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PubMedDate not supplied

Some haematological and clinical-chemical parameters of sight hounds (Afghan hound, saluki and whippet).

Blood was collected from 111 clinically healthy dogs of sight hound breeds for haematological and clinical chemical analyses. The distributions according to age, breed and sex are tabulated. Reference values for haemoglobin were established as 172-240 g/l for adults and 136-217 g/l for growing dogs; the respective packed cell volume values were 50-69% and 41-64%. Ten serum parameters were determined: AP, ALAT, ASAT, GT, CK, urea, cholesterol, creatinine, total protein and albumin. The results are given as means +/- S.D., and a reference value for serum creatinine was established as less than or equal to 165 mumol/l for adults.

Age Factors↗

PubMed1978

An improved procedure for genetic selection against hip dysplasia in dogs.

Rapid weight gain can educe hip dysplasia of dogs with normal hip joints. It is proposed that progeny whose parents have "excellent genotypes" would not be susceptible to this stress and would develop normal hip joints. The method for reducing the incidence of hip dysplasia in dogs would be to use stress to identify carriers (parents) and potential carriers (progeny), and select for breeding only dogs with proved genotypic value and those progeny with the best hip joint conformation.

Animals↗

PubMed1980

Development of an enzyme-linked immunosorbent assay for detecting antibodies in sera of Brucella suis-infected swine.

An enzyme-linked immunosorbent assay was developed using a heat-killed Brucella suis antigen for detecting antibodies in the sera of swine from which B. suis was isolated. Optimal enzyme-linked immunosorbent assay reactions were obtained using heat-killed B. suis antigen at a concentration comparable to McFarland Standard No. 1. Statistically significant differences were observed in the enzyme-linked immunosorbent assay results of 40 animals from which B. suis was isolated and the results for 48 noninfected swine at serum dilutions of 1:25 and 1:50 (P < 0.0001). The enzyme-linked immunosorbent assay is a rapid reproducible test which can be readily automated that appears to have practical value for screening large numbers of breeding and slaughter swine for brucellosis.

Animals↗

PubMed2006

Statistical analysis of individual assignment tests among four cattle breeds using fifteen STR loci.

Assignment tests based on multilocus genotypes are becoming increasingly important to certify quality and origin of livestock products and assure food safety and authenticity. The purpose of this study was to determine the potential of microsatellites (STR) for determining the breed origin of beef products among cattle breeds present in the market. We typed 19 STR in 269 animals from 4 cattle breeds. Based on Wright's F-statistics, 4 loci were discarded, and the remaining 15 loci (FIT = 0.101, FST = 0.089, and FIS = 0.013) were used to compute the likelihood that each multilocus genotype of the total sample was drawn from its true breed instead of another breed. To avoid occurrence of zero likelihood when one or more alleles were missing from a tested breed, sample allele frequencies were estimated assuming uniform prior distributions. Log-likelihood ratio [log(LR)] distributions of the individual assignments were determined for all possible breed contrasts, and their means and SD were used to infer the true-positive and false-positive rates at several values of the log(LR). The posterior probability that the animals of a presumed breed were actually drawn from that breed instead of any another breed was then calculated. Given an observed value of log(LR) > 0 and assuming equal priors, these probabilities were > 99.5% in 10 of 12 possible breed contrasts. For the 2 most closely related breeds (FST = 0.041), this probability was 96.3%, and the probability of excluding the origin of an animal from an alleged breed when it was actually derived from another breed was similar.

Animals↗

PubMed2006

Identification and characterization of porcine mannan-binding lectin A (pMBL-A), and determination of serum concentration heritability.

