Effects of supplementing pregnant heifers with methionine or melatonin on the anatomy and other characteristics of their lateral hind claws

Three groups of four primiparous Holstein-Friesian heifers were fed throughout pregnancy either a control diet or that diet supplemented with either 5 to 6 g per day of rumen-protected intestinally available methionine or 25 mg melatonin. They were euthanased three days after calving. The dietary supplements had no effect on the impression hardness or the concentrations of cysteine and methionine in samples of claw horn collected from a range of sites, or on the areas of erosion in the sole and heel. Significant differences were recorded for the hardness of the horn in the order wall >sole >heel. These differences were associated with higher concentrations of cysteine and lower concentrations of methionine in samples of horn from the dorsal wall than in samples from the prebulbar region of the sole. There were no significant differences attributable to the dietary supplements in the soft tissue anatomy of the solear dermis and epidermis.

Improvement of the nutritive value of soybean meal by protease and alpha-galactosidase treatment in broiler cockerels and broiler chicks

1. Tube-fed broiler cockerels were used in three experiments to measure the effect of different enzyme treatments on true metabolisable energy (TME) and true nitrogen digestibility (TND) of commercial solvent-extracted, heat-treated soybean meal (SBM). 2. In experiment 1, proteases P2 and P3 (from Aspergillus niger) and alpha-galactosidase (from A. oryzae) improved TME and TND while protease P1 (from Bacillus subtilis) had little effect. The effects of enzyme treatment were similar whether treatment was applied by pre-incubation of enzymes (proteases P1, P2 and P3, 1.0 g/kg; alpha-galactosidase, 0.1 g/kg) with SBM for 2 h at 50 degrees C or by simple mixing of enzymes (proteases P1, P2 and P3, 0.25 g/kg; alpha-galactosidase, 0.1 g/kg) with SBM prior to feeding. 3. In experiment 2, the effects of mixing SBM with each of protease P1 (0 or 0.25 g/kg), protease P3 (0 or 0.25 g/kg) or alpha-galactosidase (0 or 0.1 g/kg) alone or in all possible combinations were studied. Effects of protease P1 were limited, but protease P3 and alpha-galactosidase improved TME and TND. There were significant interactions between protease P3 and alpha-galactosidase for both TME and TND; the response when enzymes were applied together was less than that expected from application of the enzyme preparations individually. 4. In experiment 3, the effect of varying the concentration of protease P3 (0, 0.1, 0.25 and 1.0 g/kg SBM dry matter) and alpha-galactosidase (0, 0.025, 0.0625 and 0.25 g/kg SBM dry matter) mixed with SBM alone or in all possible combinations of protease P3 and alpha-galactosidase were assessed. Increases in TME and TND for both enzymes were non-linear with the greatest response occurring at the lowest concentration of each enzyme. There were also interactions between the two enzyme preparations. 5. Finally, either protease P3 (0, 0.1 and 1.0 g/kg SBM dry matter) or alpha-galactosidase (0, 0.025 and 0.25 g/kg SBM dry matter) were mixed with SBM alone or in all possible combinations and treated SBMs incorporated into semi-purified diets containing 450 g SBM/kg as the sole source of dietary N and offered to growing broiler chicks for 21 d. Similar patterns of increases in chick growth rate and diet digestibility to those recorded in experiment 3 were obtained when protease P3 and alpha-galactosidase where included in the diets. 6. It is concluded that responses measured by tube-feeding SBM treated with protease P3 and alpha-galactosidase were similar to responses obtained with growing broiler chicks. Further, these responses were obtained by simple addition of enzymes to diets and nutritive value of SBM was improved by both protease and alpha-galactosidase treatment.

The potential for the improvement of the nutritive value of soya-bean meal by different proteases in broiler chicks and broiler cockerels

