Effect of feeding non-fibrous carbohydrate before grazing on intake and nitrogen utilization in dairy cows throughout the grazing season

Ten lactating cows were used to determine the effect of feeding non-fibrous carbohydrate (NFC) supplement before grazing on feed intake and nitrogen (N) utilization throughout a grazing season. The experiment was conducted from June to September. Cows grazed twice a day (2.5 h × 2) under a set stocking system and were fed NFC supplement (1 kg/4 kg of milk yield) 2 h before grazing (PRE) or immediately after grazing (POST). Cows were also fed a grass and corn silage mixture ad libitum. Herbage dry matter intake (DMI) was greater for PRE than for POST throughout the experiment and decreased from June to September. Conversely, silage DMI was less for PRE than for POST throughout the experiment and increased over the grazing season. Consequently, total DMI for PRE did not differ from that for POST. Milk urea-N concentration and urinary urea-N excretion in June did not differ between the treatments, whereas that after July was higher for PRE than for POST. Proportion of urinary N excretion to absorbed N intake in June was lower for PRE than for POST, but that after July was higher for PRE than for POST. Feeding NFC supplement before grazing would improve N utilization when cows eat large amounts of herbage high in N.     

Intravaginal administration of estradiol benzoate capsule for estrus synchronization in goats

Estrus synchronization requires multiple treatments of hormonal drugs, requiring considerable time and cost. The aim of the present study was to develop an estrus synchronization protocol using intravaginal administration of estradiol benzoate (EB) capsules in goats. Two types of capsules were prepared: an EB capsule that melted immediately after administration and a sustained-release (SR) EB capsule that dissolved slowly and reached a peak after 24 h. Goats with functional corpus lutea were intramuscularly treated with prostaglandin F_2α (PG). At 24 h after PG administration, goats were administered 1 mg of EB solution intramuscularly (PG + 24IM; n = 6) or 1 mg of EB capsule intravaginally (PG + 24EB; n = 6). The SR EB capsule was administered intravaginally at the time of PG administration (PG + SR; n = 6). The control group (n = 6) received only PG. All groups showed estrus within 72 h after PG administration. The onset of estrus did not differ significantly between the PG + 24IM and PG + SR groups but was earlier than in the control group. Estradiol concentration in the PG + SR group peaked at 11.5 ± 6.1 h after EB and PG administration. Peak estradiol concentrations were not significantly different between the PG + 24IM and PG + SR groups (78.0 ± 25.8 and 64.0 ± 38.1 pg/ml, respectively), and were higher than the PG + 24EB and control groups (27.3 ± 8.8 and 14.6 ± 6.1 pg/ml, respectively). These results suggest that intravaginal administration of an EB capsule with a sustained-drug release base is applicable for estrus synchronization, as an alternative to intramuscular administration.     

Genetic polymorphism and virulence of Colletotrichum gloeosporioides isolated from strawberry (Fragaria × ananassa Duchesne)

To analyze genetic relationships among Colletotrichum gloeosporioides isolates; 34 isolates were collected from strawberries all over Japan, but primarily from Chiba Prefecture, and 20 were isolated from hosts other than strawberry. These isolates were assayed for virulence on strawberries and subjected to a fingerprint (FP) analysis by repetitive extragenic palindromic-PCR. Most of the isolates that were highly virulent to strawberries had relatively similar FPs even though they were isolated from various host plants (strawberry, cyclamen, nipplefruit and Japanese pear) in different regions. A cluster analysis revealed that the highly virulent and the weakly virulent isolates tended to form individual clusters, indicating that the highly virulent strains of C. gloeosporioides, which were genetically close to isolates with similar FPs and distinguishable from the weakly virulent strains, were responsible for strawberry anthracnose in Japan.     

Effects of supplementary probiotics to two different diets on dry matter intake, daily gain, digestibility, ruminal pH, and fecal microbial populations and metabolites in ewes

To study the effects of supplementary probiotics on dry matter intake (DMI), daily gain (DG), digestibility, ruminal pH, and fecal microbial populations and metabolites in ruminants, two reversal trials were conducted by using four Suffolk ewes fitted with rumen cannula. The ewes were fed with oat hay and with concentrate and oat hay in the ratio of 60 : 40 in experiments 1 and 2, respectively. The ewes in the treatment groups were supplemented with 10 g/day/head probiotics for 49 days. Fresh fecal samples were collected to measure microbial populations and metabolites. On days 43–47 total feces was collected to measure digestibility, and on the days 48 and 49 ruminal pH was measured. No significant difference of DMI, DG, dry matter digestibility, and ruminal pH was observed between the control and treatment groups. The probiotics treatment tended to increase crude fiber (P = 0.11) and organic cell wall digestibility (P = 0.18). In the final week, probiotics treatment significantly increased the fecal population of Bacilli (P < 0.05) and mold (P < 0.01) in experiment 1 and 2, respectively. No significant difference of fecal VFA and ammonia concentrations between the control and treatment groups was observed. The supplementary probiotics changed population of some microbial strains in the feces and possibly the large intestine of ewes.     

