The effect of two teeth resection procedures on the welfare of piglets in farrowing crates. Part 1

Teeth resection is a method of controlling the injurious effects of the aggression displayed when newborn piglets fight to establish a teat order. Recent European legislation discourages the practice. The objective of this study was to assess the effect of clipping and grinding piglets’ needle teeth, compared to leaving them intact, on the welfare of piglets in farrowing crates.

Six days pre-partum, 60 sows were assigned to one of three treatments. Litters had their teeth clipped (C), ground (G) or left intact (I) at birth. The time taken to carry out each procedure was recorded. Piglet weights and facial lesions, which were scored according to severity, were recorded on days 1, 4, 11, 18 and 27. Piglet weights were also recorded at birth. Mouth lesions were recorded on days 1, 4 and 27. Instantaneous scan samples of piglet behaviour were carried out for 30 min post-teeth resection procedure (1 min intervals), and for 6 h on days 1, 4, 8, 14, 21 and 26 (5 min intervals). One male and one female piglet per litter were chosen as focal animals and observed for 5 min each post-procedure and for 10 min each twice per day on days 1, 5, 12, 20 and 26. Mortalities were recorded throughout lactation.

Grinding took significantly longer than clipping the teeth or leaving them intact (F = 638.87, P < 0.001). I piglets had higher facial lesion scores than C and G piglets (F = 10.58, P < 0.001). A smaller proportion of piglets in I litters than C and G litters and a smaller proportion of piglets in G litters than C litters had at least one mouth lesion (F = 4.74, P < 0.001). During 30 min post-procedure, I piglets were active on the heatpad in more observations than C and G piglets (F = 3.49, P < 0.05). During 5 min post-procedure C piglets spent longer chomping than I piglets (F = 5.92, P = 0.05). On day 21, I piglets were active in more observations than G piglets (F = 2.11, P < 0.05). On day 26, G piglets were inactive in more observations than C and I piglets (F = 5.02, P < 0.05). On days 14 and 26, C piglets were sleeping in more observations than G piglets (F = 2.87, P = 0.05). There was a tendency for a larger proportion of I than C piglets to die due to overlying (F = 2.68, P = 0.08).

In conclusion, although all three options were associated with welfare problems, grinding can be recommended in preference to clipping or leaving the teeth intact.     

The effect of two piglet teeth resection procedures on the welfare of sows in farrowing crates. Part 2

Recent EU legislation discourages the practice of resecting piglets’ needle teeth. However, the effect of leaving piglets’ teeth intact on the welfare of sows in farrowing crates is poorly understood. Therefore, the aim of the study was to compare the effects of clipping and grinding piglets’ needle teeth, compared to leaving them intact, on the welfare of sows in farrowing crates.

Six days pre-partum 60 multiparous sows were assigned to one of three treatments. Litters had their teeth clipped (C), ground (G) or left intact (I) at birth. Sows’ teats were inspected for lesions pre-partum (day −3) and on days 1, 4, 11, 18 and 27 post-partum. Instantaneous scan samples (5 min intervals) of sow behaviour were carried out during three 2 h periods on days 1, 4, 8, 14, 21 and 26. On days 1, 4 and 11 all piglets were removed from the crate for 60 min. On re-introduction of the piglets, sow maternal behaviour was recorded continuously for 20 min.

The number of sows with teat lesions tended to differ between treatments on days 11 (P = 0.06) and 18 (P = 0.10). There was an interactive effect between treatment and day on sow dog-sitting behaviour throughout lactation (P < 0.001) and a tendency for an interactive effect on posture-changing behaviour (P = 0.08). On day 21, I sows were dog-sitting in more observations than C sows (P < 0.05) and on day 26 in more observations than C and G sows (P < 0.001). There was an interaction between treatment and day in the latency of sows to suckle their piglets following 60 min separation (P < 0.05). On day 4, I sows had a shorter latency to suckle than C and G sows (P < 0.05). There was an effect of treatment on the number of sows that terminated bouts of post-suckling udder massage (P < 0.05). On day 4, more I than C sows terminated post-suckling udder massage (P = 0.01). Finally, there was an effect of treatment on the time spent lying in the ventral posture in the observations of maternal behaviour (P < 0.05). C sows spent less time lying in the ventral posture than G and I sows (P < 0.05).

There were indications that leaving the teeth intact and to a lesser extent grinding caused injury and disturbance to sows. In farrowing crates, leaving piglets’ teeth intact cannot be recommended.     

Some effects of thyroidectomy on growth, heat production and the thermoregulatory ability of the immature fowl (Gallus domesticus)

1. 1.|The effect of thyroidectomy at 12 days of age on weight gain, and on heat production and thermoregulatory ability of 4- to 5-week-old chickens at temperatures within and below the thermo-neutral zone was investigated.

