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1.
Although no clinical signs of atrophic rhinitis (AR) were recognized in 2- and 5-week-old pigs, approximately 60% of 2- to 6-month-old pigs showed clinical signs of AR in an affected pig farm. None of the pigs had normal turbinate at slaughter. Bordetella bronchiseptica was not isolated from any of the pigs before onset and incipient stage of the outbreak (2-week to 2-month-old). Pasteurella multocida of capsular type D was not isolated from any of those pigs. However, toxigenic P. multocida of capsular type A was isolated from a number of the pigs immediately before onset and incipient stage of the outbreak. Thirty-six-day-old primary specific-pathogen-free pigs were inoculated intranasally with a toxigenic type A P. multocida isolated from a 5-week-old pig. Severe nasal turbinate atrophy was observed in those pigs which were necropsied at 3 weeks post-inoculation. This is the first report on outbreak of severe nasal turbinate atrophy induced by toxigenic type A P. multocida in Japan.  相似文献   

2.
Effect of atrophic rhinitis on growth rate in Illinois swine herds   总被引：4，自引：0，他引：4  
Influence of atrophic rhinitis (AR) on mean daily weight gain (MDG) was studied in hogs randomly selected from 7 farrow-to-finish herds in Illinois. Herds were selected to obtain a wide range of clinical signs and lesions of the disease; thus, prevalence of clinical signs of AR in finishing hogs ranged from 0% to 20% among herds, and in hogs examined at slaughter the proportion of hogs with turbinate lesions ranged from 5% to 92%. None of the herds investigated had any obvious problems with pneumonia; nevertheless, hogs with moderate to severe pneumonic lesions were excluded from the study, to minimize any combined effect of AR and pneumonia. In 3 herds, MDG in AR-free pigs was 15% to 18% better than in pigs with severe AR lesions. Prevalence of clinical signs ranged from 5% to 20%, and of turbinate lesions, from 66% to 92%. In 4 herds in which MDG appeared to be unaffected by AR, prevalence of clinical signs of the disease ranged from 0% to 5%, and of turbinate lesions, from 5% to 74%. No consistent pattern of influence on AR lesions was found for bacterial infections, as determined by culturing of nasal swab specimens on MacConkey agar and blood agar.  相似文献   

3.
A group of 85 commingled feeder pigs was fed on a totally confined feeding floor until slaughter. Mean daily weight gain was calculated for each pig. At slaughter, the nose of each pig was cross-sectioned and scored for conchal atrophy by use of 2 methods. One method ascribed a score based on a linear measurement of the distance between the ventral scroll of the ventral conchae and the ventral floor of the nasal cavity. The other method ascribed a score based on a subjective evaluation of the degree of conchal degeneration according to previously published guidelines. The amount of pulmonary consolidation attributable to pneumonia was also estimated for each pig. Association was not found between growth rate and conchal atrophy, as determined by linear measurement scores. A negative correlation existed between growth rate and conchal atrophy, as determined by subjective evaluation scores. Pigs with extensive pneumonic lesions (consolidation of 20 to 30% of total lung volume) grew slower than pigs with milder pneumonic lesions. Results of this study indicate that subjective evaluation scores of conchal atrophy may be more useful in predicting growth rate than are linear measurement scores.  相似文献   

4.
Four hundred and sixty-two pigs from 37 herds were examined at slaughter for the presence and extent of turbinate atrophy and pneumonia. Turbinate atrophy was scored by measuring the mm space between the turbinate bone and the floor of the nasal cavity on both sides of the nasal septum. The total percentage of pneumonic involvement for each lung was evaluated by scoring the percentage of each lobe that was consolidated.

There was a low, positive correlation between individual scores of turbinate atrophy and the associated percentage of lung involved with pneumonia (r = + 0.177; p < 0.001). There was a postive correlation between the herd mean turbinate atrophy score and the herd mean percentage pneumonia score (r = + 0.515; p = 0.001).

The age at slaughter was known for 95 pigs from four herds and was not significantly correlated with the mm of turbinate atrophy, or the percentage of pneumonia.

