Body condition of sows across parities and relationship to reproductive performance

Weight, heartgirth, backfat and body condition of sows was monitored in a commercial, farrow-to-finish unit during 1 yr. Measurements were obtained during the third, ninth and fifteenth week of gestation and the day after weaning. Litter performance and rebreeding rate also were recorded. Body weight and heartgirth increased (P less than .01) over parities because gestational gains were larger than lactational losses. Backfat tended to be lower in later parities. Body weight, heartgirth and backfat, but not condition score, declined from weaning to the third week of the subsequent gestation in both first and second litter sows. Correlations among measures of body condition were low (less than .45), except the overall correlation between body weight and heartgirth. Number of pigs born alive increased and interval to estrus decreased in later parities. There were no significant relationships between changes in body condition and rebreeding performance of sows. These results suggest that changes in body condition typically observed in sows housed in commercial production units may be too subtle to have an effect on reproductive performance.     

Effect of dietary folic acid supplementation on sow performance through two parities

One hundred fifty-three gilts were maintained in three breeding groups and fed gestation-lactation diets supplemented with either 0 (control), 1.65 or 6.62 mg of supplemental folic acid/kg of diet for two consecutive parities. Serum folate concentrations of sows were linearly (P less than .05) increased by dietary additions of folic acid during both gestation and lactation, but serum glucose and urea concentrations were unaffected by treatment. Serum folate concentrations decreased from breeding to d 60 and 90 of gestation and then increased through lactation for all treatments. Number of pigs born and live pigs at birth, d 14 and d 21 were quadratically (P less than .05) increased by folic acid additions. Average pig weights were similar among treatments (P greater than .10) on both d 0 and 14 of lactation but were less (P less than .01) than the other treatment groups on d 21 for pigs from sows fed the 1.65 mg/kg treatment. Litter weights were quadratically (P less than .01) increased on d 0 and d 14 by folic acid supplementation. Sow weight gain and backfat thickness loss were unaffected by treatment during gestation (P greater than .06); sow weight loss and backfat thickness loss increased quadratically with increasing level of folic acid during lactation (P less than .06 and .05, respectively). More control sows exhibited estrus by d 7 postweaning than sows receiving folic acid supplementation in parity I (P less than .05); however, no differences (P greater than .10) were detected among treatments by d 14, nor were any differences observed by d 7 in parity II. Conception rate was unaffected by folic acid additions. Dietary folic acid supplementation improved sow reproductive performance by increasing the number of pigs born alive.     

Reproductive performance in gilts through their first two parities

Fertility data were collected for 766 gilts from 12 breeding and commercial herds. The age at first breeding was 244.5 days and at first farrowing 363.2 days. The litter size was 9.91 piglets born (9.16 live). The farrowing rate at the first service was 87.8%. The total farrowing rate was 95.5% of the mated gilts and 88.4% of all the gilts. 9.8% were repeat breeders. 2.6% of the once mated gilts never returned to oestrus and still did not farrow. The culling rate was 11.6%. The major reason for culling was delayed puberty/anoestrus (7.7%). Of the 565 gilts having a first litter 85.3% were mated after weaning. The age at second farrowing was 541.7 days. The litter size was 10.9 piglets born (10.3 live). The farrowing rate after first service was 83.0%. The total farrowing rate of the 482 sows was 92.9% and of the 565 weaned sows 79.3%. 12.2% were repeat breeders. 4.8% of the sows once mated never returned to oestrus and still did not farrow. The culling rate was 20.7%. Culling because of anoestrus was 4.4%. The month of birth significantly influenced the number of gilts culled because of anoestrus, the age at first breeding and at first and second farrowing. The season also influenced the interval from weaning to service, the percentage of sows served within 7 days of weaning and culled because of anoestrus. No correlation between a high ultrasonic index and lowered fertility was found. The age at first breeding was 1.12 days younger per unit higher ultra-sonic index.     

