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1.
Ranjan K. Mohanta Kamal K. Singhal Amrish K. Tyagi Y. S. Rajput Shiv Prasad 《Tropical animal health and production》2010,42(3):431-438
The effects of feeding transgenic (Bt) whole cottonseed (WCS) were studied in lactating cows. Twenty multiparous crossbred
cows (Karan Swiss × Karan Fries) in early lactation were given a concentrate mixture containing 40% crushed delinted non-transgenic
(non-Bt) WCS, 2 kg wheat straw and green fodder ad lib for a 15-day adaptation period. Thereafter, the cows were divided in two similar groups of 10 each on the basis of milk yield,
body weight (BW) and date of calving. The non-Bt control group continued on same ration, while for the Bt group the non-Bt
WCS was replaced by transgenic WCS, in a feeding trial of four weeks. The diets provided a minimum of 2 kg cottonseed/cow/d.
Mean DMI/100 kg BW and milk yield of non-Bt and Bt groups was 3.48 and 3.45 kg and 11.4 and 12.0 kg/d, respectively. Intake
of nutrients, digestibility, milk production and body condition score (BCS) did not differ between the groups (P > 0.05),
but BW gain was higher (P < 0.05) in the Bt group than the non-Bt group, probably as a result of hoof problem in two cows
of non-Bt group, which when compared excluding two animals from each group did not differ significantly (P > 0.05). Transgenic
protein (Cry1C) was not detected in the weekly milk samples or in blood plasma at the end of the experiment, showing that
delinted WCS containing Cry1C protein can safely be fed to lactating cows. 相似文献
2.
Escrivão RJ Webb EC Garcês AP Grimbeek RJ 《Tropical animal health and production》2012,44(7):1779-1782
Sixty multiparous Brahman-type cows were randomly selected in the early postpartum period and equally allocated into a calf removal group (RG) and a non-removal group (NRG). Calves from cows in the RG were removed for 48 h prior to the breeding season and returned afterwards, whereas in the NRG, calves remained with their dams until weaning. Weaning weights were corrected to 205?days. Conception rates (CRs) were 76?% for RG and 55?% for NRG but did not differ (p?>?0.05). CR was correlated with calving to breeding interval and body condition score at the onset of the breeding season. Product-limit survival curves vs breeding to conception interval differed significantly (p?0.05) between treatment groups. It was estimated with 95?% certainty that 50?% of the cows in the RG will conceive within the first 12?days of the breeding season, while 39?days were required for cows in the NRG. Weaning weights were 135.2?±?22?kg for RG and 135.5?±?19?kg for NRG. It was concluded that 48-hour calf removal prior to breeding season increased the number of cows that conceive early in the breeding season and enhanced conception rates but did not affect calf weaning weights of Bos indicus cattle in extensive production systems. 相似文献
3.
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
4.
Sánchez Dávila F Bernal H Colín J Olivares E del Bosque AS Ledezma R Ungerfeld R 《Tropical animal health and production》2011,43(4):887-891
The objective of this study was to determine whether season and total rainfall during the breeding season, sheep parity, and/or
litter size affect the interval from the introduction of rams to estrus (IRE) in hair Saint Croix sheep in northeastern Mexico.
An analysis was made of 874 services performed during 9 years, introducing the rams into the sheep flock after an isolation
period of 60 days during the postpartum period. Estrus was recorded twice daily during 35 days. Year and season influenced
significantly on the interval between ram introduction and estrus length (P < 0.01). Winter IRE length (7.9 ± 0.1 days) was shorter than in the other three seasons (11.1 ± 0.2, 11.1 ± 0.1, and 16.2 ± 0.2 days
in summer, autumn, and spring, respectively) (P < 0.01). An interaction was observed between rainfall and season, then by rainfall between 0 and 100 mm, IRE was shorter
(P < 0.05) in winter (6.8 ± 0.3 days), and by rainfall between 100 and 199 mm, IRE was shorter (P < 0.05) in autumn (10.2 ± 0.5 days); however, when rainfall was beyond 200 mm, IRE length was shorter (P < 0.01) in summer (4.8 ± 0.5 days) than in autumn (14.5 ± 0.3 days). The IRE length was also longer in first lambing ewes
(P < 0.05) and was not affected by litter size. In the present study, several factors, including the breeding season, rainfall
and parity, directly influenced the interval between the male introduction and the onset of estrus by Saint Croix hair sheep. 相似文献
5.
