1. The efficiency of food conversion of Brown Leghorn fowls inbred for egg number, or egg size, or egg number and egg size have been compared.

2. Comparison between the lines was made for egg numbers, total egg weight and total egg energy. Egg energy was the best measure of production, total egg weight was the next best and egg number the poorest.

3. When allowance was made for differences in rates of egg production and egg size, there were no differences in the efficiency of conversion of food to eggs between the lines.

4. The standard errors of the means for the analytical data on the twelve replicate mixes of the diet were relatively small, but the range in values was appreciable. The importance of analysing diets in nutrition experiments is stressed, particularly for ‘iso-caloric’ diets.

Cultivar mixtures of winter barley and spring barley, together with their component monocultures, were grown in field trials to assess the effect of cultivar combinations on both straw and grain yield. The overall grain yields for all trials were significantly higher for the cultivar mixtures than for the corresponding component monocultures. Also, significant decreases in rhynchosporium disease severity for cultivar mixtures were recorded for most non-fungicide treatments. The size of these responses was often significantly correlated with the component number of the mixtures. The amount of straw produced in mixtures was sometimes changed significantly, but not always in a positive direction and it was only correlated with increasing mixture component number in two environments. No correlation of straw yield potential of cultivars with performance in mixtures was found. Cultivar × cultivar mixture × environment interactions appeared to affect the relative yield of grain and straw differentially and therefore it was not possible to predict the effect of mixtures on the harvest index.

Insulin-like growth factor 1 receptor (IGF1R) is a cell surface receptor, belonging to the tyrosine kinase receptor superfamily. IGF1R plays a role not only in normal cell development but also in malignant transformation, which has become a candidate therapeutic target for the treatment of human cancer. This study aimed to explore insertions and deletions (indels) in IGF1R gene and investigate their association with growth traits in four Chinese cattle breeds (Xianan cattle, Jinnan cattle, Qinchuan cattle and Nanyang cattle). The current paper identified a 28-bp indel by polymerase chain reaction within IGF1R gene. The analysis showed that there was a significant correlation between the locus and the hucklebone width of Nanyang cattle in four periods, in which it was highly correlated at 6, 12 and 18 months. At the age of 6 months, it was also significantly correlated with body height, body weight and body length. Association analysis showed that the locus in Jinnan cattle was extremely significantly correlated with body slanting length and body weight, and significantly correlated with chest circumference. There was no significant correlation between this locus and growth traits of Xianan cattle and Qinchuan cattle. The detected indel in the IGF1R gene was significantly associated with growth traits in Jinnan and Nanyang cattle, and could be used as a molecular marker for growth trait selection.

Cultivated pastures in southern China are being used to improve forage productivity and animal performance, but studies on grazing behaviour of goats in these cultivated pastures are still rare. In the current study, the grazing behaviour of Yunling black goats under low (5 goats/ha) and high (15 goats/ha) stocking rates (SRs) was evaluated. Data showed that the proportion of time goats spent on activities was: eating (0.59–0.87), ruminating (0.05–0.35), walking (0.03–0.06) and resting (0.01–0.03). Compared with low SR, goats spent more time eating and walking, and less time ruminating and resting under high SR. Goats had similar diet preferences under both SR and preferred to eat grasses (ryegrass and cocksfoot) more than a legume (white clover). The distribution of eating time on each forage species was more uniform under high v. low SR. Bites/step, bite weight and daily intake were greater under low than high SR. Results suggest that the SR affects grazing behaviour of goats on cultivated pasture, and identifying an optimal SR is critical for increasing bite weight and intake.