2. 2.|Despit the absence of thyroid tissue, as demonstrated with radioiodine, a small amount of thyroxine was found in the plasma of some thyroidectomized (TX) birds.

3. 3.|Thyroidectomy depressed weight gain; pair-fed controls grew significantly faster than TX birds.

4. 4.|Resting heat production of TX birds at thermoneutrality (30°C) was depressed by 18% (P < 0.001) and body temperature by 0.4°C (P < 0.001).

5. 5.|At 12°C heat production of TX birds was similar to that of controls but the body temperature of TX birds was 0.7°C lower (P < 0.001).

6. 6.|Thyroidectomized birds were unable to regulate body temperature at 5°C even if thyroxine was provided on the day before and at the time of cold-exposure. This inability to thermoregulate was probably due to inadequate insulation and poor nutritional status.

Evaluation of Magadi soda-treated sorghum grain for young broilers

Magadi soda (MS) is a commercially available form of sodium sesquicarbonate in Kenya. Soaking high-tannin sorghum (HTS) grain (2.5% catechin equivalents) in a 6 g l⁻¹ MS solution was shown to eliminate measurable tannin content. A feeding trial was conducted to investigate the performance of broiler chicks fed soyabean-based diets containing HTS or MS-treated HTS as the sole cereal source from 1-3 weeks of age. A third diet containing sorghum with no detectable tannin content served as the control. Diets containing 220 g kg⁻¹ crude protein were fed to 6 pens of 5 birds per pen for each treatment from 1-2 weeks of age and to 4 pens of 4 birds per pen per treatment in weeks 2-3. Feed intake, weight gain and feed efficiency (FE) were determined weekly. Apparent dry matter digestibility (DMD), metabolizable energy (AMEn) and nitrogen retention (NR) were measured over the last 3 days of each period. Gain and feed intake were not affected by treatment (P > 0.05), but FE and DMD were lower (P < 0.05) for the HTS diet than for the MS-treated HTS and control diets, which themselves were similar. Absolute NR was higher (P < 0.05) for the control diet than either of the HTS diets in week 2 but was the same for all diets in week 3. As % of intake, NR was higher (P < 0.05) for the control in both weeks 2 and 3 than for the HTS diets, although this was improved (P < 0.05) by MS treatment in week 2. AMEn values showed a similar pattern to that for NR in week 2 but in week 3 was the same for the MS-treated HTS and control diets, which were higher than the HTS diet (P < 0.05). Though total tannin content did not influence growth of birds in this study, MS treatment of HTS did reduce deleterious effects on FE, AMEn and NR as a % of intake.     

The effects of chemical and visual communication, space availability, and substratum color on growth of the juvenile freshwater prawn Macrobrachium rosenbergii (De Man)

The effects of chemical and visual communication, space availability, and substratum color on the growth of juvenile Macrobrachium rosenbergii (De Man) were studied by recording the changes in average weight and length of prawns kept at controlled densities in the laboratory for periods of 6 wk of in communal and individual compartments with constant unidirectional water currents. Chemically mediated growth inhibition increased in proportion to the number of prawns ahead of a given compartment in the water current. Since ammonia and nitrite concentrations were below reported toxic values, progressive accumulation and transmission through water currents of some other chemically mediated growth inhibitor may explain the observed differences in growth rates between compartments. Growth slowed with increasing prawn density (communal areas) and with decreasing individual compartment size (individual areas). Prawns held in contiguous individual compartments, allowing visual communication, exhibited a significantly (P < 0.01) more rapid growth rate than prawns reared in visually isolated compartments. Growth rates for individuals kept on black substrates were significantly greater (P < 0.05) than those of prawns held in aquaria with white or blue substrates. When substrates composed of all three colors in alternating bands were used, prawns showed a significant preference (P < 0.01) for black backgrounds during the afternoon and for the water column during the morning. Possible implications of these findings to the intensive aquaculture of M. rosenbergii are discussed.     