The purpose of this study was conducted to evaluate the use of a system of timed artificial insemination (TAI) and early diagnosis
of pregnancy in Nelore beef cows in order to reduce the breeding season (BS) from 150 to 90 days and analyze the factors affecting
the conception rate of cows selected for TAI. The study included 110 Nelore cows belonging to the Experimental Farm Capim
Branco, Brazil. The body condition scores (BCS) were evaluated, and those above 2.50 were included in the TAI protocol. Five
groups of cows were formed at intervals of 21 days postpartum and then commenced a 9-day progesterone protocol. Progesterone
devices were used three times. Statistical analysis of binary variables was performed by logistic regression in the program
Proc Logistic of Sas. A 5% of significance (P < 0.05) was used to determine the presence of statistical differences and the effect of independent variables on conception
rate. The TAI and early diagnosis of pregnancy reduces the BS from 150 to 90 days without changing the pregnancy rate. The
conception rate was not affected by the presence of the calf (P > 0.05), the corpus luteum (P > 0.05), the BCS (P > 0.05), or the number of reuses of the intravaginal progesterone device (P > 0.05). Therefore, this technique is beneficial for breeding Nelore beef cattle and can be used in anestrous cows with a
BCS above 2.50. Additionally, the progesterone devices can be reused to reduce the cost of the protocol without compromising
the results. 相似文献
6.
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
7.
Renan Braga Paiano Daniela Becker Birgel Jeannine Bonilla Eduardo Harry Birgel Junior 《Reproduction in domestic animals》2020,55(9):1219-1228
The aims of this study were to characterize the biochemical profile, the reproductive performance and to identify potential predictive biomarkers of disease state of dairy cows with hyperketonemia, lipomobilization and hypocalcemia raised in tropical conditions in southeastern Brazil. Dairy cows (n = 50) were divided into a group of healthy cows (n = 14), cows with lipomobilization (n = 14), cows with hypocalcemia (n = 11), and a group of cows with hyperketonemia (n = 11). Evaluation of body condition score (BCS), body weight (BW) and blood samples was performed on 21, 14, 7, 4 and 2 days before calving, parturition, 1, 7, 14, 21, 30, 45 and 60 days post-partum and milk production was recorded on days 7, 14, 21, 30, 45 and 60 after parturition. Blood samples were assayed for aspartate aminotransferase (AST), gamma-glutammyltransferase (GGT), albumin, total protein, globulin, fibrinogen, total cholesterol, triglyceride, urea and creatinine concentrations. The biochemical profile, BCS, BW, milk production and reproductive performance differed (p < .05) among the groups. Our findings indicate changes in the biochemical profile of dairy cows with metabolic diseases and impaired production and fertility of dairy cows in this group. Variable importance in projection plots demonstrated that cholesterol, urea, total protein, albumin and fibrinogen in the serum were the strongest discriminators between cows with hypocalcemia and healthy cows; and AST, cholesterol, urea and triglycerides for cows with hyperketonemia and healthy cows; and cholesterol, urea, triglycerides, total protein and fibrinogen for lipomobilization and healthy cows, which might be useful as predictive biomarkers of the disease state. 相似文献
8.
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
9.
