Bioassay of a β-exotoxin of Bacillus thuringiensis against Heliothis zea larvae

A β-exotoxin of Bacillus thuringiensis was bioassayed on 1st-, 3rd-, and 4th-instar Heliothis zea larvae. Larvae were fed continuously on diet incorporated with concentrations of 1–700 μg AI/ml diet. Larval and/or pupal death was the measured response criterion. Dosage-mortality responses were determined at two evaluation times, 7 days post-initiation and after the entire larval-pupal development period, using probit analysis procedures. The LC₅₀ values for 1st-, 3rd-, and 4th-instar larvae at these two evaluation times were 4.9, 134.6, and 286.2 μg AI/ml diet, and 4.0, 17.6, and 66.4 μg AI/ml diet, respectively. Differences in responses between instars were more pronounced at 7 days than after the entire development period. The LT₅₀ values for 1st-, 3rd-, and 4th-instar larvae decreased from 7.1 to 3.1, 12.7 to 5.4, and 11.6 to 5.2 days post-initiation, respectively, as dosages were increased. The toxin did not act as a feeding deterrent, as all increases in dosage caused increases in mortality. Nineteen and 38% of those 3rd- and 4th-instar larvae, respectively, which survived β-exotoxin intoxication pupated later than untreated cohorts.     

Mixed grazing systems of goats with cattle in tropical conditions: an alternative to improving animal production in the pastureq

Mixed grazing systems combining sheep and cattle have shown better growth performance for one or both species. This observation has been attributed to their complementary feeding behaviour and the reduced host infection by gastrointestinal nematodes. Less attention has been paid to mixed grazing systems combining goats and cattle. Here, continuously grazing goats mixed with cattle (M) were compared with control goats reared alone (C) under tropical conditions. The comparison was conducted with gastrointestinal nematode-infected (I) and non-infected (nI) goats. Thus, the four treatments were cattle with gastrointestinal nematode-infected goats (MI), gastrointestinal nematode-infected goats alone (CI), cattle with non-infected goats (MnI) and non-infected goats (CnI). Average daily gain (ADG, g/day) and grass production were measured for the four groups of animals (six goats and two heifers treated with MI or MnI) grazing for 3 months on 4 subplots. Monthly measurements were performed over 5-day periods. This pattern was replicated in space for a second set of four subplots and in time for six successive cohorts of animals (bands 1 to 6). The ADG of goats in mixed grazing conditions was higher than controls irrespective of the infection status (32.6 v. 18.4 g/day for MI v. CI; 44.2 v. 33.5 g/day for MnI v. CnI). Concomitantly, the average biomass was lower for mixed grazing animals compared with controls (174 v. 170 for MI and MnI; 235 v. 208 for CI and CnI, respectively), suggesting better use of the sward. For daily BW gain (g/kg DM), mixed grazing also yielded better results than the control (1.88 v. 0.52 g BW/kg DM per day for MI v. CI; 2.08 v. 1.47 g BW/kg DM per day for MnI and CnI). Mixed grazing of goats and heifers offers a promising alternative for increasing goat and overall animal production as well as improving the management of pastures.     

Hormonal requirements for the larval-pupal transformation of the epidermis of Manduca sexta in vitro

