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PubMed1993

Haematological and plasma biochemical values for healthy Yucatan micropigs.

Blood samples (n = 135) were collected from 36 male and 35 female 20 +/- 4-week-old Yucatan micropigs and were analysed for 19 haematological and 18 plasma biochemical parameters at weeks 20, 24, 33, 46, 59, 71 and 80. For each parameter, the total number of analyses per sex, mean values, standard deviation, lowest and highest values, and 95% confidence intervals are presented as reference values for this breed. Age- and sex-related differences in these parameters are also discussed.

Animals↗

PubMed1996

Effects of porcine somatotropin on circulating testosterone concentrations in boars and mechanism of action.

Four experiments were conducted to elucidate the effects of porcine somatotropin (pST, growth hormone) on circulating testosterone concentrations in boars. In Exp. 1, jugular-cannulated obese boars were administered 4 mg recombinant (r) pST/d for 24 d before collection of samples at 15-min intervals over 6 h for measurement of pST, testosterone, and LH. Somatotropin treatment decreased plasma concentrations of testosterone and LH (P < .05). In Exp. 2, White composite boars were administered rpST with implants (4 mg/d) for 10 to 28, 16 to 28, or 22 to 28 wk of age. Reductions in testosterone concentrations were proportional to the length of time rpST was administered; boars treated for 18 wk had the lowest testosterone concentrations. Concentrations of LH declined throughout the study in rpST-implanted boars but remained static in untreated, control boars. In vitro production of testosterone and dehydroepiandrosterone/dehydroepiandrosterone sulfate was unaffected by rpST treatment, and hCG stimulation of in vitro androgen secretion was similar in rpST and control treatments. In Exp. 3, i.v. injection of pituitary pST (USDA-B1; 5 micrograms/kg BW) into jugular-cannulated White composite and Meishan boars resulted in an acute increase in circulating LH followed by an increase in testosterone concentrations, which then declined to below preinjection levels at 6 to 7 h after pST injection. Multiple injections, two or four per day, of 5 micrograms pST/kg BW resulted in decreased testosterone concentrations in White composite boars, whereas in Meishan boars testosterone concentrations were unaffected (Exp. 4). Concentrations of LH were not different from control values in either breed, but in both breeds, four injections of pST per day produced lower LH concentrations than did two injections per day (P < .01). Depression of circulating concentrations of androgens in boars requires extended periods of pST treatment.

Animals↗

PubMed1998

Experiential learning in the animal sciences: effect of 13 years of a beef cattle management practicum.

As the source of students shifts from rural to urban and suburban communities, students entering agricultural programs have less practical livestock experience. The career goals indicated by most of these students require knowledge of and experience with practical applications of their course work. The objective of this study was to examine the profile of students enrolled in an experiential beef cattle course 1) to describe the demographic and occupational characteristics of students enrolled and 2) to assess the perceived value of course activities to graduates completing the course as related to their skill attainment and career development. The questionnaire was sent to all 312 students who were enrolled in the course from 1983 to 1996. Over 61% of the respondents indicated they had enrolled in the course to gain experience working with beef cattle. Over 39% took the course to enhance their application to the College of Veterinary Medicine. When asked to rate the value of the course, as it related to skill development, they noted it was most helpful in teaching cattle handling skills, growth performance measurement, live animal evaluation, nutritional management, carcass and meat product value determination, and breed identification.

Animal Husbandry↗

PubMed1993

Optimal genetic improvement for the high producing herd.

Genetic merit for milk production is increasing over 150 kg of milk/yr in the Holstein cow population. Nationwide decreases in payments for fat differential since 1987 have not been counter-balanced by similar increases in payments for protein differential, resulting in a steady increase in the value of carrier. Protein yield should be emphasized rather than specific casein or whey fractions of protein because national recording, evaluation, and payment structures are not in place. Genetic merit of bulls for markers may differ across families, making selection for marker traits of limited value in current breeding schemes. Conformation traits that appear to have the highest correlation with measures of herd life are udder depth, for udder attachment, and teat placement. Selection for health traits is difficult because of limited genetic information. National evaluations for SCC are being developed, but average difference between extreme bulls is only slightly more than one linear SCC. Managers of high producing herds should continue with primary selection emphasis on production traits. The greatest challenge to dairy producers is to develop management systems, particularly in nutrition, that allow maximal expression of genetic potential.