  相似文献   

5.
The efficacy of a Bordetella bronchiseptica bacterin was evaluated in 2 commercial swine herds affected with mild and severe enzootic atrophic rhinitis (AR). In the 1st herd study, (mild AR), the degree of clinical AR, nasal turbinate evaluation, blood serum titer to B bronchiseptica antigen, and adjusted days from birth to 100 kg were determined for individual pigs. Bacterin inoculation reduced the incidence and severity of gross turbinate atrophy 57% and reduced clinical AR over 93%. Inoculated swine had an average blood serum-agglutinating titer greater than 1:2,793 and noninoculated (control) swine had an average titer of 1:112. Increased serum titer significantly (P less than 0.05) correlated with decreased degree of nasal turbinate atrophy. Inoculated and control pigs reached 100 kg in an average of 171 and 178 days after birth, respectively. In the 2nd study (severe enzootic AR), inoculated and control pigs were individually evaluated for clinical AR and total average daily weight gain. Inoculation reduced clinical AR over 90%. The total average daily gain for the inoculated and control pits was 435.84 g and 340.50 g, respectively. Inoculated pigs and control pigs reached 100-kg market weight in 184 and 238 days, respectively.  相似文献   

6.
Three commercial swine herds were selected for study, because pigs at slaughter consistently had lung lesions typical of bronchopneumonia and snout lesions consistent with atrophic rhinitis. Pigs were reared in the conventional system for each herd except that they were identified at birth and weighted at various intervals. At slaughter, individual pig lungs and snout were examined for lesions of pneumonia and atrophic rhinitis, respectively. Lesions were scored and correlated with growth indicators for each pig. Included in the growth indicators were: average daily gain (growing phase), average daily gain (finishing phase), average daily gain (total), and days to reach 104.5-kg body weight. Additionally, for each pig, scores for lung lesions were correlated to grades for snout lesions. Three correlation coefficients for measurements of pigs within herd B were significant and included days to 104.5-kg body weight and grades for snout lesions, -0.15 (P less than 0.02); average daily gain (finishing) and grades for snout lesions, 0.17 (P less than 0.01); and average daily gain (total) and grades for snout lesions, 0.16 (P less than 0.01). Contrary to findings in other investigations, pigs that attained market weight at the youngest age did not have the lowest score for lung lesions, the lowest grade for snout lesions, or the least extensive or severe lesions. Combining data from all 3 herds, the mean scores for lung lesions and mean grades for snout lesions decreased significantly (P less than 0.05) as the age of pigs at slaughter increased. All other statistical correlations were not significant.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

7.
In each of three trials, 240 crossbred barrows weaned at 17 d of age (5.1 kg BW) were assigned to one of three experimental treatments based on light and heavy weight outcome groups. Experimental treatments were 1) wean-to-finish at 0.69 m2/pig and 15 pigs/pen; 2) wean-to-finish double-stocked at 0.35 m2/pig, 30 pigs per pen for 8 wk and then randomly split into two pens (either stayed in same pen or moved to new pen) for growth to slaughter at 0.69 m2/pig; and 3) nursery facility for 8 wk at 0.35 m2/pig and 15 pigs/pen followed by move to the same grow-finish facility housing wean-to-finish and double-stocked pigs and maintaining pen integrity. Beginning at 38 kg BW, diets were supplemented with either bacitracin methylenedisalicylate at 33 mg/kg to slaughter or tylosin at 44 mg/kg to 59 kg BW and 22 mg/kg thereafter. There were no trial x treatment interactions, even though there was considerable variation in health status among trials. At the end of the 56-d nursery period, wean-to-finish pigs weighed more than nursery (28.7 vs 27.7 kg; P = 0.071) and double-stocked pigs (28.7 vs 26.9 kg; P = 0.002), due to greater ADG (wean-to-finish vs nursery; P = 0.062; wean-to-finish vs double-stocked; P = 0.002) and greater ADFI (wean-to-finish vs nursery; P = 0.024; wean-to-finish vs double-stocked, P = 0.002). There was no effect of treatments (P > 0.1) on ADG, feed conversion, carcass lean percentage, or lean gain during the growing-finishing period. There was also no effect of treatment (P > 0.1) on ADG or ADFI from weaning to slaughter. There was no difference (P > 0.1) between bacitracin methylenedisalicylate and tylosin for ADG, feed conversion, carcass lean percentage, or daily lean gain. These data suggest that housing 5-kg weaned pigs in fully slatted growing-finishing facilities from weaning to slaughter was not detrimental to overall performance. In this experiment, dietary additions of bacitracin methylenedisalicylate or tylosin from 38 kg BW to slaughter weight resulted in similar growth performance.  相似文献   