日粮纤维对母猪繁殖性能的影响

通常 ,为保证最佳的经济性状和健康水平 ,对繁殖母猪要限制饲养以保持其体况在整个繁殖周期中相对恒定 (Dourmad等 ,1 994、1 996)。而限饲所提供的饲料水平仅占随意采食量的 0 40～ 0 60(Pettigrew和Blackshaw ,1 989;Brouns等 ,1 995 ) ,显然不能满足其采食需要 ,从而导致群饲时的攻击性和争食现象 (Appleby和Lawrence ,1 987;Terlouw等 ,1 991 ;Edwards,1 992 ;Terlouw和Lawrence ,1 993;Spooler,1 995 )。妊娠期限饲会降低仔猪初生重和成活率 ,母猪分娩和断奶时体脂沉积过少还会延迟断奶后的发情 ,并降低受孕率 ,导致母猪繁殖性…     

Assessment of the influence of dietary vitamin E on sows and offspring in three parities: reproductive performance, tissue tocopherol, and effects on progeny

Sixty crossbred (Yorkshire-Hampshire X Duroc) gilts were fed one of four corn-soybean meal diets fortified with .3 ppm Se and 0, 16, 33, or 66 IU of DL-alpha-tocopheryl acetate/kg. The study was conducted over a three-parity period to evaluate sow reproductive performance and the vitamin E tissue status of both sows and progeny at various time periods postcoitum and(or) postpartum. The basal diet averaged 8.4 mg of alpha-tocopherol/kg and .38 ppm of Se. Although litter size at birth was lowest (P less than .15) when sows were fed the basal diet, a higher incidence of agalactia when sows were fed the lower dietary vitamin E levels resulted in an increased (P less than .05) litter size at 7 d postpartum as dietary vitamin E increased. Sow serum alpha-tocopherol increased (P less than .01) at each measurement period as dietary vitamin E level increased. Colostrum and milk alpha-tocopherol concentrations increased (P less than .01) as dietary vitamin E level increased, and colostrum values were three to five times higher than at later milks. Colostrum alpha-tocopherol declined by parity from sows fed less than or equal to 16 IU/kg but was similar at each parity for sows fed greater than or equal to 33 IU/kg, resulting in a dietary vitamin E x parity interaction (P less than .01). The Se content of sow milk declined with parity but was not affected by dietary vitamin E level. Sow liver tocopherol at weaning (28 d postpartum) increased (P less than .01) as dietary vitamin E increased and increased with parity (P less than .05). Pig serum and liver alpha-tocopherol concentrations were elevated at birth and 7 and 28 d of age as sow dietary level of vitamin E increased. Upon weaning, pigs were fed a torula yeast-dextrose diet that contained 3.0 mg of alpha-tocopherol/kg and .32 ppm Se for a 28-d postweaning period. Liver and serum alpha-tocopherol concentrations declined during the postweaning period. Evidence of the vitamin E deficiency occurred at 28 d postweaning in the progeny from sows fed the basal diet or 16 IU of vitamin E; the incidence was more prevalent in the pigs from Parities II and III. These results suggest that a supplemental level of 16 IU of vitamin E/kg of diet was inadequate for the reproducing sow; higher levels are justified, particularly when females are retained in the herd for several parities.     

母猪妊娠期背膘厚度对仔猪均匀度及繁殖性能的影响

为研究母猪不同阶段的背膘厚度与仔猪均匀度及部分繁殖性能之间的关系,试验采用二次项回归拟合的方法,对9458头纯种长白母猪和13317头纯种大白母猪的分娩、背膘厚度进行分析。结果表明:母猪背膘厚度处于合理的范围有利于提高其产仔性能和窝产仔均匀度,母猪过肥和过瘦均不利母猪繁殖效率的提高。该场的长白母猪配种当天、妊娠30日龄、妊娠80日龄和妊娠105日龄背膘厚度分别为14.0~18.0mm、15.0~20.0mm、16.0~20.0mm、17.0~20.0mm更有利于仔猪均匀度及母猪繁殖性能的提高;该场的大白母猪配种当天、妊娠30日龄、妊娠80日龄和妊娠105日龄背膘厚度分别为13.0~16.0mm、14.0~17.0mm、15.0~18.0mm、15.0~19.0mm更有利于仔猪均匀度及母猪繁殖性能的提高。妊娠期间的背膘厚度对仔猪均匀度及繁殖性能有一定影响,但母猪产仔性能最好的背膘状态并不是产仔均匀度最佳值。     