Mannan-binding lectin (MBL) is an innate immune collectin present in the serum of humans and many farm animals. This oligomeric pattern-recognition protein effectively binds to the glycoconjugate arrays present on the surfaces of microorganisms and activates the complement system to enhance pathogen killing and clearance. MBL deficiency is often associated with immunodeficiency in humans. Although two MBLs (MBL-A and MBL-C) have been characterized in various species, the identity of porcine MBL (pMBL) was not clearly defined. In this study, we purified an MBL from porcine serum by mannose affinity, ion exchange, and size exclusion chromatography and determined many of its characteristics. Based on the N-terminal sequence, multiple sequence alignment, and relative affinities to various carbohydrate ligands, we propose that the MBL purified in this study is pMBL-A. We have generated antibodies to this protein and established an immunoassay to quantify pMBL-A in serum. Using this assay, we found breed differences in pMBL-A concentration distributions and heritability estimates. In the Duroc breed (n=588), pMBL-A concentrations show a unimodal distribution with a mean of 9,125 ng/ml. In contrast, the pMBL-A concentration distributions in the Landrace breed (n=533) show three distinct mean values: 301, 2,385, and 11,507 ng/ml. Furthermore, heritability calculations based on an additive genetic variance model with no fixed effects indicate that serum pMBL-A concentration is highly heritable in the Landrace (h (2)=0.8) but not in the Duroc breed (h (2)=0.15). These genetic differences may be useful in selecting breeding pigs for improved disease resistance.

Amino Acid Sequence↗

PubMed1991

Role of the thyroid gland in seasonal reproduction. II. Thyroxine allows a season-specific suppression of gonadotropin secretion in sheep.

A series of four experiments was conducted to examine the previously described phenomenon that the thyroid gland is required for the breeding season to end in female sheep. Exp 1 tested the hypothesis that the thyroid is required because of its secretion of T4. Ewes thyroidectomized (THX) in the anestrous season either received T4 replacement or no further treatment; seasonal reproductive shifts were compared to those of thyroid-intact controls. All ewes were housed in conditions in which the end of the breeding season results from the expression of an endogenous annual rhythm. The ewes were ovariectomized and given constant-release estradiol (E) implants; reproductive state was assessed from serum LH levels to monitor seasonal shifts in response to E negative feedback. THX did not alter onset of the breeding season (LH rise) but, in the absence of T4 replacement, blocked its end (LH fall). T4 replacement reversed this effect of THX. Exp 2 tested the hypothesis that the thyroid is required only until the onset of the breeding season for reproductive activity to end at its normal time. THX after the breeding season began, however, sustained the elevation in LH, suggesting that the thyroid is required after reproductive onset for the breeding season to end. Exp 3 tested the hypothesis that THX causes a widespread disruption of steroid feedback responses. No effect of THX, however, was observed with respect to either the ability of an E rise to elicit the LH surge or the ability of E, or progesterone, to suppress LH secretion in the breeding season. Of the steroid feedback responses tested, THX altered only the seasonal shift in potency of E negative feedback. Exp 4 examined circulating T4 in thyroid-intact ewes over a 2-yr period. An annual cycle of serum T4 was detected; values reached a peak in winter (late breeding season) and a nadir in summer (late anestrus). Our findings support the concept that the thyroid gland plays a fundamental role in seasonal reproduction in the ewe. In this regard, secretion of T4 after the onset of reproductive activity is required for an endogenously generated change in the neuroendocrine axis that leads to an intensified E negative feedback and an end to the breeding season.

Anestrus↗

PubMed2000

Evaluation of Dorset, Finnsheep, Romanov, Texel, and Montadale breeds of sheep: I. Effects of ram breed on productivity of ewes of two crossbred populations.

