富含γ-氨基丁酸青春双歧杆菌的酸奶稳定性研究

本文研究了富含γ-氨基丁酸青春双歧杆菌酸奶在保质期内乳酸菌活菌数、γ-氨基丁酸含量以及感官指标变化。结果表明,富含γ-氨基丁酸酸奶在感官指标方面与普通酸奶相比无明显差异;随着保藏时间的增加,乳酸菌活菌数逐渐降低但始终保持在108cfu/mL以上;在保质期内γ-氨基丁酸含量相对稳定。     

黄连等六味中药对双歧杆菌和大肠杆菌体外生长的影响

将六味治疗腹泻的常用中药黄连、黄柏、秦皮、白头翁、地锦草、马齿苋煎汁后,各按5%用量加入营养肉汤和20% PTYG液体培养基中,再分别接种双歧杆菌和大肠杆菌,于适宜的条件培养后,进行菌落计数.结果发现:黄连对双歧杆菌的生长略有抑制,但幅度较小;其余各药对双歧杆菌均无明显的抑制作用;而六味中药对大肠杆菌的生长均有明显的抑制作用.     

Leptin in sow: Influence on the resumption of cycle activity after weaning and on the piglet gain

In sows, a strong relationship exists between body condition and reproductive efficiency and milk yield. Leptin may act as a metabolic gate which permits the activation of reproductive axis: in the sow, serum concentration of leptin was positively correlated with adiposity at farrowing. An interesting aspect useful to clarify the biology of leptin, was the discovery that the placenta expresses the ob gene, the ob receptor gene and it is a site of leptin production, suggesting a possible role of the hormone in fetal growth; after birth, the placenta functions were taken over from milk, especially to the delivery of maternal hormones and growth factors to the neonate. The exact role of maternal leptin in the physiology of neonatal piglets remains to be determined. Our aim was to evaluate if maternal leptin levels at the beginning of lactation and at weaning could predict the resumption of cycle activity and/or the piglet gain. Thirty-eight Large White × Landrace pregnant sows (16 nulliparous and 22 pluriparous) were used. Blood samples were taken from sows and piglets at d 5 and d 21 after farrowing; in the same days, milk samples were taken after oxytocin injection by means of complete manual milking of all mammary glands of one side. On the basis of the blood leptin at d 5, sows were divided into 3 groups (Low: < 2.3 ng/ml; Medium: 2.3 to 2.6 ng/ml; High: > 2.6 ng/ml). Our results show a correlation at d 5 between backfat thickness and blood leptin (r = 0.342; P < 0.05). The resumption of the cyclic activity was faster in sows with a leptin level at d 5 greater than 2.3 ng/ml (P < 0.01). Milk composition at d 5 and 21 was not affected by parity and leptin. Piglet ADG was significantly (P < 0.05) influenced by sow leptin groups (0.180 kg day^− 1 for piglets from Low group and 0.224 for High group). Piglets weaned by High group sows have shown a greater blood leptin content at weaning (P < 0.01) than other groups. In conclusion we have found a significant correlation between leptin and productive and reproductive performances of pigs. This paper underlines the pleiotropic actions exerted by leptin in the productive sow.     

高剂量氧化锌在乳仔猪饲料中的应用

高剂量氧化锌能控制乳仔猪腹泻,在养猪业上应用广泛,但长期应用有很多副作用。本文就高剂量氧化锌在乳仔猪上的应用效果、作用机理、影响氧化锌作用效果的因素及目前存在的问题和解决途径作以综述,旨在为合理、有效、合法利用氧化锌提供帮助。     

早期断奶仔猪的消化生理及饲粮组合研究

仔猪早期断奶受心理、环境及营养应激影响，常表现为“仔猪早期断奶综合症”。主要是营养应激，即仔猪由液态母乳转向固体饲料。由于仔猪消化系统尚未发育成熟，不能适应这种营养物质的骤变。因此配制适合早期断奶仔猪消化生理的饲粮是克服早期断奶综合症的最有效方法。     

