天然饲料补充正辛酸减少商品肉鸡空肠弯曲菌的寄居

空肠弯曲菌能引起人类的食物性传染疾病,且流行病学研究也表明家禽及其产品是人类感染该疾病的重要来源。减少家禽肠道中的空肠弯曲菌会减少其对家禽产品的污染。正辛酸是中链脂肪酸,据报道其可有效杀死包括空肠弯曲菌在内的各种细菌性病原体,但对于已经寄居在商品肉鸡肠道中空肠弯曲菌的治疗效果还未见报道。试验旨在研究正辛酸对42日龄鸡盲肠中空肠弯曲菌的治疗效果。试验共设4个试验组。前两个试验组,     

Uterine infection with bovine herpesvirus type 4 in dairy cows

Diseases of the reproductive tract are a frequent problem in dairy herds. Herpesviruses are uterine pathogens also involved in other clinical diseases; for example, bovine herpesvirus type 4 BoHV‐4 induces abortion, enteritis, metritis, pneumonia and vaginitis, but it can also be detected in healthy cows. The role of BoHV‐4 in the development of clinical endometritis (CE) or subclinical endometritis (SE) has not clearly been described. Therefore, the objective of this study was to describe the prevalence of uterine BoHV‐4 infection and its relationship with clinical, bacteriological and cytological findings in dairy cows 20–30 days after calving. The experiment was performed as a completely randomized block design, with farm (n = 10) as blocking criterion and with cow (n = 397) as the experimental unit. Logistic regression models were used to assess the effect of BoHV‐4 infection on CE, SE and reproductive performance. Proportion of cows infected with BoHV‐4 was 5.8% (n = 23/397). BoHV‐4 was isolated in 11.0% (n = 12/109), 4.8% (n = 4/84) and 3.6% (n = 7/194) of cows diagnosed as CE, SE or healthy, respectively. A logistic model revealed that BoHV‐4 infection showed a tendency to increase the risk for CE (AOR = 2.17; p = .10) but significantly reduced both, the odds for artificial insemination within 80 days post‐partum (dpp) (AOR = 0.37; p = .035) and for pregnancy within 200 dpp (AOR = 0.13; p = .004). Furthermore, BoHV‐4 infection increased the chance for intrauterine infection with Trueperella pyogenes (AOR = 5.55; p < .001) and vice versa (AOR = 5.79, p < .001). In conclusion, BoHV‐4 infection is associated with reduced chances for insemination and pregnancy by 200 dpp and showed a trend to be associated with increased risk for CE. Furthermore, BoHV‐4 and Trueperella pyogenes infections are strongly related.     

Effect of hCG on Early Luteal Serum Progesterone Concentrations in PG600‐Treated Gilts

Gilt oestrus and ovulation responses to injection of a combination of equine chorionic gonadotrophin (eCG) and human chorionic gonadotrophin (hCG) (PG600) can be unpredictable, possibly reflecting inadequate circulating LH activity. The objective of this study was to determine the effect of PG600 followed by supplemental hCG on gilt ovarian responses. In experiment 1, 212 Hypor gilts (160 day of age) housed on two farms in Spain received intramuscular (i.m.) injections of PG600 (n = 47), or PG600 with an additional 200 IU hCG injected either concurrently (hCG‐0; n = 39), or at 24 h (hCG‐24; n = 41) or 48 h (hCG‐48; n = 45) after PG600. A further 40 gilts served as non‐injected controls. Ovulation responses were determined on the basis of initial blood progesterone concentrations being <1 ng/ml and achieving >5 ng / ml 10 d after the PG600 injection. The incidence of ovulating gilts having progesterone concentrations >30 ng/ml were recorded. During the study period, 10% of control gilts ovulated whereas 85–100% of hormone‐treated gilts ovulated. There were no significant differences among hormone groups for proportions of gilts ovulating. The proportions of gilts having circulating progesterone concentrations >30 ng/ml were increased (p ≤ 0.02) in all hCG treated groups compared with the PG600 group. In experiment 2, a total of 76 Hypor gilts at either 150 or 200 days of age were injected with PG600 (n = 18), 400 IU eCG followed by 200 IU hCG 24 h later (n = 20), PG600 followed by 100 IU hCG 24 h later (n = 17), or 400 IU eCG followed by 300 IU hCG 24 h later (n = 21). Blood samples were obtained 10 days later for progesterone assay. There were no effects of treatment or age on incidence of ovulation, but fewer 150‐day‐old gilts treated with PG600 or 400 IU eCG followed by 200 IU hCG had progesterone concentrations >30 ng / ml. We conclude that hCG treatment subsequent to PG600 treatment will generate a higher circulating progesterone concentration, although the effect is not evident in older, presumably peripubertal, gilts. The mechanism involved and implications for fertility remain to be determined.     