Animals↗

PubMed2002

Microsatellite polymorphism in locus OMHC1 (MHC Class I) in Polish Heath Sheep and Polish Lowland Sheep (Zelazna variety).

Our study aimed at comparative analysis of microsatellite polymorphism in locus OMHC1 (MHC Class I) in Polish Heath Sheep and Polish Lowland Sheep (Zelazna variety). The study was conducted on 100 ewes of each breed. We identified 13 alleles of the gene in Polish Heath Sheep and 9 in Polish Lowland Sheep. We found marked differences in frequency of OMHC1 alleles between both breeds. The heterozygosity coefficient and PIC, amounting to 0.79 and 0.77 for Polish Heath Sheep, and 0.82 and 0.80 for Polish Lowland Sheep, respectively, suggest considerable variability in both breeds. Additionally, the values of both coefficients indicate that OMHC1 locus can be used as a genetic marker.

Animals↗

PubMed2005

Diversity of diploid androgenic Brussels sprout plants of R0 and R1 generations.

Androgenic Brussels sprout plants were produced by the use of anther culture from the donor cultivar 'Philemon F1'. A total of 96 plants obtained from 20 androgenic R0 genotypes assigned as diploids were evaluated both in the generative and vegetative stage, in respect of their morphological characters: mean plant height; leaf size, colour and waxiness; leaf blade shape, blistering and attitude; number of sprouts; as well as their self-incompatibility and fertility. Androgenic R0 plants derived from each of the 20 embryos were highly diversified and differed from the donor in one or more morphological traits in the vegetative stage. Evaluated populations also varied in fertility and self-incompatibility. Six androgenic genotypes that set a sufficient amount of seeds of the R1 generation and 'Philemon F1' were evaluated in the field in respect of plant height, total and marketable yield per plot, shape of stem with sprouts, shape and density of sprouts, and spacing between sprouts. Only four diploid R0 and R1 populations may have some value for further breeding, as they are characterised by good vigour, high or medium ability for sprout generation, and sufficient fertility.

Brassica↗

PubMed1990

[Evolution of plasma concentrations of testosterone and insulin-like growth factor I during the peripubertal period of cattle catheterized at the hepatic level].

To study endocrinal control of growth development in cattle during puberty, major hepatic vessels were cannulated in 8-13 week old Holstein male calves. In our experimental conditions, chronic hepatic cannulation with "grey" polyurethane catheters was performed for a long period (more than 65 d) without any rejection problems. A physiological washing solution containing at least 5 x 10(5) IU/l heparin-lithium was required to prevent cannula occlusion. Moreover, echography was utilized for rapid and accurate introduction of catheters into the vessels. With chronic hepatic cannulation, we have observed that plasma testosterone and insulin-like growth factor I (IGF-I) levels in cattle were lower in portal and in portal and cava veins respectively than in the other vessels. Our experiment has also shown that average plasma testosterone and IGF-I concentrations sharply increased at puberty to reach adult values. However, no relation was observed between these two hormones during the pubertal period. In conclusion, both testosterone and IGF-I plasma levels can be used as predictive factor of age at puberty but more investigations are needed to establish standard values for each breed.

Animals↗

PubMed1979

Testicular measurements and reproductive characteristics in stallions.

Factors affecting testicular measurements in situ and the relationships among the measurements and various reproductive characteristics were studied using data from 48 stallions. Mean values during the breeding season are provided for scrotal width, widths and lengths of individual testes, combined weight of testicular parenchyma, daily sperm production and daily sperm output. Testicular measurements were highly repeatable from day to day and for repeated measurements on a given day; technician provided the largest source of variation in the measurements of a given stallion. Age significantly affected all testicular measurements; testicular size for 2- to 3-year-old stallions did not differ (P greater than 0.05) from that for 4- to 6-year-olds, but was smaller (P less than 0.05) than testicular size of stallions greater than or equal to 7 years old. Scrotal width was correlated (P less than 0.01) with daily sperm production (r = 0.75) and daily sperm output (r = 0.55) and was generally the most repeatable measurement.

