Evaluation of a fixed-time artificial insemination protocol for postpartum suckled beef cows     

Perry GA  Smith MF  Patterson DJ 《Journal of animal science》2002,80(12):3060-3064

Treatment with melengestrol acetate (MGA), an oral progestin, prior to administration of gonadotropin-releasing hormone (GnRH) and prostaglandin F2alpha (PG) effectively synchronizes estrus and maintains high fertility in postpartum beef cows. The objective of this experiment was to determine whether treatment with MGA prior to a GnRH-PG-GnRH protocol would improve pregnancy rates resulting from fixed-time artificial insemination (AI). Multiparous crossbred beef cows at two University of Missouri-Columbia farms (n = 90 and n = 137) were assigned by age and days postpartum to one of two treatments. Cows were fed carrier (1.8 kg x animal(-1) x d(-1)) with or without MGA (0.278 mg x kg(-1)) for 14 d. All cows were administered GnRH (100 microg; intramuscularly) on d 12 after MGA or carrier withdrawal and 7 d before PG (25 mg; intramuscularly). All cows received a second injection of GnRH and AI 72 h after PG. Mean days postpartum for MGA and control cows at the initiation of treatment were 39.6 and 38.9 d for herd 1; and 51.9 and 50.9 d for herd 2, respectively (P > 0.70 within herds). Blood samples were collected from all cows at 10 and 1 d before the feeding of MGA or carrier began and at the times GnRH and PG were administered. Concentrations of progesterone in serum at the initiation of treatment were elevated (>1 ng/mL) in 0% of MGA and 7% of control cows in herd 1, and 54% of MGA and 49% of control cows in herd 2 (P > 0.05 within herds). Pregnancy rates to fixed-time AI were determined by transrectal ultrasonography 50 d after AI. Pregnancy rates in herd 1 were 58% (26/45) and 51% (23/45) for MGA-treated and control cows, respectively (P = 0.52), and 63% (44/70) and 45% (30/67) for MGA-treated and control cows in herd 2, respectively (P = 0.03). Differences in pregnancy rates to fixed-time AI were significant (P = 0.04) when data from the two herds were combined (with MGA = 70/115 [61%]; control = 53/112 [47%]). There was no difference (P > 0.20) in final pregnancy rates (timed AI plus 45 d exposure to bulls) between treatments, within herds, or when herds were combined. In summary, pregnancy rates resulting from fixed-time AI may be improved with treatment of MGA prior to a GnRH-PG-GnRH protocol.  相似文献   

Molecular cloning and phylogenetic analysis of a cDNA encoding the cat (Felis domesticus) Ig epsilon constant region     

Weber ER  Helps CR  Foster AP  Perry AC  Gruffydd-Jones TJ  Hall L  Harbour DA  Duffus WP 《Veterinary immunology and immunopathology》2000,76(3-4):299-308

A feline splenic cDNA library was screened with a (32)P-labelled cDNA probe encoding the canine IgE epsilon heavy chain subunit. A cDNA sequence of 1614 nucleotides encoding the complete feline IgE heavy chain, as well as a portion of a variable region, was identified. A search of the GenBank database revealed an identity of 82% at the nucleotide level and 76% at the amino acid level between the feline epsilon heavy chain sequence and the canine homologue. In a separate study, feline genomic DNA, isolated from whole feline embryo cells, was subjected to PCR amplification using primers based on known partial genomic DNA sequences for the feline C epsilon gene. Following removal of an intron from the 683 bp PCR product, the coding sequence yielded an ORF of 506 bp. The DNA sequence of this PCR clone differed by a single nucleotide from the cDNA clone. This difference is silent, and therefore the proteins encoded by the two sequences are identical over the regions cloned and sequenced. Phylogenetic analysis of the constant regions of nine immunoglobulin epsilon genes revealed that the feline cDNA is most similar to the canine homologue.  相似文献   

Transmissibility of Cucumber mosaic virus by Aphis gossypii Correlates with Viral Accumulation and Is Affected by the Presence of Its Satellite RNA     

Escriu F  Perry KL  García-Arenal F 《Phytopathology》2000,90(10):1068-1072

ABSTRACT Satellite RNAs (satRNAs) are associated with Cucumber mosaic virus (CMV) in tomato, most often causing severe epidemics of necrotic plants, and not associated with specific host symptoms. Laboratory studies on virus transmission by the aphid vector Aphis gossypii were performed to better understand the dynamics of field populations of CMV. The presence of satRNAs correlated with lower concentrations of virus in infected plants and with a decrease in the efficiency of transmission from satRNA-infected plants. Both the concentration of virus in CMV-infected tomato and the efficiency of transmission varied more extensively with nonnecrogenic satRNAs than with necrogenic satRNAs. A negative effect of satRNAs on virus accumulation can account, in part, for a decrease in the field transmission and recovery of CMV + satRNAs. Aphids behaved differently and probed less readily on plants infected with CMV + necrogenic satRNAs compared with plants containing non-necrogenic satRNAs. Aphid-mediated satRNA-free CMV infections were observed in test plants when aphids were fed on source plants containing CMV + nonnecrogenic satRNA; no comparable satRNA-free test plants occurred when aphids were fed on source plants containing necrogenic satRNAs. These results indicate that factors associated with transmission can be a determinant in the evolution of natural populations of CMV and its satRNA.  相似文献   