In the tobacco hornworm, Manduca sexta, metamorphosis occurs in response to two releases of ecdysone that occur 2 days apart. Epidermis was explanted from feeding final-instar larvae before the first release of ecdysone and was cultured in Grace's medium. When exposed to 1 μg/ml of β-ecdysone for 24 hr and then to hormone-free medium for 24 hr, followed by 5 μg/ml of β-ecdysone for 4 days, the epidermis produced tanned pupal cuticle in vitro. During the first 24 hr of exposure to β-ecdysone, the epidermis first changed its cellular commitment to that for pupal cuticle formation (ET₅₀ = 14 hr), then later (by 22 hr) it became committed to tan that cuticle. Then, for most of the pupal cuticle to be tanned, at least a 12-hr period of culture in hormone-free medium was required before the cuticle synthesis was initiated. Consequently, some events prerequisite to sclerotization of pupal cuticle not only occur during the ecdysone-induced change in commitment but also during the ecdysone-free period. When the tissue was preincubated in 3 μg/ml of juvenile hormone (JH I or a mimic epoxygeranylsesamole) for 3 hr and then exposed to both ecdysone and juvenile hormone for 24 hr, it subsequently formed larval cuticle. The optimal conditions for this larval cuticle formation were exposure to 5 μg/ml of β-ecdysone in the presence of 3 μg/ml of epoxygeranylsesamole for 48 hr. When the epidermis was cultured in Grace's medium for 3 days and then exposed to 5 μg/ml of β-ecdysone for 4 days, 70% of the pieces formed pupal cuticle. By contrast, if both ecdysone and JH were added, 77% formed larval cuticle. Therefore, the change from larval to pupal commitment of the epidermal cells requires not only the absence of JH, but also exposure to ecdysone.     

Pulsatile infusion of luteinizing hormone-releasing hormone: Effects on luteinizing hormone secretion and ovarian function in prepuberal gilts

Ten intact and hypophysial stalk-transected (HST), prepuberal Yorkshire gilts, 112–160 days old, were subjected to a pulsatile infusion regimen of luteinizing hormone-releasing hormone (LHRH) to investigate secretion profiles of luteinizing hormone (LH) and ovarian function. A catheter was implanted in a common carotid artery and connected to an infusion pump and recycling timer, whereas an indwelling external jugular catheter allowed collection of sequential blood samples for radioimmunoassay of LH and progesterone. In a dose response study, intracarotid injection of 5 μg LHRH induced peak LH release (5.9 ± 0.65 ng/ml; mean ± SE) within 20 min, which was greater (P < 0.001) than during the preinjection period (0.7 ± 0.65 ng/ml). After HST, 5 μg LHRH elicited LH release in only one of three prepuberal gilts. Four intact animals were infused with 5 μg LHRH (in 0.1% gel phosphate buffer saline, PBS) in 0.5-ml pulses (0.1 ml/min) at 1.5-h intervals continuously during 12 days. Daily blood samples were obtained at 20-min intervals 1 h before and 5, 10, 20, 40, 60 and 80 min after one LHRH infusion. Plasma LH release occurred in response to pulsatile LHRH infusion during the 12-day period; circulating LH during 60 min before onset of LHRH infusion was 0.7 ± 0.16 ng/ml compared with 1.3 ± 0.16 ng/ml during 60 min after onset of infusion (P < 0.001). Only one of four intact gilts ovulated, however, in response to LHRH infusion. This animal was 159 days old, and successive estrous cycles did not recur after LHRH infusion was discontinued. Puberal estrus occurred at 252 ± 7 days in these gilts and was confirmed by plasma progesterone levels. These results indicate that intracarotid infusion of 5 μg LHRH elicits LH release in the intact prepuberal gilt, but this dosage is insufficient to cause a consistent response after HST.     

