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1.
Wongkaweewit K Prommachart P Raksasub R Buranaamnuay K Techakumphu M De Rensis F Tummaruk P 《Tropical animal health and production》2012,44(3):467-470
The aim of the present study was to evaluate the control of ovulation by the administration of human chorionic gonadotropin
(hCG) or gonadotropin-releasing hormone (GnRH) at the onset of estrus. Thirty-three multiparous sows housed under tropical
conditions and showing standing estrus within 5 days after weaning were included. The sows were allocated to three groups,
spontaneous ovulation (control group, n = 10), induced ovulation using 750 IU hCG (hCG group, n = 10), and induced ovulation using 50 μg GnRH (GnRH group, n = 13). The hormones were given at the onset of estrus and the occurrence of ovulation was monitored every 6 h by transrectal
ultrasonography. Data for weaning-to-estrus interval, onset of estrus-to-ovulation interval (EOI), and the length of estrus
were recorded. All sows in the control and hCG groups ovulated, while 3 out of 13 sows treated with GnRH developed cystic
ovaries (did not ovulate). Of those sows ovulating, the EOI of the hCG (40.2 ± 1.7 h) and GnRH (37.5 ± 3.3 h) groups were
shorter than that of the control group (63.6 ± 9.6 h; P < 0.05). In conclusion, the administration of either hCG or GnRH at the onset of estrus can control time of ovulation but,
at the dose employed, sows receiving GnRH may develop ovarian cysts. 相似文献
2.
Effect of feed flushing on ovulation rate was investigated during the autumn seasons on 24 adult Malpura ewes (BW 34.8 ± 0.58 kg
and age 4–7 years) equally divided into two groups. Ewes in G1 (group 1) were grazed 8–10 h daily on Cenchrus ciliaris pasture interspersed with seasonal shrub. In addition to grazing, concentrate was provided at 1.5% of BW to the animals in
G2 (group 2) for a period of 35 days. Estrus was synchronized by a double injection schedule of PGF2α at 0 and 10 days of the experiment and detected by parading aproned rams at 6 h intervals. Blood samples were collected at
weekly interval during the estrous cycle. A rumen fermentation study was conducted on day 23 of the experiment at 0 and 4 h
post-concentrate feeding. Ovarian responses in terms of number of corpora lutea and large follicles was examined on all the
ewes by laparoscopy after 3 to 6 days of each estrus and were found to be similar in both the groups. Hemoglobin and packed
cell volume, total protein, albumin, and globulin were similar among the groups. Concentration of plasma glucose (12 and 22 days)
was higher (P < 0.05) in G2 vis-à-vis control. Plasma urea was higher (P < 0.01) in the control than G2. Rumen liquor pH, concentration of total N, TCA–ppt N, NH3–N, and TVFA were significantly higher (P < 0.01) in G2 than the control. Thus, it can be concluded that concentrate supplementation in ewes prior to mating (flushing)
did not enhance ovulation response during the autumn season. 相似文献
3.
Mengistie Taye Girma Abebe Solomon Gizaw Sisay Lemma Abebe Mekoya Markos Tibbo 《Tropical animal health and production》2010,42(4):659-667
A study was conducted to evaluate growth performances of Washera sheep under smallholder production systems in the Yilmanadensa
and Quarit districts of the Amhara National Regional State, Ethiopia. Data were collected and analysed on the growth of 690
lambs owned by 110 households from October 2004 to September 2007. Weight (kilograms) of Washera lambs at birth, 1, 3, 6,
9 and 12 months of age was 2.69 ± 0.02, 7.10 ± 0.16, 12.42 ± 0.11, 16.12 ± 0.91, 20.05 ± 0.55 and 23.47 ± 0.68, respectively.
Birth weight was significantly (P < 0.05) affected by district, year of birth, parity of the dam, birth type and sex of lamb and by the interaction effect
of parity by birth type and parity by sex of lamb. Weaning weight was also affected by year of birth, type of birth and sex
of lamb. Yearling weight was affected by only year of birth and sex of birth. The average daily weight gain (ADG; grams) from
birth to 30 days, birth to 90 days, 90 to 180 days and birth to 1 year of age was 143.37 ± 13.46, 107.09 ± 2.67, 39.78 ± 9.73
and 60.13 ± 1.89, respectively. Growth rates from birth to 30 and 90 days of age were significantly (P < 0.05) affected by birth year, birth type and sex. ADG from birth to 1 year of age was affected by lamb sex and district.