1. The potential for improving the nutritive value of commercial solvent-extracted, heat-treated soya-bean meal (SBM) by protease treatment was measured using growing broiler chicks and tube-fed broiler cockerels. 2. SBM was pre-treated (50 degrees C for 2 h) with water alone; at alkaline pH (initial pH 8.25) with and without protease P1 (isolated from a Bacillus species) or at acid pH (initial pH 4.5) with and without protease P2 (isolated from an Aspergillus species) and incorporated into diets (290 g SBM/kg diet) for broiler chicks (20 chicks/treatment). Only protease P2 treatment improved chick performance; from 7 to 28 d of age, chicks fed on treated SBM had greater feed intakes and gained more weight than chicks fed on untreated SBM. Both proteases P1 and P2 significantly reduced chick serum anti-soya antibodies while protease P2 treatment increased apparent ileal nitrogen (N) digestibility and apparent N retention across the whole digestive tract. 3. Two tube-feeding experiments established that, of the treated SBMs used in experiment 1, only protease P2 treatment improved apparent N digestibility and true metabolisable energy. Also it was shown that increasing the temperature at which treated SBM was dried to 60 degrees C, compared with freeze-drying or drying at 50 degrees C reduced apparent N digestibility and true metabolisable energy of SBM with no significant interactions between enzyme treatment and drying temperature for both apparent N digestibility and TME. 4. It is concluded that, overall, the nutritional value of SBM assayed in a growth trial and by tube feeding was improved by treatment with protease P2 and not by treatment with protease P1.

Using landscape ecology to focus ecological risk assessment and guide risk management decision-making

Ecological risk assessment (EcoRA) generally suffers from limited application of ecological knowledge in the definition and characterization of real-world sites. Not surprisingly, most remediation decisions, which follow, have little or no relationship to the valued ecological resources of the site or the broader region. The practice has evolved to favor engineering-based mitigation strategies, which eliminate excess chemical concentrations at sites, or otherwise break exposure pathways, but which may not be ecologically beneficial. The heavy emphasis of EcoRA on toxicity threshold levels tends to focus dollars on clean up of small areas or volumes with high concentrations. Moreover, intrusive remediation technologies often render an area uninhabitable to the very species that were to be protected. Infusion of ecological knowledge into EcoRA has been difficult. Most professional ecologists choose not to venture into the messy applied fields, leaving their impressive knowledge untapped. Moreover, narrowly defined responsibilities within government circles can limit cooperation and coordination. The realization that land use activities often have greater adverse consequences to wildlife than do chemicals provides an opportunity to change attitudes and practices. We are developing procedures that incorporate landscape features into the environmental management process. Specifically, we are using an iterative approach to: a) identify scenarios where habitat value is important in EcoRAs; b) guide selection of appropriate assessment species, i) keyed to wildlife distribution ranges; ii) keyed to a database of habitat suitability models; iii) cross-linked with the EPA exposure handbook species; iv) referenced to wildlife distributions (e.g., breeding bird survey); c) define data collection needs for reconnaissance-, screening-, and definitive-level characterization of habitat quality for potential assessment species; d) generate spatially explicit descriptions of habitat quality for various assessment species; and e) allocate exposure estimates using both habitat quality and spatial variations in chemical concentration. These refinements in theEcoRA process are expected to improve risk estimates and provide valuable information to be used instructuring risk management options. The approach can guide the planning process so that an assessment considers the most relevant species of the area and defines the relevant parameters to be measured. In risk characterization, these data are used to calculate more realistic exposure assessments. In guiding remediation, the approach logically considers a wider range of land management options than are considered at most sites today. For example, habitat enhancement can be used to draw animals away from contaminated zones. Contaminated localities that also have poor-quality habitat may be allowed to go through a slower, less costly bioremediation process until the risk level is lowered to acceptable levels. And direct comparisons of lost resources stemming from destructive remediation options can be assessed instead of merely focusing on the lowering of contaminant concentrations. This paper presents the conceptual foundation for incorporating landscape ecology into the risk assessment process.

Effects of metals and arsenic on riparian communities in southwest Montana

: Concentrations of metals and arsenic in floodplain soils of Silver Bow Creek and the upper Clark Fork River in southwest Montana were related to phytotoxic responses by individual plants in laboratory experiments, vegetative community structure and composition in the field and wildlife habitat. Samples collected from barren or very sparsely vegetated mixed mine tailings and alluvium deposits (slickens) in the floodplains along Silver Bow Creek and the Clark Fork River had concentrations of As, Cd, Cu, Pb and Zn that were significantly elevated relative to reference sites. Laboratory phytotoxicity tests demonstrated severe and rapid effects of the elevated concentrations of metals and As on hybrid poplar and standard test species (alfalfa, lettuce and wheat): growth inhibition of hybrid poplars was nearly 100% and of standard test species ≥75%. Vegetation community measurements revealed that slickens have replaced riparian forest, shrub, hay fields and pasture land; in doing so, the slickens have reduced both the compositional and structural heterogeneity of the riparian habitat. This reduction in habitat complexity has reduced the capacity of the area to provide a diversity of suitable wildlife habitat.

