs were slaughtered immediately after the second sampling and worms were collected. Mean worm burden was calculated and the length of adults worms from an aliquot was measured.FEC of Rhön sheep was higher compared with Merinoland sheep (P<0.01). H. contortus L(3)-larvae specific antibody (IgL) level was higher in Rhön sheep (P<0.05). However, no differences in haematocrit, worm burden and IgG antibody values could be found between the breeds. Heritabilities for log FEC (+/-S.E.) were 0.0 and 0.07 (+/-0.07) for the first sample in Rhön and Merinoland sheep, respectively. Values for the second sample were higher in both breeds (Rhön 0.35+/-0.14, P<0.05; Merinoland 0.17+/-0.07, P<0.05). Corresponding heritabilities for haematocrit were higher in Merinoland (0.56+/-0.20 and 0.51+/-0.27) compared with Rhön (0.29+/-0.12 and 0.08+/-0.13). Heritabilities for worm burden were high in Rhön (0.54+/-0.2) and low in Merinoland (0.06+/-0.14 and 0.11+/-0.15). Estimated values for IgL were between 0.13 (+/-0.11) for the first sample in both breeds and 0.30 (+/-0.18) for the second sample in Rhön sheep. Corresponding heritabilities for IgG were not different from 0.0 in both breeds (P>0.05). Positive phenotypic correlations were estimated for IgG and IgL values in both breeds (P<0.01). IgG was significantly (P<0.05) and positively correlated with worm burden in male Merinoland and IgL with worm burden in male Rhön sheep.
Animals↗