Right sides of carcasses of 12 buffalo, nine ½ Friesian ( Friesian x Egyptian Baladi) and nine ¾ Friesian ( Friesian x ½ Friesian) bulls slaughtered over the body-weight ranges 161–560 kg for buffaloes and 176–448 kg for cattle were cut according to the Chicago style of cutting. Allometric growth pattern and distribution of muscle and bone in the various cuts were examined.

Buffaloes were similar to cattle in that muscle and bone in the limbs showed an increasing distoproximal growth gradient. On the ventral line of the trunk, muscles showed an increase in growth impetus from plate to brisket while bone followed a reverse pattern. In buffaloes, growth coefficients of muscle and bone of all dorsal cuts were similar except in the sirloin and chuck where bone was later maturing. In cattle, there appeared a posterior-anterior increase in growth impetus of muscle from the shortloin towards sticking. Within and between genotype-group results indicated that growth of a fatless cut is governed by the growth of its muscle rather than that of its bone.

Compared with Friesian crosses, buffaloes had significantly greater percentages of their total muscle and muscle-plus-bone in the expensive cuts. As total muscle weight increased, the proportion of muscle in BLRC (see p. 318) decreased in cattle but remained almost constant in buffaloes. It was concluded that the previously reported inferior carcass composition of buffaloes relative to cattle is compensated by better carcass conformation and tissue distribution of buffaloes.

The voluntary food intake (VFI) and apparent digestibility of chopped timothy hay by six Scottish Blackface (BF), Shetland (SH) and Dorset Horn (DH) non-breeding ewes were assessed in summer and winter. In two experiments VFI was higher in summer than in winter but did not differ between the breeds. In Expt 1, the seasonal difference in VFI was greater in BF and SH than in DH ewes and the apparent digestibility of dry matter (DM), organic matter (OM) and total nitrogen was consistently higher in all three breeds in summer than in winter. The higher digestibility of DM of the hay in summer than in winter was confirmed in Expt 2, in which the whole tract mean retention time (MRT) of the undigested residues was measured using 103ruthenium-phenanthroline as a marker. The MRT was lower in all three breeds in summer than in winter. In a third experiment, following at least 6 months ad libitum feeding on the hay, for all three breeds the contents of DM and liquid in the reticulorumen were smaller in summer, and the liquid fraction formed a greater proportion in summer than in winter. The results contrast with the expectation that intake and digestibility within a given forage type are negatively correlated. Although an increase in digestibility may facilitate a higher VFI in summer (BF and SH) it does not necessarily do so (DH).

Nitrogen balances from 283 conventional dairy farms situated in southern Sweden were investigated using the farm gate method. Nitrogen balances were determined for 1997 and 1998. Three N balances were calculated; for the whole farm, for crop production and for milk production. The aims of the investigation were to study if factors such as manure handling system, the amount of N obtained from mineral fertilizer per hectare and the proportion of sugar beet have an influence on the N balance. There was no significant effect of manure handling system on the N surplus per hectare or on N efficiency. The results showed that N efficiency was significantly improved by including sugar beet in the crop rotation and was negatively correlated with milk yield per hectare and fertilizer N per hectare. The N surplus per hectare was positively correlated with milk yield per hectare and fertilizer N per hectare. The comparison did not find a strong relationship between the amounts of N obtained from mineral fertilizer per hectare and supplied as manure. The latter was calculated theoretically. There was a weak, but significant, negative correlation between N from manure in 1997 and N from mineral fertilizer in 1998.