Martin JL Rasby RJ Brink DR Lindquist RU Keisler DH Kachman SD 《Journal of animal science》2005,83(11):2663-2670
A 2-yr study using primiparous and multiparous, spring-calving, crossbred beef cows was conducted to evaluate the effects of supplemental whole corn germ on reproductive performance, calf performance, and serum leptin concentrations. Each year, cows were blocked by age and BCS and assigned randomly to one of three treatments: PRE (n = 115) cows received 1.14 kg/d (DM basis) of whole corn germ for approximately 45 d before calving; POST (n = 109) cows were fed 1.14 kg/d of whole corn germ for approximately 45 d after calving; and control cows (n = 118) were fed similar energy and protein from dry-rolled corn (1.82 kg of DM/d) for 45 d before and after calving. Additionally, PRE cows were grouped with controls after calving, and POST cows were grouped with control cows before calving, so that corn germ-supplemented cows received the control supplement in the alternate feeding period. Cow BW (538 +/- 13 kg) and BCS (5.4 +/- 0.13) did not differ among treatments at any time during the experiment. Calf birth weight (39 +/- 2 kg), weaning weight (225 +/- 7 kg), and age-adjusted weaning weight (234 +/- 8 kg) did not differ because of dam supplementation regimen. Treatment did not affect the proportion of cows exhibiting ovarian luteal activity before the start of the breeding season (67%) or pregnancy rate (91%). The interval from exposure to bulls until subsequent calving did not differ (P = 0.16) among PRE (298 +/- 2.3 d), POST (303 +/- 2.6 d), and control (304 +/- 2.3 d) cows. Leptin concentrations did not differ among treatments and were 2.15 +/- 0.75, 1.88 +/- 0.76, and 1.91 +/- 0.75 ng/mL for control, POST, and PRE cows, respectively. Age and week relative to calving influenced leptin concentration. Primiparous cows had similar leptin concentrations to 3-yr-old and mature cows for wk -7 and -6 relative to calving, but lower (P < 0.10) concentrations than mature cows for wk -5, and lower (P < 0.05) concentrations than either 3-yr-old or mature cows for wk -4 to +7 relative to calving. Serum leptin was correlated with BCS (P < 0.0001; r = 0.35) at initiation of the feeding period and was correlated with BCS (P = 0.02; r = 0.12) and weight (P < 0.01; r = 0.14) at the completion of the supplement period, but it was not correlated with initial BW or interim BCS. Calving interval was not correlated (P > 0.12) with weekly measures of serum leptin concentration. Supplementing beef cows with whole corn germ had no effect on cow performance, calf performance, or serum leptin concentrations of cows. 相似文献
10.
Henderson Ayres Roberta Machado Ferreira Jos Ribamar de Souza Torres-Júnior Clarice Garcia Borges Demtrio Csar Gonalves de Lima Pietro Sampaio Baruselli 《Livestock Science》2009,123(2-3):175-179
The aim of the present study was to determine the relationship among body weight (BW), body condition score (BCS) and rump fat thickness (RFAT) measured by ultrasonography, and validate the relationship between BCS and RFAT over the time. Two hundred sixty and six Nelore cows had their BW, BCS and RFAT evaluated at five different moments during the production cycle: M1) weaning; M2) parturition, M3) 42 days post-partum; M4) 82 days post-partum and M5) 112 days post-partum. A BCS value was attributed for each cow following a 1 to 5 points scale. Ultrasonographic images for RFAT measurement were obtained using a 3.5 MHz linear transducer. Images were immediately analyzed as soon as they were formed and frozen. Body condition scores and ultrasound measurements were collected on the same day by a single trained technician. The relationship between BCS and RFAT values was investigated by regression models. The analysis of similarity among the five obtained models was performed using the proc MIXED from SAS and the correlations among variables were analyzed with proc CORR from SAS. The BCS was able to predict RFAT in Nelore cows in all different moments evaluated. Also, it was shown that BCS presented high correlation (r = 0.82 to 0.93) and relationship (R2 = 0.73 to 0.92) with RFAT. However, both BCS and RFAT showed low correlation (r = 0.37 to 0.50) and relationship (R2 = 0.13 to 0.25) with BW. The BCS classification by visual method using a 1 to 5 point scale, was able to predict the RFAT in Nelore cows over the time. 相似文献
11.