Aging↗

PubMed1995

[Seasonal effect on serum levels of thyroid hormones in German shepherds and dachshunds and their health status].

A relatively frequent prevalence of dermatoses in summer has drawn our attention. Dermatoses of endocrine origin occur very often. We have noticed the deterioration of skin changes in animals with hypothyroidism. Bubeník et al. (1983), Webster et al. (1991), Reiter et al. (1988) reported that changes in concentrations of thyroid hormones were found in fallow-deer, sheep and hamsters due to the effect of temperature and season. Based upon this knowledge we have decided to observe the health status and function of the thyroid gland in two randomly selected groups of various size dogs--German shepherd and dachshund during four seasons. We observed following parameters: concentration of triiodothyronine (T3), thyroxine (T4), cholesterol (Chol) and total lipids (TL) in the blood serum, average temperatures in individual seasons. Blood was always withdrawn fasting in the morning from vena antebrachii. Concentrations of T3 and T4 were determined by the commercial kits RIA-test-T4 and RIA-test-T3 (Human-Lab, Kosice, Slovak Republic). The levels of cholesterol and total lipids were determined by the BIO-LA-tests (Lachema, Brno, Czech Republic). March, April, May were included into spring season; June, July, August into summer; September, October, November into autumn; and December, January, February into winter. The Slovak Hydrometeorologic Institute in Kosice provided the values of average temperatures in observed seasons. The average temperatures in individual seasons were the following: spring +9.8 degrees C, summer +18.4 degrees C, autumn +8.5 degrees C, winter -1.2 degrees C. During the observed period concentrations of cholesterol and total lipids ranged within the reference values in both breeds.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1993

Potential shortcomings of output:input ratios as indicators of economic efficiency in commercial beef breed evaluations.

In recent years animal breeders have increasingly made use of output:input ratios and simple measures of economic efficiency, such as annual profits, as a basis for comparisons and evaluations of the commercial applicability of alternative beef breeds. In many instances, however, output:input ratios may produce fallacious indications of economic efficiency that may, in turn, lead to erroneous conclusions regarding the true commercial applicability of the breeds evaluated. Errors potentially arising from the use of output:input ratios in breed evaluations may be attributed to a combination of 1) a narrow range of input use values under which most breeds are evaluated and 2) the inability of output:input ratios, including average annual profitability, to reflect consistently the economic objectives of commercial cow-calf producers. An alternative basis for breed comparison and evaluation is, therefore, developed from economic theories related to optimal investment and asset replacement. Comparison of the results obtained with this alternative to those obtained from output:input ratio evaluation, including annual profitability, indicate that potential value differences of as much as 33% may result from the use of output:input ratios as a primary basis of commercial breed evaluation.

Animals↗

PubMed1990

Differences in production values between high- and low-productivity swine breeding herds.

Data were collected from 80 North American users of a computerized health and management software program for the period August 1985 through July 1986. Fifty-four herds were selected for analysis based on selection criteria of 1) stable herd inventory, 2) complete recorded data, 3) weaning-to-first service interval greater than 3 d and less than 20 d, and 4) culling rate greater than 10%. These herds had an average of 18.2 pigs weaned/(female.year) (PWFY), 2.1 litters/(female.year) (LFY), 81% farrowing rate, 10.2 pigs born live/litter and 14.5% preweaning mortality. Compared with the 14 herds with the lowest values for pigs weaned/(female.year), high-productivity herds (i.e., the 14 herds with the highest values for PWFY) had higher LFY, farrowing rate, total and live pigs born/litter and sow-gilt ratio; they also had lower nonproductive female days (NPFD), lower preweaning mortality and fewer gilts as a proportion of female inventory. Herd size and PWFY were not correlated. A negative correlation between herd size and pigs born live remained after controlling for average lactation length (r = -.30). Nonproductive female days was highly correlated with LFY (r = -.87). Increasing herd age, measured by the sow-gilt ratio, was associated mainly with a reduction in NPFD, although there was a slight positive association with pigs born alive (r = .29).

Agriculture↗

PubMed1990

Evaluation of the Schirmer tear test in clinically normal rabbits.