Silages were prepared from the tropical grasses, pangola grass (Digitaria decumbens) and setaria (Setaria sphacelata), with the addition of molasses (4% w/w) and/or leaves (33%) from the leguminous trees leucaena (Leucaena leucocephala) and gliricidia (Gliricidia sepium). All forages were grown at the University of Queensland farm in south eastern Queensland during 1985. These silages, together with hays made from these grasses and sorghum silage (13 diets) were fed to sheep to assess their nutritive value. All silages were well preserved, as indicated by low pH (3·5–4·4), low ammonia N (26–57 g/kg total N) and high lactic acid (73–95% total acids) contents. The addition of legumes increased both the dry matter (DM) and total N (TN) contents of silages to the same extent as the addition of both legumes and molasses at ensiling. Sheep given silages prepared from pangola grass and legumes (±molasses) consumed similar DM intakes (22·9–25·4 g/kg0·75 per day) as sheep given pangola grass hay (23·9 g/kg0'75 per day). Silage made from pangola grass + molasses was of low palatability (16·1 g/kg0·75 per day). The digestibilities of silage DM (DMD) and its fibrous components were significantly (P<0·05) lower (DMD 53·3–60·6%) than that of pangola hay (DMD 64·7%). Silages and hay made from setaria, and sorghum silage, were of lower nutritive value than those from pangola grass. The addition of leucaena and molasses increased silage DM intakes (21·1 g/kg0·75 per day) above those for setaria hay and setaria + molasses silage (16·7 and 19·0 g/kg0·75 per day respectively). The intakes of silages made from gliricidia (17·1 g/kg0·75 per day) were significantly (P <0·05) improved when molasses was included at ensiling (21·8 g/kg0·75 per day). The digestibilities of silage DM were significantly (P<0·05) higher (DMD 53·6–60·4%) than that of setaria hay (DMD 40·6). Liveweight change in sheep was significantly (P<0·05) correlated with intakes of digestible DM (r2= 0·74) and with N intake (r2= 0·82). The inclusion of legumes in the silages increased N retention and, for setaria silages, also increased rumen ammonia concentration. It was concluded that tropical grasses can be effectively ensiled by the addition of legumes alone and, with the exception of setaria/gliricidia silages, the resultant silages were of sufficiently high quality to merit their use in tropical animal production systems.

An account is given of the considerations which have been found in practice to govern the design of a small cabinet for growing plants under closely controlled conditions of atmospheric environment. Starting with questions of size, shape and material, the connexion between size of chamber and type of illumination is considered, followed by general policy on air supply. The main outlines of design having been laid down in this way, the various environmental factors to be controlled are reviewed. These include: (a) composition of the air, with particular reference to carbon dioxide; (b) light intensity. Various possible sources are reviewed, and the difficulties of imitating natural conditions of illumination are discussed, together with methods of measuring the illumination and checking for stability; (c) temperature. The degree of control needed for various purposes is considered, particularly in connexion with control of humidity, followed by systems of control, and the most advantageous arrangements for them. The cycle of operations of a control system is considered in some detail, and division of the system into a small relay-operated heater and a background heating or cooling system is advocated; (d) humidity. A similar division between background and relay-operated humidifiers is also advisable, and methods of achieving this are outlined. Dew-point control is shown to be most suitable for the background humidity, while a hot wick of low thermal capacity suffices for the relay-operated device. Finally, the principal uses of such cabinets are dealt with: (a) as adjuncts to field experimentation; (b) for work on plant pathology; (c) for producing standard plant material at any time of year; and rough estimates of running costs are given.

In the past twenty years there has been no noticeable decrease in the number of Helminthosporium infected oat and barley seed samples examined at the Official Seed Testing Station, Cambridge, and in the course of advisory practice. No reduction in the intensity of the seedling diseases caused by Helminthosporium has been noted during the first ten years under review. Formalin and copper carbonate were ineffective as seed disinfectants in reducing seedling mortality, and copper sulphate, although partially effective, had serious phytocidal effects and consequently cannot be recommended. Since the advent of the organo-mercury seed disinfectants a steady improvement in the control of these diseases has been noted, and field tests of such dressings have shown them to be eminently satisfactory. Barley straw infected with H. gramineum has been shown to be a source of secondary infection of barley seedlings.

The growth and feed intakes of Corriedale wether sheep when grown from 30 to 50 kg body weight by five different growth paths are described.

Group A (control) grew continuously (fed ad libitum). After reaching ca; 40 kg body weight, group B and C animals lost 21% of their initial body weight over 9 and 18 weeks and at 122 and 63 g/day, respectively, and began realimentation at 30 kg body weight. Group D and E animals were ca. 50 kg body weight when weight loss was imposed and they lost body weight at similar rates (125 and 157 g/day) respectively. Animals in group D lost 34% of their initial body weight over 18 weeks and began realimentation at 30 kg body weight (the same as groups B and C). Group E animals lost 23% of their initial body weight over 9 weeks to begin realimentation at 35 kg body weight. Except during periods of weight loss, animals were fed ad libitum. Compensatory growth was observed in all groups which had lost weight, with early recovery growth rates 1·6–1·8 times higher than control sheep of the same weight.

Rate of body-weight loss did not induce any significant differences in response to realimentation but results (groups B and C) suggest that the more rapid the loss, the more rapid will recovery be during realimentation. When sheep at different body weights lost the same proportion of their initial body weights, the heavier sheep (group E) attained final slaughter weight quicker than the lighter sheep (group B). When the proportion of body weight lost to reach a particular lower body weight was varied (groups B and D), the greater weight loss was associated with higher and more persistent growth rates during realimentation.