Alonso L Maquivar M Galina CS Mendoza GD Guzmán A Estrada S Villareal M Molina R 《Tropical animal health and production》2008,40(8):667-672
With the objective of evaluating the effect of methionine supplementation prior to a breeding program, thirty one heifers
(Bos taurus x Bos indicus) were used averaging 386 ± 29 days of age and a mean body weight of 402.6 ± 28 kg. Fifteen of the animals received a
supplement (SG) during 45 days with molasses-urea mixture (2 kg molasses + 407 g urea/head/day), plus 10 g of ruminally protected
methionine. The other sixteen heifers did not receive supplement (CG). Fecal and pastures samples were collected to assess
dry herbage intake and digestibility. Serial ultrasound measurements from the ovary were performed in both groups to evaluate
follicular dynamics. The heifers were categorized according to their follicular size and presence of a CL. Forage intake and
dry matter digestibility were reduced (P < 0.05) and body condition tended to improve (P = 0.07) in the supplemented heifers,
however, total intake, final weight, daily gain and dorsal back fat were not affected. After the supplementation period, the
percentage of females in the categories < 3 mm and 3 to < 6 mm, was greater (P < 0.05) in CG (25% and 43.7%) that in SG
(0% and 26.6%) but in the follicle category of ≥ 9 mm, the percentage of animals was 60% in SG and 18.8% in CG (P < 0.05).
The percentage of ovulation for the SG and CG was 86.7% and 62.5%, respectively (P < 0.05). The combination of supplementation
with methionine-urea and molasses at the end of the dry season and the anticipated onset of the rainy season favored the establishment
of ovarian activity and follicular dynamics. 相似文献
12.
The effects on cow performance and calf birth and weaning weight of replacing grass silage with brewers grains in a barley straw diet offered to pregnant beef cows of two different breeds
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J. A. Rooke C.‐A. Duthie J. J. Hyslop C. A. Morgan T. Waterhouse 《Journal of animal physiology and animal nutrition》2016,100(4):629-636
The effects on cow and calf performance of replacing grass silage with brewers grains in diets based on barley straw and fed to pregnant beef cows are reported. Using a 2 × 2 factorial arrangement of breed and diet, cows pregnant by artificial insemination (n = 34) of two breeds (cross‐bred Limousin, n = 19 and pure‐bred Luing, n = 15) were fed diets ad libitum which consisted of either (g/kg dry matter) barley straw (664) and grass silage (325; GS) or barley straw (783) and brewers grains (206, BG) and offered as total mixed rations. From gestation day (GD) 168 until 266, individual daily feed intakes were recorded and cow body weight (BW) and body condition score (BCS) measured weekly. Calving date, calf sex, birth and weaning BW, and calf age at weaning were also recorded. Between GD 168 and 266, cross‐bred Limousin cows gained more weight than Luing cows (p < 0.05) and cows offered BG gained more weight than cows offered GS (p < 0.001). Luing cows lost more BCS than cross‐bred Limousin cows (p < 0.05), but diet did not affect BCS. There were no differences in dry matter intake as a result of breed or diet. Calf birth BW, however, was greater for cows fed BG than GS (44 vs. 38 kg, SEM 1.0, p < 0.001) with no difference between breeds. At weaning, calves born to BG‐fed cows were heavier than those born to GS‐fed cows (330 vs. 286 kg, SEM 9.3, p < 0.01). In conclusion, replacement of grass silage with brewers grains improved the performance of beef cows and increased calf birth and weaning BW. Further analysis indicated that the superior performance of cows offered the BG diet was most likely due to increases in protein supply which may have improved both energy and protein supply to the foetus. 相似文献
13.
