ALBERT

Description: SUMMARYA model of the growth, pregnancy and lactation of red deer was developed for incorporation into a whole-farm systems model in order to improve the understanding of venison supply systems. The model estimates the level of metabolic demand for a deer, which depends on the maximum capacity of its tissues to use energy. A function that takes account of satiation signals and rumen capacity is used to convert the metabolic demand into an estimate of the deer's forage intake demand, which can be used as an input into a foraging model. The actual energy intake of the deer is subsequently used to predict live weight (LW), body condition score, foetal growth and gestation length in pregnant hinds, and milk yield in lactating hinds. In order to make these predictions, the model requires inputs that include values for mean daily temperature, mean daily wind speed, day length and season, as well as pasture quality. Values for model parameters were obtained from the literature, rather than by fitting to data, and model predictions were then compared with measurements obtained in independent trials.In simulations, the model predicted that 152-day-old stags and hinds, weighing, respectively, 44 and 48 kg, would grow to, respectively, 106 and 90 kg when 517 days old, compared with trial results of, respectively, 103 and 84 kg. Predictions for the weight of pregnant hinds, gestation length and calf birth weight compared well with an experiment for hinds on a high plane of nutrition but poorly for hinds on medium and low planes. Weekly predictions of hind LWs for days 132–230 of pregnancy had respective residual means of 0·08, 6·2 and 8·5 kg, and respective residual standard deviations of 1·33, 4·6 and 5·2 kg for the high, medium and low nutritional planes. Predicted gestation length for high, medium and low planes of nutrition were, respectively, 231·5, 238·0 and 242·0 days compared with experimental values of, respectively, 231·3, 234·7 and 239·2 days, while predicted birth weights were, respectively, 8·5, 8·3 and 8·9 kg compared with measured values of, respectively, 8·4, 9·5 and 9·3 kg. Predicted calf growth from birth to 14 weeks agreed well with data (residual mean and standard deviation being 0·04 and 1·15 kg, respectively).The existing software structure of the whole-farm model dictated that the deer model use the Euler method with a fixed, daily time step. Therefore, the model was constructed using difference (rather than differential) equations and used a traditional, energy-balance method for predicting growth. This empirical approach tacitly imposed a standard body composition and standard metabolic rate for adults, with values corresponding to well-fed deer. This does not cater for variation in body composition and metabolic activity, and in retrospect, caused the model to perform poorly for the medium and low nutritional regimes.

Description: The importance of mechanistic models for ration balancing with forages is indicated and physical limitations to intake emphasized, because these limit energy and nutrient supply to cows grazing forages, especially grass. Ration-balancing models using fresh or ensiled forages to complement pasture will need to accommodate intake limitations due to rumen fill, clearance, chewing or other criteria. The potential of the Cornell Net Carbohydrate and Protein System (CNCPS) model to predict milk production from diets based on pasture and forage supplements was tested using data from two experiments. Data were obtained from studies in which pasture was complemented with contrasting silages including maize, pasture, sulla, lotus and forage mixtures, comprising 0·30–0·40 of dry matter intake (DMI). Twelve diets were used in the evaluation. DMI, liveweight (LW), days in milk, and diet composition were determined during the trials and used as inputs in the model. Across all diets, a significant relationship existed between predicted and actual values for DMI (R2=0·58), milk yield (R2=0·59) and LW change (R2=0·51), but there were still large unexplained sources of variation. No significant mean bias was observed for any of the variables, but the slope of residual differences against predicted values was significantly different from zero for milk yield, LW change and for DMI (P

Description: The earlist, and almost the only published, notice of the ‘Bridlington Crag’ is contained in a single page of London's ‘Magazine of Natural History’ for 1835, vol. viii. p. 355, entitled ‘A Short Account of an Interesting Deposit of Fossil Shells at Burlington Quay, by Mr. William Bean.’ Writing from Scarbro’ on March 30th, Mr. Bean states that ten days previously he had made a geological excursion to ‘Burlington Quay,’ when Mr. Walter Wilson, an intelligent lapidary of that place, directed his attention to a deposit of fragile and broken shells, which the late high tides had exposed on the north side of the harbour, and near the pleasure-ground called the Esplanade. On arriving at the spot, he found a heterogeneous mass, only a few yards long, and as many high, composed of sand, clay, marine shells, and pebbles of every description, chalk and flint being most abundant. The colour and appearance of this shelly bed resembled London Clay, but the fossils had the character of those found in the Crag formation. It would be necessary to collect a greater number of species than he had then obtained, and to exercise much caution before the geological position of the bed could be truly determined; but of this much he was certain, that the shells were coeval with, if not of higher antiquity than the Crag. More than half of them could not be referred to any existing species. The writer concluded by mentioning that he had already made a second visit to the place, in company with Dr. Murray, and reaped an abundant harvest.

Description: The idler picking up pebbles on the sea-shore, and the geologist breaking stones in a gravel-pit, frequently meet with banded flints, which display their markings like a painting on the smoothly fractured internal surface, or, in other cases, in the form of lines more or less deeply engraved on the exterior by the action of the weather. The bands seen in section are often accompanied by discolorations of fanciful shape, in which imaginative people find pictures of their friends and others.

Description: Everyone who has collected the fossils of the Upper Chalk will have noticed how the Echinoderms and Belemnites are overgrown by small oyster-like shells with a striated disk, commonly passed by as the fry of Ostrea vesiculosa. There is a beautiful example of Micraster cor-anguinum in the Museum of the Geological Society (given by Mr. Bayfield, of Norwich, to the late Daniel Sharpe), on which a dozen of these little shells, each about half an inch across, have left their lower valves; and above twenty are congregated on a fragment of Ananchytes (occupying a space of about three square inches) in the British Museum.