The design, construction and use of a device to detect changes in deer pedicle volume are described. The device is highly sensitive for detecting the initiation of pedicle growth. Between-sample differences of 170 mm3 in the pedicle volume of live deer were detected (triplicate measurements) using the detector; these correspond to a change in height of the pedicle of at most 0.67 mm. The within sample coefficient of variation was 1.4%. The pedicle growth detector enables more precise measurements to be obtained for identifying the onset of pedicle development to the nearest week than is currently possible with palpation. 相似文献
Commercial ram flocks in the Tamworth area of northern New South Wales were surveyed to estimate the proportion of flocks, and rams, infected with Brucella ovis. The flock prevalence (percentage of flocks containing seropositive rams) of 9.1% for Merino flocks was significantly lower than that for British-breed flocks (43.8%, p=0.006) and mixed-breed flocks (46.7%, p=0.017). The mean flock prevalence over all flock types was 32.9%. These estimates were supported by data obtained from diagnostic testing for brucellosis carried out during the previous 6 years. The seroprevalence in rams was 10.8% overall, 2.5% for Merinos, 19% for Border Leicester and 26% for Dorset rams. Within infected flocks, the estimated prevalences were 21%, 65% and 67% for Merinos, Border Leicester and Dorset rams respectively. The seroprevalence in Merino rams was significantly lower than that for both other breeds (p<0.001) for all flocks and in infected flocks. There was no apparent association between age and serological status, or age and the prevalence of epididymitis. 相似文献
SUMMARY: A crossbreeding experiment was carried out in Egypt using a local breed (Baladi Red, BR) and New Zealand White (NZ) to estimate direct heterosis, maternal additive effects and direct sire effects on some growth and carcass traits in rabbits. Data of body weight (at 5, 6, 8, 10, 12 weeks) and daily gains (at intervals of 5-6, 6-8, 8-10, and 10-12 weeks) on 2153 weaned rabbits were collected. Carcass performance at 12 weeks of age (weight and percentages of carcass, giblets, head, fur, blood and viscera) on 213 male rabbits was evaluated. Estimates of coefficients of variation (CV) for most growth and carcass traits were high and ranged from 10.0 to 40.2%. Sire-breed was of considerable importance in the variation of growth traits and some carcass traits, while dam-breed contributed little. Sire-breed × dam-breed interaction affected (P<0.01 or P<0.001) most body weights and gains studied, while it contributed little to the variation of carcass traits. The purebred NZ resulted in rabbits with heavier weights and carcass and with lighter non-edible carcass (blood and viscera) compared to the BR. Heterosis percentages for most growth traits were significant and ranged from 2.5% to 5.0% for body weights and from 0.7% to 9.5% for daily gains. Insignificant positive direct heterosis was observed for most carcass traits. Crossbred rabbits from NZ sires with BR dams were superior to from the reciprocals. Maternal-breed effects on most weights and gains were insignificant, while sire-breed contrasts for some weights and gains proved significant. Postweaning growth and carcass performances of BR-mothered rabbits generally surpassed the NZ mothered, while NZ-sired rabbits were superior at later ages. High edible carcass was observed for BR-sired rabbits, while more non-edible carcass wastes (blood and viscera) for NZ-sired rabbits. Maternal-breed effects appeared to be less important than paternal-breed effects in influencing most weights, gains and carcass traits studied. ZUSAMMENFASSUNG: Heterosis, maternale und direkte Wirkungen bei Wachstums- und Schlachtk?rpermerkmalen in Kaninchenkreuzungen Der Kreuzungsversuch wurde mit lokalen ?gyptischen Rassen (BR) und Neuseeland Wei?en (NZ) zur Sch?tzung direkter Heterosis, maternaler additiver Wirkungen, direkter Vater-Wirkung auf einige Wachstums- und Schlachtk?rpermerkmale von Kaninchen durchgeführt. Angaben über K?rpergewicht (5, 6, 8, 10, 12 Wochen) und Zuwachs (Intervalle 5 bis 6, 6 bis 8, 8 bis 10, 10 bis 12 Wochen) wurden von 2153 abgesetzten Kaninchen gewonnen. Die Schlachtk?rperleistungen bei 12 Wochen Alter (Gewicht und Anteil von Schlachtk?rper, Kopf, Pelz, Blut und Innereien) stammen von 213 m?nnlichen Kaninchen. Sch?tzungen der Variationskoeffizenten (CV) für meiste Wachstums- und Schlachtk?rpermerkmale waren hoch und bewegten sich zwischen 10 und 40,2%. Vaterrasse hatte erheblichen Einflu? auf Unterschiede in Wachstumsrate und einige Schlachtk?rpermerkmale, w?hrend die Mutterrasse weniger beigetragen hat. Interaktion zwischen beiden beeinflu?te die meisten K?rpergewichts- und Zuwacnsleistungen, w?hrend sie wenig zur Variabilit?t der Schlachtk?rpermerkmale beigetragen hat. Reinrassige NZ waren schwerer und hatten weniger nicht nutzbare Schlachtk?rperteile (Blut und Eingeweide) verglichen mit BR. Heterosis-Prozente für die meisten Wachstumsmerkmale waren signifikant und schwankten zwischen 2,5 und 5% für K?rpergewicht, 0,7 bis 9,5% für Zuwachs. Insignifikante positive direkte Heterosis wurde für die meisten Schlachtk?rpermerkmale beobachtet. Kreuzungskaninchen von NZ V?tern waren den reziproken überlegen. Maternale Wirkungen auf meiste Gewichtsmerkmale waren insignifikant, w?hrend Vaterrassenkontraste hierfür signifikant waren. Zuwachs- und Schlachtk?rperleistung von BR ges?ugten Kaninchen haben im allgemeinen die von NZ ges?ugten übertroffen, w?hrend von NZ B?cken gezeugte in sp?teren Altersabschnitten überlegen waren. Hohe Werte für Schlachtk?rper wurden für BR ges?ugte Kaninchen gefunden, w?hrend mehr nicht verzehrbare Abf?lle (Blut und Eingeweide) bei NZ gezeugten vorhanden war. Maternale Rassenwirkungen schienen weniger wichtig als paternale zu sein. 相似文献