Multiparous, spring-calving beef cows (n = 250) were used to determine whether large changes in body energy reserves during mid- to late gestation influenced subsequent reproductive performance of cows calving in moderate body condition. In three states, cows were blocked by BW and body condition score (BCS; 1 = emaciated to 9 = obese) then allotted to receive either a high or low plane of nutrition from late summer to early winter over a 3-yr period. This generated an array of BCS by the beginning of the last trimester of pregnancy when cows were grouped by BCS as follows: Group 1, BCS < or = 4; Group 2, BCS of 5 or 6; and Group 3, BCS > or = 7. Each group was managed so that individual cows would calve with a BCS of 5 to 6. At the time of group assignment, mean BW and BCS differed (P < .01) among groups and were 480 kg and 3.6, 541 kg and 5.5, and 594 kg and 7.1 for Groups 1 to 3, respectively. Within 28 d before calving, BW and BCS were similar (P > .20) among groups averaging 555 kg and 5.1. Prepartum BCS changes averaged 1.4, -.4, and -2.0 units for Groups 1 to 3, respectively (P < .01). Cows were managed as a single group after calving in each state. Location effect was significant for the prepartum and postpartum BW and BCS changes but not for postpartum reproductive performance. Significant location x BCS group interactions were found for the 90-d prepartum BW, BCS at calving, and prepartum changes in BW, but were caused by differences in magnitude among locations. The percentage of cows with luteal activity at the start of a subsequent breeding season was not affected (P > .20) by either location or BCS group, and averaged 66%. Mean pregnancy rates at 20, 40, and 60 d of a subsequent breeding season were 55, 76, and 89% for Group 1; 51, 67, and 82% for Group 2; and 64, 79, and 89% for Group 3 (P > .30). Mean days to conception were 89, 87, and 85 for Groups 1 to 3, respectively (P = .70). Neither calf birth weight (x = 38.6 kg) nor adjusted 205-d weight (x = 223.6 kg) were affected by prepartum BW and BCS changes. We conclude that reproductive performance of cows calving in moderate body condition is not influenced by large changes in body energy reserves during the last trimester of pregnancy. 相似文献
14.
The effects of prepartum supplementary feeding on the productive and reproductive performance were investigated using grazing
gestating Bunaji cows with an average initial body weight of 294.50 ± 3.75 kg. Twenty cows were allocated to a completely
randomized design, with five animals per treatment. The treatments were: A, range grazing (RG); B, RG + 100% corn bran (CB);
C, RG + 60% CB + 40% palm kernel cake (PKC), and D, RG + 60% CB + 40% dried brewer’s grains (DBG). The average daily gains
(ADG) and body condition scores (BCS) of supplemented cows were significantly better than the non-supplemented cows. Postpartum
weight loss was markedly reduced in supplemented cows compared to their non-supplemented counterparts. Mean milk offtake and
mean milk yield per lactation were significantly lower in non-supplemented cows than the supplemented ones. Among the supplemented
cows, ADG, BCS, mean milk offtake and milk yield per lactation were significantly better for cows on treatments C and D than
those on treatment B. Though insignificant, longest lactation length (LL) and shortest calving interval were obtained for
supplemented cows. Calf’s birth weight was similar among the treatments. Milk yield was significantly influenced (R2 = 0.8601) by cow’s weight, BCS and LL. 相似文献
15.
I. Aranda-Ávila J. Herrera-Camacho J. R. Aké-López R. A. Delgado-León J. C. Ku-Vera 《Tropical animal health and production》2010,42(7):1435-1440
The aim was to evaluate the effect of corn oil supplementation during postpartum anoestrus on ovarian activity, pregnancy
rate, progesterone (P4), and lipid metabolites (cholesterol, CHO; low and high density lipoproteins; LDL and HDL, respectively) concentrations in
blood of F1 (Bos taurus × Bos indicus) grazing cows. Cows were randomly assigned to an experimental group, fed with a supplement containing 4% corn oil on dry
matter basis (OG, n = 11), and a control group with the same supplement without corn oil (CG, n = 12). Both supplements contained equivalent amounts of crude protein and metabolizable energy and were fed for 34 days continuously.