The indigenous Washera sheep had faster growth rate than those sheep breeds of Ethiopia extensively studied thus far. Integrated
efforts combining improved nutrition, health and participatory community-based breeding would help the smallholder farmers
to utilise and conserve this immense sheep genetic resource of Ethiopia. 相似文献
4.
Mellado M Véliz FG García JE De Santiago Á 《Tropical animal health and production》2012,44(3):389-394
Data from 82 kiddings from mixed-breed (native x dairy goats) goats reared on rangeland (n = 47) or confinement (n = 35) were used to determine the influence of various factors on length of labour, standing of newborn kids and time to first
suckling in pluriparous goats. Both groups were mated at the same time to bucks of the same genotype in February. During the
kidding time in July, the goats were monitored for 24 h in order to register parturition traits and kid birth weight and body
measurements. For all goats, blood samples were collected at parturition in order to establish the nutritional state of goats.
Grazing goats had lower body weight and body condition score (P < 0.01) than pen-fed goats, as well as lower values for some blood metabolites indicative of low body energy reserves. For
both grazing and pen-fed goats, the majority of kiddings (>93%) occurred during daylight hours. No kiddings were registered
from 2300 to 0500 hours. No effects of height at withers, thoracic circumference and sex of kids at birth were found to influence
length of labour. Labour was shorter (P < 0.01) for pen-fed does than grazing goats (10.6 ± 1.18 min vs. 15.4 ± 1.2 min; mean ± SD). The length of parturition was
considerably longer (P < 0.05) for twin-bearing does than for single-bearing does (16.6 ± 1.76 min vs. 11.2 ± 0.81 min, respectively). The interval
between parturition and standing of kids was shorter (P < 0.05) for kids from litters weighing >3.3 kg (entire litter) than kids from litters with <3.3 kg (22.7 ± 1.82 min vs. 31.1 ± 2.76 min).
Time to first suckling was longer (P < 0.05) for kids delivered from pen-fed does than kids from grazing does (57.8 ± 7.57 min vs. 42.9 ± 3.05 min). These results
confirm that, independently of type of production system (intensive or extensive), kiddings of does are concentrated during
daylight hours. These results also indicate that conformation of kids does not alter duration of labour, and that nutritional
stress of goats during gestation (extensive conditions) does not interfere with the neonate’s level of alertness and arousal. 相似文献
5.
Luna-Orozco JR Guillen-Muñoz JM De Santiago-Miramontes Mde L García JE Rodríguez-Martínez R Meza-Herrera CA Mellado M Véliz FG 《Tropical animal health and production》2012,44(1):71-75
The objective of this study was to evaluate the efficacy of treating sexually inactive bucks with artificial long photoperiod
or testosterone on the induction of estrus in anovulatory grazing goats. A total of 91 multiparous mixed-breed anestrous goats
were randomly assigned to one of three treatment groups: (1) joining with bucks subjected to 2.5 month of artificial long
days (16 h of light/day; n = 31), (2) joining with testosterone-treated bucks (n = 30), and (3) joining with untreated bucks (control; n = 30). There were no differences between the light-treated (100%) and testosterone-treated (93%) bucks in their ability to
induce estrus in anovulatory does. On the other hand, none of the goats in contact with control bucks exhibited estrus. The
interval from start of mating to estrus was shorter in goats with the light-treated bucks (37.9 ± 4.8 h) compared with does
in contact with testosterone-treated bucks (58.3 ± 8.7 h). The overall pregnancy rate in goats joined with light-treated,
testosterone-treated and control bucks was 84%, 77% and 0%, respectively, with no difference (P > 0.05) between the first two groups. Anogenital sniffing, approaches, mounting attempts, and mounts were highest (P < 0.01) in light-treated bucks and lowest in control bucks. It was concluded that testosterone-treated bucks and long-day-treated
bucks were equally effective in synchronizing estrus in anovulatory goats and resulted in similar levels of fertility. Given
that light-treated bucks are unviable in communal production systems of goats raised by resource-poor farmers, the sexual arousal of bucks with testosterone is a practical and reliable method to induce ovulation in anovulatory
goats in pastoral goat systems in hot environments. 相似文献
6.
