Effects of transportation on early embryonic death in mares

Incidence of early embryonic death (EED) and associated changes in serum cortisol, progesterone and plasma ascorbic acid (AA) in transported mares were investigated. Mares were transported for 472 km (9 h) during either d 16 to 22 (T-3 wk, n = 15) or d 32 to 38 (T-5 wk, n = 15) of gestation. Blood samples were drawn from control, nontransported mares (NT-3 wk, NT-5 wk, n = 24) and transported mares pre-trip, midtrip, and at 0, 12, 24, 48 and 72 h post-transport and daily for the next 2 wk. Incidence of EED between transported and nontransported mares was not different (P greater than .05). Serum cortisol in all transported mares increased (P less than .05) relative to pre-trip values at midtrip and 0 h post-transport. Relative to NT mares, serum cortisol was higher (P less than .05) at midtrip in T-3 wk mares and 0 h post-transport in T-5 wk mares. Serum progesterone in all T mares increased (P less than .05) at midtrip relative to pre-trip values and was higher (P less than .05) in T-3 wk mares than in NT-3 wk mares at midtrip and 0 h post-transport. Post-transport decreases (P less than .05) in concentrations of progesterone were observed in mares that aborted. Plasma AA in transported mares increased (P less than .05) at midtrip in T-5 wk mares and decreased (P less than .05) relative to pre-trip values at 24 and 48 h post-transport (T-3 wk and T-5 wk mares, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)     

Further studies on competitive exclusion of Salmonella typhimurium by lactobacilli in chickens

Competitive exclusion of Salmonella typhimurium by isolates of lactobacilli was studied in day-old chicks. Protection was evaluated by enumerating salmonella in feces and cloacal swab cultures from test chickens. Neither single nor multiple treatment with six morphologically distinct isolates of lactobacilli resulted in major protection against infection by S. typhimurium.     

Screening for neonatal isohemolytic anemia in calves

Anti-erythrocytic immunoglobulins in serum and colostrum of 124 anaplasmosis-vaccinated cows were detected with a saline agglutination test. Positive results were correlated with the occurrence of neonatal isohemolytic anemia (NIA) in calves and were used to predict the occurrence of NIA. The disease was prevented by withholding colostrum from calves with a high potential for NIA.     

Pathogenesis of helminths in equines

This review summarizes information on the clinical signs, gross and microscopic lesions associated with nematode and cestode infections and discusses the development of these conditions in the equine host.     

Reduction of Salmonella typhimurium concentration in broiler chickens by milk or whey

Whey (5%) in the feed of chicks for the first 10 days of life reduced the mean log10 number of viable S. typhimurium from 5.68 in control chickens to 3.38 in whey-fed chickens. Lactose in drinking water or reconstituted dry milk (5% wt: vol) in drinking water reduced the mean log10 number of S. typhimurium to 2.60 and 2.11, respectively. Milk (5% wt: wt) in feed was not effective in reducing S. typhimurium colonization. The lack of effect of milk in the feed is believed to be because not enough lactose was provided at the 5% (wt: wt) concentration. Lactose in whey or nonfat dried milk offers alternatives to the use of pure lactose in preventing or lowering S. typhimurium numbers in young broiler chickens.     

Correlation between thyroid hormone level and blood pH in cows and in their offspring

Thyroid hormone levels in the plasma and blood pH were compared in 38 newborn calves and their dams immediately at parturition, then 24 and 72 h thereafter. Both thyroid hormone levels and pH exhibit much higher variation in calves than in cows. Applying a linear model at different sampling times, a weak (r = -0.112 to -0.397) but significant (P less than 0.05) negative correlation was found between thyroid hormone levels and blood pH in calves 24 and 72 h postpartum. At birth, when no correlation was found with linear approach, a polynomial regression model showed curvilinear relationship between thyroid hormone levels and blood pH in calves. Since these correlations could not be substantiated by comparing data of different sampling times, one can conclude that the possible relationship of thyroid hormone levels and blood pH is a complex one. Revealing the underlying mechanism of the above observations requires further study.     

Gas chromatographic-mass spectrometric confirmation of 19-nortestosterone in the urine of untreated boars--effect of the administration of Laurabolin

The presence of 17 beta-19-nortestosterone (nandrolone, NT, 17 beta-19-NT) and its epimer 17 alpha-19-nortestosterone (epiNT, 17 alpha-19-NT) was investigated in the urine of six untreated boars, obtained from experimental farms. The presence of 17 beta-19-nortestosterone was screened by RIA and HPTLC and confirmed by GC-MS analysis. Additionally, the two epimers (NT and epiNT) were investigated in the urine of a boar (two-year-old miniature male pig weighing 50 kg) before and after injection of 100 mg Laurabolin (nortestosterone laurate, Intervet N.V., Belgium). The isolation of the steroids was based on sample clean-up with solid phase extraction and subsequent high-performance liquid chromatography. Both gas chromatographic retention data and mass spectrometric data (selected ion monitoring and full spectrum) were used for detection and identification. The presence of 17 beta-19-nortestosterone in the urine of the boars that were not injected proves the endogenous production of the steroid. The absence of the 17 alpha-epimer in the urine of the injected boar suggests that 17 alpha-19-nortestosterone is not a major metabolite of 17 beta-19-nortestosterone.