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1.
Toll-like receptor (TLR) family is one of the important members of innate immune system that recognizes conserved microbial
patterns and induces innate immune response. They also act as a link to adaptive immune response. Nitric oxide (NO) is a multi-functional
mediator with diverse physiological and immunological roles. In the present study TLR mRNA expression in heterophils, serum nitric oxide level and iNOS (inducible Nitric Oxide Synthase) gene polymorphism were investigated in cockerels of two Indian native chicken breeds, Aseel
and Kadaknath. TLR (4 and 5) mRNA expression as quantified by real time RT-PCR revealed Kadaknath males expressed significantly (P < 0.01) higher TLR4 mRNA than Aseel males. iNOS gene polymorphism analyzed by PCR-RFLP method revealed difference in allele frequency. Kadaknath males had higher allele
B frequency (0.81) than Aseel males (0.56). However, there were no genotype and breed effect on serum nitric oxide level.
Based on the present study we conclude that Kadaknath has comparatively higher innate immunity levels than Aseel, however
further investigations are needed. 相似文献
2.
Differential expression of Toll-like receptor mRNA in White Leghorn and indigenous chicken of India 总被引:1,自引:0,他引:1
Kannaki T. Ramasamy Maddula R. Reddy Dhanutha N. Raveendranathan Shanmugam Murugesan Rudra N. Chatterjee Rajkumar Ullengala Santosh Haunshi 《Veterinary research communications》2010,34(7):633-639
In the present experiment, the expression profile of Toll-like receptor mRNA in indigenous and pure line chickens was studied.
The expression of TLR3, TLR4, TLR5 and TLR7 were quantified in heterophils of Aseel, Kadaknath, Naked neck, Dwarf and White
Leghorn lines by Quantitative Real-time PCR. White Leghorns expressed significantly (P < 0.01) higher levels of TLR3 mRNA
compared to other lines. TLR4 and TLR5 mRNA were significantly highly expressed in Kadaknath line. Among the TLRs investigated
TLR5 was more expressed in all lines studied. TLR7 was highly expressed in indigenous chicken Aseel and Kadaknath than other
lines. Dwarf chicken expressed significantly (P < 0.01) lower levels of all TLRs investigated. On the basis of the present
study we conclude that the differential expression of TLR mRNA in the heterophils of indigenous and other chicken breeds might
contribute to their variable disease resistance/susceptibility. 相似文献
3.
Rajkumar U Sharma RP Padhi MK Rajaravindra KS Reddy BL Niranjan M Bhattacharya TK Haunshi S Chatterjee RN 《Tropical animal health and production》2011,43(6):1129-1136
The juvenile growth and carcass traits were evaluated in a 4 × 4 full diallel crossing involving four colored broiler chicken
lines viz., Naked neck (NN), Dwarf, Punjab Broiler-1 (PB-1), and Punjab Broiler-2 to study the performance and crossbreeding
parameters. The data on 2,280 chicks were analyzed using least squares techniques to assess the effect of genetic group, and
the significant traits were further analyzed for crossbreeding parameters. Genetic group had significant influence on the
body weights and carcass traits. The cross of PB-1 × NN recorded significantly (p ≤ 0.05) higher body weight at 6 weeks of age. The data revealed that general combining ability (GCA), specific combining
ability (SCA), maternal ability (MA), sex-linked effect (SE), and purebred effects significantly influenced the growth and
carcass traits in the broiler crosses. The crossbred PB-1 × NN showed positive heterosis for growth as well as carcass traits.
The results suggest that GCA, SCA, SE, and MA are important in the inheritance of the body weights and carcass traits indicating
the presence of both additive and nonadditive genetic variation along with reciprocal effects. Therefore, pure line selection
along with development of specialized sire and dam lines followed by crossing will improve the growth performance and benefit
the poultry farmers. It is concluded that PB-1 as a male line and NN as a female line performed significantly higher, therefore,
may be used for improving the performance of colored broilers. 相似文献
4.
