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1.
OBJECTIVE: To evaluate the effect of passive transfer status (determined from measurements of serum IgG concentration at 24 hours after parturition [sIgG-24]) on preweaning growth performance in dairy goat kids. DESIGN: Prospective observational study. ANIMALS: 20 healthy nursing dairy doe kids in a natural nonintensive breeding environment. PROCEDURES: For each kid, sIgG-24 was measured. Body weight was measured at birth and at the time of weaning 30 days (ie, 29 to 31 days) after birth; average daily gain from birth to day 30 and weight at day 30 were used as measures of preweaning growth performance. Regression analysis was used to evaluate associations between sIgG-24 and measures of preweaning growth performance. RESULTS: Mean +/- SD sIgG-24 was 31.7 +/- 10.3 mg/mL. Mean body weights at birth and weaning were 4.105 +/- 0.981 kg (9.031 +/- 2.158 lb) and 9.310 +/- 2.554 kg (20.482 +/- 5.619 lb), respectively; average daily gain was 0.174 +/- 0.072 kg/d (0.383 +/- 0.158 lb/d). No significant association was detected between sIgG-24 and birth weight. However, sIgG-24 was significantly associated with average daily gain (R(2) = 0.48) and weight at day 30 (R(2) = 0.56). Each increase in sIgG-24 of 1 mg/mL was associated with an increase in average daily gain of 0.005 kg/d (0.011 lb/d) and an increase in weight at day 30 of 0.185 kg (0.407 lb). CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that passive transfer status (determined as sIgG-24) was a significant source of variation in preweaning growth performance in dairy doe kids reared in this nonintensive breeding environment.  相似文献   

2.
Data collected from 1957 through 1985 from a Hereford herd located in the Southwest were analyzed separately for each sex to evaluate the heritabilities of and genetic correlations among preweaning growth traits within groups of environmentally similar years. Data were grouped into years with poor, moderate and good environments based on contemporary group means for male calves' weaning weight. A total of 7,690 records were analyzed for birth weight, weaning weight and preweaning daily gain with a model that included year of birth, sire within year of birth, age of dam and a covariate of day of birth for birth weight or age at weaning for the weaning traits. Year of birth was a significant source of variation in all environments for all traits, accounting for more of the variation in the good and poor years than in moderate years. Heritability estimates for all traits were greater in good and moderate years than in poor years for bull calves. For heifers, however, estimates for weaning weight and preweaning daily gain were greater in the poor environment. Genetic correlations among birth weight and preweaning gain increased from the good environment to the poor environment (-.49 +/- .26 to .82 +/- .56 for male calves and -.09 +/- 2.6 to .46 +/- .25 for female calves) but phenotypic correlations were near zero in all environments.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

3.
OBJECTIVE: To evaluate associations between neonatal serum IgG1 concentration and pre- and postweaning morbidity and mortality rates and average daily gains (ADGs) in beef calves and define a cutoff point for serum IgG1 concentration necessary for optimal health and performance of beef calves. DESIGN: Nonconcurrent cohort study. ANIMALS: 1,568 crossbred beef calves. PROCEDURE: Single radial immunodiffusion was used to quantitate IgG1 concentration in sera collected from calves between 24 and 72 hours after birth. Logistic regression, ANCOVA, and likelihood ratios were used to analyze data. RESULTS: In the preweaning period, lower perinatal IgG1 concentrations were significantly associated with higher morbidity rates, higher mortality rates, and lower ADGs. Calves with serum IgG1 concentration < 2,400 mg/dL were 1.6 times as likely to become ill before weaning and 2.7 times as likely to die before weaning as calves with higher serum IgG1 concentrations. Calves with serum IgG1 concentration of at least 2,700 mg/dL weighed an estimated 3.35 kg (7.38 lb) more at 205 days of age than calves with lower serum IgG1 concentration. No significant association of serum IgG1 concentration with feedlot morbidity, death, or ADG was identified. CONCLUSIONS AND CLINICAL RELEVANCE: By use of likelihood ratios, the threshold of serum IgG1 concentration for optimal health and performance of calves was higher than values reported previously. Implementation and maintenance of management and intervention strategies designed for early detection and treatment of calves at risk for failure of passive transfer will likely result in increases in preweaning health and performance parameters.  相似文献   