After weight loss, ad libitum dry-matter intake was significantly lower during the first 10 kg of gain during realimentation in all treatment groups (B, C, D, E) than in control group A. There were no differences between treatment groups in recovery of dry-matter intake.

Gross efficiency in all treatment groups was higher than in the control group A during the first 10 kg of recovery of body weight, but it then declined rapidly. This increase in gross efficiency was considered to be due to a combination of increased growth rates, reduced feed intakes and lower maintenance requirements. When the complete growth paths from 30 to 50 kg were considered, there were no significant differences in total feed consumed by the sheep following the five different growth paths.

1. The effect of low-temperature grain pre-treatment on two winter varieties of wheat and two winter varieties of barley is seen in a very definite reduction in the number of tillers produced, which, however, had no subsequent effect on the number of ears surviving at harvest. Very little effect resulted from the treatment of spring varieties of wheat and barley in the number of tillers produced, although the spring wheat variety did show a slight reduction.

2. Gross yields per plot were unaffected by the treatment in all the varieties, but the yields per plant were affected in the wheat experiment, and the yield per ear in the barley experiment. There was a general increase in the yield per plant of all wheat varieties, while in the yield per ear one barley variety was unaffected, another showed an increase, while the third suffered a reduction.

3. The grain from treated plants was affected in 1000-grain weight and nitrogen content in the wheat experiment, while only the 1000-grain weight suffered any change in the barley experiment. Only one wheat variety showed an increase in 1000-grain weight, while each of the three varieties responded differently with regard to the nitrogen content of the grain. Similarly, each of the three barley varieties was affected differently with regard to 1000-grain weight, one being unaffected, another showing a decrease, while the third showed an increase.

4. Analysis of the behaviour of the varieties with regard to tillering and ear production showed clearly that the maximum of tillers produced bears little relation to the number of ears at harvest. In the barley varieties high yield and low nitrogen were associated with the largest number of ears, which in turn was associated with the lowest tillering. In the wheat varieties high yield was associated with high 1000-grain weight. In both experiments the spring varieties outyielded the winter varieties whether the latter had been treated or not.

Vicia faba cv. Minden was precision planted at densities of 12–100 plants/m2 in 1977 and 30–60 plants/m2 in 1978 with and without seed-bed applications of aldicarb (10 kg/ha).

Nitrogenase activity per plant decreased significantly with increased plant density but this was compensated for on an area basis by increased numbers of plants. When expressed on the basis of area, nitrogenase activity was higher with closely, than with widely spaced plants both early and late in the season. Irrespective of planting density nitrogenase activity reached a peak during vegetative growth of the plant and a second peak during rapid pod and seed development. In 1977 the second peak was interrupted by very dry soil conditions but later activity increased following rain.

Aldicarb consistently increased nitrogenase activity at all harvests after Sitona damage to the nodules was evident. Over this period plots treated with aldicarb had twice the nitrogenase activity of untreated plots in 1977 and 55% more in 1978.

Observations on oryx, sheep and cattle under natural grazing conditions in both a wet and a dry season are given and discussed.

Dry faecal outputs by the sheep and oryx were less in the wet than in the dry season. Output by the cattle was greater than both, and showed little seasonal difference. Faecal nitrogen concentrations showed no interspecific overlap, in the rank order sheep > oryx > cattle. All were greater in the wet season, and the rank order maintained.

Drinking water intakes were similar for oryx and sheep in both seasons. The cattle's water intake was greater in the wet season. Expressed as ml/kg W0·85/day, there were no overlaps in species' mean intakes, in the order cattle > sheep > oryx, in the ratio 100:57:24. In the dry season, the herd walked 16 km on non-drinking days, and a further 7 km on alternate days when receiving water. Under wetter conditions with more forage available, the herd walked only 11 km daily.

Slight interspecific differences in the times spent walking, feeding, standing and lying were found over a 48 h period. In the wet season less time was spent walking and feeding, with corresponding increases in the other activities. The oryx were notable in that rumination occupied far less of their daytime activity than for the sheep or cattle although the total times spent ruminating were similar.

The results are discussed in relation to differences in the species’ feeding habits and strategies of diet selection, combining the grazing results with observations from penned animals on a common diet. The intakes of water agree with the results from penned animals, confirming oryx's adaptation to hot, dry conditions. The advantages of a low water requirement, met by intermittent drinking, are discussed.