Estimates of (co)variance components and genetic parameters for growth traits of Avikalin sheep 总被引:2,自引:2,他引:0
Leslie Leo L. Prince Gopal R. Gowane Ashish Chopra Amrit L. Arora 《Tropical animal health and production》2010,42(6):1093-1101
(Co)variance components and genetic parameters for various growth traits of Avikalin sheep maintained at Central Sheep and
Wool Research Institute, Avikanagar, Rajasthan, India, were estimated by Restricted Maximum Likelihood, fitting six animal
models with various combinations of direct and maternal effects. Records of 3,840 animals descended from 257 sires and 1,194
dams were taken for this study over a period of 32 years (1977–2008). Direct heritability estimates (from best model as per
likelihood ratio test) for weight at birth, weaning, 6 and 12 months of age, and average daily gain from birth to weaning,
weaning to 6 months, and 6 to 12 months were 0.28 ± 0.03, 0.20 ± 0.03, 0.28 ± 0.07, 0.15 ± 0.04, 0.21 ± 0.03, 0.16 and 0.03 ± 0.03,
respectively. Maternal heritability for traits declined as animal grows older and it was not at all evident at adult age and
for post-weaning daily gain. Maternal permanent environmental effect (c
2) declined significantly with advancement of age of animal. A small effect of c
2 on post-weaning weights was probably a carryover effect of pre-weaning maternal influence. A significant large negative genetic
correlation was observed between direct and maternal genetic effects for all the traits, indicating antagonistic pleiotropy,
which needs special care while formulating breeding plans. A fair rate of genetic progress seems possible in the flock by
selection for all traits, but direct and maternal genetic correlation needs to be taken in to consideration. 相似文献
5.
Kaeoket K Chanapiwat P Tummaruk P Techakumphu M Kunavongkrit A 《Tropical animal health and production》2011,43(5):1049-1055
The aim of this study was to evaluate the effect of post-thawing dilution with autologous and heterologous sperm supernatant
on motility of frozen-thawed boar spermatozoa. During the cryopreservation, sperm supernatant (a combination of seminal plasma
and semen extender, 50% v/v) or seminal plasma from nine boars (Duroc, Large White, and Landrace; three in each) was collected by centrifugation and
stored frozen until use as post-thawing solution. Sperm pellets were further processed and cryopreserved using control-rate
freezer and was thawed at 50°C for 12 s. After thawing, frozen thawed semen samples were diluted with seminal plasma (group
A), supernatant from Landrace (group B), supernatant from Large White (group C), supernatant from Duroc (group D), and Modena™
semen extender (group E). Post-thawing motility was evaluated using a phase-contrast microscope after thawing at 1, 10, 20,
and 30 min. The present results show that at 1 min, a significantly higher percentage (P ≤ 0.001) of progressive motility was found in groups B (53.3%) and C (53.9%) than the other groups. At 10 min, the highest
(P ≤ 0.001) progressive motility was found in groups B (65%) and C (61%). At 20 and 30 min, a significantly higher percentage
(P ≤ 0.001) of progressive motility was found in groups B (58.9%), C (53.5%), and D (45.6%) than groups A (3.9%) and E (20.6%).
It can be stated that supernatant from the freezing processes (consisting of seminal plasma and Modena™, 50% v/v) had a beneficial effect on post-thawing progressive motility of frozen boar semen. 相似文献
6.
Xiujin Li Bo Jiang Xibin Wang Xiaohong Liu Qin Zhang Yaosheng Chen 《Zeitschrift für Tierzüchtung und Züchtungsbiologie》2019,136(3):183-189
The economic profitability of a boar station largely depends on semen quantity and quality traits. However, genetic analysis of semen traits has not yet been done in the boar population in China. In this study, we aimed to estimate genetic parameters for semen traits and the influence of seasons on these traits by using data of Duroc, Landrace and Yorkshire boars in South China. The following four semen traits were analysed: semen volume (ml; VOL), sperm concentration (106/ml; DEN), sperm motility (MOT) and percentage of abnormal sperm (ABN). Genetic parameters and season effects were estimated simultaneously for each breed by using a multiple‐trait (4 × 4) repeatability animal model. The four traits had a moderate heritability with average estimates of 0.23, 0.28, 0.26 and 0.17 across the three breeds, respectively. The estimates of genetic correlations among four traits differed in the three breeds. In particular, in Yorkshire, the four traits were nearly genetically independent. The season of collecting semen had a significant impact on these four semen traits except ABN in Duroc (Bonferroni adjusted p < 0.05/6). The moderate heritabilities indicate the possibility of effective selection of boars for semen traits. Different genetic correlations for the three breeds suggest that the selection strategy for the four traits should be investigated separately for each breed. Some necessary actions should be taken to reduce the influence of seasons on semen traits. 相似文献
7.