In Morocco, sugar-beet seed production represents a new challenge to meet the main breeding programme goals. The identification of a suitable zone for plant vernalization represents a bottleneck for seed production. This study aimed chiefly at evaluating the vernalization aptitude of 18 sugar beet half-sib progenies. Trials were conducted during three selection cycles in a specifically chosen environment. The experimental site of Merchouch is 40 km south-east of Rabat city. Field trials design is according to an open-pollinated experimental block. Yield components and five phenological traits were recorded during the growing cycle and at the plant maturation. The variance analysis showed a significant effect of the selection cycle on the phenological traits and grain yield. The plant cycle duration increased by 10.7 days between the first and the third selection cycles. According to the principal component analysis and the hierarchical clustering, F2, F5, F6, F9, F10, F11, F14 and F15 half-sib progenies are described as long cycle and high grain yield families. Grain yield reached 257.3 g per plant, the duration to maturity 350.6 days and the germination rate 93%. The three selection cycles and the suitability of the site vernalization conditions are potentially effective for seed production progress. Our results are relevant as they established an adequate site for the sugar beet seed production. The half-sib selection is a valuable method for sugar beet germplasm enhancement.

The control of Campylobacter in poultry is considered a public health priority and some intervention strategies have been implemented in Denmark. Nonetheless, Campylobacter infection in poultry can still be considerable particularly during the summer when the most promising Campylobacter control strategy seems to be the use of fly screens. The use of cost-effective vaccines against Campylobacter is also desirable. In order to control Campylobacter, poultry producers need to make crucial decisions under conditions of uncertainty. With the aim of assisting poultry producers in decision making regarding Campylobacter control strategies, the objective of the present study was to produce a decision support system that integrated knowledge and used a Bayesian approach to handle uncertainty. This decision support system integrated epidemiological data, microbiological considerations, financial information and potential control strategies (the use of fly screens and hypothetical vaccines). In conclusion, results from model and sensitivity analyses indicated that the financial variables (cost–benefit functions) and the effectiveness of the different control strategies drove the results.

A method that allows the effect of temperature treatments on plant quality to be quantified is described. The proposed method is based on the analysis of temperature regions for plant quality characteristics and enables an easier and more precise analysis of the influence of day and night temperature on plant growth and development. Plant quality may be evaluated by the combination of any number of plant characteristics. The proposed method can assist growers in determining what temperature regimes are necessary to produce acceptable-quality crops on specified days.

In tropical regions, water stress is one of the main causes of the reduction in forage productivity, and irrigation strategies can mitigate the problem, especially for highly productive species. The objective of this study was to evaluate the effects of irrigation, genotype and plant size on productive responses and water use efficiency (WUE) of elephant grass (Cenchrus purpureus [Schumach.] Morrone), in the rainy and dry season. The experimental design was randomized in blocks, arranged in split plots, the main plots were established based on the use of irrigation and the subplots were the tall-sized genotypes (IRI 381 and Elephant B) and dwarfs (Taiwan A-146 2.37 and Mott). The genotypes were evaluated for two years and harvested every 60 days. Water use efficiency, total forage accumulation per year and harvest, forage accumulation rate and forage density were evaluated. There was a significant difference between the genotypes in terms of total forage accumulated (P < 0.05). The most productive genotype was IRI 381, which showed the greatest total forage accumulation (42 168 kg of DM/ha in two years) in the irrigated plots. During the rainy seasons, IRI 381 stood out in terms of forage accumulated (24 667 kg of DM/ha). Irrigation favoured increases in forage accumulation around 60%, in both years of evaluation. Irrigation and plant size influenced the productivity and WUE of elephant grass harvested in 60-day intervals. Tall genotypes and Taiwan A-146 2.37 (dwarf size) stood out in most of the productive traits analysed, while Mott was highlighted by its forage density.

Frequently in near-infrared reflectance spectroscopy, a calibration is developed using very restricted data sets, e.g. material from one season, a small area or of a limited type: consequently, the predictions may have limited validity. This paper describes the use of both restricted and wide calibration sets for the prediction of crude protein in grass, silage and hay. Results show that predictions from the wider calibration sets are often as good as or better than predictions from restricted calibration sets. Therefore the use of wide calibration sets should be considered much more frequently in near-infrared reflectance.