The possible detrimental effects on productivity of a regime of day-grazing and night-penning under hot conditions are discussed. In the light of these, some advantages to oryx of scheduling its rumination to the night hours are suggested.

Observations on the time of development of the permanent anterior teeth in a herd of Friesian female cattle (heifers + cows) are described. The animals were examined at approximately monthly intervals. A modified longitudinal survey method was employed. A table is presented of the maximum and minimum (i.e. the range), mean and median ages for the stages of development for each permanent pair of teeth. The stages were defined as: one of permanent pair present and/or one/both temporary teeth absent, both permanent teeth emerging, ¼ up, ½ up, ¾ up and fully up. A large amount of variation was found in the ages for each stage of development in individual animals. Tables are included for the time taken for a pair of permanent teeth to pass from first to complete emergence, the time a pair of teeth were fully up before any further development was observed and the time taken between a tooth being at one stage in one pair of teeth to the same stage in the succeeding pair of teeth.

The current study was conducted in 2013 to identify the seeds of three species of Amaranthus, Amaranthus viridis L., Amaranthus retroflexus L. and Amaranthus albus L., by using the artificial neural network (ANN) and canonical discriminant analysis (CDA) methods. To begin with, photographs were taken of the seeds and 13 morphological characteristics of each seed extracted as predictor variables. Backward regression was used to find the most influential variables and seven variables were derived. Thus, predictor variables were divided into two sets of 13 and seven morphological characteristics. The results showed that the recognition accuracy of the ANN made using 13 and seven predictor variables was 81.1 and 80.3%, respectively. Meanwhile, recognition accuracy of the CDA using the seven and 13 predictor variables was 74.0 and 75.7%, respectively. Therefore, in comparison to CDA, ANN showed higher identification accuracy; however, the difference was not statistically significant. Identification accuracy for A. retroflexus was higher using the CDA method than ANN, while the ANN method had higher recognition accuracy for A. viridis than CDA. In addition, use of 13 predictor variables yielded a greater identification accuracy than seven. The results of the current study showed that using seed morphological characteristics extracted by computer vision could be effective for reliable identification of the similar seeds of Amaranthus species.

Pregnancy toxaemia in ewes is a metabolic disorder which may occur during the last month of pregnancy. Typical symptoms are anorexia, hypoglycaemia, hyperketonaemia, blindness, ataxia and recumbency. The condition usually proves fatal. Reid & Hogan (1959) have put forward the suggestion that pregnancy toxaemia is an adrenal steroid diabetes. However, pregnancy toxaemia in ewes is generally associated with starvation or severe undernutrition, and McClymont & Setchell (1955) have suggested that under these conditions the symptoms of pregnancy toxaemia are due to cerebral depression caused by hypoglycaemia. As part of investigations on pregnancy toxaemia, adrenal steroid metabolism in ewes was studied. This paper presents data on plasma cortisol levels during the last month of pregnancy in ewes, and the possible effects of undernutrition and cold on these levels.

Heading date (HD) and flowering date (FD) are critical for yield potential and stability, so understanding their genetic foundation is of great significance in wheat breeding. Three related recombinant inbred line populations with a common female parent were developed to identify quantitative trait loci (QTL) for HD and FD in four environments. In total, 25 putative additive QTL and 20 pairwise epistatic effect QTL were detected in four environments. The additive QTL were distributed across 17 wheat chromosomes. Of these, QHd-1A, QHd-1D, QHd-2B, QHd-3B, QHd-4A, QHd-4B and QHd-6D were major and stable QTL for HD. QFd-1A, QFd-2B, QFd-4A and QFd-4B were major and stable QTL for FD. In addition, an epistatic interaction test showed that epistasis played important roles in controlling wheat HD and FD. Genetic relationships between HD/FD and five yield-related traits (YRTs) were characterized and ten QTL clusters (C1–C10) simultaneously controlling YRTs and HD/FD were identified. The present work laid a genetic foundation for improving yield potential in wheat molecular breeding programmes.

An investigation of the relative importance in small plot pasture productivity experiments, of plot variations and of field and laboratory errors in sampling and subsampling for percentage dry matter and percentage nitrogen figures, revealed little advantage from duplicate sampling or subsampling in reducing the experimental error, which was due mainly to plot variation.

The effect of sampling errors was of even less importance in the estimation of the actual yields of dry matter or of nitrogen.