Effects of Dorset, Finnsheep, Romanov, Texel, and Montadale breeds for performance as sires were estimated in the initial phase of a comprehensive evaluation of these breeds as contributors to sheep crossbreeding systems. Objectives were to evaluate the effects of ram breed, ewe breed, season of mating, and two-way interactions. Rams from the five breeds were single-sire-mated with ewes from two breed types to produce lambs over a 3-yr period. Ewes were assigned to one of three distinct 35-d mating seasons initiated each year in August, October, and December. A different sample of six rams per breed was used each year across all three seasons, and each ram was penned with ewes of both breeds. Traits evaluated and number of ewe records were conception rate and litter weaning weight per ewe exposed (n = 3,261) and number born, litter birth weight, average birth weight, number weaned, and litter weaning weight per ewe lambing (n = 2,751). Ram breed and ewe breed interacted (P < .01) for conception rate and litter weaning weight per ewe exposed, implicating mating preferences, particularly of Romanov rams. In mixed groups of ewes exposed to Romanov rams, conception rate was 12.7% lower and litter weight weaned was 8.4 kg lower in the ewe breed presumably less preferred for mating by the rams. On a per ewe exposed basis, Romanov-sired litters produced either the largest or the smallest values for litter weaning weight, depending on the breed of ewe. Effects of ram breed on number born and litter birth weight interacted (P < .05) with season of mating. The largest litters within each ram breed were associated with the October mating season. Montadale and Romanov rams sired larger and heavier litters from August matings than from December matings, whereas the opposite was true for Dorset-sired litters. Texel- and Finnsheep-sired litters were similar in size and weight from August and December matings. Breed of ram differences affected per ewe lambing productivity measurements (P < .01). Differences between ram breeds for ewe productivity were noted, with increased number born and improved survival of crossbred progeny to weaning for Romanov-sired litters. These results may have implications for using these ram breeds as sires in different crossbreeding systems. Structured mating systems or the creation of new composite populations involving these breeds could be used to match the resources, environment, and market of specific production situations.

Animals↗

PubMed2004

Characterization of biological types of cattle (Cycle VI): carcass, yield, and longissimus palatability traits.

Carcass (n = 568) and longissimus thoracis palatability (n = 460) traits from F1 steers obtained from mating Hereford (H), Angus (A), and U.S. Meat Animal Research Center (MARC) III cows to H, A, Norwegian Red (NR), Swedish Red and White (RW), Friesian (F), or Wagyu (W) sires were compared. Data were adjusted to constant age (471 d), carcass weight (356 kg), fat thickness (1.0 cm), percentage of fat trim (24%), and marbling (Small35) end points. For Warner-Bratzler shear force and trained sensory panel traits, data were obtained on longissimus thoracis steaks stored at 2 degrees C for 14 d postmortem. The following comparisons were from the age-constant end point. Carcasses from H- and A-sired steers (377 and 374 kg, respectively) were the heaviest (P < 0.05) and carcasses from W-sired steers (334 kg) were the lightest (P < 0.05). A greater (P < 0.05) percentage of carcasses from A- and W-sired steers graded USDA Choice (88 and 85%, respectively) than carcasses from other sire breeds (52 to 71%). Adjusted fat thickness for carcasses from A-sired steers (1.3 cm) was highest (P < 0.05), followed by H-sired steers (1.1 cm) and W- and F-sired steers (0.9 cm); NR- and RW-sired steers (0.8 cm) had the lowest (P < 0.05) adjusted fat thickness. Longissimus thoracis area was not different (P > 0.05) among sire breeds (mean = 80.6 cm2). Carcass yield of boneless, totally trimmed retail product was least (P < 0.05) for A-sired steers (60.1%), intermediate for H-sired steers (61.5%), and similar (P > 0.05) for all other sire breeds (62.5 to 62.8%). Longissimus thoracis steaks from carcasses of A- (3.7 kg) and W-sired (3.7 kg) steers had lower (P < 0.05) shear force values than longissimus thoracis steaks from other sire breeds (4.1 to 4.2 kg). Trained sensory panel tenderness, juiciness, or beef flavor intensity ratings for longissimus thoracis steaks did not differ (P > 0.05) among the sire breeds. Sire breed comparisons were affected by adjusting data to other end points. Heritability estimates for various carcass, yield, and palatability traits ranged from very low (h2 = 0.06 for percentage of kidney, pelvic, and heart fat) to relatively high (h2 = 0.71 for percentage of retail product yield). Relative to the other sire breeds, W-sired steers had the highest percentage of USDA Choice, Yield grade 1 and 2 carcasses, but their carcasses were the lightest.

Adipose Tissue↗

PubMed1991

Social control of reproduction in breeding and non-breeding male naked mole-rats (Heterocephalus glaber).