Mean (+/- SD) value for results of the Schirmer tear test without use of topical anesthesia on 142 rabbit eyes was 5.30 (+/- 2.96) mm/min; range was 15 mm/min, with low value of 0 and high value of 15 mm/min. Two SD from the mean provided a normal clinical range of 0 to 11.2 mm/min for inclusion of 95% of the population. Significant differences were not evident between eye (right vs left) or gender or among breeds; interaction among eye, gender, and breed also was not observed. Although mean values for 2 breeds were significantly different from values in the other 10 breeds and from each other, they were still within the proposed normal range of 2 SD. The Schirmer tear test without topical anesthesia may be useful in rabbits for evaluation of increased values correlated with ocular irritation, rather than for determination of decreased values associated with keratoconjunctivitis sicca.

Anesthesia↗

PubMed1987

Maternal heterosis and grandmaternal effects in beef cattle: postweaning growth and carcass traits.

Crossbred steer and heifer progeny from 5-, 6- and 7-yr-old dams produced in a four-breed diallel crossing experiment involving the Brown Swiss, Red Poll, Hereford and Angus maternal grandsires and maternal granddams were evaluated for postweaning growth and carcass traits to estimate breed mean maternal heterosis, maternal heterosis for specific breed cross females, average maternal heterosis for all crosses, breed grandmaternal effects and net breed effects in crosses. All progeny evaluated were born in 1979 and 1980 and were sired by 7/8 or 15/16 Simmental bulls. Average maternal heterosis was significant for 200-d weight in heifers but not in steers and was not significant for final weight (444-d) in either heifers or steers. The effects of maternal heterosis on postweaning growth were not important. Differences among breeds in mean maternal heterosis values were small for growth-related traits. Breeds did not differ (P greater than .05) in grandmaternal effects for growth-related traits; Brown Swiss tended to be highest, Red Poll lowest, with Hereford and Angus intermediate. Differences in net breed effects in crosses favored Brown Swiss over the three other breeds and were generally significant for growth traits. Average maternal heterosis, though generally positive, was not significant for carcass traits on either an age-constant or weight-constant basis. Differences among breeds were small in grandmaternal effects, specific heterosis and net effects in crosses for carcass traits associated with both weight or composition; generally the Brown Swiss breed was favored on carcass traits associated with weight in the age-constant analysis and generally had a higher lean-to-fat ratio than the three other breeds in both the age-constant and weight-constant analyses.

Animals↗

PubMed2005

Genetic analysis of herd life in Canadian dairy cattle on a lactation basis using a Weibull proportional hazards model.

The objectives of this study were to identify the most important factors that influence functional survival and to estimate the genetic parameters of functional survival for Canadian dairy cattle. Data were obtained from lactation records extracted for the May 2002 genetic evaluation of Holstein, Jersey, and Ayrshire breeds that calved between July 1, 1985 and April 5, 2002. Analysis was performed using a Weibull proportional hazard model, and the baseline hazard function was defined on a lactation basis instead of the traditional analysis of the whole length of life. The statistical model included the effects of stage of lactation; season of production; the annual change in herd size; type of milk recording supervision; age at first calving; effects of milk, fat, and protein yields calculated within herd-year-parity deviations; and the random effects of herd-year-season of calving and sire. All effects fitted in the model had a significant effect on functional survival of cows in all breeds. Milk yield was by far the most important factor influencing survival, and the hazard increased as the milk production of the cows decreased. The hazard also increased as the fat content increased compared with the average group. Heifers that were older at calving were at higher risk of being culled, and expanding herds were at lower risk of being culled compared with stable herds. More culling was found in unsupervised herds than in supervised herds. The heritability values obtained were 0.14, 0.10, and 0.09 for Holstein, Jersey, and Ayrshire, respectively. Rank correlation between estimated breeding values (EBV) obtained from the current national genetic evaluation of direct herd life and the survival kit used in this study ranged from 0.65 to 0.87, depending on the number of daughters per sire. Estimated genetic trend obtained using the survival kit was overestimated.

Animals↗

PubMed1992

Comparison of histomorphometric values in iliac trabecular bone of beagle dogs raised under different breeding systems.