Corpus luteum Function and Pregnancy Outcome in Buffaloes during the Transition Period from Breeding to Non‐Breeding Season

The aim in this study was to investigate corpus luteum function and embryonic loss in buffaloes mated by artificial inseminations (AI) during the transitional period from breeding to non‐breeding season. The study was carried out using 288 multiparous Italian Mediterranean Buffalo cows at 110 ± 4 days in milk. The buffaloes were mated by AI after synchronization of ovulation by the Ovsynch‐TAI protocol 25 days after AI buffaloes underwent trans‐rectal ultrasonography to assess embryonic development. Pregnancy diagnosis was confirmed on Days 45 and 70 after AI by rectal palpation. Buffaloes pregnant on Day 25 but not on Day 45 were considered to have undergone late embryonic mortality (LEM), whilst buffaloes pregnant on Day 45 but not on Day 70 were considered to have undergone foetal mortality (FM). Corpus luteum size and blood flow were determined by real‐time B‐mode/colour‐Doppler on day 10 after AI in 122 buffaloes. The resistive index (RI) and pulsatility index (PI) were recorded at the time. Milk samples were collected on Days 10, 20 and 25 after AI in all inseminated buffaloes for the assay of whey P4 concentrations. Data were analysed by anova . Pregnancy rate on Day 25 after AI was 48.6% (140/288) and declined to 35.4% (102/288) and 30.6% (88/288) by Day 45 and Day 70 respectively. The incidences of LEM and FM were respectively 27.1% (38/140) and 13.7% (14/102). Pregnant buffaloes had greater (p < 0.01) whey concentrations of P4 from Day 20 onwards than buffaloes which showed LEM, whilst P4 in buffaloes that showed FM did not differ from the other two groups on Day 10 and Day 20. Corpus luteum blood flow on Day 10 after AI showed higher RI (p < 0.05) and PI (p = 0.07) values in buffaloes that subsequently were not pregnant on Day 25 compared with pregnant buffaloes. Buffaloes that were not pregnant on Day 45 also had a higher (p = 0.02) RI value on Day 10 than pregnant buffaloes, whilst PI values on Day 10 did not differ for the two groups of buffaloes. It was concluded that blood flow to the corpus luteum on Day 10 after AI influences corpus luteum function as judged by P4 secretion and also embryonic development and attachment in buffaloes.     

Nutrition of captive reptiles.

In reptile practice, most nutritional problems arise from improper husbandry, including poor feeding management and provision of imbalanced diets. Each reptile species has its own requirements for temperature and humidity, space and social interaction, lighting, and habitat components. Failure, to provide these requirements often results in failure to thrive and secondary nutritional disorders. Common dietary problems include deficiencies of energy, calcium, vitamin D3, vitamin A, and fiber.     

Leptospira interrogans serovar hardjo is not a major cause of bovine abortion in Victoria

The aim of this study was to determine whether evidence could be obtained of foetal infection with Leptospira interrogans serovar hardjo in aborted foetuses collected from dairy farms. Material from 197 abortions occurring over a wide area of Victoria was collected over 3 years. None of 195 foetal kidney cultures or 7 cultures from membranes was positive for leptospiral organisms. Immunogold silver staining for leptospires was performed on sections of kidneys, lungs or heart from 156 foetuses, with negative results. Evidence of transient leptospiral infection in 11 of 123 foetuses was obtained by foetal heart blood serology. Two isolates of L. interrogans serovar hardjo were obtained from the urine of milking cows. These strains were examined by restriction endonuclease analysis and both were shown to be of the genotype Hardjobovis, as have been all Australian isolates studied so far. It appears that foetal infection with serovar hardjo is not associated with any substantial proportion of bovine abortions in Victoria, in contrast to the situation in Northern Ireland. The apparent absence from Victoria of the pathogenic genotype Hardjoprajitno is a possible explanation.     

Patterns of Follicular Growth in Superovulated Sheep and Influence on Endocrine and Ovarian Response

Objectives of this study were to characterize patterns of follicular development in sheep superovulated with purified follicle stimulating hormone (FSH) (OVAGEN^TM, ICP, Auckland, New Zealand) and to determine its influence on preovulatory events (onset of the oestrus behaviour and timing of the preovulatory luteinizing hormone surge) and ovarian response (ovulation rate and embryo yield). Number and size of all ≥ 23 mm follicles from the first FSH injection to withdrawal of progestagen sponges was determined by transrectal ultrasonography just prior to every FSH injection in nine Manchega ewes superovulated with eight decreasing doses (ml) (1.5 × 3, 1.25 × 2 and 1 × 3) of OVAGEN injected twice daily from 60 h before to 24 h after the withdrawal of 40 mg fluorogestone acetate sponges. Oestrous detection and jugular blood sampling for LH radioimmunoassay were performed every 3 h from 14 to 53 h after sponge removal and ovulation rate and number of embryos were determined 4 days after progestagen withdrawal. Administration of OVAGEN induced a significant rise (p < 0.0005) in the number of follicles ≥ 4 mm in size because of an increased growth in size of follicles from the first FSH injection to sponge removal, an increase in the number of newly detected follicles from 12 to 36 h of the first FSH dose (p < 0.005) and a decrease in regression rate from 24 h (p < 0.001). The number of follicles 2–3 mm in size at first FSH dose (10.4 ± 1.5) was positively correlated with the number of ≥ 4 mm follicles at 0 h (19.0 ± 2.7, p < 0.01). A higher number of ≥ 4 mm follicles at 0 h was related with an earlier appearance of oestrus (31.5 ± 1.5 h, p = 0.08) and LH surge (45.0 ± 2.3 h, p < 0.005), and a higher ovulation rate (18.2 ± 3.8, p < 0.005). On the other hand, the rate of embryo recovery was decreased in ewes with earlier preovulatory LH peaks (p < 0.005), with a shorter interval between oestrus and LH peak (p < 0.05).