Eight male naked mole-rats, from three colonies were studied in captivity. When non-breeding male naked mole-rats were removed from their colonies and paired with a non-breeding female, or removed and housed singly for 6 weeks before pairing with a female, concentrations of urinary testosterone and plasma luteinizing hormone (LH) increased significantly (P less than 0.05). Concentration of these hormones were highest while the males were singly housed: urinary testosterone (mean +/- s.e.m.) increased from 8.2 +/- 1.3 ng/mg urinary creatinine (Cr) in a non-breeder in a colony to 49.1 +/- 5.5 ng/mg Cr when singly housed and 21.8 +/- 2.5 ng/mg Cr when paired with a female. Plasma LH concentrations increased from 4.7 +/- 1.0 miu/ml when a non-breeder in a colony to 19.8 +/- 4.0 miu/ml when singly housed and 9.9 +/- 1.1 miu/ml when paired with a female. After pairing with a female, the pattern of urinary testosterone secretion in the male was synchronized with the ovarian cycle of the female mate, such that urinary testosterone concentrations were significantly higher during the early follicular phase of the female's cycle (P less than 0.05). These results suggest that active suppression of reproductive physiology by social cues occurs in non-breeding male naked mole-rats, and that this is readily reversible if social cues are removed and males are housed singly. When a male was subsequently paired with a female, endocrine suppression was partially reimposed on the reproductively active males, such that urinary testosterone concentrations were suppressed to values similar to those in non-breeding males, except for periods prior to mating.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed2002

Dynamic upper airway changes and arterial blood gas parameters during treadmill exercise.

The primary goal was to investigate the relationship between dynamic upper airway abnormalities and arterial blood gas tensions during exercise. Horses that completed a high-speed treadmill examination consisting of upper-airway videoendoscopy, blood gas evaluation and electrocardiogams and, postexercise, echocardiograms and tracheal washes, were included. An age-matched group of fit, healthy Thoroughbreds, trained to run on a high-speed treadmill, served as controls for blood gas values at specific exercise speeds. One hundred and nineteen horses completed the treadmill examination. Sixty (50%) were Thoroughbreds (TB), 51 (43%) Standardbreds (STD) and 8 (7%) other breeds. Mean +/- s.d. age TB 3.8 +/- 2.2 years and STD 4.0 +/- 1.7 years, with no gender predilection. Fifty-four horses (45%) had abnormal upper respiratory tract (URT) abnormalities alone or in combination with abnormalities in another body system. Thirty-eight (70%) were TB, 14 (26%) were STD and 2 (4%) were other breeds. Of these, 24 (45%) had exercising PaO2 values significantly lower than those observed in healthy TB. Nineteen (35%) horses also had significantly elevated exercising PaCO2. Only 14 (12%) horses had abnormal clinical findings in the URT alone, and of these, only 3 (21%) had an abnormally low PaO2 and/or elevated PaCO2. Multiple URT abnormalities were more commonly associated with abnormal exercising blood gases than were single disorders, but pharyngeal collapse (PC) was much more commonly associated with abnormal values if only one disorder was detected. Fifty-five percent (n = 65) of all cases admitted had no evidence of URT disease. Twenty-two (35%) were TB and 37 (57%) were STD. Twenty (31%) of these had abnormally low PaO2 and 14 (22%) had elevated PaCO2 values. Seventy percent (14) of the horses with abnormal PaO2 were STD, while almost 80% (11) of the horses with elevated PaCO2 were STD. These data suggest that dynamic URT dysfunction can adversely affect gas exchange during exercise. While multiple abnormalities were more commonly associated with gas exchange problems than were single disorders, pharyngeal collapse, either alone or in combination with other URT problems, was the disorder most frequently associated with blood gas abnormalities. Additionally, URT disease was more commonly seen in TB, and the proportion of URT diagnoses in horses with abnormal blood gases reflected this percentage, while STD without URT disease had a much higher incidence of abnormal blood gases than did TB without URT abnormalities.

Animals↗

PubMed1992

Optimal effective population size for the global population of black and white dairy cattle.