In order to clarify individual differences in bone metabolism among colony-raised beagle dogs, histomorphometric values of iliac trabecular bone and values of serum biochemical constituents related to bone were examined in 10 and 17 beagle dogs raised, respectively, under our two breeding systems in which differences in factors such as exercise, ultraviolet rays, and mineral content of the diet affect bone metabolism. At the age of 14 months, all dogs were injected with tetracycline hydrochloride and calcein twice for double bone labeling in order to measure dynamic as well as static parameters by bone histomorphometry and the ilium was later biopsied. The measurement on cancellous bone areas of undecalcified iliac sections was performed with a semiautomatic image analyser. Values of total calcium, phosphorus, alkalinephosphatase activity, parathyroid hormone and calcitonin in serum were also determined. The results showed that there were no significant differences between the two groups in histomorphometric values, except for the osteoid volume (p less than 0.05) and osteoid surface/trabecular surface ratio (p less than 0.01) in females, or in serum biochemical constituents, except for alkalinephosphatase activity (p less than 0.001) in males, indicating there were virtually no individual differences in bone metabolism in normal colony raised beagle dogs.

Alkaline Phosphatase↗

PubMed1995

Genetic characterization of highly inbred chicken lines by two DNA methods: DNA fingerprinting and polymerase chain reaction using arbitrary primers.

Thirteen highly inbred chicken lines were analysed at the DNA level by DNA fingerprinting (DEP) and by polymerase chain reaction (PCR) using random primers. In general, the DFP patterns of individuals within a line were identical. The DFP band-sharing (BS) values among lines from different breeds (Leghorn, Fayoumi, Spanish) ranged from 0.10 to 0.20. The DFP BS values among Leghorn lines from different genetic backgrounds ranged from 0.42 to 0.79. The DFP BS values among lines selected for different major histocompatibility complex serotypes from a common genetic background ranged from 0.70 to 0.95. Some randomly amplified polymorphic DNA (RAPD) PCR products were specific to a single line, some to all lines from the same genetic base, and some to all lines from the same breed. The RAPD-PCR band-sharing values ranged from 0.66 to 0.99 for all between-line comparisons. Thus, the ability to detect biodiversity at the DNA level was greater in this study for DFP than for RAPD-PCR. The possible origin of line-specific bands, relative advantages of detecting biodiversity by using different molecular screening techniques and uses of highly inbred chicken lines in molecular analysis are discussed.

Animals↗

PubMed1976

Growth and carcass characteristics of cattle and buffalo breeds reared on a dry zone pasture in Sri Lanka (Ceylon).

Growth and carcass characteristics were measured on calves from three cattle breeds-the Sinhala, Red Sindhi and Friesian-and two buffalo breeds-the local buffalo and Murrah. The growth study was carried out on Brachiaria brizantha pasture over a period of 48 weeks. The two buffalo breeds grew fastest followed by the two Bos indicus breeds. The Friesian cattle grew at the slowest rate. The Sinhala and local buffalo had normal haematocrit values while the values for all other breeds were lower. The Sinhala and local buffalo had the highest carcass dressing percentages and the highest muscle; bone ratios. Tenderness measured by Warner-Bratzler shear force values and palatability scores by a taste panel were similar for meat from cattle and buffalo.

Animals↗

PubMed1976

Haematological values of Nigerian goats and sheep.

Haematological parameters were determined in healthy Nigerian breeds of goats and sheep. Most values in the Nigerian goats were similar to those reported for temperate breeds of goats although the haemoglobin concentrations and the MCHC were lower. The haematocrit, haemoglobin concentrations and red cell counts of the West African Dwarf sheep were lower while the MCV were higher than those reported for sheep in the temperate climate. RBC values decreased with age in both Nigerian goats and sheep. Although sex pregnancy appeared to have little or no influence on the erythrocytic values, pregnant ewes had higher haematocrit and haemoglobin values. The low erythrocytic values were attributed to a low but constant parasitic burden which affected the flocks studied. Total leucocyte counts were considerably higher in the Nigerian goats and sheep than those reported for temperate breeds of animals. Young goats had higher total leucocyte counts while pregnant goats had reduced leucocyte counts. The leucocytic values were not affected by age and sex. Pregnant ewes also had higher leucocyte counts than non-pregnant ewes and rams.

Animals↗