4.
Data from 439 Brahman (B) and grade Brahman (GB; 7/8 Brahman or more) calves born from 1970 through 1975 at the USDA Subtropical Agricultural Research Station were used to estimate least-squares means, heritabilities and genetic correlations for sheath area and preweaning growth traits. Grade Brahman calves weighed more (P less than .01) at birth and gained more (P less than .01) preweaning than B calves, although sheath areas were not different. Males exceeded (P less than .01) heifers in all preweaning growth traits and had larger (P less than .01) sheath areas. Heritabilities were: sheath area, .45 +/- .13; birth weight, .25 +/- .13; average daily gain, .38 +/- .15 and weaning weight, .35 +/- .15. Genetic correlations between sheath area and birth weight, average daily gain and weaning weight were .23 +/- .35, .58 +/- .25 and .52 +/- .27. These results suggest selection could be effective in reducing sheath area in B and B-derivative breeds, but would be antagonistic to preweaning growth traits. Because of relatively low phenotypic correlations between sheath area and preweaning growth rate (.27) and weaning weight (.29), continued emphasis on increasing growth rate or weaning weight could generally be maintained with careful attention to avoiding large sheath areas through independent culling level or index selection procedures.  相似文献   

5.
Production data were collected on mature cows produced by mating Angus and Hereford (pooled AH), Brahman (Bh) and Boran (Br), and Tuli, a tropically adapted Bos taurus, sires by AI or natural service to Angus and Hereford cows. These cows were mated to Charolais bulls for the purpose of this study. Within each sire breed of cow, cows were assigned randomly to one of three feeding rates, 49 or 76 g of DMI/ BW0.75 or ad libitum (10 to 12 cows/feeding rate group), with weekly individual animal feed consumption recorded. Lactation yields were recorded via the weigh-suckle-weigh protocol at approximately 14, 28, 56, 84, 112, 140, 168, and 196 d postpartum for each cow/calf pair. Means for milk yield at peak lactation, total milk yields, calf birth weight, age-adjusted weaning weights, preweaning daily gain, and feed efficiency were estimated. Peak yield (kg/d) for Bh (10.3 +/- 0.36) was greater (P < 0.05) than for Tuli (9.0 +/- 0.31). Total yield (kg, 212 d) for Bh (1802 +/- 68) was greater (P < 0.05) than for Tuli (1532 +/- 59). Birth weight of AH (44 +/- 0.9) was heavier than for Bh and Br (P < 0.05). Preweaning daily calf gain (g/d) and adjusted weaning weight (kg) of Bh (813 +/- 28, 212 +/- 6.1) and Br (766 +/- 24, 202 +/- 5.1) differed (P < 0.05) from AH (589 +/- 24, 169 +/- 5.2) and Tuli (634 +/- 24, 176 +/- 5.3). Efficiency estimates (grams of adjusted weaning weight/kilograms DMI of the cow) for Bh (88 +/- 2.5) and Br (85 +/- 2.1) exceeded (P < 0.05) those for Tuli (74 +/- 2.1) and AH (73 +/- 2.1). Bos indicus breed crosses exhibited greater peak and total yield, lower birth weight, greater daily gain and adjusted weaning weight, and higher feed efficiency than did Bos taurus breed crosses (P < 0.05). Total yield, daily gain, adjusted weaning weight, and feed efficiency were higher (P < 0.05) for cows sired by bulls from tropically adapted breeds, and the peak yield was less (P < 0.10). Tuli exhibited lower total yield and birth weight than did Angus/Hereford (P < 0.05). The efficiency of crossbred Tuli cows did not differ from Angus/Hereford F1 females, but neither equaled the efficiency of crossbred cows produced using Bos indicus breeds.  相似文献   