8.
The prevalence and extent of respiratory tract lesions were measured in 1425 pigs from 27 randomly selected herds in the summer of 1982 and winter of 1983. About 75% of pigs had lesions of enzootic pneumonia, approximately 60% had atrophic rhinitis and approximately 11% had pleuropneumonia and/or pleuritis. Individual pig growth rate was recorded on two of the farms, and it was found that the correlations between growth rate and severity of enzootic pneumonia lesions were positive on one farm and negative on the other. Negative correlations between severity of turbinate atrophy and growth rate existed in one of the two herds. Extent of pneumonia and severity of turbinate atrophy were poorly related in individual pigs but herd averages were moderately and positively correlated. Prevalence of diffuse pleuritis and of pleuropneumonia were positively related, as were the extent of pneumonia and prevalence of localized pleuritis. Prevalence of pleuropneumonia was strongly correlated with increased days-to-market. A method of estimating the average days-to-market using weekly herd data (inventory) was developed.  相似文献   

9.
The immunogenicity and safety of an attenuated Bordetella bronchiseptica vaccine for swine atrophic rhinitis (AR) was evaluated in 22 hysterectomy-produced, colostrum-deprived pigs and 18 conventional pigs. None of 8 pigs inoculated at 7 days of age intranasally with greater than or equal to 3 X 10(5) colony-forming units (CFU) of vaccinal strain/pig and 2 of 5 pigs inoculated at 7 days of age intranasally with 3 X 10(4) CFU of the vaccinal strain/pig developed AR after intranasal challenge exposure with a virulent strain at postinoculation week (PIW) 3. The remaining 3 vaccinated pigs and 4 nonvaccinated pigs developed AR. Thirteen pigs were inoculated intranasally with 3 X 10(6) to 3 X 10(9) CFU of the vaccinal strain at 7 days of age. At PIW 12, the pigs were killed and necropsied. None of the pigs had clinical signs of AR and/or pneumonia. Virulence was studied by transmission of vaccinal strain through 3 serial growing passages on the nasal mucosa of a litter of hysterectomy-produced colostrum-deprived pigs. Inoculum (nasal swab samples from 2 pigs 4 days after inoculation with 10(8) CFU of vaccinal strain at 5 days of age) was inoculated into the nasal cavity of 2 nonvaccinated pigs. This procedure was repeated 3 times. After the 1st passage, the vaccinal strain was recovered on postinoculation day 4, but after postinoculation day 4, the vaccinal strain was not recovered until the end of the 3rd passage. Turbinate atrophy or pneumonia was not recognized in these inoculated pigs. The vaccinal strain provided immunogenicity without ill effects.  相似文献   

10.
旨在分析母猪的出生年份、出生季节、初生重、开测日龄等固定效应对长白、大白猪主要生长性状的影响,并对目标生长性状进行遗传参数估计（遗传力、遗传方差、表型相关和遗传相关）,为猪的遗传改良提供基本依据。本试验利用GLM模型分析试验猪群（398头长白猪和1 176头大白猪）的固定效应对猪生长性状的影响,并采用多性状动物模型对目标性状进行遗传参数估计。目标生长性状包括达100 kg体重日龄（age to 100 kg,AGE）、达100 kg背膘厚（backfat to 100 kg,BF）、100 kg平均日增重（average daily gain to 100 kg,ADG）。研究表明,在大白和长白猪中,猪的出生年、出生季、初生重以及开测日龄对生长性状均具有极显著的影响（P<0.001）;长白猪的AGE、ADG和BF的遗传力分别为0.321、0.327和0.324,大白猪对应性状的遗传力分别为0.454、0.469和0.408;长白猪的ADG和AGE之间的遗传相关、表型相关分别为-0.990、-0.995,大白猪的ADG和AGE之间的遗传相关、表型相关分别为-0.993、-0.998,均呈现较强的负相关。长白、大白猪的生长性状（AGE、ADG、BF）均属于中等遗传力性状,其出生年份、出生季节、初生重和开测日龄对猪的生长性状影响较大。在遗传参数估计分析时,提高样本数量并提升表型数据质量,可以增加遗传参数估计的可靠性。本研究中的生长性状遗传参数估计结果较为可靠,可为后续的遗传改良提供参考。  相似文献   

11.
Antimicrobial agents were added to the feed of swine for three weeks to determine the interrelationships of potentially pathogenic agents in the nasal tract, turbinate atrophy and weight gains.

Bordetella bronchiseptica was not isolated from the groups fed the combination of chlortetracycline, penicillin and sulfamethazine. B. bronchiseptica was found in some pigs after the feeding trail, but this organism was not significantly associated with turbinate atrophy at the time of slaughter.