Quintero-Elisea JA Macías-Cruz U Álvarez-Valenzuela FD Correa-Calderón A González-Reyna A Lucero-Magaña FA Soto-Navarro SA Avendaño-Reyes L 《Tropical animal health and production》2011,43(8):1567-1573
The aim of this study was to evaluate the effects of dose and application time of pregnant mare serum gonadotropin (PMSG)
on reproductive performance of hair sheep ewes synchronized with fluorogesterone acetate (FGA) under tropical conditions of
Northeastern Mexico. Ninety-nine hair ewes (63 Blackbelly and 36 Pelibuey) were treated with intravaginal sponges during 10 days.
After insertion of FGA sponges, ewes were divided into four groups, and PMSG was injected intramuscularly at doses of 100,
200, and 400 IU. Relative to FGA sponge removal, PMSG was administrated at −48 h, −24 h, and at sponge removal. PMSG was not
administered to the control group. Control ewes had similar (P > 0.05) lambing rate, fertility, and fecundity than those treated with 100 IU of PMSG, but lower (P < 0.05) percentages to these variables than those treated with 200 and 400 IU of PMSG. Time to estrus decreased linearly,
and ovulation rate increased quadratically as PMSG dose increased (0 to 400 IU). Administration of PMSG before sponge removal
increased (P < 0.01) response to estrus and decreased (P < 0.01) interval to estrus compared with control. Ovulation rate, lambing rate, fertility, and fecundity were not affected
(P > 0.05) by administration time of PMSG. Both dose and time of PMSG application did not affect (P > 0.05) pregnancy rate, percentage of single and multiple lambing, and prolificacy. In conclusion, results show that the
dose of 400 IU of PMSG administered before sponge withdrawal in an estrus synchronization protocol improved reproductive efficiency
of hair sheep ewes. 相似文献
7.
Thirty yearling male intact Arsi-Bale sheep with initial body weight (BW) of 15.5 ± 0.21 kg (mean ± SD) were used in 90 days
feeding trial, 10 days digestibility trial followed by evaluation of carcass parameters at Bokoji, Ethiopia. The objectives
were to evaluate effects of supplementation with linseed (Linum usitatissimum) cake (LSC), wheat bran (WB), and their mixtures at 2:1 and 1:2, respectively on feed intake, digestibility, daily BW gain,
and carcass parameters. The five treatments included ad libitum feeding of natural pasture hay (control) and with daily supplementation
of 300 g dry matter (DM) sole LSC, 2LSC:1WB mix, 1LSC:2WB mix, and sole WB. Six sheep were randomly assigned to each treatment
using randomized complete-block design. Four sheep in each treatment were randomly selected and used for determination of
digestibility and carcass characteristics using a completely randomized design. The intake of hay DM was higher (P < 0.001) for the non-supplemented sheep compared with the supplemented ones, but the contrary was true for total DM intake.
Sheep in the control treatment lost BW (−1.5 g/day), while the supplemented ones gained 69.0–104.1 g BW/head/day. Digestibility
of CP was higher (P < 0.001) for supplemented sheep as a result of higher (P < 0.001) CP intake. Slaughter weight, empty BW, and hot carcass weight were lower (P < 0.001) for sheep in the control treatment compared with the rest. Sheep supplemented with LSC and its mixtures with WB
had better (P < 0.001) performance in daily BW gain than sole WB supplemented ones indicating the advantages of using supplements as mixed
rations. Moreover, supplementation proved to be profitable, whereas feeding hay alone led to economic loss. 相似文献
8.