6.
The apparent efficiency of absorption and the decrease of specific colostral IgG after its passage into the blood stream were determined in newborn lambs fed with a single dose of colostrum containing anti-peroxidase IgG at 30 minutes, 12 hours and 24 hours after birth. When colostrum was given at 30 minutes after birth, a value of 16.9+/-4.0 per cent of anti-peroxidase IgG ingested appeared in lamb circulation. This percentage was reduced to 9.8+/-0.8 per cent when the feeding was done at 12 hours after birth and no specific IgG was detected in lambs fed at 24 hours after birth. The concentration of anti-peroxidase IgG in lambs' serum declined quickly within 96 hours of age to about 48 per cent of the initial value, and afterwards the level decreased slowly reaching a value of 10 per cent at 32 days of age. This behaviour probably reflects the protein distribution and use of absorbed antiperoxidase IgG.  相似文献   

7.
Data for the current study were obtained from a divergent selection experiment in which the selection criterion was the average serum IGF-I concentrations of 3 postweaning blood samples collected from purebred Angus calves. Multiple-trait derivative-free REML procedures were used to obtain genetic parameter estimates for IGF-I concentrations and for BW and BW gains measured from birth to the conclusion of a 140-d postweaning performance test. Included in the analysis were 2,674 animals in the A(-1) matrix, 1,761 of which had valid records for IGF-I concentrations. Direct heritability estimates +/- SE for IGF-I concentration at d 28, 42, and 56 of the postweaning period and for mean IGF-I concentrations were 0.44 +/- 0.07, 0.51 +/- 0.08, 0.42 +/- 0.07, and 0.52 +/- 0.08, respectively. Heritability estimates for maternal genetic effects ranged from 0.10 +/- 0.05 to 0.20 +/- 0.06. The proportion of total phenotypic variance due to the maternal permanent environmental effect was essentially zero for all measures of IGF-I concentrations. Genetic correlations of IGF-I concentrations with weaning and post-weaning BW ranged from 0.07 +/- 0.12 to 0.32 +/- 0.11 and generally demonstrated an increasing trend during the postweaning period. Averaged across the various measures of IGF-I, the genetic correlation of IGF-I with preweaning gain was 0.14, whereas the genetic correlation with postweaning gain was 0.29. Genetic correlations between IGF-I and BW gain were positive during all time intervals, except between weaning and the beginning of the postweaning test and from d 84 to 112 of the postweaning period. Environmental and phenotypic correlations of IGF-I with BW and BW gains were generally positive, but small. These results indicate that postweaning serum IGF-I concentration is moderately to highly heritable and has small positive genetic, environmental, and phenotypic correlations with BW other than birth weight and with pre- and postweaning gain. Therefore, if IGF-I proves to be a biological indicator of an economically important trait (e.g., efficiency of feed use for growth) in beef cattle, it should be possible to rapidly change IGF-I concentrations via selection without significantly altering live weight or rate of gain.  相似文献   

8.
Immunologic factors related to survival and performance in neonatal swine   总被引：1，自引：0，他引：1  
Logistic regression was used to develop models predicting preweaning survival in 334 neonatal swine. Measured risk factors included birth weight, litter size (live born), dam parity, serum IgG concentration, serum ELISA titers recognizing common gram-negative core antigens, and serum concentrations of the third component of complement. Larger birth weights were associated with increased probability of preweaning survival. The highest mortality was observed in litters with more than 12 pigs. Pigs with serum concentration of the third component of complement (C3) in the lowest stratum, less than 20% adult pooled C3 standard (APC3), had reduced mortality, compared with high (greater than 38% APC3) and middle (20 to 38% APC3) groups. Associations between all other variables, including total serum IgG concentration and preweaning survival were not significant. Few pigs had hypogammaglobulinemia, less than 3% of the study population had serum IgG concentrations less than 1 g/dl. Of all measured variables, only birth weight and dam parity were significant predictors of preweaning gain. Larger pigs and pigs born to third or greater parity dams had more preweaning gain than other pigs.  相似文献   