Bhakat M Mohanty TK Raina VS Gupta AK Khan HM Mahapatra RK Sarkar M 《Tropical animal health and production》2011,43(6):1161-1168
The objective of the study was to determine the effect of season, period, age, bull, and ejaculate on semen quality in Sahiwal
bulls. Semen production records from 1996 to 2006 of 5,483 ejaculates from 46 Sahiwal bulls maintained at Artificial Breeding
Complex, NDRI, Karnal, India were analyzed using least square analysis of variance by LSML software package. The overall least
squares means of ejaculate volume (VOL), total volume per day (VOLD), mass activity (MA), initial motility (IM), sperm concentration
per ml (SPC), and sperm concentration per ejaculate (SPCE) were 3.79 ± 0.02 ml, 5.81 ± 0.06 ml, 2.32 ± 0.01, 55.47 ± 0.001%,
766.69 ± 5.50 × 106/ml and 3023.25 ± 30.15 × 106, respectively. All semen traits (VOL, VOLD, MA, IM and SPCE) were significantly (P < 0.01) affected by age groups, season and period, whereas season had significant effect on VOL at 5% level. During hot-humid
season, highest value of VOL, VOLD, MA, IM, SPC, and SPCE were observed followed by summer and cold season. Highest value
of VOL, VOLD, IM, and SPCE were observed during period-3 (2004–2006), whereas highest value of MA and SPC were observed during
period-1 (1996–1999). However, lowest magnitude of MA, IM, SPC, and SPCE during period-2 (2000–2003) was observed. Ejaculate
characteristics like VOL, VOLD, and SPCE increased with the increasing age of bull up to 5 years and then decreased. Significant
(P < 0.01) bull to bull variation was found in VOL, VOLD, MA, IM, SPC, and SPCE traits. First ejaculate had significantly (P < 0.01) higher MA, IM, SPC, and SPCE. Hence, it could be concluded that during rainy season and period-1 and period-3 the
quality of semen is quantitatively and qualitatively good. Better quality semen was obtained up to 5 years of age in Sahiwal
bulls. 相似文献
8.
Corrales R Näsholm A Malmfors B Philipsson J 《Tropical animal health and production》2011,43(6):1137-1143
Reyna Creole cattle in Nicaragua comprise about 650 purebred animals, and the breed has been shown to have a high level of
inbreeding. To characterize the breed, as basis for a conservation program, information from two herds on birth weight (BW,
n = 1097), age at first calving (AFC, n = 449) and calving interval (CI, n = 1,347) was analysed. Overall averages were 27.8 kg for BW, 37.4 months for AFC and 424 days for CI. Large differences between
the herds were observed for all traits. Thus, there would be opportunities for management interventions to improve reproduction
results. The heritability for BW was 0.34. For CI, the heritability of 0.20 and the additive genetic standard deviation of
36 days were comparatively high values. No genetic variation was found in AFC. Estimated inbreeding effects were associated
with large standard errors due to the small size of the data and incompleteness of pedigrees. Nevertheless, significant effects
were shown of dam inbreeding level on all traits. For each percentage of increased inbreeding, BW decreased by 0.06 kg, AFC
increased by 3.5 days and CI increased by 1.4 days. The effects of the inbreeding level of the individual itself were not
significant. The relatively good reproduction traits of Reyna Creole cattle shown in this study, despite high inbreeding levels,
will be supplemented with a characterization of milk production traits. 相似文献
9.
Genetic and phenotypic parameter estimates for body weights and egg production in Horro chicken of Ethiopia 总被引:1,自引:0,他引:1
Nigussie Dana E. H. vander Waaij Johan A. M. van Arendonk 《Tropical animal health and production》2011,43(1):21-28
A breeding program has been established in 2008 to improve productivity of Horro chicken, an indigenous population in the
western highlands of Ethiopia. The pedigree descended from 26 sires and 260 dams. Body weights were measured every 2 weeks
from hatch to 8 weeks then every 4 weeks for the next 8 weeks. Egg production was recorded to 44 weeks of age for one generation.
