Milk production, water consumption, and somatic cell count responses of cows subject to one to two volts of alternating current.

A dairy farm located in central New York was visited because of complaints of electrical shock in the farmhouse shower and the milk house sink. As much as 2 volts AC of potential difference was measured between the waterline and the cow platform (cow-contact voltage). Voltage was coming from the primary neutral wire. The farm's electrical service was modified so that the farmstead could be connected or disconnected from the primary neutral wire at 2-week intervals for 12 weeks. When connected to the primary neutral wire, voltage between waterline and floor ranged between 0 and 1.8 volts, producing estimated current flow through cows of 3.6 to 4.9 mA; when disconnected from primary neutral wire, voltage between waterline and floor was less than 0.1 volt. There was no difference in mean milk production, bulk tank milk somatic cell count, or water consumption among periods when cows were exposed or unexposed to voltage. Despite statistical nonsignificance, the values for somatic cell count were lower and water consumption was higher when cows were exposed to voltage than when they were not.     

Seasonality of cattle feed sources in Pabna,Bangladesh

Summary Cattle feed sources were studied at village level in Pabna district, Bangladesh. A large quantity of feed was offered. In the monsoon the average amount of DM fed to a mature animal of 210kg was 7·1kg d⁻¹, consisting of about equal amounts of straw, weeds and leaves. In winter animals grazed for an average of 3·7hd⁻¹ and were supplemented with 3·9kgDMd⁻¹ (two-thirds straw). In summer they were offered 5·4kgDMd⁻¹ (one-third straw and two-thirds weeds and leaves) and they grazed for 0·5hd⁻¹. The major limiting constraint on cattle production is the quality of the feed offered, particularly in the monsoon period when animals cannot graze. In future, feed quality will become even more of a problem because grazing lands are gradually disappearing.

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Resumen Se estudiaron las fuentes de alimentos para el ganado a nivel de villorrio en el distrito de Pabna, Bangladesh. Se ofreció gran cantidad de alimento. En la época de monsones, la cantidad promedio de materia seca (MS) suministrada a un animal maduro de 210kg fue 7·1kgd⁻¹, la que consistió en cantidades iguales de paja, malezas y hojas. En invierno los animales pastorearon un promedio de 3·7hd⁻¹ y fueron suplementados con 3·9kgMSd⁻¹ (dos tercios paja). En verano se ofrecieron 5·4kgMSd⁻¹ (un tercio paja y dos tercios malezas y hojas), pastoreando los animales 0·5hd⁻¹. La mayor limitante encontrada, fue la calidad del alimento ofrecido, particularmente en la época de monsones, cuando los animales no pueden pastorear. En el futuro, la calidad del alimento empeorará, ya que las pasturas están desapareciendo gradualmente.

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Résumé Les disponibilités alimentaires du bétail ont été étudiées dans le district de Pabna (Bangladesh), au sein d'un village. Une grande quantité de nourriture fut offerte. Lors de la mousson, la quantité moyenne de matière sèche présentée à un adulte de 210kg était de 7,1kg/j, consistant en proportion à peu près équivalente de paille, mauvaises herbes et feuilles. En hiver, les animaux paturaient en moyenne 3,7kg/j et recevaient un supplément de 3,9kg/j de matières sèchs (deux tiers de paille). En été, on leur a distribué 5,4kg/j de matières sèches (un tiers de pailles, deux tiers de mauvaises herbes et de feuilles) et ils paturaient pendant une demi-heure (0,5h/j). Le facteur majeur limitant réside dans la qualité nutritive offerte, particulièrement pendant la mousson, période où les animaux ne peuvent pas paturer. La qualité de l'alimentation risque de devenir encore plus problématique du fait de la disparition progressive des paturages.

     

Serological responses of specific pathogen-free foals to equine herpesvirus-1: primary and secondary infection, and reactivation.

Serum antibody (virus neutralisation, complement fixation, IgM and IgG) responses to equine herpesvirus-1 (EHV-1) infection were measured in six foals which were initially free from EHV-1 and EHV-4 infection and maternally-derived antibodies. Following primary infection, high titres of virus neutralisation and complement fixation antibodies were detectable against EHV-1, however, corresponding antibody levels against EHV-4 were low or inapparent, although the two viruses share a number of cross-reactive epitopes. In addition, following the primary infection with EHV-1, IgM levels increased before those of IgG, virus neutralisation and complement fixation antibodies, peaked sooner and thereafter declined. Stimulation of IgM levels was observed on secondary infection with EHV-1 given 61 days later. In contrast, IgG, virus neutralisation and complement fixation antibodies following primary infection were more sustained and no increase in their levels was observed on secondary infection. No consistent changes in IgM or IgG levels were seen after administration of dexamethasone to reactivate latent virus.     

