Porcine urogenital disease.

Porcine urogenital disease is the result of an imbalance of the normal microflora of the urinary and reproductive tracts brought about by hormonal, environmental, and management-related stress factors. Production and economic losses can be substantial, and diagnosing and treating the problem can be frustrating. Through proper hygiene, facility design, and culling procedures, the severity of the problem can be minimized.     

Abattoir condemnation of pigs and its economic implications in Singapore

Losses due to mortality and rejection of carcases and viscera in a population of 2,959,607 pigs admitted for slaughter in Singapore abattoirs between 1984 and 1986 were studied. Mortality losses were 2822 pigs (9.5 per 10,000 admissions) while 3039 whole carcases (10.3 per 10,000 admissions) were condemned at post-mortem examination. The main reason for rejection of carcases was pyaemia (30.3%). Kidneys and livers were the two main organs of economic value rejected. Rejection of kidneys was primarily due to nephritis (54.8%) while liver condemnation was mainly due to cirrhosis (38.6%). The financial loss from abattoir rejection was S$5.27 millions or S$1.78 per pig admitted. The value of abattoir condemnation data as a tool in preventive medicine is discussed.     

Effect of Heat Stress on Grain Growth, Starch Synthesis and Protein Synthesis in Grains of Wheat (Triticum aestivum L.) Varieties Differing in Grain Weight Stability

The effect of heat stress on the components of grain weight was analysed in wheat ( Triticum aestivum L.) varieties differing in grain weight stability. The wheat varieties PBW154, Sonalika and Hindi62 were raised in the field (New Delhi, India; 77°12' E, 28°40' N, 228.6 m a.s.l.) at three dates of sowing: 19 November 1992 (DOS I), 14 December 1992 (DOS II) and 18 January 1993 (DOS III). The late-sown crop (DOS III) experienced 6–8 °C warmer temperatures during grain development than the crop sown at the normal time (DOS I). The heat susceptibility index (S) revealed that grain weight was less susceptible to heat in Sonalika and PBW154 than in Hindi62. Heat stress reduced both the grain growth duration (GGD) and the grain growth rate (GGR). The grain weight reduction in PBW154 and Sonalika was mainly due to a reduction in GGR, while that of Hindi62 was due to a reduction in GGD. In vivo studies on starch and protein synthesis in excised endosperm at 15, 25 and 35 °C revealed that both processes were more thermotolerant in Hindi62 than in PBW154. The grain starch content was stable in Hindi62 while that in PBW154 was significantly reduced under heat stress. The grain nitrogen content at maturity increased in both varieties under heat stress. It was concluded that the heat susceptibility of grain weight in Hindi62 was mainly due to a reduction in GGD, although GGR, starch and protein synthesis were more thermotolerant in developing grains of Hindi62 than in those of PBW154.     

Alfalfa Phytoestrogen Content: Impact of Plant Maturity and Herbage Components

Legumes contain a range of non‐nutritional phytochemicals that may have health‐promoting effects in humans. In this study, we determined the concentrations of four phytoestrogens (coumestrol, apigenin, luteolin and quercetin) in field‐grown alfalfa (Medicago sativa L.). Differences between plants of different stages of maturity, between plant parts, and different canopy segments were assessed. The concentration of individual phytoestrogen in whole herbage varied between 15 and 225 μg g^?1 dry matter (DM) and was strongly affected by stage of maturity. Coumestrol and apigenin concentrations were highest at early vegetative stages, luteolin and quercetin at early vegetative and late flowering stages. All phytoestrogens were found in lowest concentrations at the early flowering stage (average 68 μg g^?1 DM); stage at which alfalfa is usually harvested when used as a forage source for animals. At vegetative stages, apigenin was the predominant phytoestrogen in herbage followed by coumestrol, the reverse being observed upon initiation of flowering; luteolin and quercetin were found at all stages in similarly lower concentrations. Concentrations of luteolin, quercetin and apigenin were 225, 410 and 690 % greater, respectively, in flowers than in leaves or stems; coumestrol concentration was similar between plant parts. In flowers and stems the predominant phytoestrogens were apigenin and quercetin, followed by coumestrol and luteolin. Similar concentrations (average 26 μg g^?1 DM) of each of the four phytoestrogens were found in leaves. Concentrations through the herbage canopy varied and were greatest at >60 cm from the soil surface for apigenin and coumestrol, but greatest at >60 and 0–20 cm for quercetin and at 0–20 cm for luteolin. The results suggest that if alfalfa is to be used as a source of phytoestrogens and is harvested for the production of herbal supplements or nutraceuticals, management will need to be adapted.     