Genetic parameters were estimated using animal model fitted with common environmental effects for growth traits and ignoring
common environment for egg production traits. Direct heritabilities ranged from low (0.15 ± 0.08), for body weight at 6 weeks,
to moderate (0.40 ± 0.23), for hatch weight. Heritabilities of common environmental effects on growth were high at hatch (0.39 ± 0.10)
and remained low afterwards. Age at first egg showed a very low heritability (0.06 ± 0.15). Heritabilities of egg numbers
in the first, second, third, and fourth months of laying were 0.32 (±0.13), 0.20 (±0.16), 0.56 (±0.15), and 0.25 (±0.14),
respectively. Heritabilities of cumulative of monthly records of egg numbers were from 0.24 ± 0.16 (for the first 2 months,
EP12) to 0.35 ± 0.16 (over the 6 months, EP16). Body weight at 16 weeks of age (BW16) has a strong genetic correlation with
the cumulative of monthly records: 0.92 (with EP12), 0.69 (with EP36), and 0.73 (with EP16). Besides their strong association,
BW16 and EP16 showed higher heritability, relative to their respective trait categories. These two traits seemed to have common
genes and utilizing them as selection traits would be expected to improve both egg production and growth performance of local
chicken. However, the standard errors of estimates in this study were mostly high indicating that the estimates have low precision.
Parameter estimations based on more data are needed before applying the current results in breeding programs. 相似文献
10.
A study was conducted to evaluate the semen production and sperm motion characteristics of ram lambs by computer-aided semen
analysis technique. Eight Malpura rams were raised under intensive management system and were trained for semen collection
at a weekly interval from the age of 6 months. Rams were scheduled for semen collection at a weekly interval up to 1 year
of age to assess their potential for semen production and objective evaluation of semen quality. The average age of ram lambs
at the time of first ejaculation was 219 days ranging from 186 to 245 days. The age of ram lambs significantly (p < 0.05) influenced sperm concentration, sperm velocities, and beat frequency of spermatozoa, which were higher in 9–12-month-old
compared to 6–9-month-old ram lambs. However, the effect of age was not significant on semen volume, percent motility, percent
rapid, medium or slow motile spermatozoa, percent linearity, percent straightness, amplitude of lateral head displacement,
percent elongation, and area of sperm head. The body weight of ram lambs was significantly (p < 0.01) and positively correlated (r = 0.46) with age. The results indicate that Malpura ram lambs of 9–12 months of age raised under the intensive management
system in a semiarid tropical environment can produce good quality of semen. 相似文献
11.
12.
Amin Tamadon Mojtaba Kafi Mehdi Saeb Abdolah Mirzaei Saedeh Saeb 《Tropical animal health and production》2011,43(1):29-34
The relations between body condition score (BCS), milk yield, serum insulin-like growth factor-I (IGF-I) profile, and luteal
activity were investigated in postpartum dairy cows. Seventy-one healthy high-producing multiparous Holstein cows were subjected
to transrectal ultrasound scanning twice weekly from the first to the eighth week postpartum. Blood samples were collected
twice weekly to measure serum progesterone (P4) and every 2 weeks to detect serum IGF-I concentrations. BCS was monitored
weekly after calving. Cows with serum P4 concentrations ≥1 ng/ml on at least two consecutive samplings were considered to
have commenced luteal activity. Commencement of luteal activity (C-LA) was observed earlier than 45 days postpartum in 71.8%
of cows while 28.2% showed C-LA later than 45 days. Prolonged luteal phase was the most common abnormal pattern of luteal
activity observed. Cows with a C-LA earlier than 45 days postpartum had higher (P ≤ 0.05) mean serum concentrations of IGF-I than those with later C-LA. In addition, cows which showed C-LA earlier than 45 days
postpartum had more optimal productive indices including shorter calving to conception interval and calving to first service
interval (P ≤ 0.05), and fewer services per conception (P = 0.07). C-LA was significantly later in cows that lost more than 0.5 BCS units within 3 weeks postpartum than in those that
lost less than 0.5 units BCS during the same interval (P = 0.02). We conclude that high-producing dairy cows with higher postpartum serum IGF-I concentrations have earlier commencement
and normal luteal activity, and better reproductive performance. Severity and duration of BCS loss adversely affect commencement
of luteal activity. 相似文献
13.