Effect of intramuscularly administered beta-carotene on reproductive performance in sows

The present study investigated the effects of intramuscularly administered beta-carotene on reproductive parameters in female pigs. A total of 216 multiparous sows were observed from weaning of their litters until the next farrowing. On the day of weaning, the animals were allocated to two groups. Sows of the treatment group were injected with 70 mg beta-carotene both at the day of weaning and after the last insemination, sows of the control group were left untreated. For all sows, intramuscular injection of beta-carotene resulted in a significant increase of the total number of piglets born per litter by 1.2 (p < 0.05). When sows were divided by parity, beta-carotene treatment in second parity sows increased the total number of piglets per litter (beta-carotene 13.7 +/- 1.2, control 11.2 +/- 3.7, p < 0.01) and the number of piglets born alive (beta-carotene 12.0 +/- 2.7, control 10.0 +/- 3.4, p < 0.05). No such effect was seen in sows of third or higher parity. No other reproductive parameters were affected by beta-carotene supplementation. Tolerability and safety of the administered preparation were good. No side effects related to the medication were observed. The effect of beta-carotene on reproduction is thus affected by parity of the sows. This effect seems to be exerted mainly during early pregnancy and is most likely beta-carotene-specific and independent from its role as a vitamin A precursor.     

Effects of dietary salt level during gestation and lactation on reproductive performance of sows: a cooperative study

Two experiments involving 1,020 litters were conducted at eight research stations to determine the effects of dietary NaCl (salt) concentration during gestation and lactation on reproductive performance of sows. Primiparous and multiparous sows were fed fortified corn- or grain sorghum-soybean meal diets at 1.82 kg/d during gestation. During the winter months (December, January, February) the feeding level was increased to 2.27 kg/d. Sows had ad libitum access to diets during lactation. Dietary concentrations of added salt were .50 and .25% in Exp. 1 and .25 and .125% in Exp. 2. When more feed was fed during gestation, the salt concentrations were reduced to .40, .20, .20 and .10%, respectively, in order to maintain a constant daily intake of Na and Cl during gestation. Gestation weight gain and lactation (21-d) weight loss of the sows were not affected by dietary salt level in either experiment. In Exp. 1, lowering the salt concentration did not influence the number of pigs farrowed, but it resulted in a .05 kg/pig reduction (P less than .01) in average birth weight. Average 21-d pig weights also tended (P less than .19) to be lower in the low-salt group. There was a decrease in litter size from the first to the second farrowing for sows fed low salt, but not for sows fed the higher salt concentration. In Exp. 2, reducing the salt content from .25 to .125% did not alter reproductive performance. The overall ratio of males to females at birth in the population of greater than 10(4) pigs was 52.3:47.7. Lower salt intakes tended to reduce the percentage of males born in both experiments, although the differences were not significant (P greater than .3). The results indicate that reducing the salt concentration in sows diets from .50 to .25 or .125% reduces birth weight in newborn pigs. When continued for more than one reproductive cycle, feeding less than .5% salt appears to reduce litter size at birth and weaning.     