9.
文章旨在评估日粮添加不同酸化剂对断奶仔猪生长性能、免疫性能和微生物菌群的影响.试验将384头平均初始体重为(6.16±0.23)kg的21?d断奶仔猪随机分为4组,每组6个重复,每个重复16头,各组断奶仔猪分别饲喂基础日粮、基础日粮+45?mg/kg抗菌肽、基础日粮+4?kg/T柠檬酸及基础日粮+3?kg/T复合酸化剂...  相似文献   

10.
To investigate the influence of maternal Se supply and plane of nutrition on lamb morbidity, mortality, and passive transfer of IgG, pregnant ewe lambs were used in 2 experiments with 2 × 3 factorial treatment arrangements. Supplementation of Se began at breeding and was either adequate Se (ASe, 9.5 μg/kg of BW) or high Se (HSe, 81.8 μg/kg of BW) in Exp. 1 or ASe (11.5 μg/kg of BW) or HSe (77.0 μg/kg of BW) in Exp. 2. On d 50 or 40 of gestation for Exp. 1 or 2, respectively, ewes were assigned randomly to 1 of 3 nutritional planes: 60% (RES), 100% (control, CON), or 140% (HI) of NRC requirements. This resulted in the following treatments: ASe-RES, ASe-CON, ASe-HI, HSe-RES, HSe-CON, and HSe-HI. Upon parturition, lambs were separated from their dams and serum samples obtained. Lambs were fed artificial colostrum for the first 20 h and then placed on milk replacer and grain pellets until completion of the study (Exp. 1, 57 d; Exp. 2, 21 d). Twenty-four hours after parturition, lamb serum samples were collected for IgG analysis. All lambs were reared similarly and morbidity and mortality assessed. Main effects were considered significant when P ≤ 0.05. In Exp. 1, there was a Se × plane of nutrition interaction (P ≤ 0.01) for lamb morbidity from birth to weaning and for 24-h IgG concentration. Lambs from ASe-RES and HSe-HI ewes were treated more frequently (P < 0.01) for respiratory and gastrointestinal disease, and lambs from HSe-HI ewes had the smallest (P < 0.01) 24-h serum IgG concentration. In Exp. 1, lambs from HI ewes also had the greatest (P < 0.01) mortality rates from birth to weaning compared with lambs from CON and RES ewes. In Exp. 2, there was an effect (P < 0.01) of maternal plane of nutrition with lambs from RES ewes having increased 24-h IgG compared with lambs from CON and HI ewes. There was no effect of maternal Se supplementation on lamb 24-h IgG in Exp. 2; however, there was a Se × plane of nutrition interaction (P < 0.01) for morbidity. From birth to 21 d of age, lambs from ASe-CON ewes had fewer (P < 0.01) treatment days compared with lambs from any of the other treatment groups. There also tended (P = 0.08) to be an effect of maternal Se supplementation on lamb mortality with increased mortality observed in lambs from HSe ewes. Results from the studies show a restricted maternal plane of nutrition can increase lamb serum IgG concentration. Selenium results were not consistent between the 2 experiments and may be due to differences in maternal Se.  相似文献   