Using long-term averted goats for selective grazing in olive groves

Conditioned taste aversion (CTA) is a useful tool to modify animal feed preferences, allowing the implementation of selective grazing to control weeds in tree orchards without damaging the trees or affecting fruit production. LiCl is commonly used for inducing CTA. However, studies investigating the long-term persistence of CTA by LiCl in small ruminants are scarce. With this aim, we evaluated the efficiency of two LiCl doses (AV1 and AV2, 175 and 200 mg/kg BW, respectively) and a control (C, 0 mg/kg BW) for averting non-lactating dairy goats (n=15) to olive tree leaves. Aversion induction was reinforced on day 9 in those goats that consumed >10 g of olive leaves. Mid-term aversion effectiveness was assessed by five double-choice feeding tests (days 16, 24, 31, 38 and 53) of 30 min each, where 100 g of olive leaves were offered side-by-side with 390 g of Italian rye-grass (as-fed). Long-term aversion effectiveness was assessed in C, AV1 and AV2 goats by grazing for 30 min in paddocks with a simulated olive tree (days 59, 90, 121, 182 and 420). Moreover, C and AV2 goats were compared under on-field conditions (days 143, 211 and 363) in a commercial olive grove also for 30 min. The CTA proved to be established with a single LiCl dose in all goats and persisted for 4 and 55 days in AV1 and AV2 goats, respectively (P<0.001). However, 80% AV1 and 20% AV2 goats needed to be reinforced at day 9. When grazing under simulated olive tree and commercial olive grove conditions, the CTA goats, especially AV2 group, avoided the contact with the olive trees and minimally used a bipedal stance to feed leaves, than control goats. On average, time proportion spent consuming olive leaves and sprouts was much greater (P<0.05) for C (50.7±9.1%) than for AV1 (14.4±3.9%) and AV2 (3.1±0.9%). In conclusion, the 200 mg LiCl/kg BW dose was more effective than the 175 mg LiCl/kg BW dose for inducing an effective long-term CTA to olive tree leaves in goats.     

In vitro cultivation of Hymenolepis diminuta: effect of antibiotics on the growth of three-day-old worms removed from the rat

The effects of several antibacterial or antifungal antibiotics on the growth of 3-day-old Hymenolepis diminuta cultivated in vitro were investigated. Worms were recovered from the rat and cultured in roller tubes for 4 days without a medium change. The medium contained horse serum, yeast extract, and liver extract; the gas phase was 5% CO₂ in N₂. It was found that penicillin and streptomycin did not inhibit the growth of worms at concentrations lower than 5000 units and μg/ml of medium, respectively. Cycloheximide was toxic to H. diminuta, retarding or inhibiting growth at levels higher than 1.5 μg/ml. The antifungal antibiotics nystatin and amphotericin B did not affect worm growth at concentrations lower than 1000 units and 123 μ/ml of medium, respectively.The use of penicillin and streptomycin, and nystatin or amphotericin B can be recommended for the control of bacterial and fungal contaminants in the cultivation of H. diminuta removed from the rat.     

Diet choice by goats as effect of milk production level during late lactation

The diet self-regulation ability of goats during late lactation has been studied with regard to their production level. Two groups of seven Girgentana goats producing 1100 ± 157 g/day (H group) and 613 ± 138 g/day (L group) were housed in individual pens and were given alfalfa pelleted hay (1.5 kg), whole grains of maize (0.5 kg), barley (0.5 kg), faba bean (0.5 kg) and pelleted sunflower cake (0.5 kg) on a daily basis. During a 7-day pre-experimental period, goats received a mixed ration based on the same feeds used during the experimental period (1.5 kg of hay and 0.4 kg of each concentrate). Individual choice of feeds was continuously recorded for 7 days using a 24-h IR video surveillance system equipped with four video cameras. The nutrient intake in both groups was much higher than needed. Goats in the H group ate more (2016.3 v. 1744.3 g dry matter (DM)/day) and selected less hay (26.9% v. 34.6% DM), more high-protein feeds (faba bean and sunflower cake: 14.0% and 15.9% v. 8.8% and 7.9% DM, respectively) and less maize (21.5% v. 25.0% DM), reaching a higher CP concentration in the diet (17.3% v. 15.0% DM) compared with the goats in the L group. During the 24-h trial period, hay was more constantly selected (on average never reaching <20% of the total hourly basis feeding time, apart from the first hour after feed administration) compared with concentrate feeds. This feeding behaviour has probably exercised a ‘curative’ effect that enabled the goats to continue to take in very high levels of starch and protein, without manifesting any symptom of metabolic disease. Shifting goats from the pre-experimental diet, based on a mixture of the same feeds used during the experimental period, to the free-choice feeding caused more than 20% increase in milk production in both groups. From the results of the intake, we are unable to conclude that the goats can select their diet to meet their requirements, as goats consumed much more than needed. However, when free to choose their diet, the animals improved milk performance, despite the late-lactation stage.     