<Emphasis Type="Italic">Agrobacterium tumefaciens</Emphasis>-mediated transformation as a tool for random mutagenesis of <Emphasis Type="Italic">Colletotrichum trifolii</Emphasis>

We transformed Colletotrichum trifolii, the causal agent of alfalfa anthracnose, using Agrobacterium tumefaciens as a new tool for random insertional mutagenesis. Fungal spores of C. trifolii were transformed with T-DNA including the hygromycin phosphotransferase gene (hph). Southern analysis showed that every randomly selected transformant had a unique hybridization pattern of T-DNA, suggesting that the T-DNA was randomly integrated into the fungal genome. More significantly, about 75% of transformants had a single copy of the T-DNA. The results demonstrate that insertional mutagenesis via A. tumefaciens is a useful tool for studying the function of C. trifolii genes.     

Isolation and expression of five-amino-acid-deleted variant of feline hepatocyte growth factor (HGF) cDNA

Hepatocyte growth factor (HGF) is a pleiotropic cytokine that stimulates a wide array of cellular targets, including hepatocytes and other epithelial cells, melanocytes, endothelial and hematopoietic cells. We have cloned a different form of cDNA, with a deletion of 15 base pairs predicted to result in the loss of 5 amino acids from the first kringle domain. To investigate the biological activity, original and deleted variant of feline HGF cDNAs were transiently expressed in COS-7 cells. Both recombinant feline HGFs showed almost the same dose-response curves in the stimulation of the growth of BNL CL.2 cells (a mouse hepatocyte cell line) and scatter activity of Madin-Darby canine kidney (MDCK) cells. The findings reported here suggest that the deleted variant of feline HGF has almost the same biological activity as the original in terms of the proliferation and scatter activity.     

Effects of beta-thujaplicin on anti-Malassezia pachydermatis remedy for canine otitis externa

The antifungal activity of beta-thujaplicin was evaluated against 51 Malassezia pachydermatis strains isolated from canine ear canals with or without otitis externa. For comparison, sensitivity tests were performed on M. pachydermatis isolates for nystatin, ketoconazole, and terbinafine HCl, all clinically available antifungal agents. The minimal inhibition concentrations over 50% of the tested isolates (MIC50) were 3.13 microg/ml for beta-thujaplicin and nystatin, 0.016 microg/ml for ketoconazole, and 1.56 microg/ml for terbinafine HCl. The antifungal effect for M. pachydermatis of beta-thujaplicin compared favorably with commercial antifungal agents. None of the 51 M. pachydermatis isolates showed resistance against any of the tested antibiotics investigated in this study. Ten representative isolates of M. pachydermatis were subcultured for 30 generations at concentrations close to the MIC levels of beta-thujaplicin, nystatin, ketoconazole, and terbinafine HCl, and examined to determine whether they had acquired resistance to each drug. As a result, M. pachydermatis was found to achieve resistance more easily for ketoconazole and terbinafine HCl than for beta-thujaplicin or nystatin. The MIC50 of beta-thujaplicin did not change during the course of subculture, and it is thought that the potential development of a resistant strain is low, even with continuous infusion for otitis externa therapy. beta-Thujaplicin is an inexpensive and safe treatment with anti-inflammatory and deodorant effects that can be recommended as an effective remedy for canine otitis externa.     

Nonsuppurative myocarditis caused by porcine circovirus type 2 in a weak-born piglet

Reproductive failure associated with porcine circovirus type 2 (PCV2) was observed in a farm, and a weak-born 8-day-old piglet was examined pathologically. Focal to locally extensive lesions, including infiltration of macrophages and lymphocytes, fibrosis and degeneration of the myocardium were observed in the heart. PCV2 antigens and nucleic acids were detected in degenerated cardiomyocytes and macrophages infiltrating the heart by immunohistochemical staining and in situ hybridization. Depletion of lymphocytes with occasional infiltration of multinucleated giant cells was seen in the lymphoid organs and PCV2 antigens were demonstrated in histiocytic cells. Crystalline arrays of viral particles were observed in infiltrated macrophages in the heart and, rarely, in cardiomyocytes by electron microscopy. Although myocarditis is a common finding in aborted or stillborn piglets in reproductive failure due to PCV2, it was also observed in the 8-day-old piglet with PCV2 association.     

Molecular cloning of canine nm23 cDNAs and their expression in normal and tumor tissues

Two canine nm-23 cDNAs, designated as nm23-C1 and -C2, were isolated and characterized. Both have a putative open reading frame consisting of 459-bp encoding 152 amino acids and are highly similar to human, mouse and rat homologues. To understand the potential role of nm23-C1 and -C2 in the development of mammary gland tumors (MGT), we analyzed the mRNA expression in 14 MGT samples by RT-PCR. The samples were divided into categories according to their histopathology (benign/malignant) and metastasis. No significant difference in the mRNA expression levels of either nm23-C1 or -C2 were observed between the benign and malignant groups or the metastatic and non-metastatic groups. These results suggest that nm23-C1 and -C2 are not related to the establishment of malignancy and metastatic lesions in canine MGT cases.