Arora G Mishra SK Nautiyal B Pratap SO Gupta A Beura CK Singh DP 《British poultry science》2011,52(6):675-685
1. The study investigated the extent of hyperpigmentation (a trait fixed in native Indian Kadaknath chickens), bodyweight, carcase quality and leanness at 12 weeks of age in F(1) and back-crosses of Kadaknath with White Leghorn, White Plymouth Rock and Aseel Peela chickens. 2. The objective of the study was to determine if hyperpigmentation was affected by the major gene Fibromelanosis (Fm) and to evaluate the effects of different proportions of Kadaknath genes on growth and carcase quality. 3. The pigmentation pattern of skin indicated that Fm behaved as the primary locus affecting dermal-hyperpigmentation and that the sex-linked Id locus produced an epistatic effect. 4. The results suggested that variable allelic forms of Id were acting in different crosses, which resulted in variation in melanosis of the host. However, no conclusive pattern for shank pigmentation could be explained through genotyping of the Id and Fm loci. 5. Analysis of quantitative traits indicated the positive impact of a Kadaknath genomic proportion of 50% or more on meat texture and carcase leanness. Improvement in leanness occurred in White Rock crosses but not in White Leghorn and Aseel Peela crosses. 6. Thigh-meat texture was influenced more by enhanced Kadaknath genomic proportions than the breast-meat. It was concluded that introgression of Kadaknath genomic proportion beyond 50% in a cross with meat-type chickens, irrespective of the impact Fm, brought improvement in meat quality whereas no such advantage was obtained for growth traits. 7. The beneficial impact of the Kadaknath genome on meat quality calls for further studies to identify causative genes for their selective use to improve meat quality in Kadaknath crossbred chickens. 相似文献
14.
The study was conducted to evaluate reproductive performances and estimate genetic parameters for reproduction traits in Arsi-Bale
goats. A total of 792 kidding records collected from 2001 to 2007 were used. Parity of dam, year, season and type of kidding
were investigated as fixed effects by PROC GLM of SAS. Derivative-Free Restricted Maximum Likelihood (DFREML) method was used
to estimate genetic parameters by fitting four animal models. Parity of dam and year of kidding influenced (P < 0.05) all the traits. The overall means for age at first kidding (AFK), kidding interval (KI), litter size at birth (LSB),
litter size at weaning (LSW), litter weight at birth (LWB), litter weight at weaning (LWW), abortion and dystocia were 574.9 ± 8.3 days,
280.0 ± 13.7 days, 1.6 ± 0.03, 1.37 ± 0.03, 3.7 ± 0.08 kg, 9.11 ± 0.38 kg, 3.8% and 0.13%, respectively. The estimates of
direct additive heritability for the traits, except for abortion and dystocia, under the best model (direct animal for AFK
and repeatability model for other traits) were 0.245 ± 0.19, 0.060 ± 0.08, 0.074 ± 0.05, 0.006 ± 0.05, 0.125 ± 0.05, 0.053 ± 0.07,
respectively, while the corresponding permanent environmental effects were 0.00 ± 0.00, 0.07 ± 0.07, 0.08 ± 0.05, 0.172 ± 0.06,
0.03 ± 0.04 and 0.07 ± 0.05, respectively. Repeatability estimates for KI, LSB, LSW, LWB and LWW were 0.13, 0.15, 0.18, 0.16
and 0.12, respectively. Genetic correlations between reproductive traits vary from medium to high. Arsi-Bale goats have good
reproductive performance with low incidence of reproductive disorder. Except for AFK, other traits have low estimates of heritabilities
with high genetic correlation among the traits. Repeated measures of the traits are needed before deciding to keep or cull
the animal. 相似文献
15.
V. Tufarelli G. M. Lacalandra G. Aiudi F. Binetti V. Laudadio 《Tropical animal health and production》2011,43(2):339-345
The aim of the present study was to assess the effects feeding level on body weight changes and semen parameters in adult
Sardinian rams reared under intensive conditions in a semi-arid area of southern Italy. During an experimental period of 90 days,
24 healthy Sardinian rams were divided into three equal groups that differed in their feeding level, in terms of concentrate
amount. The control-concentrate (CC; n = 8) group received 1.0 times their maintenance requirements, the medium-concentrate (MC; n = 8) group received a diet that supplied 1.2 times their maintenance requirements, and high-concentrate (HC, n = 8) group received a diet that supplied 1.5 times their maintenance requirements. Mixed vetch–oat hay was offered ad libitum
to ram groups and water and mineral licks were freely available. Body weight and feed intake was recorded weekly, and semen
characteristics were determined every 2 weeks. Dietary treatment affected final body weight (P < 0.01) as feeding level increased. Total dry matter and protein intake changed significantly (P < 0.05 and P < 0.01, respectively) among experimental groups. Semen volume and concentration were positively influenced by feeding level
for HC group, whereas no differences were observed in sperm viability and scrotal circumference of rams. It was concluded
that dietary level with higher concentrate supplementation resulted in improved body weight gain, feed intake, sperm production,
and semen quality in Sardinian rams. 相似文献
16.