The aversion of broiler chickens to concurrent vibrational and thermal stressors

The requirement for assessing the effects of multiple concurrent stressors in improving the welfare of broiler chickens during transport has not been widely recognised. A discrete-choice technique was used to investigate the aversion of broiler chickens to concurrent vibrational and thermal transport stressors. In experiment 1, 12 female broiler chickens, aged 42+/-3 days were studied individually using two choice-chambers. Each chamber had four compartments connected via a central zone and offered four treatments; thermal (T: air temperature; 40 degrees C, 21% RH), vibrational (V: frequency; 2Hz, acceleration; 1ms(-2)), concurrent vibrational and thermal (VT) and no applied stressors (N). Coloured compartment wall panels, allocated at random, assisted chickens' identification of compartments. Birds were fasted overnight and were required to make five consecutive choices on each of four consecutive days. A choice was defined as entering a compartment and feeding (5g pellets), whereupon confinement for 60min was initiated. Choices were totalled over all birds and analysed using a log-linear generalised linear model. The vibration was significantly avoided (V and VT versus N and T; P<0.05) but the thermal stressor was not (T and VT versus N and V; P>0.05) and there was no interaction. In experiment 2, the procedure was repeated with 12 more birds and modifications to increase method sensitivity and maximise bird learning. Choices were more disparate than before with vibration avoided to a greater extent (V and VT versus T and N; P<0.01) but there was still no main effect of the thermal treatment or a significant interaction. Substantial differences between individuals were observed in both experiments. The overall response to vibration supported previous findings for short-term exposure, however, non-avoidance of the thermal treatment was unexpected. Possibly, the birds were unable to associate the delayed heat stress with the compartment. Alternatively, the thermal conditions were not perceived as aversive either initially or throughout the 60min confinement. The preference method provides a useful starting point for assessing combinations of stressors which affect broiler welfare, allowing relative ranking of treatments from an animal-centred perspective.     

Effect of feeding tree leaves as supplements on the nutrient digestion and rumen fermentation pattern in sheep grazing on semi-arid range of India – I

A study was carried out to determine the effect of feeding different tree leaves as supplements on nutrient digestion, rumen fermentation and blood parameters of sheep grazing on a semi-arid rangeland. Thirty adult Malpura rams of uniform body weight (39.0 ± 0.75) were divided into five groups of six each. They were grazed as a single flock from 08.00 to 17.00 h on a semi-arid rangeland. After the end of the grazing period, the first group (G1), which was not provided with any supplementation, served as the control. The second group (G2) was supplemented with 200 g of a concentrate mixture per head per day, whereas the third, fourth and fifth groups (G3–G5) were provided with approximately 200 g DM d⁻¹ of freshly cut foliage from Prosopis cineraria, Acacia nilotica and Albezia lebbek. The foliage from P. cineraria contained 133.4 g kg⁻¹ DM condensed tannin (CT) with protein precipitating capacity (PPC) of 66 g kg⁻¹ DM, whereas A. nilotica contained 18.9 g kg⁻¹ DM hydrolysable tannin (HT) with PPC of 11.5 g kg⁻¹ DM. However, A. lebbek did not contain any tannin. The protein contents were 119, 139 and 194 g kg⁻¹ DM, respectively. The DMI (g d⁻¹) was 688, 916, 1024, 1003, 999 in G1, G2, G3, G4 and G5, respectively. Digestible crude protein (DCP) and metabolizable energy (ME) intakes in supplemented groups G2–G5 were higher (P < 0.05) than in the control (G1). Supplementation improved the DM digestibility in all groups, whereas CP digestibility was lower (P < 0.05) in G3 compared to G2, G4 and G5. Rumen fermentation study conducted 6 h after supplementation revealed that total N, ammonia N, and total VFA levels were lower (P < 0.05) in G3 compared to the other supplemented groups. Although the haemoglobin (Hb) levels were similar among groups, blood urea N (BUN) was lowest in G3 compared to the other groups. The initial body weights were similar among groups (mean 39 kg). After 60 days of experimental feeding, all groups maintained their body weight, except the control group (G1), which lost body weight. It was observed, that supplementation with tree leaves containing CT like P. cineraria helps in better rumen fermentation pattern by preventing excessive loss of nitrogen. It was concluded that maximum nutritional benefits of tree leaves could be harvested, if used as supplement rather than as a sole feed.     

Letrozole versus tamoxifen in the treatment of advanced breast cancer and as neoadjuvant therapy

Letrozole, a third generation aromatase inhibitor, has been compared with tamoxifen in the treatment of advanced breast cancer and as neoadjuvant therapy. In a first-line trial in advanced disease, 939 post menopausal women were randomised double blind to receive treatment with letrozole 2.5 mg daily or tamoxifen 20 mg daily. Letrozole was significantly superior in terms of median time to progression (9.4 months versus 6.1 months, P = 0.0001), objective response (30% versus 20%, P = 0.0006), and clinical benefit (49% versus 38%, P = 0.0001). Superiority of letrozole was independent of disease site, receptor status, or prior adjuvant anti-oestrogen therapy. In an extended phase of this trial, 200 patients were crossed over to tamoxifen after letrozole, compared with 197 crossed over to letrozole after tamoxifen. Median overall survival was 34 months for letrozole versus 30 months for tamoxifen (not significant).

In a similar randomised double-blind neoadjuvant trial, 337 post menopausal patients with large ER/or PgR positive T2–T4 cancers, either requiring mastectomy or locally advanced, were randomised to preoperative letrozole or tamoxifen for 4 months prior to surgery. Overall response was 55% for letrozole versus 36% for tamoxifen (P < 0.001). Conservative surgery was possible in 45% of patients treated with letrozole versus 35% with tamoxifen (P = 0.022).