Introductions of red clover indigenous to the Atlas mountains of North Africa were shown to have a high degree of resistance to Sclerotinia trifoliorum when a natural attack occurred in field trials at Cambridge. Differences between the two classes of clover varieties: (1) North African populations, and (2) the British varieties Essex broad red and S. 123, were highly significant for the proportion of row affected, the number of affected areas and the average length of affected area. The North African material is expected to be a useful source of resistance to Sclerotinia trifoliorum, in breeding programmes.

We are indebted to Mr H. H. Rogers for his guidance and for collecting the red clover plants during the 1962 North African expedition which was supported by the Agricultural Research Council. We also acknowledge valuable criticism of the manuscript and provision of a computer programme by Mr J. L. Fyfe and help with field records by Mr M. Pope and Mrs H. E. Pape.

The use of silvopastoral systems with tree legumes is a viable alternative to recover and develop pastures, as they add N to the system influencing pasture growth. This study hypothesized that the herbage and litter of signalgrass (Urochloa decumbens Stapf) is affected by legume trees in the pasture. Treatments were composed of (1) signalgrass + Mimosa caesalpiniifolia Benth.; (2) signalgrass + Gliricidia sepium Jacq.; and (3) signalgrass monoculture. The 3-year experiment followed a randomized complete block design with three replications. Tree legumes were planted in double rows (15 × 1 × 0.5 m), in 1 ha paddocks. Litter samples were taken in five distance points (0, 1.8, 3.7, 5.6 and 7.5 m) perpendicular to tree legume rows. Signalgrass was taller at longer distances from the trees (P < 0.05). Signalgrass height differed between treatments, with taller signalgrass found in pastures mixed with G. sepium (15.6 cm) compared to M. caesalpiniifolia (9 cm) (P < 0.05). Herbage N content decreased with increasing distance from tree rows (P < 0.05). Litter N content followed a similar pattern, ranging from 23 g/kg under the trees to 12 g/kg at 7.5 m away from tree rows. Signalgrass did not grow under the tree crown (0–1.8 m), especially when intercropped with M. caesalpiniifolia. The findings of this study suggest that the type of legume trees used in the silvopastoral system has the potential to modify the pattern of grass growth and content of N in pasture litter.

Mixed crop–livestock systems, the world's most widespread farming systems, promote farm resilience through diversification and allow for crop–livestock integration (CLI). Intensification and specialization challenge these systems. In Northwest Vietnam, the standard farm model is based on mixed crop–livestock family farms but is shifting towards more specialized farming systems. The aim of the current study was to identify the new balance between livestock and crops on farms in Northwest Vietnam and to examine the effects of specialization on CLI practices and production system intensification by identifying current CLI practices and performing a retrospective analysis of changes in these practices. One hundred farms were surveyed and 24 interviews on farm trajectories were conducted in Dien Bien district (Dien Bien province) between January and April 2022. Based on the level of CLI and farm diversification, seven types of farms were identified and classified into three categories: (B) mixed farms, (A) farms specializing in livestock and (C) farms specializing in crops. The study of farm trajectories revealed three main changes: the conversion of mixed crop–livestock farms into more specialized crop systems, a change from mixed crop–livestock to more specialized family livestock farms and a change in the management of large ruminant herds and their feed system from free grazing to forage-fed systems. Understanding these changes will help identify drivers and potential constraints to the development of new practices for the integration of crop and livestock farming.

Grain weight and size significantly influence wheat yield and quality. This study aimed to dissect the genetic basis of quantitative trait loci (QTL) associated with grain weight and size in hexaploid wheat (Triticum aestivum L.) using the novel wheat-Agropyron germplasm Pubing3228. A population of 210 F8 recombinant inbred lines derived from Pubing3228 and Jing4839 was evaluated across multiple environments for grain length, width, thickness and thousand-grain weight (TGW). Genotyping was conducted using the Illumina Infinium iSelect 55 K SNP chip, followed by QTL mapping with QTL IciMapping software. A total of 114 QTLs were identified across 20 wheat chromosomes, highlighting major QTLs for grain length, width/thickness and TGW. Candidate gene analysis revealed 22 genes expressed in grains, including those specifically associated with TGW, grain width/thickness and grain length. These findings enhance our understanding of the genetic mechanisms underlying wheat grain traits, providing insights for marker-assisted selection in wheat breeding programmes.