Interference of the humoral immune response against resident and nonresident intestinal commensal strains in weaning pigs

Not nocuous bacteria are important for the maturation and the modulating activity of the gut immune system. However, the humoral immune response against commensal and probiotic bacteria is less documented, particularly in farmhouse animals. Blood serum and saliva were collected in two trials where probiotics, Lactobacillus rhamnosus GG (LbR), well-defined human isolate (Trial A), and a novel and abundant porcine commensal, Lactobacillus sobrius strain 001^T (LbS) (Trial B), were supplemented to weaning pigs. Anti-LbR IgA were present in serum of pigs before treatment with LbR, but also after 1 or 2 weeks in control pigs, notwithstanding the absence of DNA from LbR in colon. Pigs fed or not LbS for 1 or 2 weeks had LbS-specific IgA, in saliva and in serum. Colon contents of control subjects were positive for DNA from LbS. We hypothesized that part of this IgA strain-specific activity is partially related to immune cross-reactivity between different Lactobacillus-species. With the procedure of Shu et al. [Shu, Q., Bird, S.H., Gill, H.S., Rowe, J.B., 1999. Immunological cross-reactivity between the vaccine and other isolates of Streptococcus bovis and Lactobacillus. FEMS Immunol. Med. Microbiol. 26, 153–158], after ELISA test on blood serum or saliva pre-incubated with LbR or LbS, each strain blocked a relevant part of IgA specific for the other. So bacteria with different affinity for the pig present reciprocal crossed immune activity. When probiotics are supplied to weaning pigs, the possible action of already present multi-effective IgA should be considered. The mechanism of IgA induction by certain probiotics needs to be addressed in further studies.     

Variation in the expression of Hsp27, αB-crystallin mRNA and protein in heart and liver of pigs exposed to different transport times

Twenty pigs were randomly divided into four groups of five pigs each (not transported – control, 1, 2 and 4 h of transportation). A significant increase of ALT, AST and CK in the blood serum and acute parenchyma cell lesions were observed and those were characterized by acute degenerations in the heart and liver. Hsp27 expression levels increased significantly in the heart after 2 h and in the liver after 4 h of transportation, accompanying with the hsp27 mRNA increasing significantly in the heart and liver after 1 h of transportation. αB-crystallin expression levels were fluctuant (not significantly) in the heart and liver during transporting, however, αB-crystallin mRNA increase notably in the heart after 1 h and decrease significantly in the liver at 1 and 2 h of transportation, respectively. In conclusion, the cellular damage to the heart and liver is highest after 1 h of transportation, Hsp27 and αB-crystallin play dissimilar roles and show tissue-specific response in different tissues during transportation.     

Interactions between dietary fatty acids and hepatic gene expression in livers of pigs during the weaning period

The aim of the present study was to evaluate the impact of dietary fatty acids (FA) during the weaning period on expression of genes involved in the oxidation and metabolism of FA (peroxisome proliferator-activated receptor (PPAR-), stearoyl-CoA-desaturase (SCD), Δ6-desaturase (D6D), acetyl CoA carboxylase (ACC) and fatty acid synthase (FAS)). Liver samples were obtained from littermates, either on day 28 of age just before weaning, or at day 56 after the 4 weeks ad lib. provision of 5% of either animal fat, fish oil or sunflower oil. In conclusion, genes involved in the regulation of FA conversion (SCD, D6D) were influenced by the n-6 to n-3 ratio, whereas the FA oxidation, as indicated by the expression of PPAR-, was highly likely regulated by the hepatic ratio between mono- and poly-unsaturated FA. Furthermore, weaning and/or age affected the hepatic expression of genes involved in FA synthesis and conversion, but not the expression of PPAR-.     