Growth of secondary hair follicles of the Cashmere goat in vitro and their response to prolactin and melatonin

The isolation and viability in vitro of anagen secondary hair follicles of the Cashmere goat were studied. Isolated hair follicles were used to determine the effects on hair shaft elongation, of prolactin and melatonin, hormones considered to influence hair follicle growth and activity in vivo. Intact hair follicles were isolated from the dermal layer of the skin singly or in groups using watchmakers' forceps under a dissecting microscope. The isolated follicles were maintained floating in Williams E medium. The medium was supplemented with 1 of 6 concentrations of ovine prolactin (0, 50, 200, 400, 800 and 4000 micrograms/l) for the culture of hair follicles isolated during July and August, and with 1 of 5 concentrations of melatonin (0, 50, 150, 300, 600 ng/l) for the culture of hair follicles isolated during September and October. There was clear evidence of DNA synthesis, observed by autoradiography, in matrix cells of freshly isolated follicles incubated for 6 h in the presence of [methyl-3H]-thymidine. Similar measurements after 96 h of maintenance indicated a marked reduction in the incorporation of [methyl-3H]-thymidine in matrix cells of the follicles studied. Prolactin and melatonin were shown to have a stimulating effect on hair shaft elongation of secondary follicles during 24 h periods of measurement and cumulatively over 120 h. Maximum hair follicle growth was observed in follicles exposed to 400 micrograms/l of prolactin and follicles exposed to 300 ng/l of melatonin. The number of follicles remaining viable during each 24 h measuring period was not affected by prolactin, but was significantly reduced by melatonin treatment after 96 h of maintenance.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of different dietary supplemental fats and oils on the tissue fatty acid composition and growth of female broilers

1. A study was undertaken to examine the effect of supplementation of diets with fats of different chain length and degree of unsaturation on the performance, carcase characteristics and tissue fatty acid composition of broilers. 2. Three hundred and sixty 19-day-old female broilers were fed on diets containing supplemental fat/oil (50 g/kg) in the form of beef tallow (BT) (diet T-T), soyabean oil (SBO) (diet S-S), rapeseed oil (RSO) (diet R-R), marine oil (MO) (diet M-M) or binary mixtures (0.5:0.5 w/w) of these lipids (diets T-S, T-R, T-M, S-R, S-M, and R-M) to 54 d of age. Food intake, live weight, plucked weight and the lipid concentration and fatty acid composition of abdominal fat pad, liver and breast muscle were measured. 3. Food intake, plucked weight and live weight were greatest for diet T-T and lowest for diet R-R. Food conversion ratio was poorest for birds fed on diets containing BT. Lipid concentration in abdominal fat pad was significantly higher in birds fed on diets containing SBO. Liver lipid concentration was significantly reduced by diets containing RSO. 4. Abdominal fat pad fatty acid profile was most readily altered by dietary fatty acids. There was a strong correlation between dietary fatty acid composition and tissue fatty acid composition for all fatty acids except C14:0, C20:0, C20: 2n-6 and C20: 4n-6. The tissue P/S ratio ranged from 0.40 for diet T-T to 1.40 for diet S-S. The n-6/n-3 ratio was significantly increased by the inclusion of SBO and decreased by the inclusion of MO. 5. Liver fatty acid profile was least modified by dietary fatty acids. There was an inverse relationship between liver and dietary C20:4n-6 concentration. Tissue C18:2n-6 and C20:4n-6 were highly correlated, suggesting significant interconversion by delta-6 desaturase in this tissue. The n-6/n-3 ratio was significantly increased by inclusion of SBO and significantly decreased by the inclusion of MO. 6. In breast muscle MO-based diets increased the proportion of n-3 PUFA at the expense of n-6 PUFA. The tissue concentrations of C18:1n-9, C18:2n-6, C20:1n-9, C20:5n-3, C22:5n-3 and C22:6n-3 were strongly correlated with dietary fatty acid composition. Muscle and diet P/S and n-6/n-3 ratios were highly correlated.