Mycoplasma hyorhinis was not found in the nasal passages of the pigs that received feed containing high concentration chlortetracycline but was found in pigs that received other diets. Hemophilus suis was not significantly reduced by any of the treatments used.

The organisms studied in the pigs were not isolated from the personnel handling the pigs.

  相似文献   

12.
Crossbred pigs (n = 1,400) were used to evaluate the effect of group size (25 vs 50 vs 100 pigs/pen) in a wean-to-finish production system on growth performance and carcass measures. Pigs were weaned at 17 d (range = 15 to 19) of age with a mean initial BW of 5.9 +/- 0.02 kg and taken to a final mean pen weight of 116 +/- 0.9 kg. A 10-phase dietary regimen was used, and pigs had free access to feed and water. Feeder-trough space (4.3 cm/pig) and floor-area allowance (0.68 m2/pig) were the same for all group sizes. Compared to groups of 25, pigs in groups of 50 and 100 animals were lighter (P < 0.001) at the end of wk 8 after weaning and had lower (3%, P < 0.01) ADG and gain:feed (G/F) but similar (P > 0.05) ADFI during the first 8 wk of the study. At the end of the study, pig weight and the coefficient of variation in pig weight within a pen were similar (P > 0.05) across group sizes. During the period from 8 wk after weaning to the end of the study, pigs in groups of 100 compared to 50 animals had greater (3%, P < 0.01) ADG, and pigs in groups of 25 were intermediate for ADG. Average daily feed intake during this period was similar (P > 0.05) for all group sizes; however, G/F was greater (3%, P < 0.01) for groups of 100 compared to 25 or 50 animals. For the overall study period, ADG, ADFI, and G/F from weaning to slaughter weight were similar across group sizes (P > 0.05; 655, 648, and 658 g; 1,759, 1,755, and 1,759 g; and 0.37, 0.37, and 0.37; for ADG, ADFI, and G/F, respectively, for groups of 25, 50, and 100 pigs, respectively). Mortality was similar (P > 0.05) across group sizes; however, morbidity (pigs removed due to poor health or injury) was higher in groups of 25 pigs compared to the other two group sizes (7.0, 3.5, and 3.9% for groups of 25, 50, and 100, respectively; P < 0.05). Group-size treatment did not affect (P > 0.05) carcass dressing percentage, backfat thickness, or loin-eye depth. In summary, growth performance from weaning to market weight was not affected by group size.  相似文献   

13.
Growth, morbidity, and slaughter data from 2,036 calves in 2 South African feedlots were used to estimate the effect of bovine respiratory disease (BRD) and of lung lesion type and extent on growth during the early (processing to d 35) and late (d 35 to slaughter) finishing periods. Calves were weighed at processing (d 5 after arrival), on d 35, and at slaughter after a mean of 137 d on feed. All calves were monitored twice daily and were treated for BRD if rectal temperature was > 40 degrees C or if other specific signs of BRD were present. After slaughter, the occurrence and extent of parenchymal bronchopneumonic lesions and pleural adhesions were recorded. Subclinical BRD (never treated but with lung lesions at slaughter) occurred in 29.7% and clinical BRD in 22.6% of calves. Lung lesions were present in 43% of calves at slaughter; 8.6% had parenchymal lesions and 38.8% had pleural adhesions. Using a combined case definition (treated for BRD and/or lung lesions present at slaughter), the incidence of BRD was 52.5%. During the early finishing period, clinical BRD reduced ADG by 216 g (P < 0.001), subclinical BRD reduced ADG by 91 g (P < 0.001), and the combined effect of BRD was a 143 g reduction in ADG (P < 0.001). After d 35, animals treated for BRD tended to grow faster than those with subclinical BRD (P = 0.11), indicating that treatment was generally successful in reducing economic losses. The extent of bronchopneumonic lesions at slaughter was not associated with reduced growth during the early finishing period (P = 0.27), but extensive lesions reduced ADG by 88 g during the late period (P = 0.02). In contrast, the extent of pleural adhesions was not associated with reduced growth rate during the late finishing period (P = 0.37) but was strongly associated with reduced ADG before d 35; there was a 101 g reduction (P < 0.001) and a 220 g reduction (P = 0.01) for adhesions involving < 50% and > 50% of the pleural surfaces, respectively. Thus, although the presence of bronchopneumonic lesions and pleural adhesions at slaughter were both associated with reductions in overall ADG, they were indicative of production losses having occurred at different times during the finishing period. The overall effect of BRD was a 24 g reduction in ADG (P = 0.02) and a 5.1 d increase in days on feed (P < 0.001). The hidden cost of reduced growth rate due to BRD amounted to $3.41 per calf with clinical or subclinical BRD, or $1.79 per animal entering the feedlot.  相似文献   