Doses of prostaglandin analogue “cloprostenol” by intravulvo-submucosal (IVSM) injections effective for the induction of oestrus in goats

In order to ensure that all goats responded equally to varying dosages of cloprostenol (Clo.) without considering the stage of the oestrous cycle, 25 goats were injected (treatment A) between days 11 and 14 of the oestrous cycle with 125 μg Clo./goat intramuscularly (IM). At the time of the second injection, given 11 days later, five different treatments (treatment B), consisting of 125 μg Clo.IM, 125 μg Clo. IVSM, 62.5 μg Clo. IVSM, 31.25 μg Clo. IVSM and saline IM, were given to groups 1, 2, 3, 4 and 5, respectively. Oestrus was monitored by teaser bucks. Blood samples taken at the time of treatment B and daily for 6 days thereafter were assayed for progesterone to confirm that luteolysis had occurred as expected. All goats in groups 1, 2 and 3, and one out of five in group 4 exhibited oestrus within 68 h of treatment B. Serum progesterone levels exhibited values below 1 ng/ml within 24 h of treatment B in groups 1, 2 and 3 and decreased to nadir levels within 48 h of treatment B. Lack of luteolysis in goats of groups 4 and 5, as shown by progesterone concentrations, was the reason for failure of synchronization in these groups. It is concluded that a small dose of cloprostenol given by intravulvo-submucosa injection is effective in inducing oestrus in dioestrous cycling goats.     

Using dried orange pulp in the diet of dairy goats: effects on milk yield and composition and blood parameters of dams and growth performance and carcass quality of kids

Although dried orange pulp (DOP) may conveniently replace cereals in ruminant diets, few studies have considered similar diet substitution for goats. We hypothesised that DOP could replace cereal-based concentrate in goat diets without detrimental effects on growth performance and carcass quality of suckling kids and milk performance and blood biochemical parameters of dams in early lactation. We also hypothesised that DOP substitution may increase the levels of antioxidants, such as phenolic compounds and vitamin E, in milk and improve its total antioxidant capacity (TAC). Therefore, 44 primiparous Payoya dairy goats were allocated to three experimental groups, each fed a different diet: control (CD, n = 14) based on a commercial concentrate with alfalfa hay as forage; and DOP40 (n = 16) in which 40% and DOP80 (n = 14) in which 80% of the cereal in the concentrate were replaced by DOP. The experiment lasted from the final month of pregnancy to 55 days postpartum. The DOP diets did not affect suckling kids’ carcass quality, but at 28 days, led to improvement in live weight (LW) and average daily gain (ADG) from birth, although no differences were found between DOP40 and DOP80 (for CD, DOP40 and DOP80, LW at 28 days was 8.00, 8.58 and 8.34 kg and ADG was 184, 199 and 195 g/day, respectively). Diet had no significant effect on milk yield (average daily milk yield and total yield at 55 days were 1.66 l/day and 90.6 l, respectively) and commercial and fatty acid composition. Nevertheless, α-tocopherol, total phenolic compound (TPC) and TAC concentration in milk increased with substitution of cereals by DOP (for CD, DOP40 and DOP80, concentration of α-tocopherol was 21.7, 32.8 and 42.3 μg/100 g, TPCs was 63.5, 84.1 and 102 mg gallic acid equivalents/l, and TAC was 6.63, 11.1 and 12.8 μmol Trolox equivalents/ml, respectively). Every plasma biochemistry parameter considered was within reference values for healthy goats; therefore, no pathological effect was detected for these variables due to dietary treatment. However, DOP diets caused a reduction in plasmatic creatine kinase and aspartate aminotransferase, implying reduced oxidative damage to muscles. In conclusion, DOP may be an interesting alternative to cereals in early lactation goat diets for increasing farmers’ income and the healthy antioxidant capacity of milk.     