Genetic susceptibility of indigenous chicks to subgroup A Rous sarcoma virus inoculated via the chorioallantoic membrane. 总被引:3,自引:0,他引:3
An investigation was made using chicks of two Indian indigenous breeds of fowl, Kadaknath and Aseel, to ascertain genetic resistance to infection by Rous sarcoma virus of subgroup A. A standard inoculation dose of 0.2 ml virus containing 1000 pock forming units ml-1 was injected via the chorioallantoic membrane (CAM) into the 11-day-old embryos that were subsequently hatched. The sensitivity of the two indigenous breeds was compared with the highly susceptible exotic White Leghorn (WL) strain maintained in the laboratory. The Kadaknath breed was about three-fold and Assel, about six-fold less sensitive than the WL strain, indicating superiority of the indigenous breeds over the exotic breed of fowl. Most of the CAM-susceptible chicks died of liver tumour (LT) and most of the CAM-resistant chicks survived. However, conversely associated tumour phenotype subclass chicks, i.e. CAM-susceptible LT-negative chicks that survived and CAM-resistant LT-positive chicks that died, occurred consistently in the three breeds of fowl. Nevertheless, the overall survival potential of Kadaknath chicks measured up to 8 weeks post-hatching was greater than that of Aseel chicks. Neither transformation of embryonic tissue prior to hatching nor the visceral metastasis including liver conformed with the degree of CAM-infection as measured by number of pocks on CAMs. 相似文献
17.
Growth performance of Nigerian local chickens in crosses involving an exotic broiler breeder 总被引:1,自引:1,他引:0
Adeleke MA Peters SO Ozoje MO Ikeobi CO Bamgbose AM Adebambo OA 《Tropical animal health and production》2011,43(3):643-650
Six-hundred-and-seven-day-old chicks were generated from Nigerian local chickens consisting of three genotypes (Normal-feathered;
Frizzled-feathered; Naked neck) and an exotic broiler breeder (Anak Titan) to evaluate growth performance for possible meat-type
chicken development. Growth parameters measured were body weight, breast girth and keel length on weekly basis for 20 weeks.
Effects of sire, dam and chick genotypes were significant (P < 0.001) on growth traits. At week 20, chickens sired by the Anak Titan weighed 1,614.82 g followed by Normal-feathered local
chickens with body weight of 1,211.32 g. Progenies of Anak Titan and Naked neck dams weighed 1,761.96 and 1,292.80 g at week
20, respectively. Among purebreds, Anak Titan weighed 35.05 g at day-old and had heaviest body weight of 2,360.29 g at 20 weeks
compared to the three local strains. The average body weights for the crossbred, Normal-feathered×Anak Titan at day-old and
week 20 were 36.39 and 1,577.63 g, respectively. This was followed by Anak Titan×Naked neck with 33.32 g at day-old and 1,514.14 g
at week 20. Sex had significant effect (P < 0.05) at weeks 16 and 20 with the males having higher mean values than their female counterparts. This study revealed that
crosses involving Anak Titan sire×Naked neck dam had highest growth performance, and there was no strain differences among
the growth performance of purebred Nigerian local chickens. 相似文献
18.