Effect of gilt development diet on the reproductive performance of primiparous sows

The objective of this study was to evaluate the effect of development diet on first-parity reproductive performance across different genetic types of females. Gilts (n = 708) 8 to 15 d of age from five genetic lines were assembled using a segregated early weaning protocol. Genetic types represented industry variation for reproductive capacity and lean growth potential. Sampling procedures were not designed to evaluate performance differences among the genetic lines. When the gilts weighed approximately 20 kg, they were moved from the nursery facilities to a slotted-floor, environmentally controlled facility, and seven to eight animals within a genetic type were penned together. When the gilts weighed approximately 40 kg, they were moved to a modified open-front facility. Nineteen gilts were allotted to each pen (.92 m2 per pig). Gilts were assigned to one of three development diets at 120 d of age. Diet 1 (high energy, 18% CP) and Diet 2 (high energy, 13% CP) were provided for ad libitum consumption to the assigned gilts until they weighed approximately 113 kg. Gilts receiving Diet 3 (23% CP) were fed 1.8 kg/d from 82 kg until they reached 180 d of age (approximately 100 kg). Gilts were fed 2 kg daily of a gestation diet from 180 d to 200 d of age and 2.7 kg daily from 200 d until mating. To stimulate the estrus cycle, gilts were commingled and exposed to vasectomized boars beginning at 180 d of age. Gilts that were in estrus and 210 d of age or older were artificially inseminated with commercial semen. Gilts not detected in estrus within the first 50 d of observation were injected with PG600 and estrus detection continued for 30 additional days. Of the 657 gilts entering breeding pens, 422 farrowed. Bred gilts were distributed to 10 cooperator facilities before farrowing. Mixed model procedures were used to analyze the data. Significant (P < .05) genetic type x gilt development diet interactions were found for number of pigs born, number of pigs born alive, total litter birth weight, and litter birth weight of pigs born alive. Significant interactions consistently involved one genetic line and gilt development Diets 1 and 2. Gilts from this genetic line-diet subclass had poorer farrowing performance (P < .05) than gilts from the same line fed development Diet 3. Only two other significant genetic line x gilt development diet interactions were found. Gilt development diet had little influence on first-parity reproductive performance.     

日粮代谢能水平对母猪生理状态及繁殖性能的影响

本研究旨在研究不同代谢能水平日粮对妊娠和哺乳期母猪生理状态、繁殖性能及血清生化指标的影响。试验将60头妊娠28?d、平均体重为（131.96±0.52）kg的头胎二元母猪随机分为3组,每组4个重复,每个重复5头。T1～T3组妊娠母猪分别饲喂代谢能水平为3150、3250和3350?kcal/kg的日粮,粗蛋白质水平均为13%,妊娠期结束后在整个哺乳期饲喂代谢能为3300?kcal/kg、粗蛋白质为17.5%的同一种日粮。结果：T3组母猪妊娠110?d的体重变化较T1和T2组分别显著提高9.69%和9.74%（P＜0.05）,而背膘厚度变化分别显著提高89.67%和112.63%（P＜0.05）。T3组母猪在整个哺乳期的体重变化较T1和T2组分别显著降低197.87%和221.43%（P＜0.05）。T1组的死胎数较T3组显著提高56.25%（P＜0.05）,而T3组断奶数较T1和T2组分别显著提高10.38%和6.95%（P＜0.05）,同时T3组断奶窝重较T1和T2组分别显著提高11.82%和10.48%（P＜0.05）。不同代谢能日粮对母猪分娩前1?d和断奶时的血清葡萄糖、尿素氮、甘油三酯和肌酸酐浓度均无显著影响（P＞0.05）。结论：妊娠母猪日粮代谢能水平为3350?kcal/kg,粗蛋白质水平为13%时可以提高整个妊娠期母猪的体重和背膘厚度,同时提高哺乳母猪的断奶仔猪数,降低死胎数。 [关键词]代谢能|母猪|生理状态|繁殖性能     

长大、长本和内江母猪繁殖成绩调查分析

本研究调查了97头农民散养哺乳母猪（其中长大二杂母猪33头,长本二杂母猪33头,内江母猪31头）的繁殖成绩,结果表明,在窝产间隔、窝产仔数、产活仔数、断奶窝重上,长本二杂母猪、内江母猪表现正常,长大二杂母猪在断奶窝重上表现较好成绩,但其余3项指标差,存在着严重的繁殖障碍,问题在于圈舍规划不合理、营养水平不科学和饲养管理技术不成熟.     