The effect of experimental, long-term exposure to low-dose zearalenone mycotoxicosis on the histological condition of ovaries in sexually immature gilts

Farm animals are at risk of exposure to zearalenone (ZEA) in feedstuffs, which may lead to aberrations in their reproductive development, thereby adversely affecting production outcomes. The objective of this study was to determine the effect of long-term (48 days), per os administration of low ZEA doses (50% [20 μg ZEA/kg body weight (bw)] and 100% [40 μg ZEA/kg bw] NOAEL values) on anatomopathological changes in the ovaries of sexually immature gilts. The experiment involved 12 clinically healthy gilts aged 2 months with an initial body weight of about 40 kg and a determined immune status. The animals were randomly divided into two experimental groups (E1, E2) and a control group (C; all n = 4). Group E1 received per os 20 μg ZEA/kg bw for 48 days; group E2 received per os 40 μg ZEA/kg bw for 48 days; and group C received per os placebo for 48 days. Analytical samples of the mycotoxin were administered daily per os in gelatine capsules before morning feeding. Animals were sacrificed at the end of the experiment. The results of anatomopathological examinations of the ovaries in immature gilts subjected to long-term, low-dose ZEA exposure showed that ZEA-induced experimental hyperoestrogenism lowered the proliferative ability of granulosa cells of the ovarian follicle walls and of the connective tissue of the ovarian stroma, in particular at the lower ZEA dose.     

Effect of bacterial lipopolysaccharide on the in vitro secondary antibody response in mice. II. Abrogation of the suppressive capacity of endotoxin

Previous experiments have shown that bacterial endotoxin (ET) can be highly inhibitory to the in vitro secondary IgG antibody response when added 1–2 days after antigen. This paper examines the capacity of ET and another adjuvant, poly(AU), to circumvent the suppressive capacity of ET. It was found that ET or poly(AU) given simultaneously with antigen prevented any subsequent inhibition by ET added later to the cultures. Poly(AU) was effective in amounts as low as 1 μg/ml and ET in amounts as low as 0.1 μg/ml. Poly(AU) in greater amounts (50–100 μg/ml) also suppressed antibody synthesis when added 1–2 days after antigen, similar to ET. As with ET suppression, both ET and poly(AU) when added simultaneously with antigen were capable of overcoming the suppressive capacity of poly(AU). The capacity of small amounts of poly(AU) and ET to circumvent suppression in vitro by ET may help to explain why suppression by ET given after antigen has not been routinely observed in vivo. Lymphoid cells in vivo are most likely constantly exposed to either nuclear material released upon natural cell turnover or to ET from bacteria habitating the gut, resulting in an abrogation of any subsequent suppression by ET.     

Biodesulphurization of coal: effect of pulse feeding and leachate recycle

Biodesulphurization of coal was carried out under four modes of operation namely: conventional batch, constant volume pulse feeding (CVPF), increasing volume pulse feeding (IVPF) and leachate recycle. The effects of different pulse feeding strategies and leachate (product) recycle on biological performance were studied and compared with a conventional batch process. The sulphur removal rates for each of the four processes were 0.04 g/day (batch), 0.09 g/day (CVPF), 0.19 g/day (IVPF) and 0.05 g/day (leachate recycle). The values of iron solubilization rate (batch-83 μg/ml/day; CVPF-136 μg/ml/day; IVPF-198 μg/ml/day; leachate recycle-133 μg/ml/day) also followed the same trend. The percentage sulphur removal on the 30th day using batch, CVPF, IVPF and leachate recycle processes was 72%, 93%, 97% and 90%, respectively. IVPF was found to be the best operational strategy for biodesulphurization process at enhanced rates for longer duration.     