Herd dynamics and contribution of indigenous pigs to the livelihoods of rural farmers in a semi-arid area of Zimbabwe

Herd dynamics of indigenous pigs were determined in a semi-arid farming area of Chirumanzu, Zimbabwe. Thirty-two pig herds were monitored once every month for 12 months. Consequently, pig production potential (PPP) and pig production efficiency (PPE) were computed for each month. Incidences of farrowing were higher in times of pig confinement (57%) than in times when the pigs were free ranging (43%). About 23% of the farmers interviewed had access to irrigation. The mean pig herd size per household was 3.3. The average litter size per farrowing was 7.7. Pigs were free ranging for most of the year and penned during the rainy season. Herd sizes changed with month (P < 0.05). Farmers who had access to irrigation had higher (P < 0.05) herd sizes, number of piglets and the number of adult pigs. Highest piglet numbers were observed during the rainy months. The number of mature pigs contributing to pig production efficiency was low. Piglet mortality was the major cause of exits from the herd and was higher in farmers with no access to irrigation facility (P < 0.05). The PPP was highest in farmers who had access to irrigation (P < 0.05), except in June and July. The PPE was low and not affected by either month, village or access to irrigation (P > 0.05). It can be concluded that pig production efficiencies were low and intervention strategies to improve them need to be developed.     

The effect of feeding system at weaning on performance,health and feeding behaviour of pigs of different sizes

Abstract

Pigs weaned at 31 to 34 days of age (n=280) were mixed into groups of 10 and fed from either feeders (2 feeding places per pen) or troughs (10 feeding places per pen). Analyses on performance, diarrhoea scores and feeding behaviour were made separately on small-, medium- and large-sized pigs, defined as their relative size in the group. During the second week after weaning, feed conversion ratio (FCR) was lower for pigs fed from feeders. Trough feeding resulted in lower total diarrhoea scores for small (p=0.002) and large (p=0.04), and higher scores for medium pigs (p=0.03). Small pigs had lower scores on individual days around the peak on day 6. All three size categories of pigs spent a numerically higher amount of time feeding when fed from a trough. Feeding bouts were longer in pigs fed from a trough (p=0.0002 – 0.05).     

我国常见典型仔猪日粮系酸力和电解质平衡水平的调查研究

本文旨在对我国常见典型仔猪日粮的系酸力(acid-binding capacity,ABC)和电解质平衡(dietary electro-lyte balance,dEB)进行调研,为合理配制仔猪日粮提供必要参考。选取了6个省份18个有代表性的大型饲料企业断奶仔猪饲料的pH、ABC、Na、K、Cl百分含量状况进行调研,并计算了dEB值。结果表明:断奶仔猪日粮pH、ABC、Na、K、Cl百分含量及dEB值分别为(5.91±0.42)、(37.72±8.64)mmol/100g、(0.32±0.34)%、(0.83±0.27)%、(0.77±0.85)%及(132.58±86.93)mEq/kg DM,不同饲料企业间的各项指标差异很大。     

Effect of exogenous thyroxine on the interval from weaning to estrus of the primiparous sow

A total of 159 primiparous sows were fed 0 (C) or 675 mg/d of thyroprotein (TP) from d -2 until d 14 postweaning. Sows received 8 (LE) or 14 (HE) Mcal of ME/d during a 28-d lactation period. Plasma levels of 3,5,3'-triiodothyronine (T3) and 3,5,3',5'-tetraidothyronine (T4) were determined for d -4, -2, 0, 1, 2, 3, 5 and 7 postweaning. Sows consuming LE lost more weight and backfat during lactation (P less than .01) than HE sows. Litters of sows consuming LE gained less weight than litters of sows consuming HE (P less than .01). Thyroprotein increased plasma levels of both T3 and T4 (P less than .01), whereas energy intake had no effect (P greater than .10) on either of the two hormones. The response to thyroid hormone was not consistent across days postweaning (TP x day, P less than .01). Feeding TP increased T4 (P less than .01) on all days, and T3 was increased (P less than .05) on d 0, 2 and 3 postweaning. Thyroid hormones rose markedly following weaning regardless of TP level. Percentage of sows in estrus by d 7 postweaning for LE-C, LE-TP, HE-C and HE-TP were 80, 78, 92 and 90, respectively. Energy restriction during lactation resulted in fewer sows returning to estrus by d 7 (P less than .03) than those fed HE. However, feeding TP postweaning had no effect on return to estrus, suggesting that the effect of dietary energy restriction during lactation on the interval from weaning to first estrus is not mediated through postweaning thyroid hormone concentrations.     