Effect of dietary fibre on the performance of laying hens

1. In tests to determine whether gizzard weight could be influenced by dietary fibre concentrations, caged layers were fed on diets containing 15, 30 or 60 g pine shavings/kg diet.

2. As dietary fibre content increased, gizzard weight increased, but there was no effect on body weight, hen‐day production, egg weight, efficiency of food conversion, mortality, percentage of liver ether extract or egg shell breaking strength. Percentage of body ether extract tended to be lower when pine shavings were fed.     

Effect of dietary energy intake during lactation on performance of primiparous sows and their litters

A total of 146 primiparous sows was used in four replications of an experiment to investigate the effect of energy intake during a 28-d lactation on sow and litter performance. Dietary treatments consisted of three energy intakes; 10, 12 or 14 Mcal of metabolizable energy (ME) X sow-1 X d-1. All sows were fed equal amounts of crude protein, vitamins and minerals daily, which met or exceeded standard recommendations. The experiment was initiated at parturition. Sow weight and backfat loss during lactation decreased linearly (P less than .001) as energy intake increased. There were no differences in litter size at either 14 d of lactation or weaning. Pig weights on d 14 increased linearly (P less than .05) and litter weights tended to increase linearly (P = .13) as energy intake increased. At weaning, pig weights and litter weights increased (P less than .05) as sow energy intake increased. There were no significant differences in the percentages of sows in estrus by 7, 14, 21 and 70 d postweaning, but sows fed 10 Mcal ME/d had a slightly longer interval from weaning to first estrus than sows fed higher energy intakes. Serum urea concentrations of sows were inversely related to energy intake during lactation. Serum creatinine concentrations were not affected by energy intake. An intake of 10 Mcal ME/d by primiparous sows during a 28-d lactation resulted in reduced sow and litter performance; there was little difference between sows fed 12 and 14 Mcal ME/d.     

镁对母猪繁殖性能的影响及其可能机理

镁是生物体内重要的阳离子,有重要的生理学功能,镁影响母猪繁殖性能已有报道.有关镁影响母猪繁殖性能的机理目前还缺乏深入研究报道.文章简述镁对母猪繁殖性能的影响,根据镁的生理功能从其抗应激、抗氧化、影响骨骼发育和免疫状态等角度阐述其可能机理.     

日粮纤维对繁殖母猪生产性能和行为的影响

怀孕期一般实行限饲以避免母猪过肥,虽然这样能使经济效益最大化,但母猪的行为需求被抑制。为提高限饲母猪的福利,研究者多采用提供纤维饲料或增加日粮纤维的方法增加母猪的饱食感,延长采食时间,降低口头条件反射（OCT）测试中的反馈,减少刻板行为发生以达到改善母猪福利的效果。另一方面,欧洲法律规定2010年起必须对未孕母猪实行群养,而纤维饲料的使用有效降低了群养母猪间侵略行为的发生。文章综述了将纤维饲料用于怀孕母猪的研究结果,结论是只有当日粮养分满足动物需要时,日粮纤维才能发挥出作用。     

Effects of dietary lysine intake during lactation on blood metabolites, hormones, and reproductive performance in primiparous sows