In both trials, both treatments were well tolerated with no significant differences in side effects.

These results indicate that letrozole is more active than tamoxifen both as neoadjuvant therapy and as first-line treatment in advanced disease. They support the importance of current adjuvant trials comparing the two treatments.     

A method to reduce the invasiveness of fetal catheterization in the cow

Surgical intervention in general anesthesia (GA) of the cow in late gestation is a stressful condition for both mother and fetus, potentially leading to premature delivery or fetal death. The present study hypothesized that fetal catheterization at days 246–253 (90% of gestation) is done with less physical and metabolic stress for the mother and fetus, when the surgery is performed on a standing cow and local anesthesia (LA) rather than on a recumbent cow in general anesthesia. Fetal and uterine maternal intra-vascular catheters were implanted during general anesthesia (GA, n=24) or local analgesia (LA, n=7). Blood gases and metabolite levels in the fetal calves and their mothers were measured during surgery and for 5 days post-operatively. During surgery, venous blood pH was higher (7.44±0.01 versus 7.39±0.01, P<0.05) and hemoglobin and oxygen contents lower in LA cows compared with GA cows (9.3±0.3 mg/dl versus 11.8±0.2 mg/dl, P<0.001 and 10.1±0.3 ml/dl versus 12.6±0.6 ml/dl, P<0.05). The differences between the two groups of fetuses reflected those of their dams in that LA fetuses showed lower arterial oxygen pressure (18.3±1.4 mmHg versus 24.8±1.4 mmHg, P<0.05) and hemoglobin (7.81±0.30 mg/dl versus 9.22±0.21 mg/dl P<0.01) and furthermore, they also showed higher blood glucose (2.4±0.2 mM versus 1.4±0.1 mM, P<0.01). During the 5 days post-surgery, 10 GA fetuses (42%) and 1 LA fetus (14%) died in utero. Bacterial contamination was implicated in six of the GA deaths and in the one LA death. In the dams with surviving calves, differences in hemoglobin (9.49±0.21 mg/dl versus 11.17±0.23 mg/dl P<0.001) and O₂ct (10.9±0.3 ml/dl versus 12.5±0.5 ml/dl, P<0.05) were still present, and in addition, blood glucose was higher in LA versus GA cows (4.3±0.2 mM versus 3.8±0.1 mM, P<0.05). The choice of surgical method did not affect post-surgery blood chemistry in the surviving fetuses, except that the higher blood glucose in the LA fetuses at surgery tended to be maintained also post-operatively (2.0±0.2 mM versus 1.5±0.1 mM, P=0.07). The observed differences in blood chemistry parameters between the two methods of surgery and possibly in the fetal death may be explained by differences in catheterization method and the associated differences in physical and metabolic stress during and after surgery. Thus, surgery upon a standing cow in local anesthesia should be considered as an alternative to surgery in universal anesthesia for fetal catheterization in the cow in late gestation.     

An unexpected ‘4+2’ [N3S]/[NS] rhenium(IV) complex formed upon cleavage of a Re(V) imido bond

The reaction of [Re(NMe)Cl₃(PPh₃)₂] with the pentadentate [N₃S₂] ligand pyN₂H₂S₂---H₂ [2,6-bis(2-mercaptophenylamino)dimethylpyridine] (1) in the presence of triethylamine did not yield the anticipated six-coordinate complex [Re(NMe)(η⁵-pyN₂HS₂)] (2), but rather resulted in cleavage of the Re(V)=NMe bond. A novel six-coordinate Re(IV) [N₃S]/[NS] complex [Re(η⁴-SC₆H₄---2-NCH₂---C₅H₃N---C=NC₆H₄---2-S)(η²-NHC₆H₄---2-S)] (4) was thus obtained with the simultaneous coordination of 2-aminothiophenol, a dianionic bidentate [NS] donor resulting from the decomposition of the parent ligand and ligand 3, a dianionic tetradentate [N₃S] donor formed by partial self-condensation and subsequent oxidation of the parent ligand 1. Crystal data for 4: C₂₅H₁₈N₄S₃Re·CH₂Cl₂, monoclinic, space group P2₁/n, a=9.255(2) Å, b=11.181(2) Å, c=25.316(4) Å, β=97.434(3)°, V=2587.8(7) Å³ and Z=4.     

