The ability of a high surface-area gibbsite to adsorb Cu2+ was studied using a Cu2+ ion-selective electrode, electron spin resonance, infrared spectroscopy, and electron microscopy. The gibbsite chemi-sorbed small amounts of monomelic Cu2+ (<0.5 mmole/100 g) which was oriented with its z-axis perpendicular to the (001) plane of the mineral. The proposed chemisorption sites are at gibbsite crystal “steps” observed by electron microscopy. Although Cu2+ adsorption on gibbsite as a function of pH was largely reversible, exposure of the chemisorbed Cu2+ to NH3 did not result in desorption from the surface despite the displacement of several OH− or H2O ligands by NH3. The results indicate that at least one Cu-O-Al bond is formed in the process of chemisorption.

At pH > 5, the gibbsite appeared to promote the hydrolysis and polymerization of Cu2+, with further adsorption at the surfaces. Infrared spectroscopy revealed no effect of the adsorption on the (001) surface hydroxyl groups, although the anisotropic diffusion of protons in the gibbsite structure was verified from deuteration studies.

Adverse uterine environments caused by maternal stress (such as bacterial endotoxin) can alter programming of the fetal hypothalamic–pituitary–adrenal axis (HPAA) rendering offspring susceptible to various adulthood diseases. Thus, protection against this type of stress may be critical for ensuring offspring health. The present study was designed to determine if maternal supplementation with omega-3 polyunsaturated fatty acids (n-3 PUFAs) during pregnancy helps to protect against stress-induced fetal programming. Briefly, 53 ewes were fed a diet supplemented with fishmeal (FM) or soybean meal (SM) from day 100 of gestation (gd100) through lactation. On gd135, half the ewes from each dietary group were challenged with either 1.2 μg/kg Escherichia coli lipopolysaccharide (LPS) endotoxin, or saline as the control. The offspring’s cortisol response to weaning stress was assessed 50 days postpartum by measuring serum cortisol concentrations 0, 6 and 24 h post weaning. Twenty-four hours post-weaning, lambs were subjected to an adrenocorticotropic hormone (ACTH) challenge (0.5 μg/kg) and serum cortisol concentrations were measured 0, 0.25, 0.5, 1 and 2 h post injection. At 5.5 months of age, offspring were also challenged with 400 ng/kg of LPS, and serum cortisol concentrations were measured 0, 2, 4 and 6 h post challenge. Interestingly, female offspring born to FM+LPS mothers had a greater cortisol response to weaning and endotoxin challenge compared with the other treatments, while female offspring born to SM+LPS mothers had a faster cortisol response to the ACTH stressor. Additionally, males born to FM+LPS mothers had a greater cortisol response to the ACTH challenge than the other treatments. Overall, FM supplementation during gestation combined with LPS challenge alters HPAA responsiveness of the offspring into adulthood.

In recent years, livestock producers have been supplementing animal diets with fish meal (FM) to produce value-added products for health conscious consumers. As components of FM have unique neuroendocrine–immunomodulatory properties, we hypothesize that livestock producers may be influencing the overall health of their animals by supplementing diets with FM. In this study, 40 pregnant ewes were supplemented with rumen protected (RP) soybean meal (SBM: control diet) or RP FM, commencing gestation day 100 (gd100), in order to evaluate the impact of FM supplementation on the innate and acquired immune response and neuroendocrine response of sheep during pregnancy and lactation. On gd135, half the ewes from each diet (n = 10 FM, n = 10 SBM) were challenged iv with lipopolysaccharide (LPS) to simulate a systemic bacterial infection and the febrile, respiratory and neuroendocrine responses were monitored over time; the other half (n = 10 FM, n = 10 SBM) of the ewes received a saline injection as control. On lactation day 20 (ld20), all ewes (n = 20 FM, n = 20 SBM) were sensitized with hen egg white lysozyme (HEWL) and the serum haptoglobin (Hp) response was measured over time. The cutaneous hypersensitivity response (CHR) to HEWL challenge was measured on ld30 (n = 20 FM, n = 20 SBM), and blood samples were collected over time to measure the primary and secondary immunoglobulin G (IgG) response to HEWL. There was an attenuated trend in the LPS-induced febrile response by the FM treatment when compared with the SBM treatment (P = 0.06), as was also true for the respiratory response (P = 0.07), but significant differences in neuroendocrine function (serum cortisol and plasma ACTH) were not observed between treatments. Basal Hp levels were significantly lower in the FM supplemented ewes when compared with the SBM supplemented ewes (P < 0.01), and the Hp response to HEWL sensitization differed significantly over time between treatments (P < 0.01). The CHR to HEWL was also significantly attenuated in the FM treatment compared with the SBM (P < 0.01); however, treatment differences in the primary and secondary IgG responses to HEWL were not observed. These results indicate that FM supplementation differentially affects the innate and acquired immune responses in pregnant and lactating sheep compared with a typical SBM diet of commercial flocks. The long-term implications of this immunomodulation warrant further investigation.