Effects of three dietary lysine (protein) concentrations during lactation on metabolic state, protein metabolism, reproductive hormones, and performance were investigated in 36 primiparous sows. Sows were assigned randomly to one of three diets containing .4% (low lysine, LL), 1.0% (medium lysine, ML), or 1.6% (high lysine, HL) total lysine from intact protein sources. All diets contained 2.1 Mcal NE/kg and exceeded the recommended requirements for all other nutrients. Actual lysine intakes over an 18-d lactation were 16, 36, and 56 g/d for sows fed LL, ML, and HL, respectively. Fractional breakdown rate of muscle was determined on d 4 and 15 of lactation by using a three-compartment kinetic model of 3-methylhistidine metabolism. Increasing lysine intake during lactation did not affect fractional breakdown rate of muscle on d 4 of lactation but decreased it on d 15 (P < .05). Sows fed LL had a reduced number of LH pulses on d 12 and 18 (P < .05) and reduced serum estradiol (E2) concentration on d 18 of lactation compared with sows fed ML and HL treatments. However, LH pulses and E2 concentrations were similar between ML and HL treatments (P > .35). Increasing lysine intake increased serum urea nitrogen (SUN) and postprandial insulin concentrations (P < .05) during lactation but had no effect on plasma glucose concentrations (P > .20). Sows fed HL had greater serum IGF-I on d 6 and 18 than sows fed ML (P < .05). Number of LH peaks was correlated with serum insulin concentration 25 min after feeding on d 6 and 18 (r = .31 to .41; P < .1) and pre- (r = .33 to .46) and postprandial (r = .30 to .58) SUN concentrations (P < .05) during different stages of lactation. Results indicate that, compared with medium lysine intake, low lysine intake increased muscle protein degradation and decreased concentrations of insulin, SUN, and estradiol and LH pulsatility. In contrast, high lysine (protein) intake increased SUN, insulin, and IGF-I, but did not increase secretion of estradiol and LH compared with medium lysine intake. Furthermore, nutritional impacts on reproduction may be mediated in part through associated effects on circulating insulin concentration.     

不同粗纤维水平日粮对妊娠母猪生殖激素水平的影响

为研究不同粗纤维水平日粮对妊娠母猪生殖激素水平的影响,选用30头胎次、配种时间及体况均相近的经产PIC配套系父母代母猪,随机分成5组,妊娠期间分别饲喂含3%、5%、7%、9%和11%的苜蓿草粉粗纤维日粮,通过调节各组的饲喂量,使其所摄入的能量、蛋白、钙、磷等水平基本一致。3%为对照组,日粮中不另加粗纤维。研究结果显示:提高日粮中粗纤维水平会降低妊娠各阶段母猪雌二醇的浓度,但增加妊娠后期孕酮和催乳素的浓度,且当日粮中粗纤维含量达到9%时效果最佳。     

Reproductive performance of sows supplemented with dietary L-carnitine over three reproductive cycles.

The effect of L-carnitine supplementation during pregnancy and lactation on the reproductive performance of sows was studied in two separate trials over three reproductive cycles. Both trials were identical in design and conduct but were performed with different animals. The trials comprised of a total of 127 sows (trial 1) and 100 sows (trial 2) which were divided into control and treatment groups. All animals were fed individually and received basic feed mixtures with low native carnitine concentrations. The rations of the sows in the treated group were supplemented with 125 mg L-carnitine per head and day during pregnancy and 250 mg L-carnitine per head and day during lactation. The animals of the control group received identical feed mixtures in identical amounts, but without the L-carnitine supplement. In the first trial, 212 litters were produced and evaluated for number and body weight of the animals, in the second trial, 173 litters were produced. L-carnitine supplementation significantly increased body weight gains of the sows between day 1 and day 85 of weaning. The number of born piglets, stillborn piglets and piglets fit for rearing was not influenced by dietary L-carnitine supplementation. However, L-carnitine supplementation significantly increased the weights of piglets and litters at birth, weight gains of litters during suckling and weights of litters at weaning. These effects of L-carnitine were seen in both trials; they were independent of the age of the sows and remained over three reproductive cycles in which the sows where continuously treated with L-carnitine. Overall, the study shows that dietary supplementation with L-carnitine during pregnancy and lactation improves the reproductive performance of sows over several reproductive cycles, independent of the age of the sows.