All cows were induced to estrous 12 days after beginning of supplementation by using a synthetic progestagen and artificially
inseminated 56 h after retiring the implants. Pregnancy diagnosis was performed by transrectal palpation 45 days after insemination,
evaluating simultaneously ovarian activity. P4 and lipid metabolites (CHO, HDL, LDL) concentrations were determined in blood samples collected at 3-day intervals, from
the beginning of corn oil supplementation and up to 10 days after artificial insemination. Ovarian activity was affected by
treatment (p < 0.05), finding ovarian structures in 72.7% of OG cows and in 50% of CG cows. Concentration of P4 and CHO was higher for OG with respect to CG (2.52 ± 0.65 vs 1.88 ± 0.62 ng/ml and 117.79 ± 11.57 vs 85.71 ± 12.11 mg/dl,
respectively), whereas pregnancy rate and blood concentrations of HDL and LDL were not affected by treatment (p > 0.05). Addition of corn oil to the supplement stimulated ovarian activity and increased serum concentrations of progesterone
and cholesterol in grazing B. taurus × B. indicus cows with low body condition score showing postpartum anoestrus. 相似文献
16.
G. Ajitkumar T. Sreekumaran R. Praseeda K. A. Mercy K. N. Aravinda Ghosh 《Veterinary research communications》2010,34(1):65-69
Forty bitches in anoestrus for more than six months from the last heat, with a serum progesterone level less than 1 ng/ml
were subjected to oestrus induction trials using anti-prolactin drugs and levothyroxine, once daily orally for 20 consecutive
days. The mean serum progesterone level among them was found to be 0.57 ± 0.03 ng/ml. Out of 10 animals treated in each group,
five (50%) in Group I (bromocriptine @ 50 μg/kg body weight), nine (90%) in Group II (cabergoline @ 5 μg/kg body weight),
eight (80%) in Group III (thyroxine @10 μg/kg body weight) and seven (70%) in Group IV (thyroxine @ 5 μg/kg body weight) responded
by evincing proestrual bleeding. The mean (±SEM) time taken from initiation of treatment to onset of proestrual bleeding in
Groups I, II, III and IV was 28 ± 3.39, 13.44 ± 3.12 (P < 0.05), 24.50 ± 3.18 and 33 ± 2.21 days respectively. The mean (±SEM)
duration of proestrus and oestrus in the treatment groups was 9.80 ± 0.86, 10.11 ± 0.68, 11.25 ± 0.88 and 10.71 ± 0.68 days
and 7.60 ± 0.24, 8 ± 0.29, 8.5 ± 0.63 and 7.85 ± 0.46 days respectively. The conception rate in relation to the number of
animals responding to oestrus induction in the treatment groups was 80%, 78%, 63% and 57%, respectively. The mean (±SEM) gestation
length calculated from the last breeding date and litter size in the treatment groups varied from 60.50 ± 1.55 to 64.00 ± 0.82 days
and 5.14 ± 0.34 to 6.40 ± 0.40 respectively. 相似文献
17.
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
18.
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
19.