A better understanding of the factors regulating feed efficiency and their potential as predictors of feed efficiency in cattle is needed. Therefore, the potential of three classes of traits, namely, feeding behavior characteristics: daily time at feeder (TF; min/day), time per meal (TM; min), meal size (MS; g DM), eating rate (ER; g DM/min), number of daily meals (NM) and daily visits to the feeder (VF); infrared (IR) thermography traits (°C): eye (EY), cheek (CK), snout (SN), ribs (RB) and hind area (HA); and glucocorticoid levels: fecal cortisol metabolites (FCM; ng/g) and plasma cortisol (PC; ng/ml) as predictors of efficiency were evaluated in 91 steers (436 ± 37 kg) over 2 years (Y1 = 46; Y2 = 45). Additionally, the individual traits of each of these three classes were combined to define three single traits. Individual daily feed intake of a corn silage and high-moisture corn-based diet was measured using an automated feeding system. Body weight and thermographs were taken every 28 days over a period of 140 days. Four productive performance traits were calculated: daily dry matter intake (DMI), average daily gain (ADG), feed to gain ratio (F : G) and residual feed intake (RFI). Steers were also classified into three RFI categories (low-, medium- and high-RFI). Among the feeding behavior characteristics, MS and ER were correlated with all efficiency traits (range: 0.26 to 0.75). Low-RFI (more efficient steers) had smaller MS, lower ER and fewer VF in comparison to high-RFI steers. Less efficient steers (high-RFI) performed more VF during the nocturnal period than more efficient steers. More efficient steers had lower CK and SN temperatures than less efficient steers (28.1°C v. 29.2°C and 30.0°C v. 31.2°C), indicating greater energetic efficiency for low-RFI steers. In terms of glucocorticoids, PC was not correlated with efficiency traits. In contrast, more efficient steers had higher FCM in comparison to less efficient steers (51.1 v. 31.2 ng/g), indicating that a higher cortisol baseline is related to better feed efficiency. The overall evaluation of the three classes of traits revealed that feeding behavior, IR thermography and glucocorticoids accounted for 18%, 59% and 7% of the total variation associated with RFI, respectively. These classes of traits have usefulness in the indirect assessment of feed efficiency in cattle. Among them, IR thermography was the most promising alternative to screen cattle for this feed efficiency. These findings might have application in selection programs and in the better understanding of the biological basis associated with productive performance.

A variety of factors influence the voluntary intake of ruminants including reticulo-rumen fill or distension (Campling & Balch, 1961; Welch, 1967; Grovum, 1979) and rate of passage of digesta through the gastrointestinal tract (Bines & Davey, 1970). The exit point of the reticulo-rumen, the reticulo-omasal orifice, potentially serves as a control site in regulation of particle movement from the rumen.

However, little definitive information on the functional behaviour of this anatomical location is available. Therefore, a fibre-optic endoscopic technique was designed to allow visual observation of the reticulo-omasal orifice in conscious, fed cattle.

America, New Hyde Park, NY) and a 35 mm camera (Olympus 0M-2N with 1–9 focusing screen) was attached. Photographs were taken at a shutter speed of 1/30 or 1/60 sec. The film used was Kodak (ASA 160) tungsten balanced slide film. Prints were generated from slides using the Cibachrome P30 process. An Olympus CLK-3 cold light source, having a colour temperature of 3200 °K, provided the illumination for projection through the endoscope. Opening and closing of the reticuloomasal orifice were photographed using this procedure.