辣椒新雄性不育系P-MS的选育

辣椒杂种一代的制种迄今几乎全靠人工授粉进行，需要花费大量的人工或劳动力。利用雄性不育繁制杂交种子已在不少农作物和园艺作物上得到利用，至于辣椒雄性不育的研究于1958年曾有过报道(Peterson，1958)。辣椒细胞质雄性不育由与S细胞质互作的隐性基因rf控制，但雄性不育的表达对温度敏感，在冷凉条件下会产生可育花粉(Peterson，1958；Shifriss ＆ Guri 1979；Shifriss，1997)。     

Demography of Abutilon theoprasti and Setaria faberi in three crop rotation systems

Field experiments were conducted to characterize the demography of Abutilon theophrasti and Setaria faberi in a conventionally managed 2‐year (maize/soya bean) rotation, and in 3‐year (maize/soya bean/triticale + red clover) and 4‐year (maize/soya bean/triticale + lucerne/lucerne) rotations managed with 72% and 79% lower herbicide inputs respectively. Rates of weed seedling recruitment, seedling survival and adult plant fecundity were determined for populations in each phase of each rotation and used to calculate annual rates of weed population change, Δ. In both years of the study, Δ for A. theophrasti populations declined or remained stable in all three rotation systems. Despite greater rates of seedling survival and fecundity in maize and soya bean in the 3‐ and 4‐year rotations, increases in Δ for A. theophrasti populations were prevented in these systems because of low fecundity in triticale and low seedling survival and fecundity in lucerne. For Setaria faberi populations, Δ remained stable in the 2‐year rotation, increased in the 3‐year rotation in both years, and increased in the 4‐year rotation in 1 year. The results of this study indicate that when herbicide use is reduced, rotations that include triticale and lucerne can facilitate the suppression of A. theophrasti. Rotations that include lucerne can contribute to restraining S. faberi population growth, given adequate levels of seedling mortality in this crop.     

Small intestine and small colon neuropathy in equine dysautonomia (grass sickness)

The number of neurons in the coeliacomesenteric ganglia and the myenteric and submucosal plexuses of the jejunum, ileum and small colon, and the pathological changes induced in them, were studied in various types of equine dysautonomia. In all forms of dysautonomia, severe and extensive neuron loss and damage occurred in the ileum. In acute and subacute dysautonomia, jejunal neuron loss and damage were severe, but in chronic cases significantly less loss or damage occurred. The damage followed the same pattern in the small colon but it was always less obvious than in the jejunum. The distribution of the damage was uniform within a segment of the intestine. In fatal cases of dysautonomia, the clinical severity and duration of illness seems, in most instances, to be related to the amount of neuronal disruption occurring in the jejunum. Severe disruption results in acute/subacute dysautonomia, while milder damage leads to the chronic form.No case of dysautonomia was encountered in which enteric neuron loss and damage occurred without significant neuronal disruption also occurring in the coeliacomesenteric ganglia.Ileal neuronal damage and loss are not invariably worse than that in the jejunum, and the possible reasons for this, together with the relationship between neuronal damage and possible causes of dysautonomia, are discussed.Abbreviations H&E haematoxylin and eosin Deceased. Formerly of the Moredun Research Institute, 408 Gilmerton Road, Edinburgh, EH17 7JH, UK     

Effect of milk sampling techniques on milk composition, bacterial contamination, viability and functions of resident cells in milk.

Three different milk sampling techniques were evaluated during milk sampling: a direct aseptic collection from the udder through a sterile cannula was used as the reference technique, compared with either a manual or a mechanical sampling method. In this study 30 high-yielding Holstein-Friesian dairy cows at different stages of lactation and free of udder infection were used. For each milk sample, the influence of milk sampling techniques was determined for the following parameters: somatic cell count, milk composition, bacterial contamination, viability, in vitro phagocytosis and overall killing of Staphylococcus aureus Newbould 305, and cellular chemiluminescence. Because milk sampling occurred throughout lactation, the differences between early, mid- and late lactation were estimated. It was concluded that bacterial contamination was not significantly different in manual milking samples and the reference technique; bacterial contamination was, however, significantly (P < 0.001) higher in machine milking samples than in the reference technique. Among the different sampling techniques, no significant effects on SCC, milk composition, viability and functions of the cells isolated from milk were observed. It was found that viability, intracellular killing and cellular chemiluminescence of milk PMN were significantly lower (P < 0.05) in early lactation compared to mid-lactation. Phagocytosis was significantly (P < 0.05) higher in early lactation compared to mid- and late lactation, and no significant differences were observed between mid- and late lactation. From this study, it can be concluded that despite a higher bacterial contamination obtained with the mechanical sampling method, the 3 milk sampling techniques described in this study can be used for the evaluation of milk cell functions.     

Sugar beet mash silage as a component of a total-mixed-ration for dairy cows--effects on parameters of digestion and animal performance.

Sugar beet mash silage (BMS) was offered in amounts up to 35% of DM to dairy cows as a component of a total-mixed-ration (TMR). Barley and molasses in the control ration were replaced by BMS half in ration BMS 1/2 and in total in ration BMS 1/1 on the basis of the calculated contents of net energy for lactation. Two trials were carried out. In trial I each ration was tested on parameters of rumen fermentation and digestibility of crude nutrients using 4 Holstein cows with rumen fistula. Chewing activity was tested on 2 Holstein cows for each ration. With the BMS rations the ruminal NH3 concentration was lower and the drop in pH was less than in the control ration. The pattern of volatile fatty acids in the rumen fluid from the BMS groups tended towards more propionic and butyric acid. The feeding of BMS showed no negative impact on chewing and rumination. Energy digestibility raised significantly from 59.8% in the control ration to 72.6% in the BMS 1/1 ration. In trial II the same rations were fed in a change-overdesign to a herd of 24 Holstein cows to test feed intake and animal performance. The results showed no significant effects of BMS rations on DM intake and milk production. The results of both trials indicate that even high amounts of cereals can be replaced by BMS without negative effects on rumen fermentation, milk yield and milk composition with slight drop in fat content. For a better handling of BMS, it is of advantage to include it in a TMR.