Antigen recognition by T lymphocytes. 3. Evidence for two populations of thymus-dependent rosette-forming cells in spleen and lymph nodes

Rosette-forming cells, present in normal spleen, are composed of 70% theta-positive cells with “high” in vitro sensitivity to Azathioprine (AZ) (1 μg/ml) and 30% theta-negative cells with “low” sensitivity to AZ (500 μg/ml). Theta-positive RFC are also found in the thymus (with “high” sensitivity to AZ) and in lymph nodes and peripheral blood (with “intermediate” sensitivity to AZ:50 μg/ml). RFC with “high” sensitivity to AZ (T1) are eliminated from the spleen by adult thymectomy in less than 6 days; it takes more than 48 hours exposure to antilymphocyte serum (ALS) in vivo to suppress them, whereas RFC with “intermediate” sensitivity to AZ (T2), present in lymph nodes and peripheral blood, disappear 6 hours after in vivo ALS treatment but not after adult thymectomy.     

Successful Medical Management of Recalcitrant Fusarium solani Keratitis: Molecular Identification and Susceptibility Patterns

Fungal keratitis is a rare but sight-threatening infection of the cornea that may be caused by several fungal pathogens. A delay in diagnosis and inadequate treatment may even lead to loss of the affected eye. Fungal keratitis is often misdiagnosed as bacterial keratitis because isolation and identification of the fungal pathogen is difficult and requires experience, and fungal growth in culture requires time. In this report, a 14-year-old boy with recalcitrant Fusarium solani keratitis, unresponsive to initial therapy, is presented. CLSI M38-A2 in vitro antifungal susceptibility tests demonstrated that only amphotericin B (0.5 μg/ml) had potent activity against F. solani; however, fluconazole (>64 μg/ml), itraconazole (>16 μg/ml), voriconazole (8 μg/ml), and posaconazole (>16 μg/ml) had high minimum inhibitory concentrations. In addition, caspofungin (>16 μg/ml) and anidulafungin (>16 μg/ml) exhibited high minimum effective concentrations. Repeated intrastromal voriconazole injections, topical voriconazole, and caspofungin combined with systemic antifungal agents improved of the corneal lesion with a significant increase in visual acuity. Intrastromal voriconazole injection may be used as an adjunctive treatment method for recalcitrant fungal keratitis with no prominent complications. The intrastromal route could be an effective route of administration of antifungal agents, especially for F. solani keratitis, as in this case. A combination of various antifungal agents administered by different routes prevented loss of the eye.     

Anti-Bacterial Activity of Recombinant Human β-Defensin-3 Secreted in the Milk of Transgenic Goats Produced by Somatic Cell Nuclear Transfer

The present study was conducted to determine whether recombinant human β-defensin-3 (rHBD3) in the milk of transgenic goats has an anti-bacterial activity against Escherichia coli (E. coli), Staphylococcus aureus (S. aureus) and Streptococcus agalactiae (S. agalactiae) that could cause mastitis. A HBD3 mammary-specific expression vector was transfected by electroporation into goat fetal fibroblasts which were used to produce fourteen healthy transgenic goats by somatic cell nuclear transfer. The expression level of rHBD3 in the milk of the six transgenic goats ranged from 98 to 121 µg/ml at 15 days of lactation, and was maintained at 90–111 µg/ml during the following 2 months. Milk samples from transgenic goats showed an obvious inhibitory activity against E. coli, S. aureus and S. agalactiae in vitro. The minimal inhibitory concentrations of rHBD3 in milk against E. coli, S. aureus and S. agalactiae were 9.5–10.5, 21.8–23.0 and 17.3–18.5 µg/mL, respectively, which was similar to those of the HBD3 standard (P>0.05). The in vivo anti-bacterial activities of rHBD3 in milk were examined by intramammary infusion of viable bacterial inoculums. We observed that 9/10 and 8/10 glands of non-transgenic goats infused with S. aureus and E. coli became infected. The mean numbers of viable bacteria went up to 2.9×10³ and 95.4×10³ CFU/ml at 48 h after infusion, respectively; the mean somatic cell counts (SCC) in infected glands reached up to 260.4×10⁵ and 622.2×10⁵ cells/ml, which were significantly higher than the SCC in uninfected goat glands. In contrast, no bacteria was presented in glands of transgenic goats and PBS-infused controls, and the SSC did not significantly change throughout the period. Moreover, the compositions and protein profiles of milk from transgenic and non-transgenic goats were identical. The present study demonstrated that HBD3 were an effective anti-bacterial protein to enhance the mastitis resistance of dairy animals.     