The replacement of other black and white cattle strains by the North American Holstein breed, which itself is dominated by a small number of elite sires, has reduced the genetic diversity of the global population. Intense selection on a global basis leads to rapid genetic improvement but reduces effective population size. The optimal global effective population size was chosen to maximize the net present value of all future benefits from the breeding program. Two separate discount rates were used to reflect concerns about the long-term costs of small effective population size. This led to a higher optimal number of bull-sires than in past analyses. The optimum was sensitive to the magnitude of inbreeding depression and to the discount rates, but not to the variance caused by new mutations and the size of the world population. The genetic correlation between the breeding objectives of different AI studs controls the extent to which they all select the same sires of sons and, hence, affects the global effective population size. The prediction is made that different countries will select partially different sires, but genetically isolated strains will not reemerge. A better global breeding program is likely when selection of sires takes account of inbreeding depression and small genotype by environment interactions.

Animals↗

PubMed2001

Assessing genetic diversity in Italian goat populations using AFLP markers.

Amplified fragment length polymorphism (AFLP) markers were used to investigate the genetic variation in a sample of seven goat (Capra hircus) populations. A total of 210 individuals (30 per population) were analysed using seven selected AFLP primer combinations that produced 219 clear polymorphisms. Four autochthonous goat breeds (Bionda dell'Adamello, Frisa, Orobica and Verzaschese), two primary populations, one from the Lombardy Alps (Val di Livo) and the other from Sardinia island (Sarda) and a reference cosmopolitan breed (Saanen) were included in the analysis. The expected heterozygosity (Het) did not differ significantly among breeds (range 0.21-0.24). No breed specific markers were identified. The variability at AFLP loci was largely maintained within breeds, as indicated by the coefficient of genetic differentiation (Gst) value (0.11). Dice similarities calculated between pairs of individuals belonging to the same or to different breeds largely overlapped. Bootstrapping on markers indicated that the coefficient of variation (CV) of the genetic indexes tested decreases only marginally by adding markers over 100 AFLPs. Cluster analysis based on standard genetic distance between breeds indicates that Sarda is the most distant population, while Bionda, Frisa, Verzaschese and Val di Livo seem to be highly related populations. Interestingly, Saanen is closer than Orobica to the other four goat populations of the Lombardy Alps. Principal co-ordinates analysis based on Dice similarities confirms these observations. Genetic diversity of the goat populations investigated confirms what is expected on the basis of their geographical location. Results from Orobica are not correlated with geographical distances and may reflect undocumented migrations and gene flows and identify an original genetic resource.

Animals↗

PubMed2006

Assessing genetic diversity in indigenous Veneto chicken breeds using AFLP markers.

Genetic variation in four indigenous chicken breeds from the Veneto region of Italy was assessed using amplified fragment length polymorphism (AFLP) markers. A total of 99 individuals were analysed using three AFLP primer combinations that produced 70 polymorphisms. Four indigenous Veneto chicken breeds (Ermellinata, Padovana, Pépoi and Robusta) and a reference broiler line were included in the analysis. Breed-specific markers were identified in each breed. The expected heterozygosity did not differ significantly among the indigenous Veneto chicken breeds and the broiler line. The coefficient of gene variation (Gst) value across loci indicated that almost half of the total variability was observed among breeds. Nei's standard genetic distance between pairs of breeds showed that the distance between the broiler line and the Pépoi breed was greater than the distances between the broiler line and the other three chicken breeds. Cluster analysis based on standard genetic distances between breeds indicated that the Padovana and Pépoi breeds were closely related. Factorial analysis based on a binary matrix of the AFLP data showed a clear distinction of all breeds.

Animals↗

PubMed2001

Haematological and blood biochemical characteristics of Dutch warmblood foals managed under three different rearing conditions from birth to 5 months of age.