14.
A commercial swine herd was selected for study, because pigs at slaughter repeatedly had lung lesions consistent with enzootic pneumonia and had snout lesions typical of atrophic rhinitis. Pigs born during various seasons of the year were allotted to 4 investigations and were evaluated from birth to slaughter. Individual lungs and snouts were identified and collected at the slaughter plant and later examined for gross lesions of bronchopneumonia and atrophic rhinitis, respectively. Each lesion was scored, and the following comparisons were made within investigations: prevalence and mean scores for lung lesions; prevalence and mean grades for snout lesions; correlations between lung lesion scores and growth indicators; correlations between snout lesion grades and growth indicators; and correlations between lung lesion scores and snout grade scores. Included in the growth indicators were average daily gain during the growing phase, average daily gain during the finishing phase, average daily gain during growing and finishing phases, and days to attain 104.5 kg of body weight. Prevalence of lung or snout lesions, mean values for lung lesion scores, mean values for snout lesion grades, and mean values for the various growth indicators were tested for statistical differences among the 4 investigations. Prevalence of lung lesions was highest (96%) for winter-slaughtered and lowest (81%) for autumn-slaughtered pigs. Mean scores for lung lesions were 7% (summer), 5% (autumn), 9% (winter), and 16% (spring). Prevalence of snout lesions was highest (85%) for spring-slaughtered pigs and lowest (42%) for autumn-slaughtered pigs.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

15.
An outbreak of severe atrophic rhinitis is described. A toxigenic strain of P. multocida was isolated from one affected pig. Severe turbinate atrophy was not associated with significantly reduced bodyweight gain in a batch of 34 pigs examined at slaughter. The history of the outbreak suggested that pigs recently introduced from overseas may have been the source of the disease.  相似文献   

16.
选择60头长白×大蒲莲猪杂种商品猪,研究其生长肥育性能、胴体品质和肉质特性。结果表明,60头试验猪35~100kg阶段平均日增重688.39g,料重比2.79。4头屠宰测定,宰前重95.25kg,胴体瘦肉率60.22%;肉质优良,肉色和大理石纹评分分别为3.45、3.33,pH为6.38,滴水损失较低为1.57%,剪切力较小为46.80N,肌内脂肪含量较高为3.78%。每100g背最长肌中氨基酸总量、鲜味氨基酸含量和必需氨基酸含量分别为22.09g、17.11g、9.14g,鲜味氨基酸占氨基酸总量的比例和必需氨基酸占氨基酸总量的比例分别为77.45%和41.35%,肌肉营养价值较高。背最长肌的棕榈酸、硬脂酸、油酸和亚油酸含量分别为24.90%、12.53%、44.58%和8.18%。  相似文献   

17.
A total of 163 pigs from nine farrow-to-finish herds representing various levels of atrophic rhinitis (AR) were selected for postslaughter examination of AR and pneumonia. Nasal swabs and lungs were cultured for detection of Bordetella bronchiseptica and Pasteurella multocida. Seventy-three pigs were examined at eight weeks of age and 90 contemporaries at six months of age. Mean AR scores were 1.21 and 1.11 for the eight week and six month old pigs, respectively (0 = normal, 3 = severe). In individual pigs increasing AR score was related to increasing pneumonia score in eight week old pigs but not in six month old hogs. In eight week old pigs, B. bronchiseptica and P. multocida were isolated more frequently from pigs with higher AR scores. From nasal swabs of six month old hogs, Bordetella was almost never recovered while Pasteurella was frequently isolated score. Toxigenic type DP. multocida was isolated from nasal cultures of only seven (4%) pigs and from lung cultures of only one pig. Pasteurella was never isolated from lungs of the eight week old pigs and Bordetella never from the six month old hogs. The isolation rate of P. multocida, predominantly type A, from lungs of six month old pigs increased from 11% in grossly normal lungs to 86% in lungs with severe pneumonia. Pigs from one herd free from lesions of AR and pneumonia were also examined; type AP. multocida was isolated from nasal cultures of one of six eight week old pigs. Somatic antigens of P. multocida were determined for 94 nasal and 20 lung isolates. Somatic serovar 3 was found in 93% of the nasal isolates and in all lung isolates.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