Biomethanation of spent wash: Heavy metal inhibition of methanogenesis in synthetic medium

Five heavy metals detected in distillery waste were lead (1.0–8.8 μg/ml), copper (1.7–15.7 μg/ml), zinc (3.1–11.8 μg/ml), iron (36.0–43.5 μg/ml), and manganese (3.0–5.1 μg/ml). Their toxicity to biomethanogenesis in a synthetic medium containing 1% sodium acetate, propionate, or butyrate was measured by batch fermentation, after cultivating the bacterial biomass semicontinuously. Lead, copper, and zinc in decreasing order were found to be toxic to biomethanogenesis. Lead at the concentration of 10 μg/ml completely stopped methane production. Iron did not produce any notable change in the process while manganese stimulated the rate of methane production. The toxicity of lead, copper, and zinc to methanogenic bacteria and methane production was dose-dependent but the growth of acetogenic bacteria was impaired at higher concentrations (2.5–10.0 μg/ml) of lead, copper, and zinc. Manganese stimulated the growth of only methanogenic bacteria, but not that of non-methanogenic bacteria or acetic acid production. The reduction in the synthesis of acetic acid via butyrate was more in the presence of these three metals than the synthesis of this acid via propionate.     

Effect of different level of roughage availability and contrast levels of concentrate supplementation on flavour of goat milk

Rancid and tart flavours are the most common off-flavours in Norwegian goat milk. In a feeding trial, we examined the effects of different levels of concentrate and of supplementary hay feeding on the occurrence of these off-flavours. Forty-eight experimental goats grazed cultivated pasture in the lowland during spring and autumn, and mountain pasture in summer. Twenty-four of the goats were fed 0.2 kg/day of concentrate (low concentrate, LC) and the remaining 24 goats 0.7 kg/day (high concentrate, HC). Twelve animals in LC and HC groups grazed freely, while the remaining goats in the two groups were given feeding challenges (limited periods of roughage restriction and ad libitum hay feeding). This was done to examine the effect of differing roughage availability on milk flavour. The animals fed low level of concentrate and with free grazing represented the control group. During the challenge periods, the goats were kept indoors and fed 0.2 kg hay/day for 2 days (roughage restriction) or hay according to appetite for 2 days (ad libitum feeding). At least 10 days of uninterrupted grazing were allowed between the challenges. Milk samples for sensory and chemical analysis were taken at the end of the challenge periods.The level of concentrate feeding did not influence the flavour of the milk when the goats were on lush spring pasture. However, the low level of concentrate feeding (LC) increased the frequency of off-flavour during the mountain and autumn experimental periods (P < 0.05).In the end of the mountain experimental period when the frequency of rancid/tart flavour increased in all groups, the sensory quality of milk produced by goats fed hay ad libitum (S1) had better taste ratings (P < 0.001) than milk from goats that were grazing. When the goats were given restricted amounts of hay, they adapted to the treatment by reducing their milk yield. In the spring and mountain experimental periods, restricted roughage feeding resulted in higher fat content and better taste ratings, especially in the group fed low level of concentrate (LC/S1). However, this connection was not clear in the autumn.Probably, the goats are able to handle a negative energy balance as long as mobilizable body reserves exist, but start to produce milk with lower dry matter content and higher frequencies of rancid/tart flavour when the body reserves are empty and the energy deficit is still pronounced.It is concluded that increasing the level of concentrate and feeding hay supplements will reduce the frequency of flavour defects at times when grazing is suboptimal or the pasture is of medium or low quality.     