SUMMARY: Ambiguous paternity can be incorporated into the mixed model equations (MME) by including the average numerator relatinship matrix (average A), which averages the true sire-offspring relationship over the putative sires. A previous study has shown that some overestimation of genetic trend results from this substitution. A population of 40 breeding females and 2 breeding males was simulated 1,000 times with either random mating or sequential selection continuing for 8 breeding cycles. In the selection case candidates were ranked on estimated breeding values (EBVs) calculated from the MME with an animal model and the average A. Variances of the EBVs and prediction errors were computed. The results showed the average A incorrectly perceives both the variance of family sizes among males and the variance loss due to selection to be smaller. This will lead to an overestimation of genetic trend. ZUSAMMENFASSUNG: Folgerungen aus der Anwendung einer durchschnittlichen Verwandtschaftsmatrix bei der Zuchtwertsch?tzung für eine Population mit mehreren V?tern in einer Paarungsgruppe In den Mischmodellgleichungen kann eine unklare v?terliche Abstammung durch die Verwendung einer durchschnittlichen Verwandtschaftsmatrix, die die Abstammung zu gleichen Teilen über die m?glichen V?ter aufteilt, berücksichtigt werden. Eine frühere Arbeit hat gezeigt, da? diese Ma?nahme zu einer gewissen übersch?tzung des genetischen Fortschritts führt. Eine Population mit 40 weiblichen und 2 m?nnlichen Tieren wurde 1000mal über 8 Paarungsperioden simuliert und zwar mit und ohne gerichteter Selektion. Im Falle der Selektion wurden die Tiere aufgrund der mit einem Tiermodell und der durchschnittlichen Verwandtschaftsmatrix gesch?tzten Zuchtwerte geordnet. Die Varianzen der Zuchtwerte und der Sch?tzfehler wurden berechnet. Die Ergebnisse zeigen, da? durch eine durch-schnittliche Verwandtschaftsmatrix die Varianz der Gr??e der Nachkommensgruppen der V?ter und der Verlust an genetischer Varianz aufgrund der Selektion untersch?tzt wird. Dies führt zu einer übersch?tzung des genetischen Fortschritts. 相似文献
SUMMARY: Polymorphism in the second intron of the porcine growth hormone gene of 273 Austrian Landrace and 81 Austrian Edelschwein pigs was investigated with a PCR-RFLP-technique. Results showed significantly different genotype patterns between the two breeds. The frequency of the Hae II(-) allele was significantly (P < 0,001) higher in the landrace than in the Edelschwein population (0,83 and 0,47 resp.). The Msp I(+) allele was predominant in both breeds but signifanctly higher in the Landrace (0,98 versus 0,69; P < 0,01). Analyses the Hae II/Msp I locus combination revealed also in breed specific difference. In the Landrace a very low interaction was found between the Hae II and ryr 1 locus, and between Msp I and ryr 1 locus (c. c. = 0,181 and 0,186 resp.). The correlation was slightly stronger (c. c. = 0,266) between the ryr 1 and Hae II/Msp I genotypes. No correlation was detected among the three loci in the Edelschwein population. ZUSAMMENFASSUNG: Variabilit?t des Somatotropin Gens in ?sterreichischen Schweinerassen genotypisiert hinsicbtlich ryr 1 An 273 ?sterreichischen Landrasse Schweinen und 81 ?sterreichischen Edelschweinen wurde der Polymorphismus am zweiten Intron des Schweinewachstumshormons mittels PCR-RFLP-Technik untersucht. Genotypen-und Genfrequenzen waren zwischen den beiden Rassen signifikant verschie- den. Die Hae II(-) Allelfrequenz war bei den Landrassetieren signifikant h?her (P < 0,001) als bei den Edelschweinen (0,83 bzw. 0,47). In beiden Rassen überwiegte das Msp I(+) Allel, das aber signifikant ?fters bei der Landrasse auftrat (0,98 bzw. 0,69; P < 0,01). Die Verteilung der Locuskombination von Hae II/Msp I zwischen den beiden Rassen war ebenfalls unterschiedlich. Bei der Landrasse konnte nur ein sehr geringer Zusammenhang zwischen dem Hae II und ryr 1 Locus (c. c. = 0,181 bzw. 0,186) und auch zwischen dem Msp I und ryr 1 Locus festgestellt werden. Die Korrelation zwischen dem ryr 1 und Hae II/Msp I Genotyp war geringfügig gr??;er (c. c. = 0,266). Bei den Edelschweinen konnte kein Zusammenhang zwischen den drei untersuchten Loci festgestellt werden. 相似文献
