Opioidergic inhibition of flexor and extensor reflexes in the rabbit.

1. Recordings were made from gastrocnemius medialis (GM), semitendinosus (ST) and tibialis anterior/extensor digitorum longus (TA/EDL) motor nerves during mechanical and electrical stimulation of the skin of the foot in decerebrated and spinalized rabbits. 2.

Nutritional and endocrinological manipulation of lean deposition in forage-fed steers.

The effect of supplementing grass silage with fishmeal on growth, muscle composition and the rate of muscle protein synthesis was investigated in young Friesian steers with and without oestradiol implants. The effect of the beta-adrenergic agonist cimaterol was simultaneously investigated in animals fed on silage alone. Treatments lasted for 9 or 10 weeks.

Identification of a tomato gene for the ethylene-forming enzyme by expression in yeast.

The ethylene-forming enzyme (EFE), which catalyzes the last step in the biosynthesis of the plant hormone ethylene, has never been purified and no molecular probes are available. Recently, a putative cDNA clone for tomato EFE (pTOM13) has been identified by inhibiting ethylene synthesis with an antisense gene expressed in transgenic plants. A direct test of its function has been made by expression of a pTOM13 gene in Saccharomyces cerevisiae.

Prediction of the apparent metabolizable energy content of fats fed to broiler chickens.

Soybean oil and tallow acid oil were blended in the ratio 75:25, 50:50, and 25:75 to give 3 blends (A, B, and C) of increasing free fatty acid (FFA) content but decreasing ratio of unsaturated to saturated fatty acids (U:S). Tallow and soybean acid oil were blended in similar proportions to give three blends (D, E, and F) of increasing FFA content and increasing U:S ratio. The six fats were incorporated into a basal diet at rates of 40, 80, and 120 g/kg.

PCR based gene engineering of the Vibrio harveyi lux operon and the Escherichia coli trp operon provides for biochemically functional native and fused gene products.

The polymerase chain reaction (PCR) was applied to clone the luxA and luxB genes from Vibrio harveyi, and the trp poL (promoter operator leader) region and the trpB and trpA genes from Escherichia coli. PCR-derived luxA/B and trpB/A genes were shown to express bacterial luciferase and tryptophan synthase respectively, when introduced into E. coli on a plasmid cloning vehicle.

The influence of open-top chambers on the growth and development of field bean.

In 1988, open-top chambers (OTCs) based on the Raleigh (USA) design were used to investigate the effect of ambient pollutants on field-sown Vicia faba cv, Ticol. This paper reports an aspect of this study in which the effect of the chamber itself on crop growth and development was investigated. Non-filtered chamber (NF OTC) microclimates were typically 0.

The influence of free fatty acid content and degree of saturation on the apparent metabolizable energy value of fats fed to broilers.

To determine the influence of free fatty acid (FFA) content on the subsequent nutritive value of fats, the following were studied: tallow (FFA content of 138.4 g/kg) and tallow acid oil (FFA = 952.1 g/kg) in Experiment 1; palm oil (FFA = 57.

Expression of a truncated tomato polygalacturonase gene inhibits expression of the endogenous gene in transgenic plants.

Tomato plants were transformed with a chimaeric polygalacturonase (PG) gene, designed to produce a truncated PG transcript constitutively. In these plants expression of the endogenous PG gene was inhibited during ripening, resulting in a substantial reduction in PG mRNA and enzyme accumulation. This inhibition was comparable to that achieved previously using antisense genes.

Beta-adrenoceptors and the effect of beta-agonists on protein metabolism in ovine primary muscle cultures.

The beta-adrenergic receptors of differentiated ovine muscle cultures derived from either fetal or pre-pubertal lambs were characterized by binding of (+/-)-[3H]CGP-12177, directly to intact cells in monolayer. Fetal muscle cells contained a single class of specific and saturable binding sites which had a dissociation constant (Kd) of 0.38 x 10(-9) M and a binding capacity of 55.

The effect of patterns of rumen fermentation on the response by dairy cows to dietary protein concentration.

Four groups of seven dairy cows were given hay plus high-fibre concentrates based on sugar-beet feed (hay-concentrate, 40:60 w/w) or high-starch concentrates based on flaked maize (hay-concentrate, 20:80 w/w), with a crude protein (nitrogen x 6.25) content of either 160 or 220 g/kg dry matter, over weeks 4-18 of lactation. Performance during week 3 of lactation, when all cows were fed on a standard ration, was used as a covariate.