Martin G. Maquivar Carlos S. Galina Jaime R. Galindo Sandra Estrada Rafael Molina German David Mendoza 《Tropical animal health and production》2010,42(4):555-560
In order to evaluate the effect of protein supplementation on the productive and reproductive performance of heifers, 45 Bos indicus × Bos taurus heifers, 673 ± 146 days of age and weighing about 340 kg, were divided into two groups. The control group (n = 23) continued without supplementation, but the supplemented group (SG; n = 22) received concentrate at a rate of 1% BW kg per day. Animals were adapted to the concentrate over a 15-day period and
then supplemented for 30 days, after which estrus was synchronized using a progesterone implant. Back fat thickness (BFT)
was assessed by ultrasound. The SG had better average daily weight gain than the nonsupplemented group (0.63 ± 0.16 vs. 0.51 ± 0.13 kg/day,
P < 0.05) and tended to show a better percentage ovulation (P < 0.10, 77% vs. 57%, respectively). However, this tendency was not reflected in the final pregnancy rates. No differences
were observed between groups in dry matter intake and body condition scores. SG with a high BFT (>0.70 cm) showed a better
ovulation percentage than those with low BFT (<0.69 cm; P < 0.01). Additionally, the pregnancy rate of supplemented heifers with high BFT tended to be better than heifers with low
BFT in this same group (67% vs. 30%, respectively, P < 0.10). It is concluded that protein supplementation improved reproductive performance and that ultrasonography to measure
BFT may be used to estimate reproductive performance. 相似文献
9.
Kumar V Kumar P Mohan K Sarkar M Suresh KP Chauhan MS Prakash BS 《Tropical animal health and production》2011,43(3):669-674
The objective of this study was to elucidate the changes in circulating levels of plasma interleukin-8 (IL-8) during peripartum
period in Murrah buffaloes (Bubalus bubalis). IL-8 was estimated in blood plasma of healthy peripartum Murrah buffaloes (n = 6) on days ±30, ±15, ±5, ±3, ±1 and 0 pre- and postpartum with respect to the day of parturition (day 0) in each of the
two different seasons (hot–humid and spring). The mean microclimate Temperature–Humidity Index (THI) during spring season
was significantly lower (p < 0.01) than the corresponding THI in hot–humid season. In both the seasons, plasma IL-8 remained lower in prepartum period
(≤46.56 ± 14.08 pg/ml during spring and ≤ 73.18 ± 18.56 pg/ml during hot–humid season) than in the postpartum period (≥51.41 ± 13.82 pg/ml
during spring and ≥ 84.13 ± 16.97 pg/ml in hot humid season). During spring, the IL-8 levels were significantly higher (P < 0.05) on days +5 and +15 postpartum in comparison to the IL-8 levels on days −30, −5, and −3 prepartum. During hot–humid
season, IL-8 level was significantly higher (P < 0.05) on day +30 as compared to the IL-8 levels on days −30 and −5 prepartum. The correlation between IL-8 and mean microclimate
THI was significant (r = 0.25, P < 0.01). From the results, it is concluded that peripartum period in buffaloes is associated with an inflammatory response
leading to significantly higher plasma IL-8 during parturition and postpartum period than in the pre-partum period. 相似文献
10.
Three hundreds, 21 d-old slow-growing chicks were randomly divided among 5 treatments, of 5 replicates each. Each replicate
contained 12 unsexed chicks housed in (1 × 1) a floor pen. A group was kept under thermoneutral condition at 28 ± 4°C and
RH was 55 ± 3% during 21–84 d of age (positive control) and fed corn-soybean meal diet. The other four groups were kept for
three successive days per week under heat stress (HS) at 38 ± 1.4°C and 49 ± 2% RH from 12.00 to 16.00 pm. Chicks in HS treatments
were fed corn-soybean meal diet without (negative control) or with 250 mg AA/kg diet and Bet at 0.5 and 1 g/kg diet. HS decreased
productive performance, increased (P < 0.05) meat dry matter, plasma triglyceride and serum calcium whereas decreased (P > 0.05) plasma glucose, serum total protein and water holding capacity (WHC) of meat. AA and 1 g of Bet/kg diet was equally
potent for partial relief (P < 0.05) of the negative effect of HS on growth, increased (P < 0.05) feed intake, protein digestibility (P < 0.05), dressing out percentage, liver and giblets, whilst improved (P < 0.05) feed conversion ratio (FCR). Also, a complete recovery from the negative effect (P < 0.05) of HS shown on plasma glucose and partial recovery (P < 0.05) observed in total protein, triglyceride, blood pH, packed cell volume (PCV), hemoglobin (Hgb), rectal temperature
(RT) and respiration rate (RR) and improved humoral immune competence to sheep red blood cell (SBRCs) test. 相似文献
11.