Growth and viability of secondary hair follicles of the Angora goat cultured in vitro

The viability of isolated secondary anagen hair follicles from Angora goats was studied in an in vitro tissue culture system. Intact hair follicles were isolated from the dermal layer singly or in groups using watchmakers' forceps under a dissecting microscope following removal of both the epidermis at the basal layer and subcutaneous fat layers using a scalpel blade. The connective tissue sheath surrounding the follicle and the dermal papilla in the bulb were left intact. The isolated follicles were maintained floating in supplemented Williams E medium and showed significant increases in hair shaft length over 96 h. The viability of the cultured hair follicles was verified by the findings that (1) the rate of hair shaft elongation was similar to that occurring in vivo; (2) the pattern of DNA synthesis observed by autoradiography of [methyl-3H]thymidine uptake was maintained in the isolated follicles throughout culture; (3) the ATP content was significantly higher in growing follicles compared with that observed in freshly isolated follicles; and (4) Feulgen-stained preparations of fresh and maintained hair follicles confirmed the retention of mitotic activity in the matrix cells of the bulb for a maximum of 120 h of maintenance.

The action of trenbolone acetate, a synthetic anabolic steroid, on ovarian function in the guinea pig

The action of trenbolone acetate, a synthetic anabolic steroid, on ovarian function was investigated in the guinea pig. Certain comparisons were made with testosterone, the naturally occurring androgen, administered as the phenylpropionate ester. Two milligrams trenbolone acetate per kg given subcutaneously on alternate days for 20 days blocked oestrous cyclicity and ovulation in 9 of 10 animals. A similar effect was shown by 2.2 mg of testosterone phenylpropionate. Treatment of trenbolone acetate-treated animals with exogenous gonadotrophins suggested that the production of follicle-stimulating hormone had been suppressed. Signs of abnormality were seen in the livers of animals receiving 2 mg trenbolone acetate and 2.2 mg testosterone phenylpropionate.

Alpha adrenergic blocking activity of urapidil in man

Urapidil is a new antihypertensive vasodilator agent whose pharmacologic action in man has not yet been fully defined. We have assessed the alpha adrenergic blocking activity of urapidil 15 and 30 mg given intravenously in a single blind study in 8 healthy volunteers. Urapidil produced dose-dependent parallel shift of the phenylephrine log dose/blood pressure response curve, consistent with significant competitive peripheral alpha 1 antagonism. Mean dose ratios were 2.99 and 5.48 for the 15 mg and 30 mg doses respectively. The pA2 for alpha 1 blockade is 7.3. Given these data, the major mechanism of antihypertensive effect of urapidil may be alpha 1 antagonism in the peripheral vasculature.

The assessment of the beta-blocking activity of urapidil: a new method

Urapidil is an antihypertensive vasodilator agent whose pharmacological action in man has not yet been fully defined. We have assessed the beta blocking activity of urapidil 15 mg and 30 mg i.v. in a single blind study of 10 healthy male volunteers. Urapidil at plasma concentrations in the same range as those shown to have antihypertensive affect did not significantly attenuate the chronotropic effect of isoproterenol. Propranolol 5 mg iv, the positive control, significantly shifted the isoproterenol dose-response curve to the right. We describe a new method of analyzing incomplete dose response curves whereby a linear terminal segment can be reproducibly defined.

The effects of a combined implant of trenbolone acetate and oestradiol-17 beta on protein and energy metabolism in growing beef steers

1. The effects on growth performance, energy and nitrogen retention, and leucine metabolism of a subcutaneous combined implant of 140 mg trenbolone acetate (TBA)+ 20 mg oestradiol-17 beta (OE) have been examined in Hereford x Friesian beef steers (280-520 kg). Comparisons were made both with the same animals before implantation and with untreated control animals maintained under similar physiological and nutritional conditions. 2. Over a 10 week period the implanted steers showed an improvement in rate of live-weight gain (LWG) of 0.5-0.6 with an even greater proportional increase in N retention compared with control animals. Total energy retention was unaffected and thus the ratio, protein energy: total energy gain was 0.43 for implanted steers compared with 0.26 for untreated animals. 3. Estimates of protein synthesis and protein oxidation were obtained from the specific radioactivities of blood free-leucine and exhaled carbon dioxide during continuous infusions of [1-14C]leucine. Whole-body protein synthesis, based on metabolic size, and amino acid fractional oxidation remained similar for control steers throughout the experiment. Steroid-treated steers showed a slight decline in synthesis which was significant (P less than 0.05) at week +5 post-implant while amino acid oxidation was significantly lower at weeks +2 (P less than 0.01) and +5 (P less than 0.05) compared with control animals. The ratio, protein deposition: protein synthesis was 0.05 for control animals but 0.08-0.10 for steroid-treated animals after implantation. 4. There was a slight decrease in urinary N tau-methylhistidine elimination after implantation which suggested that muscle protein degradation may be reduced although the estimated decrease was insufficient to account for the total improvement in growth rate and N retention. 5. The results suggest that for both control and treated steers, less than 0.5 of total urine N elimination was derived directly from tissue catabolism of protein and amino acids. 6. The combined action of the exogenous steroids in the promotion of protein gain, primarily through a decrease in total protein degradation with little alteration of total energy retention, is compared with present understanding of the role of the endogenous sex hormones.