R Kasimanickam M Asay S Schroeder V Kasimanickam JM Gay JP Kastelic JB Hall WD Whittier 《Reproduction in domestic animals》2014,49(6):1063-1067
Profitability of a beef operation is determined by the proportion of cows attaining pregnancy early in the breeding season and those that are pregnant at the end of breeding season. Many factors, including temperament, contribute to those reproductive parameters. The objective of this study was to evaluate effects of temperament on reproductive performance of beef cows. In Experiment 1, Angus and Angus‐cross beef cows (n = 1546) from eight locations were assigned a body condition score (BCS; 1 = emaciated; 9 = obese) and chute exit and gait score (1 = slow exit, walk; calm temperament; 2 = jump, trot or run; excitable temperament). Cows were grouped with bulls (1 : 25 to 1 : 30; with satisfactory breeding potential and free of venereal disease) for an 85‐day breeding season. Pregnancy status and stage of gestation were determined (transrectal palpation) 35 days after the end of the breeding season. Controlling for BCS (p < 0.01) and handling facility (p < 0.0001) and handling facility by temperament score interaction (p < 0.001), breeding season pregnancy rate was lower in excited versus calm cows [88.6% (798/901) vs 94.1% (607/645); p < 0.001]. Cows with an excitable temperament took 24 more days to become pregnant compared to calm cows (median days to pregnancy, 35 vs 59 days; p < 0.0001). In Experiment 2, Angus and Angus‐cross beef cows (n = 1407) from 8 locations were assigned scores for body condition and chute exit and gait (as described in Experiment 1) and assigned to bulls (breeding sound and free of venereal disease; 1 : 25 to 1 : 30) for 85 days. Pregnancy status was determined by transrectal palpation at 2 and 6 months after the onset of the breeding season. Controlling for BCS (p < 0.05), pregnancy loss was higher in excited versus calm cows [5.5% (36/651) vs 3.2% (20/623), p < 0.0001]. In conclusion, beef cows with an excitable temperament had significantly lower reproductive performance than calmer cows. The modified two‐point chute exit–gait scoring method was repeatable and identified cattle with an excitable temperament. 相似文献
20.
Chay-Canul AJ Ayala-Burgos AJ Ku-Vera JC Magaña-Monforte JG Tedeschi LO 《Tropical animal health and production》2011,43(5):929-936
The objective of this work was to evaluate the effect of metabolizable energy intake (MEI) on changes in fat depots of adult
Pelibuey ewes fed roughage diets under tropical conditions. Eighteen 3-year-old Pelibuey ewes with similar body weight (BW)
of 37.6 ± 4.0 kg and body condition score (BCS) of 2.5 ± 0.20 were randomly assigned to three groups of six ewes each in a
completely randomized design. Ewes were housed in metabolic crates and fed three levels of MEI: low (L), medium (M), and high
(H) for 65 days to achieve different BW and BCS. At the end of the experiment, the ewes were slaughtered. Data recorded at
slaughter were: weights of viscera and carcass. Internal fat (IF, internal adipose tissue) was dissected, weighed, and grouped
as pelvic (around kidneys and pelvic region), omental, and mesenteric regions. Carcass was split at the dorsal midline in
two equal halves, weighed, and chilled at 6°C during 24 h. After refrigeration, the left half of the carcass was completely
dissected into subcutaneous and intermuscular fat (carcass fat). Dissected carcass fat (CF) of the left carcass was adjusted
as whole carcass. At low levels of MEI, proportion of IF and CF was approximately 50%; however, as the MEI was increased,
the proportion of IF was increased up to 57% and 60% for M and H, respectively. Omental and pelvic fat depots were those which
increased in a larger proportion with respect to the mesenteric fat depot. Regression equations between the weight of each
body fat depot and BW had a coefficient of determination (r
2) that ranged between 0.37 for mesenteric fat and 0.87 for CF. The regression with BCS had a r
2 that ranged between 0.57 for mesenteric and 0.71 for TBF. BW was the best predictor for TBF, CF, omental fat, and pelvic
fat; whereas, BCS was better than BW in predicting IF and mesenteric fat. Inclusion of both BW and BCS in multiple regressions
improved the prediction for all fat depots, except for pelvic fat, which was best estimated by BCS alone. The greater slope
of the regression for the pelvic fat depot equation, relative to TBF (1.40), EBW (4.02), and BCS (2.36), suggested that pelvic
fat has a greater capacity to accumulate and mobilize fat. These results indicated that adult Pelibuey ewes seem to store
a considerable proportion of absorbed energy in the IF depots rather than in the carcass. 相似文献