Effect of tree leaf as supplementation on nutrient digestion and rumen fermentation pattern in sheep grazing semi-arid range of India – II

A study was conducted to evaluate the effects of supplementing with different tree leaves on nutrient digestion, rumen fermentation and blood parameters of sheep. Thirty adult Malpura rams (39.0 ± 0.56 kg) were divided into five groups of six each. They were grazed as a single flock on a semi-arid rangeland and after the end of routine grazing period (08:00–17:00 h), first group (G1), which was not provided with any supplementation, served as control group. Second group (G2) was supplemented with 200 g of a conventional concentrate mixture per head per day, whereas third, fourth and fifth groups (G3, G4 and G5) were supplemented with approximately 200 g dry matter (DM) per day freshly cut foliage from Ailanthes excelsa, Azardirachta indica and Bauhinia racemosa, respectively. Protein content (g kg⁻¹ DM) in A. excelsa, A. indica and B. racemosa foliage was 197, 128 and 132, respectively. A. indica and B. racemosa foliages also contained 123.2 and 211.2 g kg⁻¹ DM condensed tannin (CT) with protein precipitating capacity (PPC) of 16.5 and 46.5 g kg⁻¹ DM. None of the tree leaves contained hydrolysable tannin (HT). Dry matter intake (DMI, g day⁻¹) was 591, 766, 865, 974 and 939 in G1, G2, G3, G4 and G5, respectively. Digestible crude protein (DCP) and metabolisable energy (ME) intakes in supplemented groups G2–G5 were higher (P < 0.05) compared to control (G1). Supplementation improved digestibility of all nutrients in all groups. Rumen fermentation study indicated lower (P < 0.05) ammonia and total N in the rumen liquor collected from G5 sheep compared to the other supplemented groups. Although haemoglobin (Hb, g dl⁻¹) levels showed small changes among groups, blood urea nitrogen (BUN, mg dl⁻¹) was lowest in G5 compared to the other groups. Initial BW were similar among the groups. After 60 days of experimental feeding, all animals maintained their BW, except sheep in the control group (G1), which lost BW. Results indicate that for adult sheep grazing on a semi-arid range, supplementation with a concentrate mixture could be replaced by tree leaves like A. excelsa, A. indica and B. racemosa, during the lean season to maintain their BW. In addition, supplementing with tree leaves containing condensed tannin has advantages in terms of N utilization.     

The effects of barley, unmolassed sugar-beet pulp and molasses supplements on organic matter, nitrogen and fibre digestion in the rumen of cattle given a silage diet

In a 4 × 4 Latin-square experiment with a 2 × 2 factorial arrangement of treatments, 4 cattle fitted with a rumen and duodenal cannula were given four grass-containing diets [480 g kg⁻¹ of the total dry matter (DM) intake] and barley (BU), barley + molasses (2:1) (BM), sugar-beet pulp (SU) or sugar-beet pulp + molasses (SM). Duodenal flow was estimated using Cr-mordanted straw and CoEDTA as markers, and microbial nitrogen entering the small intestine using purine bases of nucleic acids.

Molasses-containing diets had a higher (P < 0.01) organic matter (OM) digestibility. The proportion of digestible OM apparently disappearing in the rumen averaged 0.72 and was not significantly affected by the diet. When cattle received molasses, the quantity of microbial N entering the small intestine was higher (P < 0.05) and there was a trend towards a higher efficiency of microbial N synthesis (28.8 vs. 25.6 g N kg⁻¹ OM apparently digested in the rumen). When S diets were consumed, total non-ammonia N flow at the duodenum exceeded N intake by 7.0 g day⁻¹ and when B diets were consumed, it was 0.7 g day⁻¹ less than N intake. Feed N degradability in the rumen and apparent N digestibility of S diets were lower (P < 0.05; P < 0.001) than those of B diets.

Rumen (P < 0.05) and total (P < 0.001) digestibility of neutral detergent fibre (NDF) and acid detergent fibre (ADF) was higher when S diets were given. The proportion of digestible fibre disappearing in the rumen was not affected by the diet. The rate and extent of silage and hay DM degradation were not significantly affected by the diet. However, dietary inclusion of molasses decreased (P < 0.05) the lag time of both hay and silage DM degradation.

The rumen dilution rate of liquid averaged 0.097 and that of particles, 0.049; neither was significantly different for either B and S diets or U and M diets. Duodenal liquid flow was higher (P < 0.05) for M diets.

Average rumen pH was not affected by the diet, but the molasses diets increased (P < 0.05) the range in rumen pH. The BM diet was associated with higher (P < 0.01) rumen ammonia concentration than the other diets. Low rumen ammonia concentrations (< 2 mM) were observed for long periods between feeds. The molar proportion of butyrate was higher on B diets and there was a trend towards a higher proportion of acetate and propionate on S diets. Molasses tended to increase the molar proportion of propionate and butyrate.     