11.
Data on ewe body weights and on lamb birth and weaning weights and survival rates were recorded on a total of 557 multiparous Rambouillet, Hampshire X Suffolk and Synthetic I (composite of Finnish Landrace, Rambouillet and Polled Dorset) ewes in two experiments started after the first trimester of gestation. In Exp. 1, a 2 X 2 factorial arrangement of treatments included all combinations of low (.24% in gestation and .48% in lactation), or high (.80%) dietary Ca and low (20 ppm) or high (74 ppm) dietary Zn. No effect of dietary Ca or Zn level and no Ca X Zn interaction with respect to number of lambs born or weaned, birth weight, weaning weight or survival rate of the lambs or body weight of the ewes was shown. Mean number of lambs born was 1.63 +/- .71 with a survival rate of 85.0 +/- .3% and a weaning weight (59 d) of 19.4 +/- 4.4 kg. Experiment 2 was a repeat of Exp. 1 except that two intramuscular injections of vitamins A, D and E (d 65 and 93 of experiment) were given to one-half of the ewes in each diet group. There was no effect of dietary Ca or Zn level or of vitamin administration on ewe body weight changes, number of lambs born (1.89 +/- .55), survival rate (86.6 +/- .3%), lamb birth weight 4.6 +/- 1.5 kg) or lamb weaning weight (23.2 +/- 7.2 kg). Blood plasma Ca, inorganic P and Mg concentrations of ewes in late pregnancy were unaffected by diet or vitamin injections.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

12.
Ten foals of various breeds were deprived of colostrum from birth to 36 hours of age, then were allotted to 2 groups. Foals of group 1 (n = 6) were given 20 g (200 ml) of purified equine IgG IV in a 10% solution, and foals of group 2 (n = 4) were given 30 g (300 ml) of the same preparation. Total administration time for each 10 g of IgG in 100 ml was approximately 10 minutes. Serum IgG concentration in foals was assessed prior to, between 24 and 48 hours, and at 7 and 14 days after IgG administration. Between 24 and 48 hours after IgG administration, mean serum IgG concentration in group-1 foals was 425 mg/dl (range, 350 to 480 mg/dl). Mean body weight for this group of foals was 50.3 kg (range, 43.3 to 54.7 kg). For group-2 foals, mean serum IgG concentration was 768 mg/dl (range, 640 to 920 mg/dl) between 24 and 48 hours after administration of IgG. Foals of this group had mean body weight of 43.2 kg (range, 36.5 to 47.5 kg). Serum IgG concentration in group-2 foals at 24 to 48 hours was significantly (P = 0.005) greater than that in group-1 foals. Mean total IgG recovery at 24 to 48 hours, calculated on the basis of 94.5 ml of plasma volume/kg of body weight, was approximately 100%. Values of IgG measured in all foals 1 and 2 weeks after administration of the IgG concentrate were equivalent to values expected after normal decay of passively acquired IgG.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

13.
Data collected from 1993 to 2006 at the Animal Research Institute of Ghana was used to compare the performance of Sanga and Friesian-Sanga crossbred calves on natural pasture. Performance traits analyzed were birth weight (BWT), weaning weight adjusted to 210 days (WW7), preweaning average daily gain to 210 days (ADG 1), weight at 12 months adjusted to 365 days (W12), weight at 18 months adjusted to 540 days (W18) and postweaning average daily gain (ADG 2, from weaning to 540 days). Effects in the model describing these traits were breed, season, sex and first-order interactions between these effects. With the exception of heavier birth weight of Friesian-Sanga crossbred calves (19.98 kg vs. 19.18 kg), body weights of Sangas at weaning, 12 months and 18 months exceeded those of the Friesian-Sanga crossbred calves by 3.76 kg, 35.06 kg and 46.24 kg respectively. The Sangas were also superior in preweaning average daily gain (0.35 kg/day vs. 0.26 kg/day) and postweaning average daily gain (0.28 kg/day vs. 0.21 kg/day). There was a tendency of increasing weight difference between the two breeds with advancing age. It was suggested that improved nutrition such as supplementary feeding would be necessary for crossbreds to express their potential for growth.  相似文献   