Effects of subcutaneous implantation of trenbolone acetate and oestradiol-17 beta on plasma lipid concentrations in sheep

Twenty eight Greyface x Suffolk wethers were allocated to four treatment groups designated TG0, TG1, TG2 and TG3 and were implanted with either 0, 1, 2, or 3 pellets of Revalor containing 17.5 mg trenbolone acetate and 2.5 mg oestradiol-17 beta per pellet. Blood samples were taken at regular intervals and were analysed for plasma cholesterol, triglyceride, non-esterified fatty acids and phospholipid. Plasma cholesterol concentrations appeared to exhibit a biphasic response to implantation. The magnitude of the response was directly related to the dose level of the implant. In comparison with group TG0, significant decreases in the cholesterol levels in all implanted animals were demonstrated one week after implantation. Between weeks 3 and 5 the cholesterol concentrations in groups TG2 and TG3 showed a considerable increase. At week 5 the concentration in group TG3 was 18% higher than group TG0. These changes coincided (1) with the initial rapid release and then the gradual decrease after week 2 in the concentration of trenbolone acetate in plasma and (2) with the more gradual release of oestradiol-17 beta which reached a maximum level in groups TG2 and TG3 between weeks 5 and 6. There were significant differences between groups TG1, TG2 and TG3 at weeks 1, 3 and 5. Plasma triglyceride concentrations in all implanted groups fell markedly by week 5 and remained well below control values until slaughter. The concentration of plasma non-esterified fatty acids decreased by approximately 50% in all four treatment groups. The differences between control and treatment groups were not significant.

Effect of hexoestrol on the response of finishing steers to treatment with trenbolone acetate

The relative effectiveness of implanting 300 mg trenbolone acetate alone or in combination with either 15, 30 or 45 mg hexoestrol was studied in three 90-day experiments using 64 Friesian steers. In experiment 1 hexoestrol was shown to improve live-weight gain and efficiency of feed conversion in steers implanted with trenbolone acetate. In experiments 2 and 3 trenbolone acetate in combination with 30 mg hexoestrol gave a better growth response than when combined with either 15 or 45 mg. However, in experiment 3 trenbolone acetate plus 15 mg hexoestrol was shown to improve live-weight gain by about 36 per cent compared with untreated controls. In experiment 2 small differences between treated groups in mean values for plasma urea, serum albumin, plasma glucose and free fatty acids were recorded.

Performance, blood and carcase characteristics of finishing steers treated with trenbolone acetate and hexoestrol

Twenty British Friesian steers were divided into four uniform groups and either not treated or implanted with hexoestrol, trenbolone acetate, or hexoestrol plus trenbolone acetate. Hexoestrol was given 90 days and trenbolone acetate 70 days, before slaughter. Animals in the treatment groups grew significantly faster, converted food to live-weight gain more effciently faster, converted food to live-weight gain more efficiently and had lower levels of plasma urea and to a lesser extent serum albumin than untreated controls for the final 70 days before slaughter. The combined treatment of hexoestrol plus trenbolone acetate produced more pronounced effects than either compound given alone. Steers treated with hexoestrol had significantly greater levels of serum growth hormone than steers implanted with trenbolone acetate alone or untreated controls, but the treatments had no significant effect on levels of plasma glucose, free fatty acids or serum insulin. Carcase conformation and fat cover assessed subjectively did not differ between treated and control animals but killing out percentage was generally higher in all treatment groups.