Within-litter variation of birth weight in hyperprolific Czech Large White sows and its relation to litter size traits, stillborn piglets and losses until weaning

Data from about 2900 litters (approximately 40,000 piglets) originating from 1063 Czech Large White hyperprolific sows were analyzed. The phenotypic and genetic relations between litter size traits, piglet mortality during farrowing and from birth to weaning and several statistics referring to the distribution of the birth weight within litter were analyzed. All genetic parameters were estimated from multi-trait animal models including the following factors: mating type (natural service or insemination), parity, linear and quadratic regression on age at first farrowing (1st litter) or farrowing interval (2nd and subsequent litters), herd-year-season effect and additive-genetic effect of the sow. The phenotypic correlations of the mean birth weight with the total number of piglets born and piglets born alive were − 0.30. Traits describing the variability of the birth weight within litter (range, variance, standard deviation, coefficient of variation) were mostly positively correlated with litter size. A statistically significant phenotypic correlation (− 0.09 to − 0.15) between mean birth weight and losses at birth and from birth to weaning was found. The heritability for the number of piglets born, piglets born alive and piglets weaned was around 0.15. The number of stillborn piglets had only a very low heritability less than 0.05, whereas the heritability for losses from birth to weaning was 0.13. The heritabilities of the mean, minimal and maximal birth weight were 0.16, 0.10 and 0.10, respectively. The heritability for all statistics and measures referring to the variability of the birth weight within litter was very low and did never exceed the value of 0.05. An increase in litter size was shown to be genetically connected with a decrease in the mean piglet birth weight and an increase in the within-litter variability of birth weight. Selection on litter size should be accompanied by selection on mortality traits and/or birth-weight traits. Losses from birth to weaning and the minimal birth weight in the litter were proposed as potential traits for a selection against piglet mortality.     

Transiency of the different cholesterolaemic responses to dietary cellulose and psyllium in pigs and two strains of hamsters

The time course of the cholesterolaemic effects of dietary cellulose and psyllium was studied in two strains of hamsters and in pigs. In the first experiment, the ShHan:AURA strain from Harlan was used. Hamsters were first fed a cholesterol‐enriched (0.1%, w/w) semipurified diet containing 3% cellulose for a period of 2 weeks. Then, one group (n = 14) continued on the cellulose diet and another group (n = 14) was transferred to the psyllium diet. After 1.5 weeks on the diets, the psyllium‐fed hamsters showed a steep decrease in plasma cholesterol levels whereas the cellulose group maintained high cholesterol levels. Then, however, the cellulose‐fed hamsters showed a gradual decrease in plasma cholesterol levels and after 9.5 weeks on the diets, they had plasma cholesterol levels comparable to the hamsters fed psyllium. In the second study, the Lake View strain from Charles River was used. Two groups of hamsters (n = 14 per group) were fed a cholesterol‐enriched (0.1%, w/w) semipurified diet containing either 3% cellulose or 3% psyllium. The psyllium‐fed group had significantly lower plasma cholesterol concentrations than the cellulose group after 2, 4, and 6 weeks on the diets. After 8 weeks on the diets, however, the cholesterol levels in the cellulose group had decreased to levels similar to those in the psyllium group. In the third experiment, pigs were fed a cholesterol‐enriched (0.5%, w/w) semipurified diet containing either 5% cellulose or psyllium. After 1 and 2 weeks on the diets, the cellulose‐fed pigs had elevated plasma cholesterol concentrations, whereas the psyllium‐fed pigs maintained low cholesterol levels. After 3 weeks on the diets, the cholesterol concentrations in the cellulose‐fed pigs had decreased to the same level as in the psyllium‐fed pigs. There was no significant effect of cellulose and psyllium on liver cholesterol in the three studies, but psyllium tended to increase the faecal excretion of bile acids. Thus, the present studies showed a cholesterol lowering effect of dietary psyllium compared with cellulose in hamsters and pigs, but this effect was transient.     