Sensitivity analysis is routinely carried out in the evaluation of simulation models to identify the degree to which parameters influence model outputs. This type of sensitivity analysis is much less frequently applied to real systems, but a technique called metabolic control analysis (MCA) was developed in the 1970s for the purpose of experimentally identifying the degree to which individual enzymes in a metabolic pathway influence flux through the pathway. MCA is applied to the results of inhibition, activation or genetic manipulation of enzymatic steps in a biochemical pathway. Flux control coefficients for each enzyme are defined as the fractional change in steady-state flux through the entire pathway for an infinitesimal change in the activity of that one enzyme. The sum of control coefficients in a linear, non-branching pathway is equal to one. It is a common finding in MCA that the control, or sensitivity, is distributed over multiple enzymes and not in a single rate-limiting enzyme. The fundamental principles of MCA are reviewed and an overview of experimental methods to measure control coefficients is provided, with the objective of introducing this approach to the fields of agricultural biochemistry and modelling, where it is little known. The application of MCA to the study of glucose metabolism and fatty acid synthesis in bovine mammary tissue are reviewed. The analyses indicated that mammary hexokinase activity exerts more control than transmembrane transport of glucose over lactose synthesis, and that control of cytosolic fatty acid synthesis is shared between acetyl-CoA carboxylase and fatty acid synthase, contrary to the widely held view that acetyl CoA carboxylase is the rate-limiting enzyme. It is suggested that MCA could be a valuable aid in the integration of proteomic and metabolomic data with metabolic flux measurements to engineer desired changes in the composition of milk from dairy animals.

Methane, in addition to being a significant source of energy loss to the animal that can range from 0·02 to 0·12 of gross energy intake, is one of the major greenhouse gases being targeted for reduction by the Kyoto protocol. Thus, one of the focuses of recent research in animal science has been to develop or improve existing methane prediction models in order to increase overall understanding of the system and to evaluate mitigation strategies for methane reduction. Several dynamic mechanistic models of rumen function have been developed which contain hydrogen gas balance sub-models from which methane production can be predicted. These models predict methane production with varying levels of success and in many cases could benefit from further development. Central to methane prediction is accurate volatile fatty acid prediction, representation of the competition for substrate usage within the rumen, as well as descriptions of protozoal dynamics and pH. Most methane models could also largely benefit from an expanded description of lipid metabolism and hindgut fermentation. The purpose of the current review is to identify key aspects of rumen microbiology that could be incorporated into, or have improved representation within, a model of ruminant digestion and environmental emissions.

We report a case of giant cell tumour of the temporal bone arising in a 31-year-old man. The presenting symptoms were unusual, being rotational vertigo, unilateral tinnitus, and hearing loss. A computed tomography (CT) scan showed a large mass within the right temporal bone and the infratemporal fossa. The radiological appearance was suggestive of an aggressive primary neoplasm arising within bone. Biopsy and subsequent resection showed a giant cell tumour of bone. The tumour was histological grade 1. At two-year follow-up, there was no evidence of tumour recurrence or metastasis.

Twenty-five primigravid ewes were used in a preliminary study to investigate the effect of bovine somatotropin (bST) between 97 and 124 days of gestation, on maternaland foetal growthand development. Five ewes (reference group) were slaughteredat 96 days of gestation, and the remaining ewes were injected daily with saline (control group: no = 10) or 0·1 mg/kgbody weight of bST (bST group: no. = 10). Following bST treatment, five control- and five bST groupewes were slaughtered (slaughter group). The remaining ewes (production group) were allowed to lamb, after which the lambs were slaughtered within 2 h of birth. Bovine somatotropin reducedthe proportion of maternal body fat, but had no major impacton wool growth, maternal gain and gross skeletal measurements, and foetal growth and development. Maternal bST treatment tended to affect the number of placentomes. It should, however, be emphasized that these results are based on small numbers of animals and that further research in this area is required.