High yielding ruminant livestock require high nutritive value in forage for maintenance, growth and production. Climate change has been documented as impacting on the nutritive value of forage plants. Therefore, the aim of this study was to investigate the impact of increased temperature in combination with CO2-enhancement on the nutritive value of orchard grass (cocksfoot; Dactylis glomerata L.), as a C3 model plant, widespread in mountainous permanent grassland plant communities. Functional traits and forage quality of orchard grass were investigated both under ambient (C0T0) and under simulated, future climate conditions (C2T2) with increased temperature (+3°C) and enhanced CO2 concentration (+300 ppm) under field conditions. Plant samples were taken from each of the three growths over a period of three consecutive years and numerous functional properties and forage quality parameters were determined. Special attention was paid to the determination of water-soluble carbohydrates (WSC), crude protein (CP), non-protein N (NPN) and metabolizable energy (ME) as possible indicators for different climatic conditions. It is hypothesized that (i) functional traits and (ii) forage quality of orchard grass are altered by increased temperature and higher CO2 concentration. The results showed a negative impact of C2T2 compared to C0T0 on tiller height (54.4 v. 70.6 cm) and weight (2.42 v. 3.22 g) as average over cuts and years. The NPN content was lower in C2T2 (312 g/kg CP) compared to C0T0 (339 g/kg CP). In contrast, the WSC content was higher in C2T2 (90.3 g/kg DM) compared to C0T0 (82.5 g/kg DM). Both ME content and digestibility were increased in C2T2 (9.18 ME/kg DM and 68.2%) compared to C0T0 (8.86 ME/kg DM and 65.4%). Concluding, under increased temperature and enhanced CO2, both functional traits and certain nutrients and their fractions appear to change in orchard grass.

To investigate the potential application of replacing a proportion of a perennial ryegrass (PRG) silage diet with press cake on productivity and enteric methane (CH4) emissions in late lactation and non-lactating spring-calving dairy cows, a study was undertaken in which control cows (n = 21) were offered PRG silage, while treatment cows (n = 21) were offered a diet consisting of 60% PRG press cake and 40% of the same PRG silage. Although treatment cows had higher group average dry matter intakes (DMI) and produced more enteric CH4, carbon dioxide (CO2), milk solids, protein, fat- and protein-corrected milk yield (FPCM) in late lactation, the magnitude of the difference between treatment and control cows varied from week to week (P < 0.050). When enteric CH4 per kg of milk yield, milk solids and FPCM were considered, there was no significant difference between treatment and control. Absolute enteric CH4 was higher for cows fed press cake during the non-lactating period but this tended to vary from week to week. Similarly, CO2 (P < 0.001) and hydrogen (H2; P = 0.023) differed from week to week for cows offered press cake, and cows offered PRG silage in the non-lactating period. Although there was no significant effect of diet on body weight (BW) and body condition score (BCS), when enteric CH4 was expressed on a per kg BW basis, cows offered press cake tended to produce more enteric CH4 in both late lactation and during the dry period.

1. The degree of dispersion on shaking of the heavy clay Gezira soil has been studied in relation to its initial moisture content when it is added to the water. A minimum dispersibility was found at about 7% initial moisture content. Such behaviour is different from that found with certain English soils by Puri & Keen.

2. Spontaneous dispersion was studied using the same soil, and by this method it was found that the dispersion decreases with increasing moisture content over a range of zero to 9% moisture.

3. This relation between dispersion and water content is discussed in relation to possible effects in the field of practice. Attention is drawn to possible seasonal and daily differences in the effect of rainfall.

The scheme of soil classification which finds most favour among scientists to-day has come from Russia and is the work of a band of brilliant and enthusiastic investigators whose labours have brought some order to what was otherwise chaos. The object of this communication is to endeavour to show how it is possible to modify the views of this school so as to make them apply to British conditions, and how the majority of British soils may be brought within the envisaged scheme.