Treatment of lesions on the penis and prepuce of bulls     

RS. COPLAND  AA. BAKER  MD. RIVAL  PE. LENNON  PJ. CHENOWETH 《Australian veterinary journal》1989,66(11):378-380

  相似文献   

Effect of Captan Seed Dressing on Carrot Emergence     

D. A. Perry  T. W. Hegarty 《Plant pathology》1971,20(1):29-32

  相似文献   

Effect of a single bout of high intensity exercise on lower respiratory tract contamination in the horse, by Raidal SL, Love DN and Bailey GD     

PE HOLT  MV THRUSFIELD 《Australian veterinary journal》1997,75(6):449-449

  相似文献   

Pathology of experimental vitamin D deficiency in turkeys and the effects of various vitamin D supplements.     

R W Perry  G N Rowland  W M Britton 《Avian diseases》1991,35(3):542-553

One-day-old poults fed a vitamin D3-deficient diet were examined for clinical, biochemical, and morphological changes at 14 days of age. Changes in these parameters were compared at 15.5 and 17 days of age after one of the following vitamin D-replacement therapies was provided: water-soluble vitamin-mineral packs that contained vitamin D3; vitamin D3 in the feed; or vitamin D, 1,25-dihydroxyvitamin D3 in the feed. The vitamin D3-deficient poults were lame and had significant decreases in weight gain and in longitudinal skeletal growth. None of the therapies alleviated all these changes, but clinical lameness subsided in poults provided 1,25-dihydroxyvitamin D3. Calcium concentrations were significantly improved by all therapies. Treatment with vitamin D3 in the feed and water significantly increased 25-hydroxyvitamin D3 concentrations in vitamin D-deficient poults. The growth plate zones, with the exception of the mineralized hypertrophied zone, were all increased in length and not modified by treatment. However, the mineralized hypertrophied zones in the 1,25-dihydroxy-vitamin D3 group and the group receiving vitamin D3 in the water were comparable to that in the controls on day 15.5.  相似文献   

Reducing a spatial database to its effective dimensionality for logistic-regression analysis of incidence of livestock disease     

L. Duchateau  R. L. Kruska  B. D. Perry 《Preventive veterinary medicine》1997,32(3-4):207-218

Large databases with multiple variables, selected because they are available and might provide an insight into establishing causal relationships, are often difficult to analyse and interpret because of multicollinearity. The objective of this study was to reduce the dimensionality of a multivariable spatial database of Zimbabwe, containing many environmental variables that were collected to predict the distribution of outbreaks of theileriosis (the tick-borne infection of cattle caused by Theileria parva and transmitted by the brown ear tick). Principal-component analysis and varimax rotation of the principal components were first used to select a reduced number of variables. The logistic-regression model was evaluated by appropriate goodness-of-fit tests.  相似文献   

Response of laying hens to asymmetrical interrupted lighting regimens: reproductive performance, body weight and carcase composition     

P D Lewis  G C Perry 《British poultry science》1990,31(1):33-43

1. The performance of brown egg laying hens was compared under conventional and asymmetrical interrupted-lighting conditions. 2. Egg numbers and mean weight were similar under the two conditions, provided the apparent day perceived by the hen was the same under both lighting treatments. 3. Daily food intakes of intermittently-illuminated hens were not significantly lower than those of conventionally-lit birds. However, the reductions were of the magnitude reported in the literature and observed under commercial conditions. 4. Shell quality was unaffected by interrupted lighting in the period up to 60 weeks of age in two of the 4 genotypes studied. All breeds had lower shell weights under interrupted lighting in the last three months of lay. 5. Intermittently-lit hens had lower body weights, which approached significance, and significantly less carcase fat. There were no differences in ash, protein (N x 6.25) or water contents of the carcases, or in fat content at a given body weight. 6. There were no significant differences in the production responses of the 4-brown-egg hybrids to interrupted lighting. 7. Diets with differing concentrations of energy and protein were included in both trials, but there was no evidence of interaction between these nutritional treatments and the lighting treatments.  相似文献   

A baiting system suitable for the delivery of oral rabies vaccine to dog populations in Zimbabwe     

B D Perry  R Brooks  C M Foggin  J Bleakley  D H Johnston  F W Hill 《The Veterinary record》1988,123(3):76-79

A baiting system suitable for the delivery of oral rabies vaccine to dog populations in developing countries was studied in Zimbabwe. In a field trial, 369 sponge baits containing a placebo liquid, rhodamine B as a biomarker and a pungent attractant were distributed over an area of 60 sq km in a communal land in Manicaland with a dog population of over 500. Twenty-four hours later 21 per cent of the baits were recovered and 79 per cent of these had been significantly bitten or chewed. Twenty-five per cent of the dogs examined showed evidence of superficial staining by rhodamine B indicating that they had chewed baits or ingested their contents. It was concluded that the system would deliver an oral vaccine to dog populations more efficiently than had been the case in comparable studies in wildlife populations, but that the number of baits per unit area should in future studies be increased.  相似文献