Muscle composition of steers treated with the β-agonist, cimaterol.

The effect of the β-adrenergic agonist, cimaterol, on the nature and amount of collagen in three individual muscles (Longissimus dorsi, Vastus lateralis and Semitendinosus) from young steers was investigated. β-Agonist-treated animals showed similar rates of liveweight gain to those of control animals but the weight and protein content of the Longissimus dorsi and Vastus lateralis muscles were significantly increased (muscle weights 1216 versus 1494 g, P < 0·05; 514 versus 642 g, P < 0·01, respectively, for control and cimaterol animals). The Semitendinosus muscle, however, showed no significant increase in weight or protein content (P > 0·05).

Influence of age, chemical composition and rate of inclusion on the apparent metabolisable energy of fats fed to broiler chicks.

1. Vegetable oil (VO) and tallow (T) were evaluated at rates of 25, 50, 75, 100 and 125g/kg in a basal diet with broiler chicks aged 1.5, 3.

Identification of cDNA clones for tomato (Lycopersicon esculentum Mill.) mRNAs that accumulate during fruit ripening and leaf senescence in response to ethylene.

Changes in gene expression during foliar senescence and fruit ripening in tomato (Lycopersicon esculentum Mill.) were examined using in-vitro translation of isolated RNA and hybridization against cDNA clones.During the period of chlorophyll loss in leaves, changes occurred in mRNA in-vitro translation products, with some being reduced in prevalence, whilst others increased.

The relation between dietary restriction or clenbuterol (a selective beta 2 agonist) treatment on muscle growth and calpain proteinase (EC 3.4.22.17) and calpastatin activities in lambs.

1. Lamb growth trials were designed to modify growth and protein content of muscle by diet and also by beta-agonist treatment, and to correlate any changes to the activities of calpain proteinases (EC 3.4.

Protein metabolism in the rumen of silage-fed steers: effect of fishmeal supplementation.

1. Ryegrass (Lolium perenne cv. Cropper) silage was given to four Friesian steers (initial live weight (LW) 172 kg) alone or with a fishmeal supplement (150 g fresh weight/kg silage dry matter (DM)) in a balanced two-period change-over design.

Initial studies on leucine metabolism in the rumen of sheep.

1. [3H]leucine infused directly into the rumen of sheep labelled microbial protein and, when compared with the specific activity of the rumen free-leucine pool, indicated that 50% of the bacterial protein leucine originated from the rumen free-leucine pool. 2.

Interactions between fats of differing chemical content: apparent availability of fatty acids.

1. Tallow (A) and rape oil (E) were obtained for evaluation. They were blended in the ratios A95:E5, A90:E10 and A80:E20.

Interactions between fats of differing chemical content: apparent metabolisable energy values and apparent fat availability.

1. Tallow (A) and rape oil (E) were obtained for evaluation. They were blended in the ratios A95:E5, A90:E10 and A80:E20.

TILLERING AND LEAF AREA OF WINTER BARLEY EXPOSED TO SULPHUR DIOXIDE IN THE FIELD.

Winter barley (Hordeum vulgare L., cv. 'Igri'), grown as a crop in the field, was exposed to SO concentrations ranging from 40 to 200 ppb [parts per billion (10 ) by volume] above ambient.

Suppression of plasma FSH concentrations with bovine follicular fluid blocks ovulation in GnRH-treated seasonally anoestrous ewes.

The specific requirement for FSH in the final stages of preovulatory follicle development was assessed in seasonally anoestrous ewes given 2-h injections of GnRH (250 ng/injection), with (N = 10) or without (N = 10) concurrent treatment with bovine follicular fluid (bFF: 2 ml given i.v. at 8-h intervals).

Thermal interaction between animal and microclimate: a comprehensive model.

An equation based on heat transfer theory is developed to predict the rate of heat loss from a homeothermic vertebrate to the environment, specified by the air temperature, humidity, windspeed and radiation receipt. The analysis incorporates the animal's thermoregulatory responses--sweating ability, vasomotor action, and regulation of body-core temperature, metabolic and respiratory rate. The loss of heat and water vapour from cattle is used as an illustration, and particular attention is given to their heat balance in hot environments.