No abstract

No abstract

Abstract. The aim of this study was to investigate the relationship between the first ovulation within 3 weeks postpartum and subsequent ovarian cycles and fertility in high producing dairy cattle in Hokkaido, Japan. In Experiment 1, 110 cows (44 primiparous and 66 multiparous) were used to determine the effects of the first ovulation within 3 weeks postpartum on subsequent ovarian cycles. Milk samples were collected twice weekly from 7 to 100 days postpartum. The first ovulation was identified by an increase in milk progesterone (P4) to more than 1 ng/ml within 3 weeks postpartum. The numbers of cows showing ovulation and anovulation within 3 weeks postpartum were 31 (70.5%) and 13 (29.5%) in the primiparous cows and 35 (53.0%) and 31 (47.0%) in the multiparous cows, respectively. The patterns of ovarian resumption after calving were classified into two types (normal ovarian cycles and abnormal ovarian cycles) on the basis of milk P4 concentrations. Initiation of normal ovarian function in cows ovulated within 3 weeks postpartum occurred earlier than in anovulated cows regardless of the number of calvings (primiparous, 27.8 days vs. 44.4 days; multiparous, 30.6 days vs. 55.7 days; P<0.01). Out of the multiparous cows that ovulated within 3 weeks postpartum, initiation of normal ovarian function followed by a normal luteal phase was earlier than when it was followed by an abnormal luteal phase (25.5 days vs. 40.4 days; P<0.05). Milk P4 concentrations after the first ovulation were lower than those after the second ovulation in both the primiparous and multiparous cows (P<0.05). In Experiment 2, 22 multiparous cows were used to determine the effects of the first ovulation within 3 weeks postpartum on subsequent fertility. Blood samples were collected once a week from 0 to 3 weeks postpartum. The interval from parturition to first service in ovulated cows was shorter than in anovulated cows (68.4 days vs. 94.8 days; P<0.05). The conception rate by 100 days after calving tended to be higher in ovulated cows than in anovulated cows (50.0% vs. 16.7%, P=0.09). In conclusion, our data strongly suggests that ovulation within 3 weeks postpartum is a crucial phenomenon for subsequent resumption of ovarian function and conception, and thus it can be used as an index of subsequent reproductive performance.

e Molecular characterization of isolates from staphylococcal food poisoning (SFP) outbreaks in Japan showed that the dominant lineage causing SFP outbreaks is clonal complex 81 (CC81), a single-locus variant of sequence type 1, coagulase type VII, positive for sea and/or seb, and positive for seh. Among various CC lineages producing staphylococcal enterotoxin A, CC81 showed the highest toxin productivity. Staphylococcal food poisoning (SFP), one of the most common food-borne diseases, results from the consumption of foods containing toxic amounts of staphylococcal enterotoxins (SEs) (1-4). SFP is associated with toxigenic Staphylococcus aureus strains that produce one or more members of a family of genes encoding heat-stable SEs. Recently, a superfamily of more than 23 different SEs and SE-like toxins (SEls) was studied for their biological activities (4-8). These bacterial toxins are also known as pyrogenic superantigens that stimulate polyclonal T-cell proliferation and can potentially cause toxic shock syndrome (1-4). The genes for SEs and SEls are harbored by various mobile genetic elements and/or genomic islands, including prophages, plasmids, S. aureus pathogenicity islands (SaPIs), and Sa␤. To date, in addition to the five classical types of SEs (SEA through SEE), 18 new types of SEs and SEls (SEG through SElX) have been described (4-8). Our recent study confirmed the emetic potential of SElK, SElL, SElM, SElN, SElO, SElP, and SElQ in the monkey, and these SEls were renamed SEK, SEL, SEM, SEN, SEO, SEP, and SEQ, respectively (9). Comparing SEs and SEls, SEA is considered the most important SE causing SFP. S. aureus is a common commensal bacterium of the skin and mucosal surfaces of humans, with estimates of 20% persistent and 60% intermittent colonization (10). Food handlers carrying enterotoxin-producing S. aureus in their nasal cavities or on their skin are important sources of food contamination during the cooking process (3). Contamination with S. aureus is believed to be associated primarily with improper handling of cooked or processed foods with improper storage under conditions that allow the growth of S. aureus and the production of SEs. Reports concerning the molecular epidemiology and genetic diversity of the isolates from SFP outbreaks are limited when clinical isolates are compared. In this investigation, we ex-