Effect of monensin, fish oil or their combination on in vitro fermentation and conjugated linoleic acid (CLA) production by ruminal bacteria

An in vitro study was conducted to examine the effect of adding monensin, fish oil, or their combination on rumen fermentation and conjugated linoleic acid (CLA) production by mixed ruminal bacteria when incubated with safflower oil. Concentrate (1 g/100 ml) with safflower oil (0.2 g/100 ml) was added to a mixed solution (600 ml) of strained rumen fluid and buffer (control). Monensin (10 ppm), fish oil (0.02 g/100 ml), or monensin plus fish oil was also added into control mixture. All the culture solutions prepared were incubated anaerobically at 39 °C for 12 h. A higher pH and ammonia concentration were observed from the culture solution containing monensin at 12 h of incubation than those from the control or the culture containing fish oil. Monensin increased (P < 0.007) the C₃ content over all the collection times of culture solution while reducing the C₄ content at 6 h (P < 0.018) and 12 h (P < 0.001) of incubations. Supplementation of monensin, fish oil or their combination changed the content of C₁₈-fatty acids of ruminal culture. Monensin alone reduced (P < 0.021) the content of cis-9, trans-11 CLA compared to fish oil at all sampling times, but increased (P < 0.041) the trans-10, cis-12 CLA production compared to fish oil addition and the control which were similar at incubation for 12 h. The combination of monensin and fish oil increased the content of cis-9, trans-11 CLA (P < 0.023) and transvaccenic acid (TVA, P < 0.018) significantly compared to the control or monensin alone at incubation for 12 h.     

抗阻训练对增龄大鼠骨骼肌线粒体功能的影响*

目的: 从线粒体动力学的角度,探讨抗阻运动对增龄大鼠骨骼肌线粒体功能的影响。方法: 40只雄性SD大鼠随机分为4组:2月龄安静对照组(C1组)、2月龄抗阻运动训练组(R1组)、6月龄安静对照组(C2组)、6月龄抗阻运动训练组(R2组),每组10只。C1、C2组正常喂养,R1、R2组大鼠进行跑台坡度为35°,速度为15 m/min的抗阻运动,一次跑动15 s,间歇30 s,4次为一组,组间间歇3 min,3组为一次循环,一天为2个循环,循环间歇10 min,每周6 d,共8周。采用Western blot法测定各组大鼠股四头肌线粒体融合蛋白2(Mfn2)、GTP酶1(DRP1) 蛋白含量,使用流式细胞仪测定各组大鼠股四头肌线粒体膜电位(ΔΨm)、活性氧(ROS)和游离钙(Ca²⁺)水平。结果: ① 与C1组相比,R1组大鼠DRP1蛋白升高(P＜0.01)、Mfn2蛋白无显著变化,C2组大鼠DRP1、Mfn2蛋白均降低(P均＜0.01);与C2组相比,R2组大鼠DRP1、Mfn2蛋白均升高(P＜0.01,P＜0.05);与R1组相比,R2组DRP1、Mfn2蛋白均降低(P＜0.01,P＜0.05)。② 与C1组相比,R1组Ca²⁺含量降低(P＜0.01)、C2组Ca²⁺含量升高(P＜0.01);与C2组相比,R2组Ca²⁺含量降低(P＜0.01);与R1组相比,R2组Ca²⁺含量升高(P＜0.01)。③ 与C1组相比,R1组ROS含量有所上升,但无显著性差异,C2组ROS含量升高(P＜0.01);与C2组相比,R2组ROS含量降低(P＜0.01);与R1组相比,R2组ROS含量升高(P＜0.01)。④ 与C1组相比,C2组ΔΨm降低(P＜0.01);与C2组相比,R2组ΔΨm升高(P＜0.01);与R1组相比,R2组ΔΨm有所降低,但无统计学差异。结论: 大鼠增龄过程中股四头肌线粒体出现Ca²⁺堆积、活性氧增多、线粒体膜电位下降、融合蛋白减少等现象,抗阻训练可有效改善这些变化。     

Effects of Acacia nilotica, A. polyacantha and Leucaena leucocephala leaf meal supplementation on performance of Small East African goats fed native pasture hay basal forages

Optimal utilisation of tannin-rich browse tree fodders including Acacia spp. foliages as crude protein (CP) supplements to ruminants in the tropics is limited by less available information on their feed nutritive potential. Two studies were conducted to: (1) determine rate and extent of ruminal dry matter (DM) degradability (DMD) and (2) investigate effect of sun-dried Acacia nilotica (NLM), A. polyacantha (PLM) and Leucaena leucocephala leaf meal (LLM) supplementation on growth performance of 20 growing (7–9 months old) Small East African male goats (14.6 ± 0.68 kg) fed on native pasture hay (NPH) basal diet for 84 days in a completely randomised design experiment in north-western Tanzania. The goats were randomised into four treatment groups consisting of five animals each. Three supplement diets: 115.3 g NLM (T₂), 125.9 g PLM (T₃) and 124.1 g LLM (T₄), which was used as a positive control, were supplemented at 20% of the expected DM intake (DMI; i.e., 3% body weight) to the three animal groups fed on NPH (basal diet) compared to the animals in a control group that were fed on NPH without browse supplementation (T₁).