Effect of Oestrous Synchronization with Estradiol 17β and Progesterone on Follicular Wave Dynamics in Dairy Heifers

An experiment was designed to evaluate the effects of estradiol‐17β (E17β) on follicular wave dynamics and ovulatory response in Holstein heifers receiving either a progestogen ear‐implant (Crestar^®; Intervet International b.v. Boxmeer, The Netherlands) or an intravaginal progesterone‐releasing device [controlled internal drug release‐bovine device (Eazibreed, CIDR‐B^®; Bodinco BV, Alkmaar, The Netherlands)]. For comparison, another group of heifers was also synchronized using Crestar plus an injection of estradiol valerate (EV) and norgestomet as recommended by the pharmaceutical company. Twenty 20–22‐month‐old cycling Holstein heifers were allocated to one of the following treatment groups at random stages of the oestrous cycle: (I) simultaneous insertion of Crestar and intramuscular injection of 3 mg norgestomet and 5 mg EV (Crestar 9 + EV 9); (II) simultaneous insertion of Crestar and intramuscular injection of 5 mg E17β (Crestar 9 + E17β 9); (III) insertion of Crestar followed 2 days later by intramuscular injection of 5 mg E17β (Crestar 9 + E17β 7); or (IV) insertion of CIDR‐B device followed 2 days later by intramuscular injection of 5 mg E17β (CIDR 9 + E17β 7). The CIDR‐B or Crestar implants were removed after 9 days and all heifers received 500 μg Cloprostenol (Estrumate^®, Pitman‐Moore Nederland BV, Houten, The Netherlands). Ovarian ultrasonographic examinations were performed once daily during the synchronization period using a B‐mode scanner equipped with a 7.5 MHz linear‐array transrectal transducer. In addition, heifers were scanned every 12 h after implant/device withdrawal until 3 days after ovulation in order to monitor follicular activity, detect ovulation and subsequent early luteal formation. Detection of oestrus was performed every 6 h for 4 days after device/implant removal. Oestrus was observed 24–32 h before ovulation in all heifers. The mean hours interval from treatment withdrawal to ovulation was not significantly different (84.0 ± 16.5, 77.6 ± 4.1, 73.6 ± 4.1 and 64.0 ± 4.4 h for treatments I, II, III and IV, respectively; p > 0.1). However, the variance for heifers treated with EV + norgestomet was significantly larger (Levene’s Test; p < 0.01) than those treated with E17β. All E17β treatments resulted in dominant follicle suppression and a new wave emerged 4.1 days after treatment compared with 6.6 days for the EV + norgestomet treatment (p < 0.05). The time from emergence of the new ovulatory wave to ovulation was longer for the new wave that emerged after E17β treatment (9.2 ± 0.3 days) than after EV + norgestomet treatment (6.9 ± 0.4 days; p < 0.05). The results of this study suggest that the four treatments used were effective in inducing synchronous behavioural oestrus and ovulation. However, a higher degree of oestrus and ovulation synchrony was observed in heifers treated with E17β than in heifers treated with EV + norgestomet. Synchronization treatments with exogenous E17β or EV + norgestomet at the time of progestin device insertion (Crestar or CIDR‐B) or 2 days later in heifers can regulate a different emergence pattern of ovarian follicular development in randomly cyclic heifers. The E17β was effective in inducing follicular suppression and resulted in the consistent emergence of a new follicular wave.     

Effects of Benzyl Adenine and Abscisic Acid on Grain Yield and Yield Components in Triticale and Wheat

Grain yield and yield components (grains per ear, grain weight, 1000-grain weight, ear weight, ear seed ratio and dry matter partitioning between ear and seed) were examined in a wheat genotype (PBW-343) with well-filled grains and a Triticale genotype (DT-46) with poorly filled grains (showing grain shrivelling) grown in pots. Six days after anthesis (DAA), benzyladenine (BA) @2 µg ear⁻¹ and abscisic acid (ABA) @4 µg ear⁻¹ were injected at the base of the mother shoot ear in both species. It was observed that, in both wheat and Triticale , BA increased the grain weight, grain number and partitioning of dry matter between ear and seed, whereas ABA decreased the grain weight, grain number and dry matter partitioning between ear and seed. However, these decreases were slower in Triticale than in wheat. BA treatment increased the grain dry matter accumulation, which in turn resulted in better filling of grains and increased the grain weight in both wheat and Triticale . The average grain weight of Triticale was lower than that of wheat. Thus, it appears that variation in grain weight between wheat and Triticale might be due to different availabilities of growth-promoting phytohormones such as cytokinins and assimilates.     