Laminar bone or primary plexiform tissue, not Haversian bone, shows an alternative concentric pattern of laminar-bone units or plates around the bone marrow periphery of long bones, although the laminar bone is gradually replaced by osteons during the growth period. One laminar-bone unit is constructed with a hypercalcified line in the center, woven bone on both sides of the line, and lamellar bone with laminated appositional lines. Such a laminar bone showing a homogeneous calcification has been reported in young calves and some young large animals, but it has not been reported in foals although a previous report proposed that the bone structure was distinguishable from plexiform tissue. In this study, we compared young calves with foals by backscattered electron imaging mainly of transverse ground sections of mid-diaphysis. Foals had many hypercalcified lines arranged concentrically around the bone marrow periphery, which were similar to those of young calves. However, rows of cylindrical osteon-like structures with Haversian canal-like canals running along the long-bone axis were arranged between the concentric hypercalcified lines. Each Haversian canal-like structure was enclosed with laminated appositional rings of lamellar bone deposited on the woven bone. In the developing period, the bone units containing the concentric hypercalcified lines were basically equal to the laminar-bone units. The osteon-like structures or ‘pseudo-osteons’ were gradually replaced by ‘true osteons’ during the growth period. The blood vessels in the Haversian canal-like canals of foals ran along the long-bone axis, whereas the blood vessels in the concentrically prolonged bone cavities of young calves ran transversely to obliquely against the long-bone axis. Thus, the long-bone cortex of foals showing an alternative concentric pattern of a row of the osteon-like structures arranged between the hypercalcified lines will be histologically classified into a variety of laminar bone caused by the different arrangement of blood vessels. Such a laminar bone may have a biomechanical structure against physical stress, especially the modified laminar bone of foals with osteon-like structures, when compared with the typical concentric laminar bone of young calves and also Haversian bone possessing variously calcified numerous osteons caused by bone remodeling.

No abstract

ABSTRACT. This study determined the appropriate biochemical assay for measuring plasma tartrate-resistant acid phosphatase isoform 5b (TRAP5b) activity; this information is important to clarify the relationship between plasma TRAP5b and known biochemical bone markers in cattle. When plasma TRAP5b was measured using fluorometric and spectrophotometric methods, hemolysis products in plasma did not affect the former method. In plasma from healthy cattle, there was a good correlation (r=0.66) between the 2 methods. In agerelated profiles, plasma TRAP5b (r=-0.53), hydroxyproline (HYP, r=-0.56) and bone-specific alkaline phosphatase (BALP, r=-0.44) showed significant negative correlations with age; these three parameters decreased until 4 or 5 years of age and then remained constant. There were significant correlations between TRAP5b and HYP (r=0.83) or BALP (r=0.83). Our results show that the fluorometric assay can be performed with a high degree of precision and reproducibility without interference from hemolysis, and that the age-related changes in plasma TRAP5b, HYP, and BALP constitute additional background values for clinical guidance in bovine medicine.KEY WORDS: biochemical bone marker, cattle, fluorometry, plasma, tartrate-resistant acid phosphatase isoform 5b (TRAP5b).

We developed a novel wireless radio transmission pH measurement system to continuously monitor ruminal bottom pH in cows, and compared these measurements to pH values determined by a spot-sample method. The wireless system consists of a pH sensor, data measurement receiver, relay unit, and personal computer with special software. The bullet-shaped sensor can be easily administered orally via a catheter into the rumen, without surgery. The glass electrode, using a temperature compensation system, can detect the rumen fluid pH with high accuracy. The ruminal bottom pH in healthy rumen-fistulated cows was measured as 6.52 ± 0.18 by the wireless system and as 6.62 ± 0.20 by the spot-sample method; with a correlation between pH measurements using these different methods (n = 8, 24 samples, r = 0.952, P < 0.01). When measured serially in a cow fed a diet evoking rumen acidosis, the ruminal bottom pH decreased markedly following the morning feeding and then increased gradually by the next morning feeding. This wireless system is a ready-to-use tool for estimating circadian changes in ruminal bottom pH.