4种教槽料对断奶仔猪生长性能、腹泻和皮毛的影响

试验选取160头体重7．02．4±0．505kg的健康断奶仔猪,随机分4个处理,每个处理4个重复,每个重复10头猪。分别饲喂粉料^组、扮料B组、颗粒料C组和粉料D组。结果表明：断奶后10d试验期内,扮料A组仔猪采食量和日增重均显著高于粉料B组和颗柱料C组（P〈0．05）,与粉料D组差异不显著（P〉0．05）;粉料B组和颗粒料C组采食量．日增重均差异显著（P〈0．05）。粉料A组仔猪料肉比与扮料B组和颗粒料C组差异均显著（P〈0．0,5）,与粉料D组相比,粉料A组料肉比降低4．76％。腹泻率和腹泻指数粉料A组和粉料D组间差异不显著（P〉0．05）,但与粉料B组和颗拉料C组间差异显著（P〈0．05）。除颗粒料C组皮毛指数与各组存在显著差异外（P〈0．05）,各组间均差异不显著（P〉0．05）。以上结果表明,粉料A和粉料D提高断奶仔猪生产性能、降低仔猪腹泻率、生产效果最佳。     

不同酵母菌种富硒能力比较与发酵条件优化

将啤酒酵母、产朊假丝酵母、克鲁斯假丝酵母和葡萄汁酵母4种酵母菌株分别接种到不同硒浓度的YEPD琼脂培养基中,观察不同酵母菌株的耐硒能力;比较4株酵母菌株在相同硒浓度下的生长情况以及有机硒的转化率,选出1株富硒能力强的酵母,并对发酵条件进行优化,确定最佳的硒添加量和添加方式。结果表明:啤酒酵母的耐硒能力和富硒能力均为最强,当硒添加量为20μg/mL时,在发酵12,18和24 h分3次添加,啤酒酵母的综合富硒效果最好,活菌数为2.74×108cfu/mL,有机硒转化率为85.5%。     

Field trial to determine the impact of providing additional care to litters on weaning weight of pigs

The purpose of this field trial was to determine if maximal care of pigs from birth until 16 d of age would result in a significant alteration in the survivorship and growth performance of the pigs compared with control pigs born in the same time period. Sows were randomly assigned to treatment group prior to farrowing. Control pigs received the standard, commercial farm care. In maximal care litters, pigs were dried off at farrowing, given a rubber mat in the creep area, and given electrolytes, chilled pigs were warmed and given colostrum or glucose, surgical instruments used for processing were dipped into an antiseptic between pigs, the castration wounds were sprayed with iodine, and sows were fed 3 times rather than twice a day. Pigs that received the maximal care weighed 170 g (+/− 80 g) more at 16 d of age than standard care pigs. Factors that reduced weight at 16 d included having a low birth weight, nursing a gilt or a parity 5–6 sow, nursing in a large litter, being clinically ill or being lame after 3 d of age, being cross-fostered and nursing an ill sow. In general, maximal care did not reduce mortality. Providing maximal care did improve weaning weights and enabled small birth weight pigs to reach 3.7 kg at 16 d of age.     

Absence of strictly age-related resistance to Mycoplasma hyosynoviae infection in 6-week-old pigs

Mycoplasma hyosynoviae has never been reported to cause arthritis in pigs younger than 10 weeks of age. In order to investigate whether a strict age-related resistance exists, four 6-week-old pigs and four 13-week-old pigs, all immunologically na?ve with respect to M. hyosynoviae, were inoculated intranasally with the agent and autopsied at day 11 or 13 after infection. One uninoculated pig per age group was included as a negative control. Just as the 13-week-old pigs, the 6-week-old piglets were susceptible to blood, joint and tonsillar infection with M. hyosynoviae and developed clinical arthritis following inoculation with the agent. Thus, we found no evidence of an age-related resistance to the infection.