Aynalem Haile Abebaw Gashaw Taye Tolemariam Markos Tibbo 《Tropical animal health and production》2010,42(5):825-831
An investigation was made into the epidemiology of nematode infections of sheep in two districts of Jimma zone, southwestern
Ethiopia. We used two approaches—long-term monitoring of identified sheep for nematode infection and abattoir or market survey
for analysis. In the first monitoring regime, we used 80 lambs [40 sheep (20 per sex) from each district (Dedo and Yebu)]
averaging 4–5 months of age. Faecal egg counts (FEC), packed cell volume (PCV) and body weight changes were monitored over
a period of 1 year. Additionally, faecal samples were collected (on a weekly basis) from sheep brought to abattoir/market
for 1 year to monitor faecal egg counts. The nematode parasite burden, as judged by FEC and PCV, was generally low indicating
that the climatic conditions are not conducive to the development and survival of nematode eggs and the free-living stages;
hence, little transmission occurred. In the experimental flocks, the highest FEC and lower PCV were recorded during the long
rainy season (June to September) with peak in August and September. Faecal samples collected from abattoir/market also followed
the same trend. Results from experimental sheep indicated that location had a significant (P < 0.01) effect on FEC, PCV and average daily body weight gain. The FEC and PCV for sheep in Yebu (mid-altitude) district
were 126 ± 3.33 and 30.6 ± 0.26, whereas the values for Dedo (highland) were 93 ± 4.35 and 32.0 ± 0.21, respectively. The
results indicate that the highland areas are comparatively less favourable to the survival and development of nematodes. Female
lambs had lower FEC and higher PCV compared to male lambs (P < 0.05). The overall nematode parasite challenge in the area, however, is low. We, therefore, recommend rotational grazing
management combined with monitoring parasite load and selective treatment to reduce productivity loses and pasture contamination. 相似文献
12.
In a switch-over experiment, eight male animals, four each of sheep and goats of local breeds with mean body weight of 26.
8 ± 2.0 and 30.0 ± 2.1 kg, were fed Dichanthium annulatum (DA) grass and four browse species viz. Helictris isora, Securengia virosa, Leucaena leucocephala (LL) and Hardwickia binnata (HB) in four feeding trials to assess their supplementary effect on activity of rumen enzymes. The sheep and goats were offered
DA grass with individual browse in 75:25 and 50:50 proportions, respectively, for more than 3 months during each feeding trial,
and rumen liquor samples were collected twice at 0 and 4 h post feeding after 60 and 90 days of feeding. Glutamate oxaloacetate
transaminase (GOT), glutamate pyruvate transaminase (GPT) and glutamate dehydrogenase (GDH) enzymes were determined in the
bacteria and protozoa fractions of rumen liquor, while cellulase enzyme activity was measured in mixed rumen liquor. LL and
HB had the highest and lowest contents of CP, while fibre contents were lower in early than later browse leaves. Supplementation
of browse leaves significantly (P < 0.05) affect the specific activity of GDH enzyme in bacteria fraction of rumen liquor of animal species, while GDH activity
was similar in protozoa fraction of rumen liquor of sheep and goats on all DA grass–browse-supplemented diets except DA–HB
(42.8 units/mg protein), where activity was significantly (P < 0.05) low. Specific activities of GOT and GPT enzymes in both bacteria and protozoa fractions of rumen liquor differ significantly
(P < 0.05) due to supplementation of browse leaves to DA grass. Browse leaves significantly (P < 0.05) affect the cellulase enzyme activity in animal rumen liquor, being highest on DA–LL (193.4) and lowest on DA–HB diet
(144.8 μg sugar/mg protein). Goat exhibited higher activities of GOT and GPT than sheep in both bacteria and protozoa fraction
of rumen liquor, while cellulase activity was similar between the animal species on the grass–browse leaves diets. Results
indicate that browse leaves supplementation affect the enzyme activities of sheep and goats rumen, while the goats rumen liquor
had higher activities of GOT, GPT and GDH enzyme than sheep. 相似文献
13.