Three factorial experiments made in 1969 on Northern Ireland pastures to measure effects upon yield and mineral content of 0, 180 and 360 kg N, 0, 30 or 60 kg P and 0, 150 or 300 kg K/ha/year, both with and without 1380001 slurry/ha, were continued on the same sites with the same treatments in 1970 and two of them were continued again in 1971.

Responses to nitrogen in the second and third seasons were similar to those of the first season. There was no evidence that large nitrogen dressings plus slurry were causing nitrogen to accumulate in the soil.

Repeated cutting of herbage given neither fertilizer potassium nor slurry was beginning to reduce both yield and the potassium content of the herbage in the second and third years. Giving fertilizer potassium prevented these losses, but the potassium in the slurries was less effective because it did not maintain the potassium content of the herbage. Reasons for, and implications of this effect are discussed.

There was no evidence that soil phosphorus reserves were becoming depleted, when judged by the % P in herbage receiving neither fertilizer nor slurry even after the herbage had been cut and removed for two or three years. As there was no immediate need for fertilizer phosphorus, the P in the slurries, even though slower acting than that in mineral fertilizers, seemed suitable for maintaining the phosphorus status of these pasture soils.

A conservation experiment is described in which a comparison is made of quality and of nutrient losses in wilted and unwilted lacerated silages made by the cold fermentation process in large trench silos. The losses of dry matter in the two wilted silages were 19.7 and 16.7% and in the unwilted silages 23.3 and 22.1%.

Oilseed rape seed yield has increased in the last 40 years in most countries, but this yield gain has not been accompanied by greater yield stability. The current study aimed to quantify the genotype by environment (G × E) interaction on oilseed rape yield, identify genotypes with broad adaptability and the main environmental drivers related to seed yield. A weighted two-stage mixed-model analysis was applied to official multi-environment trials of nine spring genotypes (G), in three locations (L) during 6 years (Y) on central and southern Argentine Pampas under rainfed conditions. Best linear unbiased prediction of seed yield ranged from 0.37 to 3.73 kg/ha. Fixed effect L × Y was highly significant and G variability was estimated as 130 kg/ha of standard deviation. Contrasting genotypes were identified by Shukla's stability index and two of those showed the best yield performance in the wettest year. Factor analysis explained 0.75 of total variation and discriminated genotypes with broad and specific adaptability, as well as combined environments according to the similarities in seed yield of the evaluated genotypes. Environmental loadings of Factor 2 were linearly associated with cumulative rainfall in the post-flowering period (up to 230 mm). It is concluded that (i) a significant G × L × Y interaction underlies the high variability of seed yield, (ii) two genotypes (G6 and G7) with high yield stability were identified, and (iii) G × E effects are associated with post-flowering rainfall.

Mortality rates, calving intervals, age at first calving, generation intervals and animal productivity of Santa Gertrudis, Sahiwal, Brahman and crossbred animals were determined from 11 years' data collected at the Ebini livestock station in the Intermediate Savannahs of Guyana. These data were condensed and analysed and recommendations made as to the most important factors influencing animal production in the Intermediate Savannahs.

When the leaves of sugar-beet crops were sprayed on six occasions in late September and early October with 100 gal./acre of a 3% solution of ammonium nitrate or equivalent urea, in two experiments about 70% of the nitrogen was recovered in the plants in mid-October, compared with 40% recovered from applications of the same amounts of fertilizer to the soil at the same times. In a third experiment the recovery from similar sprayings with urea solution was less than 40%, but very little nitrogen was absorbed from soil dressings, so that the difference between the recoveries from spray and soil applications was nearly the same as in the other experiments.

Nitrogen per cent of dry matter in all parts of the plant was increased by the sprays. More than half of the nitrogen absorbed from the sprays was in the leaf laminae, and the remainder was equally divided between petioles (including crowns) and roots. Between 20 and 30% of the nitrogen supplied in spray in the first two experiments was converted to protein in the leaf laminae, and half of this was present as soluble protein precipitable by trichloracetic acid, a fraction that is extracted in the largescale preparation of leaf protein.

Spraying slightly increased the dry-matter yield of the tops, but not of the roots. It reduced the sugar content of the roots by about 1% of fresh weight. In one experiment it had no effect on sugar yield; in the others it caused losses of 2 and 5 cwt./acre.

The recovery of nitrogen in the tops from a single low-volume spraying (12½ or 25 gal./acre) with nearly saturated urea solution was about the same as from repeated high-volume sprays supplying the same total amount of nitrogen, but in the roots it was higher from the single than from the repeated sprays.