18.
Three experiments were conducted to determine the optimal level of dried distiller grains with solubles (DDGS) from a common ethanol manufacturing facility and to determine the potential interactions between dietary DDGS and added fat on performance and carcass characteristics of growing and finishing pigs. All experiments were conducted at the same commercial facility and used DDGS from the same ethanol manufacturing facility. In Exp. 1, a total of 1,050 pigs (average initial BW 47.6 kg), with 24 to 26 pigs per pen and 7 pens per treatment, were fed diets containing 0 or 15% DDGS and 0, 3, or 6% added choice white grease in a 2 x 3 factorial arrangement in a 28-d growth study. Overall, there were no DDGS x added fat interactions (P >/= 0.14). There was an improvement (linear, P < 0.01) in ADG and G:F as the percentage of added fat increased. There was no difference (P = 0.74) in growth performance between pigs fed 0 or 15% DDGS. In Exp. 2, a total of 1,038 pigs (average initial BW 46.3 kg), with 24 to 26 pigs per pen and 10 pens per treatment, were fed diets containing 0, 10, 20, or 30% DDGS in a 56-d growth study. Pigs fed diets containing DDGS had a tendency for decreased ADG and ADFI (both linear, P = 0.09 and 0.05, respectively), but the greatest reduction seemed to occur between pigs fed 10 and 20% DDGS. In Exp. 3, a total of 1,112 pigs (average initial BW 49.7 kg), with 25 to 28 pigs per pen and 9 pens per treatment, were used in a 78-d growth study to evaluate the effects of increasing DDGS (0, 5, 10, 15, or 20%) in the diet on pig growth performance and carcass characteristics. From d 0 to 78, ADG and ADFI decreased linearly (P 相似文献   

19.
Both porcine cytomegalovirus (PCMV) and Bordetella bronchiseptica produced rhinitis and pneumonia when inoculated intranasally into young gnotobiotic pigs. With PCMV the nasal lesions were confirmed to the lamina propria, while Bordetella produced atrophy of the turbinate bones and hyperplasia and degeneration of the nasal epithelium. Some exacerbation of the lesions was observed in the nasal mucosa of pigs given both agents, but the degree of bone atrophy was not increased.  相似文献   

20.
The effects of piglet birth weight and liquid milk replacer supplementation of piglets during lactation on growth performance to slaughter weight was evaluated in a study carried out with 32 sows (PIC C-22) and their piglets (n = 384; progeny of PIC Line 337 sires). A randomized block design with a 2 x 2 factorial arrangement of treatments was used. Treatments were birth weight (Heavy vs Light) and liquid milk replacer (Supplemented vs Unsupplemented). The study was divided into two periods. At the start of period 1 (birth to weaning), pigs were assigned to either Heavy or Light (1.8 [SD = 0.09] vs 1.3 kg [SD = 0.07] BW, respectively, P < 0.001) litters of 12 pigs and half of the litters were given ad libitum access to supplemental milk replacer from d 3 of lactation to weaning (21 +/- 0.2 d). In period 2 (weaning to 110 kg BW), a total of 308 pigs were randomly selected from within previous treatment and sex subclasses and placed in pens of four pigs. Pigs were given ad libitum access to diets that met or exceeded nutrient requirements. Pigs in heavy litters were heavier at weaning (6.6 vs 5.7 kg BW; SE = 0.14; P < 0.001) and tended to have more pigs weaned (11.4 vs 10.9 pigs/litter; SE = 0.21; P = 0.10). After weaning, pigs in the Heavy litter had greater ADG (851 vs 796 g; SE = 6.7; P < 0.001) and ADFI (1,866 vs 1,783 g; SE = 17.6; P < 0.001), similar gain:feed (0.46 vs 0.45; SE = 0.003; P > 0.05), and required seven fewer days (P < 0.001) to reach slaughter weight compared to pigs in the Light treatment. Feeding supplemental milk replacer during lactation produced heavier pigs at weaning (6.6 vs 5.7 kg BW; SE = 0.14; P < 0.001) and tended to increase the number of pigs weaned (11.4 vs 10.9 pigs/litter; SE = 0.21; P = 0.10) but had no effect (P > 0.05) on growth performance from weaning to slaughter. However, pigs fed milk replacer required three fewer days (P < 0.01) to reach 110 kg BW. Sow feed intake and BW loss during lactation were not affected (P > 0.05) by either birth weight or milk replacer treatment. In conclusion, birth weight has a substantially greater impact on pig growth performance after weaning than increasing nutrient intake during lactation.  相似文献   

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