Relationship of age to body weight,scrotal circumference,testicular ultrasonograms,and semen quality in Sahiwal bulls 总被引:1,自引:1,他引:0
Ahmad Ejaz Ahmad Nasim Naseer Zahid Aleem Muhammad Khan Muhammad Sarwar Ashiq Muhammad Younis Muhammad 《Tropical animal health and production》2011,43(1):159-164
The objective of the present study was to determine the relationship of age to body weight (BW), scrotal circumference (SC),
number of pixels of testicular ultrasonograms (NP), and semen quality in Sahiwal bulls. The study was based on 128 Sahiwal
bulls of different age groups (from 0 to >100 months of age). Bulls were evaluated for SC, BW, and NP. Semen was evaluated
once a week for five consecutive weeks from regularly collected donor bulls (n = 86) ranging in age from 25–30 to >100 months. Ejaculate volume, sperm motility, sperm concentration, sperm morphology,
percent live sperms, sperm plasma membrane integrity, and normal acrosome were compared among different age groups. Mean SC
and BW increased (P < 0.05) in a curvilinear manner from birth to >100 months of age. Mean NP of testicular ultrasonograms increased (P < 0.05) from 0 to 24 months and then plateaued until >100 months of age. Body weight, SC, and NP were positively correlated
with age from birth until >100 months (r = 0.91, 0.87, and 0.40, respectively). Ejaculate volume (5.7 ± 0.2 vs. 4.6 ± 0.09 ml) and sperm concentration (1,281.6 ± 17.7
vs. 1,115.8 ± 55.9 × 106/ml) increased (P < 0.05) in mature bulls compared to younger ones. However, motility (68.6 ± 0.3%), plasma membrane integrity (50.8 ± 1.0%),
and normal acrosome (74.8 ± 0.5%) remained insignificant due to age. In six of eight age groups studied, morphological abnormalities
were well within the range (18.1 ± 0.3%). In conclusion, the BW, SC, and NP of testicular ultrasonograms, ejaculate volume,
and concentration increased with age. Moreover, semen quality is fairly independent of age except volume and concentration
in Sahiwal bulls. 相似文献
19.
Characterisation of animal genetic resources has been recognised globally as an important step towards their sustainable use.
Body weight data of local chickens (213 forest and 160 savannah chickens) and 183 French free-ranging SASSO T44 chickens kept
under improved management were collected from hatch to 40 weeks of age and analysed to determine the effects of age, genotype
and sex on their growth performance. At all ages, SASSO T44 chickens had significantly (P < 0.05) higher weights (2.6–3.2 kg at 28 weeks) than the local chickens (1.2–1.7 kg at 28 weeks). The rate of growth at the
earlier ages in the local genotypes (5.57–7.80 g/day) was lower than the range of 13.81–15.42 in SASSO T44 chickens. Except
at hatch, savannah chickens were significantly heavier (P < 0.05) than the forest chickens at all ages. Male chickens had significantly (P < 0.05) superior growth rates than females across all genotypes except from the 20th to the 28th week. Growth trends in both
sexes depicted linear increase in body weights; however, the rate of increase in body weights was higher in males as compared
to females, thus showing clear sexual dimorphism. There were no significant (P > 0.05) differences in the growth rates of SASSO T44 chickens and local genotypes at the later ages (20–28 weeks). Local
chickens from the savannah zone had better growth rate than forest chickens. The significant effect of ecozone on the growth
potential of local chickens is an indication that their productive potential could be improved through interventions in the
environment such as provision of feed and some veterinary care. 相似文献
20.
Genetic parameters were estimated for production traits and primary antibody response (Ab) against Newcastle diseases virus
(NDV) vaccine among two Tanzania chicken ecotypes viz. Kuchi and Tanzania Medium (Medium). Production traits studied were body weights at 8 (Bwt8), 12(Bwt12), 16(Bwt16), and 20 (Bwt20) weeks of age, age at first
egg (AFE), egg number in the first 90 days after sexual maturity (EN-90), egg weight (EW), egg shell thickness (STH), and
egg shape index (ESI). Heritability estimates for Bwt8, Bwt12, Bwt16, Bwt20, AFE, EN-90, EW, STH, ESI and Ab for Kuchi chicken were 0.38 ± 0.10, 0.41 ± 0.07, 0.44 ± 0.08, 0.45 ± 0.09, 0.42 ± 0.10, 0.31 ± 0.05, 0.43 ± 0.08, 0.53 ± 0.11, 0.48 ± 0.13
and 0.27 ± 0.06, respectively. Corresponding estimates for Medium ecotype were 0.39 ± 0.09, 0.43 ± 0.10, 0.42 ± 0.08, 0.43 ± 0.07, 0.52 ± 0.11, 0.32 ± 0.06, 0.50 ± 0.07, 0.61 ± 0.13, 0.52 ± 0.10
and 0.29 ± 0.05, respectively. Genetic (r
g) and phenotypic (rp) correlations in both ecotypes were highest among body weights (i.e. rg = 0.60 to 0.93 and rp = 0.54 to 0.78), and were lowest (around 0.10 and below, ranging from positive to negative) among primary antibody response
against NDV vaccine and production traits, and among eggshell thickness, egg shape index and other production traits. The
magnitudes of heritability estimates obtained in this study indicate good prospects of improving these traits in both ecotypes
through selection. 相似文献