Chicken anaemia virus was isolated for the first time in New Zealand from the New Zealand domestic chicken population. The virus was recovered from diseased birds in five separate flocks of broiler chickens aged between 14 and 33 days of age. Six isolates were obtained from bone marrow and lymphoid tissues using the MDCC-MSB1 cell line derived from Marek's disease lymphoma. All isolates were resistant to chloroform and survived exposure to 70 degrees C for 5 minutes. The main clinical features consistently associated with the disease outbreaks were increased mortality, yolk sac infections, sub-cutaneous haemorrhages and atrophy of the thymus. Fungal pneumonia occurred in two flocks, and gangrenous dermatitis as a result of bacterial infection in another flock. Microscopic examination showed atrophy of the thymus, reduced medullary haematopoiesis and inflammation resulting from secondary infections. 相似文献
Goats infected with caprine arthritis-encephalitis virus (CAEV) show chronic arthritis and cachexia, which are progressive in nature. The immunopathogenic mechanisms responsible for these progressive clinical symptoms have not been fully elucidated. Various haematological and immunological parameters were evaluated in experimentally-infected goats showing typical signs of CAEV-induced disease. Infected goats showed recurrent lymphocytosis that may be due to constant presentation of antigen by infected cells of a monocyte/macrophage lineage. The serum alkaline phosphatase and -glutamyl transferase concentrations were elevated in infected goats, a characteristic of hepatic and bone disorders. All other serum chemistry parameters were similar between infected and control goats. Importantly, the serum tumour necrosis factor- (TNF-) levels were higher in infected goats. The cachexia seen in infected goats may be at least partly due to altered metabolism as a result of prolonged elevation of serum TNF- levels. Depressed natural killer cell activity was observed in infected goats and may contribute towards the establishment of a persistent infection with CAEV.Abbreviations AIDS
acquired immunodeficiency syndrome
- CAEV
caprine arthritis-encephalitis virus
- GGT
-glutamyl transferase
- HBSS
Hanks' balanced salt solution
- HIV
human immunodeficiency virus
- NK
natural killer
- PBMC
peripheral blood mononuclear cells
- PCR
polymerase chain reaction
- SAP
serum alkaline phosphatase
- TNF
tumour necrosis factor 相似文献
1. The amino acid requirements of laying type pullets during the growing period can be estimated by measuring the growth of different components of the body and making use of nutritional constants that define the amount of each amino acid that is required for the production of the tissues being formed.
2. In this experiment, carcase analyses of each of three breeds of pullets were conducted at weekly intervals throughout the growth of the pullets, to 18 weeks of age. Measurements were made of body weight, gut‐fill and feather weight, and chemical analyses consisted of water, protein, lipid and ash measurements of both the body and the feathers. Each age group comprised 10 birds of each breed.
3. Gompertz functions accurately estimated the growth of both body protein and feather protein, to 18 weeks of age, from which the rate of growth of these two components of the body could be estimated. The mature weight of pullets was overestimated by the Gompertz growth curve, which may indicate that a pullet ceases to increase in body protein content once sexual maturity has been reached.
4. Using allometric relationships between the chemical components of the body and of feathers, all the components of growth could be estimated from the growth of body protein and feather protein. These components were then added together to determine the growth rate of the body as a whole.
5. The daily amino acid requirements for 4 functions were calculated, namely, those for the maintenance of body protein and feather protein, and for the gain in body protein and feather protein. These requirements were then summed to determine the requirement of pullets on each day of the growing period.
6. Using the ‘effective energy’ system, the amount of energy required by these pullets was calculated for each day of the growing period, from which the desired daily food intake of the pullets could be predicted. By dividing the amino acid requirement by this daily food intake it was possible to determine the concentration of amino acids that would be needed in the diet in order to meet the requirements of a pullet.
7. The results indicate that the ratio between the requirement for lysine and for methionine and cysteine changes dramatically during the growing period, negating the concept of a fixed ratio between all the amino acids during growth.
8. The above process is the first step in determining the optimal feeding programme for a population of pullets of a given genotype. The constraining effects, of the diet being offered and of the environment in which the pullets are housed, on the food intake and growth rate of each pullet have to be estimated, and such a theory can then be expanded to include all the individuals in the population. Only by the use: of simulation models can all these constraining effects be considered simultaneously. 相似文献