Taşdemir U Ağaoğlu AR Kaymaz M Karakaş K 《Tropical animal health and production》2011,43(5):1035-1038
The aim of this study was to compare ovarian response and embryo yield of Day 0 protocol in Angora goats (AG) and indigenous
Kilis goats (KG) in the non-breeding season. A total of 16 Angora goats (AG group) and 11 Kilis goats (KG group) were used
in this study. In the synchronization process, after controlled internal drug release withdrawal, when estrus signs were observed,
natural mating was performed. Ovarian response was determined by synchronized laparotomy 6 days after natural mating, and
number of corpora lutea (CL) was recorded. Embryos were collected and morphologically evaluated by stereomicroscope. Synchronization
rates did not differ between AG (88%, 14/16) and KG group (91%, 10/11). In AG and KG groups, the proportion of CL on the right
(44% and 53%, respectively) and left (56% and 47%, respectively) ovaries were similar. The CL number per animal did not differ
significantly between the two breeds and was determined as 4.4 ± 0.90 in AG group and 6.4 ± 1.44 in KG group. Transferable
embryo yields were significantly higher in AG group (31/42, 74%) compared to KG group (16/46, 35%) in the non-breeding season
(P < 0.01). In conclusion, it is suggested that the day 0 protocol can be used for goat superovulation in the non-breeding season;
however, transferable embryo yields are affected by the breed. 相似文献
14.
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
15.
Factors influencing reproductive performance of cows from different Nguni ecotypes in southern Mozambique 总被引:1,自引:1,他引:0
Maciel SM Amimo J Martins M Mwai AO Scholtz MM Neser FW 《Tropical animal health and production》2012,44(3):435-444
The objective of this study was to assess the reproductive performance of two Nguni ecotypes (Nguni and Landim) raised in
a subtropical environment to enhance strategies for livestock development and restocking programmes within the southern African
region. Reproduction data collected between 1996 and 2009 from 365 cows of the Landim and Nguni ecotypes were analysed. From
the results, ecotype, place of birth, year and season of birth/calving had significant effects on age at first calving (AFC)
and calving interval (CI). Overall means for AFC and CI were 1,071 ± 166 days and 432 ± 85 days, respectively, while average
calving rate was 88.0 ± 4.7%. Heifers born in the dry season had lower AFC than heifers born in the wet season. Heifers born
at Impaputo Breeding Center were the youngest at first calving, followed by the South African born ones. Heifers of the Landim
ecotype also calved younger than heifers of the Nguni ecotype. CI was shorter in wet seasons (main breeding seasons) than
in dry seasons. Interaction between ecotype and year–season (p < 0.005) showed that, in wet and dry seasons, Nguni cows had shorter CI than the Landim. This study demonstrates for the
first time a possible genotype-by-environment interaction between Nguni ecotypes. This might aid future cattle development
and restocking programmes in southern Africa taking into consideration the adaptation of indigenous genotypes and climate
change. 相似文献
16.
Fifty-three transitional-anestrus Awassi ewes, randomly assigned to three groups: fluorogestone acetate (FGA, n = 18), FGA-Prostaglandin
(FGA-PGF, n = 18) and control (n = 17), were used to examine the effect of estrus synchronization protocols and steroid hormones
concentrations on milk somatic cell count (SCC). Intravaginal FGA sponge was inserted for 13 days and 600 IU equine chorionic
gonadotropin was administered for ewes of FGA and FGA-PGF groups at the time of sponge removal (day 0). In addition, 10 mg
was administered to ewes of FGA-PGF group on day 0. Blood and milk samples were collected from all ewes on days -13, -6,
0, 1, 2, 7 and 14. Estradiol had significant positive correlation with the SCC during the periods of sponge insertion (P = 0.015, r = 0.235) and within two days (P = 0.063 r = 0.23) after sponge removal with no correlation with SCC of both udder halves during the luteal phase. Progesterone
concentrations, on the other hand, had a significant positive correlation (P < 0.001; r = 0.420) with the SCC of both udder halves during the luteal phase of the experiment, but not during the periods
of sponge insertion and expected estrus. SCC returned under the influence of endogenous progesterone on days 7 and 14 to pre-synchronization
values. In conclusion, sheep milk SCC is affected significantly with induction of estrus and steroid hormones concentrations.
However, peak SCC recorded during estrus was far below the upper limit of the current standard for normal milk. With the current
standards for SCC of 1,000,000/ml as legal limit for abnormal milk control programs in sheep, estrus synchronization programs
and the estrus status should not be considered when bulk-tank milk SCC is being investigated, but should be considered during
the process of setting new standards. 相似文献
17.