Cryopreservation of Embryos of Farm Animals

This review contains two parts. The first part is devoted to the significant steps in cryopreservation of mammalian embryos with emphasis on cattle and sheep that serve as models of reference. These steps are: (1) shortening of cooling and warming processes; (2) addition and dilution of cryoprotectant in one step; (3) introduction of plastic straw as a freezing and dilution container; (4) the choice of ethylene glycol as the quite universal cryoprotectant because of its low toxicity and high permeability; (5) vitrification, a cryopreservation method which enable passage from the liquid to the solid state by extreme elevation of viscosity due to high concentration of cryoprotectants and very rapid cooling. There are several vitrification solutions which contain dimethyl sulphoxide, glycerol, ethylene glycol, or a mixture of them, as basic cryoprotectants. The second part considers some factors affecting the efficiency of cryopreservation concerning (i) the origin of embryos and (ii) the stage of development and species. The origin of embryos (in vivo versus in vitro): in vitro embryos show a chilling and freezing sensitivity associated with their lipid content which can be modified by the culture conditions. Both conventional freezing and vitrification have been used and it seems that vitrification is more adapted to in vitro embryos when some modifications of initial protocols are carried out, particularly the rate of cooling. Thus considerable progress has been achieved by using the open pulled straw method of Vajta which enables the use of a minimum volume of freezing medium (0.5 μl) and a very high cooling rate that permits rapid traversal of the damaging temperature zone, corresponding to chilling sensitivity. The stage of development and species: not only are there differences between species at the same stage of development but in the same species all stages of development do not survive equally under the same freezing protocol. In cattle for example, oocytes and early stages of development in vivo or in vitro do not survive whereas compacted morulae and blastocysts survive very well. In the pig hatched blastocysts survive better than the other stages. Horse embryos have special characteristics that pose problems for successful freezing. In conclusion, a lot of work remains to be done to define fundamental characteristics of embryos of certain species (pig, horse) and of embryos of some stages or of oocytes.     

Physeal Fractures in the Horse II. Management and Outcome

Seventy physeal fractures in horses were initially managed by euthanasia (18), stall confinement (25), application of a cast (7), or internal fixation (20). Of the 52 physeal fractures initially managed with stall confinement, a cast, or internal fixation, 23 (44%) healed and 13 (25%) of these horses became sound. The number of horses less than 4.5 months of age with pressure physeal fractures that became sound was significantly higher (p < 0.05) than the number of horses greater than 4.5 months of age. The number of horses with functional, pain-free limbs (sound horses) or functional limbs (lame horses) was not significantly different (p > 0.05) for Salter-Harris Type I, II, III, or IV pressure physeal fractures; however, critical examination for growth disturbances was not performed. The number of horses with pressure or traction physeal fractures of less than 5 days duration prior to presentation that healed or became sound was not significantly different (p > 0.05) when compared with those horses with fractures of greater than or equal to 5 days duration.     

An evaluation of the Olsen test as a measure of plant-available phosphorus in grassland soils derived from basalt parent material

Abstract. Anecdotal and circumstantial evidence have suggested that the Olsen test underestimates plant-available phosphorus (P) in basaltic soils in Northern Ireland. Therefore, the ability of this test to predict plant-available P in basaltic (and non-basaltic) soils was investigated by regressing Olsen-P data against herbage P indices calculated from plant tissue test data using the diagnosis and recommendation integrated system. The average Olsen-P concentration for a range of fields situated on basaltic soils was considerably lower than the average Olsen-P concentration for a range of fields situated on non-basaltic soils, and yet mean sward P status, as given by the herbage P indices, was similar for both groups of fields. Herbage P indices were also much better correlated with Olsen-P measurements in non-basaltic soils than in basaltic soils. Furthermore, at low Olsen-P values (≶9mgPL⁻¹) some swards on basaltic soils were genuinely deficient in P, while others were sufficient or even in surplus for this nutrient. The results confirm that Olsen-P is inadequate as a predictor of plant-available P in basaltic soils. It is concluded that an alternative soil test is needed to provide a reliable assessment of plant-available P in basaltic soils, to prevent overuse of fertilizer and manure P and to minimize the amounts of P entering local watercourses.