14.
Our study aimed to investigate responses to supplementation of calcium (Ca), magnesium (Mg) and sodium (Na) to lactating ewes and lambs grazing barley forage from lamb marking to weaning. A 10-ha paddock sown to barley was subdivided into eight plots as four replicates of two treatments. Merino ewes (n = 104) with lambs at foot were stratified to the eight plots (13 ewes and 21 lambs/plot) based on number of lambs (twin or single) and ewes' weight. Supplemented groups had access to mineral supplements (30 g/ewe/day) supplying 12 g/ewe/day ground limestone, 12 g/ewe/day Causmag® and 6 g/ewe/day coarse salt in a ratio of 2: 2: 1 by weight (as fed) from day 0 (a day before lamb marking) after sample collection. Control groups were not supplemented with minerals. Blood, milk and urine samples from ewes and blood from lambs were collected at different time points, namely, a day prior to lamb marking (day 0), 14 days after the commencement of study (day 14), and 28 days after the commencement of study (day 28). Weight of the lambs was also recorded at each time point. We found that the concentration of the forage minerals (Ca, Mg and potassium (K)) was lower on day 28 than on day 0 (P < 0.025). Liveweight gain was greater in the first 14 days compared with the second weight gain period (P < 0.001). The interaction of time and treatment was significant for liveweight (P < 0.001). Due to the improvement in weight gain of supplemented lambs, we recommend that mineral supplementation during late lactation is beneficial considering the low cost of minerals, even though the mineral content of the forage was not deficient.  相似文献   

15.
Seven Friesian calves were fed colostrum for four days beginning within 24 hours of birth, and milk thereafter. The concentration of alpha-lactalbumin in serum was measured by specific radioimmunoassay and compared to IgG assayed by electroimmunodiffusion. Serum concentrations of alpha-lactalbumin peaked at 387 +/- 85 ng ml-1 within eight hours of initial intake of colostrum, declining to 12 +/- 3 ng ml-1 by day 6. IgG rose steadily to 17 mg ml-1 by 48 hours of birth and remained relatively constant thereafter. The temporal pattern of alpha-lactalbumin in serum following colostrum intake confirms previous studies suggesting reduced absorption of colostral proteins between 24 and 36 hours. The presence of variable amounts of alpha-lactalbumin in serum even after 17 days, however, indicates limited transfer of milk-derived proteins across the gut at this time. The data further show that cessation of maximal gut transfer does not relate to molecular weight of transferred protein.  相似文献   

16.
Boluses of controlled release glass containing cobalt and weighing approximately either 60 g or 14.5 g were administered to 22 steers and 21 sheep respectively. The steers were housed and slaughtered at intervals between 17 and 145 days after dosing. The boluses released more than 0.85 mg cobalt daily. In both untreated and dosed animals serum and liver vitamin B12 concentrations were at the upper end of the normal range. Two types of glass were administered to sheep. In five wethers one glass released 0.07 mg cobalt per day, and in 16 grazing lambs a second glass released more than 0.15 mg cobalt per day. Fourteen of the boluses were recovered from the lambs up to 276 days after dosing. The concentration of B12 in serum of lambs increased significantly from a mean +/- sd of 1.64 +/- 0.47 to 2.02 +/- 0.04 ng/ml serum and the concentration in liver from 3.84 +/- 0.85 to 4.99 +/- 0.72 micrograms/g dry weight liver.  相似文献   

17.
OBJECTIVE: To determine the effect of split nursing (i.e., removal of the larger pigs in a litter from the dam for a short period within 24 hours after birth to allow the smaller pigs in the litter uninhibited access to the dam) on variation in growth from birth to weaning among pigs. DESIGN: Clinical trial. ANIMALS: 1,193 pigs in 118 litters. PROCEDURE: Litters were randomly assigned to 1 of 3 treatment groups: control group (pigs were not split nursed), group 1 (heaviest 50% of pigs in the litter were removed from the sow for 2 hours), or group 2 (heaviest 50% of pigs were removed from the sow for 2 hours and, after the heaviest pigs were returned to the sow, the lightest 50% of pigs were removed for 2 hours). Birth weights and weaning weights were measured. RESULTS: Significant differences in average daily gain (ADG), weaning weight, or serum IgG concentration among groups were not detected. However, significant linear improvements in the SD and coefficient of variation of the ADG were detected, but only for litters with > or = 9 pigs born alive. Percentages of pigs from split-nursed litters that weighed < 3.6 kg (8 lb) at weaning (1.3 and 1.6% for groups 1 and 2, respectively) were lower than percentage of control pigs that did (3%). CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that split nursing will decrease variation in ADG of pigs from birth to weaning but only for pigs from litters with > or = 9 pigs born alive.  相似文献   