Seventy multiparous healthy lactating Holstein cows (fat-corrected milk yield = 7,561.8 kg) were monitored from 14 days before
to 70 days after calving. Transrectal ultrasound scanning was performed twice weekly from 7 to 65 days postpartum. Blood samples
were also collected twice weekly to measure serum P4 and biweekly to detect serum β-hydroxybutyrate (βHB) and nonesterified fatty acid (NEFA) concentrations. Body condition score
(BCS) was taken biweekly after calving. Based on the serum P4 profile of 59 cows (11 cows were excluded due to the occurrence of postpartum diseases) studied, 27 (45.8%) had normal ovarian
activity, while 21 (35.6%), six (10.1%), three (5.1%), and two (3.4%) had delayed ovulation (DOV), prolonged luteal phase
(PLP), short luteal phase (SLP), and cessation of ovarian activity, respectively. Cows with PLP had an earlier ovulation compared
to that of cows with normal ovarian activity (23.16 ± 4.02 vs 31.9 ± 8.35 days; P < 0.05). PLP cows also had a greater mean ± standard deviation peak milk yield (44.2 ± 5.8 vs 37.2 ± 5.7 kg/day, 75 days
postpartum; P < 0.05) than cows with normal postpartum ovarian activity. The PLP group also had greater milk production in the previous
lactation period. Logistic regression analysis indicated that cows with P4 concentration ≥1 ng/ml on day 24 after calving were more at risk for PLP by 1.1 for each 1 kg increase in mean peak milk
yield during 75 days after calving. BCS was lower in cows with DOV compared to that of cows with normal ovarian activity at
any time after calving (P < 0.05). Serum βHB concentrations in DOV cows were significantly higher than that of normal cows on day 42 after calving
(0.69 ± 0.29 vs 0.54 ± 0.12 mmol/L, P < 0.05). No significant difference was found in the mean concentrations of NEFA between cows in different groups at any time
after calving (P > 0.05). The concentrations of P4 on days 28 and 31 were negatively correlated with βHB concentration on day 42 after calving in cows with normal ovarian activity
(R = −0.44, P = 0.02). In conclusion, these findings suggest that early ovulation and hence early postpartum P4 rise in addition to the high milk production could partly be responsible for the occurrence of PLP in dairy cows. 相似文献
18.
The effects of feeding graded levels of dried moringa (Moringa stenopetala) leaf on intake, body weight gain (BWG), digestibility and nitrogen utilization were studied using male sheep (BW of 13.8 ± 0.12 kg).
Six sheep were randomly allocated to each of the four treatment diets: Rhodes grass (Chloris gayana) hay offered ad libitum (T1), hay + 150 g moringa leaf (T2), hay + 300 g moringa leaf (T3), hay + 450 g moringa leaf (T4)
were offered daily. A 7-day digestibility trial and an 84-day growth experiments were conducted. Dry matter (DM), organic
matter (OM) and crude protein (CP) intakes increased (P < 0.05) with increasing levels of moringa leaf in the diets. Sheep fed T2, T3 and T4 diets gained (P < 0.05) 40.2, 79.1 and 110.1 g/head/day, respectively, while the control group (T1) lost weight (−13.3 g/head/day). The apparent
digestibilities of DM, OM, neutral detergent fibre and acid detergent fibre were similar (P > 0.05) among treatments. The digestibility of dietary CP increased (P < 0.05) with increasing levels of moringa leaf, but there was no significant difference between T2 and T3 diets. The nitrogen
(N) intake and urinary N excretion increased (P < 0.05) with increasing levels of moringa leaf. The N retention was highest (P < 0.05) for 450 g moringa leaf supplementation. The control group was in a negative N balance. Supplementing a basal diet
of Rhodes grass hay with dried moringa leaves improved DM intake, BWG and N retention. It is concluded that M. stenopetala can serve as a protein supplement to low-quality grass during the dry season under smallholder sheep production system. 相似文献
19.