Reference values for haematological and blood biochemical variables may vary per breed and are influenced by age and, to a certain extent, by rearing conditions. To investigate the influence of age and rearing conditions, these variables were measured in Dutch Warmblood foals from birth to 5 months of age. The foals were divided into three groups with different exercise regimens: 14 foals got boxrest with no exercise; 14 foals were kept in comparable boxes, but received daily exercise; and 15 foals were maintained on pasture with free exercise. Blood samples were collected each month and 36 haematological and biochemical variables were measured. The influence of age and rearing conditions was statistically evaluated. Significant age effects were found for all variables with the exception of band-shaped leucocytes, eosinophilic leucocytes, basophilic leucocytes, monocytes, platelets, pCO2, and sodium, potassium, calcium, magnesium, creatinine and creatine phosphokinase levels. Rearing conditions appeared to influence the haemoglobin, packed cell volume, pH, base excess, bicarbonate, chloride, urea, and alkaline phosphatase values. Most age-related differences can be explained by growth and differentiation-related processes that are specific for young animals. Differences due to the different rearing conditions can partly be explained by the higher metabolism and greater maturation of tissues in foals maintained on pasture with free exercise. Some other differences were minor and were probably of no clinical relevance. The conclusion is that haematological and blood biochemical variables in the Dutch Warmblood foal mainly depend on age, thus warranting the use of specific age-related reference values for foals of this breed.

Aging↗

PubMed1991

Effect of age and season on the establishment of spermatogenesis in the horse.

To determine the age at which adult values for hormonal and testicular characteristics are established, testes and blood from 123 slaughtered horses, aged 1-5 years, were compared. Serum concentrations of follicle-stimulating hormone (FSH), luteinizing hormone (LH) and testosterone (T) and intratesticular testosterone (ITT) were determined by radio-immunoassay. Specimens were obtained in the non-breeding (n = 46) or breeding (n = 43) season in Experiment 1 (Exp. 1) and in the breeding (n = 34) season in Experiment 2 (Exp. 2). Testicular parenchyma was fixed in glutaraldehyde and homogenized to enumerate nuclei of Sertoli cells and elongated spermatids. Paired parenchymal weight (PPar-Wt), Sertoli cell number per horse (SC/H) and daily sperm production per gram of parenchyma (DSP/g) or per horse (DSP/H) were determined. In Exp. 1, DSP/g and SC/H were higher (P less than 0.05) in the breeding season. Left (LT-Wt; adult value established at 4 years) and right (RT-Wt; 3 years) testicular weights, PPar-Wt (4 years), DSP/g (3 years), DSP/H (3 years), SC/H (3 years), number of elongated spermatids/SC (ES/SC; 5 years), LH (5 years) and T (5 years) increased (P less than 0.01) with age. FSH also increased (P less than 0.05) with age. Age was correlated (r = 0.47 to 0.72; P less than 0.01) with LT-Wt, RT-Wt, PPar-WT, DSP/g, DSP/H, SC/H, ES/SC, LH and T. DSP/H was correlated (r = 0.40 to 0.94; P less than 0.01) with PPar-Wt, SC/H, ES/SC, LH and T. In Exp. 2, left testes were processed for histology and scored for percentage of tubules with elongated spermatids (% ES) or residual bodies (% RB). LT-Wt (adult value established at 4 years), RT-Wt (4 years), PPar-Wt (4 years), T (4 years), LH (4 years), % ES (2.5 years) and % RB (2.5 years) were influenced (P less than 0.01) by age. Age was correlated (r = 0.41 to 0.84; P less than 0.01) with PPar-Wt, % ES, % RB, LH, T and ITT. Although adult values of % ES, % RB, DSP/g and DSP/H were obtained by Year 3, PPar-Wt and serum hormonal concentrations increased significantly and DSP/H tended to increase to Year 4.

Age Factors↗

PubMed2000

Impedance audiometric measurements in clinically normal dogs.

OBJECTIVE: To measure impedance audiometric values in clinically normal dogs that were sedated or anesthetized, evaluate effects of ear flushing on tympanometric measurements, and determine effects of performing acoustic reflex testing in a sound-attenuated room. ANIMALS: 35 mixed-breed and purebred client-owned dogs and 21 laboratory-bred Beagles. PROCEDURES: Tympanometry and acoustic reflex testing were performed on 27 mixed-breed and purebred dogs under isoflurane anesthesia in a non-sound-attenuated room and 21 Beagles under sedation in a sound-attenuated room. Tympanometry was performed on 8 mixed-breed dogs under halothane anesthesia before and after ear canal flushing. RESULTS: Among impedance audiometric values, ear canal volume and compliance peak were smaller in Beagles than in mixed-breed dogs; differences among other values were not detected. Ear canal volume was dependent on body weight. Differences were not found for tympanometric values measured before and after ear canal flushing. CONCLUSIONS AND CLINICAL RELEVANCE: Results of this study established reference range values for impedance audiometric measurements in clinically normal dogs under isoflurane anesthesia or sedation. Acoustic reflex testing does not need to be performed in a sound-attenuated room. The ear canals of clinically normal dogs can be flushed prior to performing tympanometry without altering the results. Impedance audiometry may be a useful noninvasive procedure for the diagnosis of otitis media in dogs.