18.
A terminal sire Composite population was formed by mating Columbia rams to Hampshire-Suffolk crossbred ewes. Subsequent generations were produced by inter se mating. The objective was to compare Composite sheep to purebred Suffolks for numerous performance traits. Young ewes lambing at 1 yr of age were evaluated separately from mature ewes (2, 3, 4, and 5 yr old) of each population. Composite and Suffolk populations did not differ significantly in components of litter weaning weight per young ewe joined. Mature Composite ewes produced more wool than Suffolk ewes. Fertility of mature ewes did not differ significantly between populations. The greater prolificacy (P less than .01) of mature Suffolk ewes was offset by a lower survival to weaning (P less than .01), particularly for twin-born lambs. Consequently, mature Composite and Suffolk ewes did not differ for number weaned and litter weaning weight per ewe joined. The average birth weight of lambs born to young and mature Composite ewes was greater (P less than .02) than the average birth weight of Suffolk lambs. The average weaning weight of lambs born to young Composite ewes was greater (P less than .05) than that of lambs born to young Suffolk ewes. Breed differences were not detected for preweaning daily gains, weaning weights, and postweaning daily gains of ewe lambs born to mature ewes. Likewise, weights of ewes at 125 d of age and weights of mature ewes at breeding did not differ significantly between breeds.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

19.
The sera of 188 lambs from seven breed groups were analyzed for the concentrations of IgG1, IgG2, IgM and IgA by radial immunodiffusion using monospecific antibodies. From each lamb, 14 blood samples were drawn before and 5 samples after weaning. The following results were obtained: 1. Immunoglobulins could not be detected in sera drawn before the first intake of colostrum. 2. In normally suckling lambs, the peak concentrations of maternal immunoglobulins are attained at 0-18 hrs after birth. They can be assessed in a single blood sample drawn between 18 and 24 hrs. 3. The half-life times of maternal immunoglobulin in lamb sera are 11 days for IgG1, 7 days for IgG2, 6 days for IgM and 18 hours for IgA. 4. The absolute peak heights relate to the amounts of colostrum ingested before 12-18 hrs after birth. 5. The decline of maternal immunoglobulins in lamb sera over-laps with the onset of lamb immunoglobulin synthesis. Renewed rises of concentrations are observed for IgG2 after week 2, for IgM after week 3 and for IgG1 after week 7. The concentrations of IgA remain at the low levels characteristic for the serum of grown sheep. 6. The role of immunoglobulin synthesis in suckling lambs is only briefly and to a small extent reduced after weaning.  相似文献   

20.
饲喂IgG对仔猪血液生化指标和生产性能的影响   总被引：3，自引：0，他引：3  
试验分两批选用 12 0 ,6 0头大白仔猪 ,出生 2 4h之内饲喂不同剂量的免疫球蛋白制剂 0 ,4 80 ,96 0mg ,均吮食初乳。于仔猪 5 ,10 ,15日龄前腔静脉采血 ,测定血清总蛋白、血清IgG、血清碱性磷酸酶和血红蛋白含量 ,并测定仔猪断奶时增重 ,哺乳前、后期平均日增重。结果表明 :饲喂不同水平的IgG ,仔猪 5 ,10日龄血清总蛋白、血清碱性磷酸酶活性和血红蛋白含量均显著高于对照组 (P <0 0 5 )。饲喂高水平IgG(96 0mg)的仔猪 ,5日龄血清IgG水平显著高于对照组 (P <0 0 5 )。哺乳前期 (0～ 15日龄 )各处理组仔猪平均日增重显著高对照组 (P <0 0 5 ) ,断奶时增重也显著高于对照组 (P <0 0 5 )。  相似文献   

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