Gomes Pöppl Á Costa Valle S Hilário Díaz González F de Castro Beck CA Kucharski LC Silveira Martins Da Silva R 《Veterinary research communications》2012,36(1):81-84
Estrus cycle is a well recognized cause of insulin resistance in bitches. The insulin receptor (IR) as well as the insulin-like
growth factor-I receptor belong to the same subfamily of tyrosine kinase (TK) receptors. The objective of this study was to
evaluate basal TK activity in muscle tissue of bitches during the estrus cycle. Twenty-four bitches were used in the study
(7 in anestrus, 7 in estrus, and 10 in diestrus). Muscle samples, taken after spaying surgery to determine TK activity, were
immediately frozen in liquid nitrogen and then stored at −80°C until the membranes were prepared by sequential centrifugation
after being homogenized. TK activity was determined by Poly (Glu 4:Tyr 1) phosphorylation and expressed in cpm/μg of protein.
TK activity was significantly lower (P < 0.001) in the animals in estrus (104.5 ± 11.9 cpm/μg of protein) and diestrus (94.5 ± 16.9 cpm/μg of protein) when compared
with bitches in anestrus (183.2 ± 39.2 cpm/μg of protein). These results demonstrate, for the first time, lower basal TK activity
in the muscle tissue of female dogs during estrus and diestrus, which may represent lower insulin signaling capacity, opening
a new field of investigation into the molecular mechanisms of insulin resistance in dogs. 相似文献
20.
The effect of GnRH administration on superovulatory response of ewes treated with equine chorionic gonadotrophin (eCG) in
breeding and nonbreeding seasons and the contribution of laparoscopic insemination to the improvement of fertilization and
embryo recovery were investigated. Twenty-four nonpregnant Awassi ewes of 3–4 years of age were randomly allocated into two
groups (n = 12). Each ewe was treated with a progesterone impregnated intravaginal sponge for 12 days. The following superovulation
treatment was used: ewes of group 1 received 1,200 IU of eCG once as an intramuscular injection 48 h prior to sponge withdrawal;
ewes of group 2 also received 1,200 IU of eCG once as an intramuscular injection, 48 h prior to sponge withdrawal and after
24 h of sponge removal. Ewes were injected with 80 μg of GnRH. Ewes of groups 1 and 2 were further subdivided into four equal
groups (n = 6). Subgroups A and C (superovulated with eCG and eCG plus GnRH, respectively) were mated naturally at least two times
with Awassi rams of proven fertility at 8-h intervals. Subgroups B and D (same as A and C) had intrauterine insemination at
44–46 h after sponge removal, under laparoscopic visualization of uterine horns, depositing 1 ml of diluted semen containing
100 × 106 motile sperm in the distal portion of each uterine horn. Ovarian response was assessed by determining the number of corpora lutea by laparoscopy at day 6 after mating. Embryo recovery was performed by using a semi-laparoscopic flushing procedure in both
uterine horns. Results of the present study showed that ewes treated in breeding season with eCG plus GnRH has a higher number
(P < 0.05) of corpora lutea than eCG alone as 7.33 ± 0.54 and 4.33 ± 0.39, respectively. There was no significant difference in the number of corpora lutea in nonbreeding season when ewes treated with eCG and eCG plus GnRH. The number of unovulated follicles was significantly
higher (P < 0.05) in eCG treated ewes than in ewes treated with eCG plus GnRH, both in the breeding and nonbreeding seasons. The number
of recovered embryos from ewes treated with eCG plus GnRH and eCG differ significantly (P < 0.05) as 4.32 ± 0.56 and 1.06 ± 0.26, respectively, in the breeding seasons. No significant difference was observed when
these hormones used for superovulation in the nonbreeding season. A higher number of unfertilized ova (P < 0.05) was observed in ewes when naturally inseminated than in ewes inseminated using the intrauterine laparoscopic technique.
Higher rate of embryo recovery (P < 0.05) was achieved when ewes were inseminated via intrauterine (4.66 ± 0.66) compared with ewes naturally mated (2.16 ± 0.74).
The fertilization rate in ewes inseminated intrauterine using laparoscopic techniques and naturally mated were 91.5% and 44.8%,
respectively. Fertilization failure in ewes inseminated intrauterine using laparoscopic techniques and naturally mated were
8.4% and 55.2%, respectively. It could be concluded that administration of GnRH 24 h after sponge removal increased ovulation
rate of Awassi ewes treated with eCG for superovulation in the breeding season. The use of eCG to induce superovulation in
Awassi ewes combined with laparoscopic intrauterine insemination increases the fertilization rate. 相似文献