1. Eighteen pigs were offered diets containing 130, 170 or 210 g protein/kg with three barrows and three gilts per diet from 20 to 60 kg live weight. Oxygen consumption, Na1, K1-ATPase (EC 3·6·1· 3)-dependent and -independent respiration and protein synthesis were measured in vitro in intercostal and sartorius muscle preparations from these pigs.

2. Increasing dietary protein concentration increased (P < 0·01) daily gain and dissectible muscle in carcass.

3. O2 consumption and Na+, K+-ATPase-dependent respiration of the intercostal and sartorius muscles increased linearly (P < 0·01) with increase in dietary protein concentration. The requirement for the support of the transport of Na+ and K+ across the cell membrane in these muscles, on average, accounted for 22–25% of the O2 consumption.

4. Synthesis rate (mg/g per d) of protein in the sartorius muscle increased (P < 0·05) from 3·05 to 5·07 and increased (P < 0·1) from 2·57 to 4.06 in the intercostal muscle as dietary protein increased from 130 to 210 g/kg diet.

5. Regression of Na+, K+-ATPase-dependent respiration against protein synthesis in each of intercostal and sartorius muscles showed a linear relation, an attestation of a close link between productive processes and auxiliary energy expenditure.

1. Oxygen consumption and ouabain-sensitive respiration was measured for liver biopsies from lactating and non-lactating ewes and for hepatocytes isolated from mature, dry ewes. O2 consumption, ouabain-sensitive respiration and 86Rb+ uptake were also measured for hepatocytes isolated from lambs, fed adult sheep and adult sheep starved for 5 d.

2. Ouabain-sensitive respiration in the liver of ewes at peak lactation accounted for 45% of the total liver O2 consumption. This percentage was 24–37% higher (P > 0.05) than measurements made during late lactation and during the non-lactating period.

3. Total O2 consumption and ouabain-sensitive respiration rates of lamb hepatocytes were greater ( P > 0.05) than similar measurements for hepatocytes isolated from adult sheep.

4. Ouabain-sensitive 86Rb+ uptake by hepatocytes from fed sheep was up to six times greater (P > 0.05) than that by cells from starved sheep.

5. The magnitude of ouabain-sensitive respiration of hepatocytes from starved sheep was 62% lower (P > 0.05) than that for hepatocytes from fed sheep.

1. Oxygen consumption and Na+,K+-ATPase(EC 3.6.1.3)-dependent (ouabain-sensitive) and -independent respiration were measured for duodenal mucosa biopsies from 10-month-old sheep given two levels of digestible energy (DE) intake (7.6–7.7 and 14.8 MJ lucerne (Medicago sativa) pellets/d) and following 48 h of starvation.

2. The mucosal biopsies were determined to be structurally intact and free of adherent bacteria on histological and scanning-electron-microscope examinations.

3. The use of D-glucose as a substrate during incubations did not elevate (P > 0.05) the respiration indices of the biopsies over those measured during acetate incubations.

4. Glucose uptake did not (P > 0.05) influence the Na+,K+-ATPase-dependent respiration of the mucosal biopsies.

5. Na+,K+-ATPase-dependent respiration accounted for 50% of the total O2, consumption of the mucosal biopsies of sheep given the lower level of DE.

6. Total O2, consumption of the duodenalmucosa was not (P > 0.05) increased when sheep were given the higher level of DE but Na+,K+-ATPase-dependent respiration of the mucosa was elevated (P < 0.01) by 37% during this period.

7. When sheep were starved for 48 h, total O2, consumption of the mucosal biopsies was not (P > 0.05) affected, however, Na+,K+-ATPase-dependent respiration of the biopsies dropped (P < 0.01) by 45%.

8. Na+,K+-ATPase-dependknt respiration accounted for 61.3% of the O2, uptakes of mucosa from the sheep given the higher level of DE and 28.3% of the 02, uptake of mucosa from fasted sheep.

The paper discusses the implications of the Social Security Pensions Act 1975 and associated Regulations for occupational pension scheme design and finance. Firstly, a general preface deals with currently topical matters. Secondly, integration of State and Occupational Schemes as practised up to the present time is described. Next, integration in future, whether contracted in or contracted out, is considered from the scheme design point of view, and some problems are mentioned. Finally, the financial background to the contracting-out conditions is described and some evaluation made of the terms available.