NPH had significantly the lowest (P < 0.05) CP of 45.5 g kg⁻¹ DM compared to NLM, PLM and LLM (159, 195 and 187 g kg⁻¹ DM, respectively). NPH had higher (P < 0.05) fibre fractions; lower ruminal DM degradability characteristics and ME than NLM, PLM and LLM. Supplementation of the animals with browse resulted to (P < 0.05) higher average daily weight gains (ADG) of 157.1 g day⁻¹ in T₄ than the animals fed on T₂ (114.3 g day⁻¹) and T₃ (42.9 g day⁻¹), and even to those fed on T₁ (control), which lost weight (−71.4 g day⁻¹). Improved weight gains were mainly due to corrected feed nitrogen (N) or CP due to supplementation of the animals with browse fodder. Too low CP of the NPH would not meet the normal requirements of CP (80 g CP kg⁻¹ DM) for optimal rumen microbial function in ruminants. Higher ADG due to LLM (T₄) and NLM (T₂) supplementation suggest optimised weight gains due to browse supplementation (20% of expected DMI); while lower weight gains from supplementation with PLM (T₃) indicate the possible utilisation of A. polyacantha leaves to overcome weight losses especially during dry seasons.     

Synthesis of one dimensional tin selenides in supercritical amines

Three new crystalline tin selenide salts have been prepared from the reactions of [PPh₄]₂[Sn(Se₄₃] in supercritical solvents. The starting material pyrolyzes in supercritical acetonitrile to form [PPh₄]₄[Sn₆Se₂₁] (I), and it also reacts with SnSe in supercritical ammonia leading to a mixture of [PPh₄]₄[Sn₃Se₁₁]₂ (II). and [PPh₄]₂[Sn(Se₄)(Se₆)₂] (III). All three compounds have been characterized by single crystal X-ray diffraction. Crystallographic data: for I, C₉₆H₉₀P₄Se₂₁Sn₆, space group triclinic, P-1, A = 18.763(3), B = 24.600(4), C = 13.137(1) Å, = 102.63(1), β = 93.66(1), γ = 108.72(1)°, V = 5544(1) ų, Z = 2, R = 0.0350, R_W = 0.0317: for II, C₉₆H₈₀P₄Se₂₂Sn₆, space group monoclinic P2₁/c, A = 31.500(4), B = 16.572(3), C = 22.352(3) Å, β = 103.53(1)°, V = 11344(3) ų, Z = 4, R = 0.0771, R_W = 0.0664: for III, C₄₈H₄₀P₂Se₁₆Sn, space group monoclinic, C2/c, A = 25.381(2), B = 13.934(4), C = 19.465(3) Å, β = 121.587(8)°, V = 5867(2) ų, Z = 4, R = 0.0807, R_W = 0.0650. One of the compounds, [PPh₄]₂[Sn(Se₄(Se₆₂], is a molecular cluster while the other two complexes [PPh₄]₄[Sn₃Se₁₁]₂ and [PPh₄]₄[Sn₆Se₂₁], are one dimensional tin selenide chains. The structures of the two chains are related and consits of tetrahedral and distorted trigonal bipyramidal tin(IV) centers bridged by Se²⁻, Se₂²⁻ and Se₃²⁻ chains.     

Prediction of total fecal output in sheep fed silage using the Captec chrome controlled-release capsule

Six Finnish wethers (average weight, 52.3 kg) were used to determine the effectiveness of a controlled-release Cr₂O₃ bolus and the internal marker acid insoluble ash (AIA) for predicting fecal output. Wethers were fed grass silage for ad libitum intake. Each wether was dosed orally with one continuous-release Cr₂O₃ bolus (CRC) on the first day of the experiment. Chronology of the trial was as follows: Day 0 to 14, marker adaptation period; Day 15 to 21, total fecal collection; Day 22 to 23, fecal grab sampling every 4 h; Day 25 to 35, once-daily fecal grab sampling. Accuracy of marker-estimated fecal output derived from each method was compared within a marker with total fecal collection values using a paired t-test. Concentrations of AIA and Cr varied (P < 0.10) between sampling times. Accuracy of fecal output estimates was better with the controlled-release Cr₂O₃ bolus (r = 0.97; P = 0.03) than with AIA (r = −0.08; P = 0.89). Grab samples taken once produced reliable (r = 0.96; P = 0.02) estimates of fecal output of silage-fed wethers using the controlled-release Cr₂O₃ bolus. The controlled-release Cr₂O₃ bolus is a better marker than acid-insoluble ash for predicting fecal output of silage-fed wethers.     

