Depression of polymorphonuclear leukocyte function associated with experimentally induced Escherichia coli mastitis in sows

In a study of susceptibilities of sows from 2 herds to experimentally induced Escherichia coli mastitis, a marked difference was seen. The "susceptible" sows were from a conventional herd and "resistant" sows were from a specific-pathogen-free herd. The purpose of the study was to determine whether deficient neutrophil function was associated with increased susceptibility to E coli-induced mastitis. Four in vitro procedures were used to evaluate polymorphonuclear leukocyte (PMN) function: (i) random migration under agarose, (ii) ingestion of 125I-iododeoxyuridine-labeled Staphylococcus aureus, (iii) quantitative nitroblue tetrazolium reduction, and (iv) iodination. After parturition and intramammary inoculation with E coli, sows from the susceptible herd were neutropenic and the neutrophils which were present in the peripheral blood had reduced function. Specifically, there were depressed random migration under agarose, S aureus ingestion, and iodination when compared with PMN function in resistant sows. These data indicate that susceptibility to E coli mastitis was associated with deficiencies in PMN numbers and function. Potential causes of the neutrophil dysfunction are discussed and include possible systemic hormonal aberrations or the presence of an inapparent viral or bacterial infection.     

Key Factors Affecting Reproductive Success of Thoroughbred Mares and Stallions on a Commercial Stud Farm

To evaluate factors contributing to fertility of thoroughbred mares, data from 3743 oestrous periods of 2385 mares were collected on a large thoroughbred farm in Ireland. Fourteen stallions (mean age 8.3 years; range 4–15 years) had bred 2385 mares (mean age 9.4 years; range 3–24 years). Maiden mares accounted for 12%, mares with a foal at foot for 64%, and barren, slipped or rested mares for 24% of the total. The mean pregnancy rate per cycle was 67.8% (68.6% in year 1 and 66.9% in year 2). Backward stepwise multivariable logistic regression analysis was utilized to develop two models to evaluate mare factors, including mare age, reproductive status, month of foaling, dystocia, month of cover, foal heat, cycle number, treatments, walk‐in status and stallion factors including stallion identity, stallion age, shuttle status, time elapsed between covers and high stallion usage on the per cycle pregnancy rate and pregnancy loss. Old age (p < 0.001) and cover within 20 days post‐partum (p < 0.003) were associated with lowered pregnancy rates. High mare age (p < 0.05) and barren, slipped or rested reproductive status (p = 0.05) increased the likelihood of pregnancy loss. Uterine inflammation or infection, if appropriately treated, did not affect fertility. Only high usage of stallions (used more than 21 times in previous week) was associated with lowered (p = 0.009) pregnancy rates. However, shuttle stallions were more likely to have increased (p = 0.035) pregnancy survival, perhaps reflecting a bias in stallion selection. In conclusion, mare age exerted the greatest influence on fertility; nonetheless, thoroughbreds can be effectively managed to achieve high reproductive performance in a commercial setting.     

Influence of compost and lime on population structure and element concentrations of forest soil invertebrates

Summary We tested the effects of two organic fertilizers (composts) and lime on the soil fauna of a spruce stand. One compost was obtained from chopped wood and the other from household garbage. At the time of distribution the pH of the control plots averaged 3.2, the garbage compost had a pH of 7.5, and the wood compost of 6.2. During the experimental period the pH of the compost layers decreased. The pH of the former litter layer beneath the composts showed a steep increase after 5 months, but beneath the treatment with wood compost this effect did no persist. Liming increased the pH only slightly in the litter layer. The two types of compost, the litter layer, and lumbricids (Lumbricus rubellus) were analyzed for concentrations of essential and potentially toxic elements. The element burden was highest in the garbage compost with 7- to 11-fold concentrations of Zn, Cd, Pb, Mg, and Cu compared to the needle litter. K, Ba, and Ca were 4 times more concentrated. L. rubellus showed an increased Cu concentration after extraction from the highly contaminated sites of garbage compost. Despite the differences in Pb contamination in the needle litter and in the two compost types, all investigated individuals of L. rubellus contained similar concentrations of Pb. In contrast to Pb, Cd accumulated in this lumbricid. Seasonal fluctuations of microarthropods, their total abundance, and differences in the colonization of the compost layers were observed. Collembola abundance was significantly increased in the garbage compost plots in July 91. There were generally more Prostigmata in the control and limed plots than in the compost plots. Oribatid numbers fell under all treatments compared to the controls. Mesostigmata were identified to species level and 33 species were found in the experimental areas. Certain species, such as Arctoseius cetratus and Uropoda minima, were only found in the treated sites.     

Compensatory growth in Atlantic halibut: Effect of starvation and subsequent feeding on growth, maturation, feed utilization and flesh quality

A group of juvenile Atlantic halibut (mean, SD, 199.5 g, 44.7) was split into two experimental groups: one group was fed in excess twice a day and later five days a week (i.e. Control group), and the other group was starved for 5 weeks and then subsequently re-fed for 10 weeks (i.e. 5/10 starvation/re-fed group). This treatment was repeated for three years until the fish were harvested (mean final weight, 4.4 kg). A size +specific compensatory response was seen; partial compensation was observed in halibut weighing less than 500 g whereas full recovery growth was seen in halibut over 2 kg. Food consumption and feed conversion efficiency was measured during two full 5/10 starvation/re-fed cycles. The Control group consumed 86% more food in the measurement period, whereas the FCE 40% higher in the 5/10 starvation/re-fed group (FCE = 0.95) compared to the Control group (FCE = 0.68). In males lower gonadosomatic index (2.2 vs. 3.0) and plasma 11-ketotestosterone (0.22 vs. 1.26 ng ml^− 1) levels in the 5/10 starvation/re-fed group were observed during late winter and spring of 2006 (age 3 years) indicating higher age at 1st maturity. Starvation had a significant effect for improving the quality as starved fish had higher muscle pH (6.4 vs. 6.2), less gaping (0.1 vs. 0.3) and harder texture (61.4 vs. 57.6 N). Overall, the rearing on a repeated 5/10 starvation/re-fed regime for 3 years led to full growth compensation, higher feed conversion efficiency, lower male maturation and improved flesh quality.     

Berhandlungen des badifchen Forftdereines bei feiner zwanzigften Jahresderfammlung in Badenweiler. Freiburg,Drud von Fr. Xav. Mangler, 1867. 92 Seiten in gr. 8

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