Leishmania donovani: Oral efficacy and toxicity of formycin B in the infected hamster

Formycin B, a structural analog of inosine, was evaluated as an orally administrable antileishmanial agent. Against Leishmania donovani in hamsters, it achieved an 85–92% reduction in numbers of parasites in livers of infected animals after oral administration at 13 mg/kg/day for 4 days. Its efficacy by oral administration was approximately four to eight times that by intramuscular administration and four times that of the positive control drug Glucantime by intramuscular administration. The levels of formycin B in serum after the final oral administration of 26 mg/kg/day were 1.4 μg/ml at 1 hr and 0.3 μg/ml at 2 hr. The concentration in liver was greater (9.0 μg/ml at 1 hr) and declined more slowly. With this latter dosage or with 104 mg/kg/day there was no acute toxicity of formycin B to bone marrow or formed elements of the blood. The only statistically significant toxicity to the liver was a doubling of serum total bilirubin levels. Comparison of the in vivo efficacy of formycin B against L. donovani to the mild acute toxicity of the drug suggests that formycin B has potential as an oral agent against visceral leishmaniasis.     

Iodine Status of Preterm Infants Born in an Area of Iodine Sufficiency: Are They at Risk of Iodine Deficiency?

ObjectiveTo the assess the iodine status of preterm infants born in an area of iodine sufficiency using the urinary iodine concentration (UIC) and thyroid-stimulating hormone (TSH) levels and compare these values across different feeding practices during the first 7 days of life.MethodsIn this cross-sectional study, 88 preterm infants born at 30 to 34 weeks of gestation and admitted to the neonatal intensive care unit of a referral hospital in Tehran (Iran) were included. The infant UIC and TSH levels and breast milk iodine concentration in mothers who were exclusively breastfeeding were measured.ResultsMedian (interquartile range [IQR]) UIC and TSH levels in the study population were 81 (39-189) μg/L and 1.60 (0.80-2.85) mIU/L, respectively. When preterm infants were stratified by the type of feeding, the median (IQR) UICs were 64 (42-126) μg/L in parenteral nutrition, 125 (41-195) μg/L in exclusively breastfeeding, 57 (28-123) μg/L in formula feeding, and 45 (35-132) μg/L in mixed feeding, with no statistically significant difference between the groups (P = .31). The median (IQR) breast milk iodine concentration was 271 (177-521) μg/L in preterm infants exclusively fed their mothers’ own milk. There was no significant difference in the proportion of the TSH levels of >5 mIU/L between preterm infants who received enteral and parenteral nutrition (P = .27).ConclusionPreterm infants are at risk of iodine deficiency even in an area where the general population has adequate iodine. Only the preterm infants who received exclusively their mothers’ own milk had marginally adequate iodine status. Further studies are warranted to determine the necessity of iodine supplementation for this vulnerable group.     

Effects of the demethylase inhibitor,cyproconazole, on hyphal tip cells ofSclerotium rolfsii: II. An electron microscope study

Hyphal tip cells ofSclerotium rolfsii, prepared by freeze substitution, were examined by transmission electron microscopy after continued growth on cyproconazole-amended potato dextrose agar at fungistatic concentrations of 0.1, 0.75, and 1.0 μg/ml which respectively produced 50, 80, and 95% growth inhibition. Alternatively, observations were made of control tip cells that were transferred onto potato dextrose agar amended with 0.75 μg/ml cyproconazole for 30, 60, and 240 min. Ultrastructural abnormalities observed in hyphal tip cells as a result of cyproconazole treatment included (1) Spitzenko¨rper disorganization, (2) proliferation of smooth endoplasmic reticulum with inflated cisternae, (3) increased vacuolar contents, (4) presence of monovesicular bodies, and (5) irregular cell wall characteristics. Alterations of the Spitzenko¨rper, endoplasmic reticulum, and vacuoles were noted 30 min after exposing control hyphae to cyproconazole (0.75 μg/ml). Abnormal wall depositions were observed 60 min after fungicide exposure. After a 140-min exposure to fungicide, tip cell morphology was similar to that of cells grown in the continual presence of 0.75 μg/ml cyproconazole. The changes in hyphal morphology are discussed relative to the mode of action of cyproconazole.