Optimal production of sulphuric acid by Thiobacillus thiooxidans using response surface methodology

Response surface methodology was applied to determine the optimal medium composition for sulphuric acid production by an indigenous Thiobacillus thiooxidans. With a view to reducing the number of experiments and obtaining the mutual interactions between the variables, a 2⁴ full-factorial central composite design was employed for experimental design and analysis of the results. Four independent variables, KH₂PO₄, (NH₄)₂SO₄, MgSO₄ and elemental sulphur, in the growth medium were tested. Elemental sulphur was found to exhibit positive correlation with the sulphuric acid yield, whereas the other three variables showed no significant effect. No mutual interactions were found between elemental sulphur and each of the other three variables. The optimal composition of the growth medium to achieve the optimal production of sulphuric acid was determined as follows (g/l): KH₂PO₄=3.5, (NH₄)₂SO₄=4.9, MgSO₄=0.7 and elemental sulphur=23.7. The corresponding sulphuric acid production and dry cell weight were 38 662 ppm and 0.7 g/l, which are about 2.6- and 1.75-fold increase, respectively, compared with those using the conventional T. thiooxidans optimum growth medium.     

艾灸对缺氧缺血性脑损伤新生小鼠的治疗作用*

目的: 探讨艾灸对缺氧缺血性脑损伤新生小鼠行为学表现、脑组织形态结构的影响及作用机制。方法: 将106只出生7 d小鼠随机分为三组:假手术组(23只)、模型组(46只)和艾灸组(37只)。采用左侧颈总动脉结扎后再置于37℃密闭舱内进行低氧处理(氧气浓度为8%,100 min),制备新生儿缺氧缺血性脑病动物模型。艾灸组同模型组,并于造模后2 h开始艾灸“大椎”进行治疗,以后每日1次,每次35 min,连续治疗4 d。采用行为学测试评价小鼠的行为学表现;HE染色观察小鼠脑组织形态结构;Western blot技术检测小鼠脑组织超氧化物歧化酶2(SOD2)蛋白表达;比色法测定小鼠脑组织丙二醛(MDA)含量。结果: 假手术组小鼠行为表现正常,脑组织细胞排列致密整齐,脑组织SOD2蛋白表达量和MDA含量正常。与假手术组相比,模型组小鼠翻正反射、趋地反射、悬崖躲避试验时间延长(P＜0.05),抓力试验时间缩短(P＜0.05);脑组织细胞大量坏死脱落;脑组织SOD2蛋白表达量明显减少(P＜0.05)、MDA含量增加。与模型组相比,艾灸组小鼠翻正反射、趋地反射、悬崖躲避试验时间缩短(P＜0.05),抓力试验时间增长(P＜0.05);脑组织细胞排列较致密、整齐;脑组织SOD2蛋白表达量增多(P＜0.05)、MDA含量降低(P＜0.05)。结论: 艾灸能减轻缺氧缺血性脑病新生小鼠脑损伤、改善行为学表现,这可能与其增加脑组织SOD2蛋白的表达、降低MDA含量,从而提高抗氧化应激能力有关。     

Chromosomal aberrations in tire plant workers and interaction with polymorphisms of biotransformation and DNA repair genes

We evaluated chromosomal aberrations in lymphocytes of 177 workers exposed to xenobiotics in a tire plant and in 172 controls, in relation to their genetic background. Nine polymorphisms in genes encoding biotransformation enzymes and nine polymorphisms in genes involved in main DNA repair pathways were investigated for possible modulation of chromosomal damage. Chromosomal aberration frequencies were the highest among exposed smokers and the lowest in non-smoking unexposed individuals (2.5 ± 1.8% vs. 1.7 ± 1.2%, respectively). The differences between groups (ANOVA) were borderline significant (F = 2.6, P = 0.055). Chromosomal aberrations were higher in subjects with GSTT1-null (2.4 ± 1.7%) than in those with GSTT1-plus genotype (1.8 ± 1.4%; F = 7.2, P = 0.008). Considering individual groups, this association was significant in smoking exposed workers (F = 4.4, P = 0.040). Individuals with low activity EPHX1 genotype exhibited significantly higher chromosomal aberrations (2.3 ± 1.6%) in comparison with those bearing medium (1.7 ± 1.2%) and high activity genotype (1.5 ± 1.2%; F = 4.7, P = 0.010). Both chromatid- and chromosome-type aberration frequencies were mainly affected by exposure and smoking status. Binary logistic regression analysis revealed that frequencies of chromatid-type aberrations were modulated by NBS1 Glu185Gln (OR 4.26, 95%CI 1.38–13.14, P = 0.012), and to a moderate extent, by XPD Lys751Gln (OR 0.16, 95%CI 0.02–1.25, P = 0.081) polymorphisms. Chromosome-type aberrations were lowest in individuals bearing the EPHX1 genotype conferring the high activity (OR 0.38, 95%CI 0.15–0.98, P = 0.045). Present results show that exposed individuals in the tire production, who smoke, exhibit higher chromosomal aberrations frequencies, and the extent of chromosomal damage may additionally be modified by relevant polymorphisms.