Acoustic Impedance Tests↗

PubMed2006

Benefits of cooperation between breeding programs in the presence of genotype by environment interaction.

Dairy cattle breeding programs and dairy farmers are selecting sires and dams across environments. Genotype x environment interaction (G x E) limits the possibilities for cooperation between breeding programs operating in different environments. The objectives of this study were 2-fold: 1) to investigate the effects of heritability, selection intensity, number of progeny per bull, and size of breeding programs on possibilities for cooperation between dairy cattle breeding programs in the short and long term in the presence of G x E, and 2) to quantify the effect of such cooperation on genetic gain. A dairy cattle situation with 2 breeding programs operating in 2 environments was simulated using a deterministic pseudo-BLUP selection index model. Long-term cooperation between the 2 breeding programs was possible in the presence of G x E, when the genetic correlation was higher than 0.80 to 0.90, resulting in up to 15% extra genetic gain. In addition, in the initial generations of selection, the breeding programs could benefit from mutually selecting sires and dams from each other when the genetic correlation was as low as 0.40 to 0.60. With more intense selection, breeding programs were less likely to benefit from cooperation with breeding programs in other environments. Heritability and number of progeny per bull had little effect on possibilities for cooperation, unless the heritabilities and the number of progeny per bull were extremely different in the 2 environments. Small breeding programs benefited more from cooperation than did large breeding programs, and benefits were possible even at lower values (i.e., <0.80) of the genetic correlation. Possibilities for cooperation across environments would affect the optimal design of dairy cattle breeding programs considering genetic gain, inbreeding, and costs.

Animals↗

PubMed1998

Urolithiasis in dogs. II: Breed prevalence, and interrelations of breed, sex, age, and mineral composition.

OBJECTIVE: To analyze selected breed-related data for canine urinary calculi. SAMPLE POPULATION: 11,000 specimens: 5,781 from female dogs, 5,215 from males, and 4 from dogs of unrecorded sex. PROCEDURE: Information was compiled for all canine urinary calculi submitted between July 1981 and January 1994. Results for a mixed-breed group and 26 of the most common breeds of stone-forming dogs were analyzed. Interrelations of breed, sex, and age of affected dogs and mineral composition of the specimens were determined. RESULTS: Prevalence of 5 specific mineral types was significantly correlated between the sexes of 27 common breed groups: struvite, calcium phosphate (apatite), calcium oxalate, brushite, and urate. Struvite-containing calculi were seen in high proportions in both sexes of 7 breeds, and in low proportions in both sexes of 7 other breeds. Male and female Lhasa Apsos, Cairn Terriers, and 5 other breeds had high proportions of oxalate-containing calculi; values in males were substantially higher. Low numbers of oxalate-containing calculi were seen in both sexes of 7 breeds; Dalmatians had the lowest numbers. Males and females of 6 breeds had high numbers of urate-containing calculi, Dalmatians and English Bulldogs had the highest numbers. Low amounts of urate were found in calculi from males and females of 6 breeds, Samoyeds had the lowest numbers. Highest proportions of cystine-containing calculi were seen in male Dachshunds, English Bulldogs, and Chihuahuas. Males of 8 breeds had no specimens that contained cystine; only 2 such specimens were obtained from females. CONCLUSIONS: Prevalence of uroliths differs among breed, age, and sex of affected dogs. CLINICAL RELEVANCE: Breed, sex, and age of dogs; mineral types of calculi in males versus females; and their anatomic location within the tract are important considerations for clinicians when evaluating risk in dogs with urolithiasis and in identifying areas that need further in-depth applied or clinical investigation, or both.

Age Distribution↗