The nutritional importance of a foodstuff in a diet depends on the composition of the raw foodstuff, the amount that is usually consumed and the extent to which nutrients are destroyed or lost during preparation of the diet.

Most Nigerian foods have to be prepared and cooked before they can be eaten. A lot of food preparation in Nigeria involves soaking, steeping, boiling, frying and roasting; at each stage of the preparation, some of the nutrients may be discarded or destroyed, while in some cases toxic substances may be discarded (Oke, 1968)

The mating response and lambing outcome in fifty-three sheep was studied after treatment with intravaginal sponges during October (normal breeding season). Bach pessary carried a dose of 30 mg ‘Cronolone’ (9α-fluoro-11β-hydroxy-17α-acetoxyprogesterone; SC-9880, G. D. Searle) in finely dispersed form and was inserted for 14 days. Half the number of pessaries carried an additional dose of 400 mg progesterone. Breeding was by natural service, using 10% rams. Ninety per cent of the fifty ewes bred immediately after treatment conceived; the average number of lambs/conception was 1·9. Sheep treated with ‘Cronolone’/progesterone pessaries showed a marginal and non-significant advantage over those treated with ‘Cronolone’. The application was effective in ensuring the birth of most lambs (87% of total) within a period of 1 week.

1. A short description is given of an apparatus that aims at measuring the motility of sperm cells in an objective way.

2. In this method it is necessary to know the concentration on the slide for the determination of the value that indicates the motility. It was intended to measure this concentration with the same apparatus.

3. The measurement of the concentration met with some difficulties. A large scatter in the results was observed. This scattering is partly apparent in that it is caused by real differences in the concentrations which originate in the preparation of the slides. However, this apparent scatter hinders the determination of the exactness of the measurements. An estimate has been obtained, among other things, by means of a photographic experiment. There is some justification for expecting that a sufficient exactness can be obtained.

4. Notwithstanding the unexplained, and for the present still undoubtedly too large a scatter in the concentration measurements, a series of measurements of motility were made. The motility appears to be measurable by the apparatus, but there is still too great an error, so that the measurement does not yet come up to the visual method.

5. An effort to measure motility independent of the concentration on the slide (determination of the speed histogram) did not succeed because facilities were not available.

The plants worked on in this Natural Order were the Carrot (Daucus carota L.) and the Parsnip (Peucedanum sativum Benth.). Both these plants store up reserve food in their thickened root and hypoeotyl, the disposition of the tissues being similar in both “roots.” For the extractions of their proteins, members of “races ” of these plants containing the minimum amount of core and fleshiest annuli of bast were taken, healthy, uniformly well-grown specimens being selected.

Individually-penned adult Merino wethers were fed for 16 weeks on a basal diet of ground, pelleted oat straw or Phalaris straw. Urea was supplied either in a salt-urea block containing 30% urea, or as crystalline urea incorporated into the pellets. A commercial mineral supplement was given during the first 8 weeks, but this was replaced with a laboratory-prepared mineral mix during the second 8 weeks.

Urea supplementation significantly reduced live-weight loss. Over the 16 weeks control sheep lost a mean of 14·5 kg, and supplemented sheep 8·7 kg body weight. Most of this response to urea occurred during the second half of the experimental period.

Food intakes of all sheep increased over the first 2 weeks and then fell. In the unsupplemented groups, levels of intake then remained fairly low, whereas in the sheep fed urea food intakes rose over the final 6 weeks of the experiment. There was a significant linear regression of live-weight change on food intake only with the urea-fed sheep. Intakes of urea-N from the blocks were extremely variable between individual sheep and between periods within sheep; in most cases, however, they appeared to be adequate, as this type of supplementation gave results similar to those obtained by mixing urea throughout the roughage.

There was no significant effect of urea on total wool growth during the experimental period, although wool growth in the supplemented shepp showed a rise towards the end of the experiment. Wool growth in any 4-weekly period was closely related to food intake and live-weight change during that period.

Preliminary experiments carried out in the summer of 1928 had indicated that sampling methods might be used to obtain a satisfactorily precise estimate of the yield of small cereal plots(1). It was thought desirable to test the method more thoroughly, and to compare the estimates with figures obtained by large-scale methods. Accordingly samples were taken from all the plots of the three Rothamsted cereal experiments of 1928, the plots later being harvested with a binder in the ordinary manner. Samples were also taken from the 16 plots of a small experiment on barley at Wellingore, Lines., but no direct measurement of total yield was made for these plots. There were 210 plots in all, but of these 50 were sampled in four sections, corresponding with minor differences in manurial treatment; so that the total number of plots dealt with amounted to 360. The large-scale method, however, treated each of the 50 as a single plot, and thus provided only 210 yield figures.

That swedes are better feeding materials under some conditions than under others is more or less generally recognised; the suggestion of controlling these conditions is perhaps not new, but little of practical importance has been achieved in this direction. About five years ago the subject was considered at the Durham College of Science (now Armstrong College), Newcastle-upon-Tyne, and experiments were started which have been repeated and added to every season. The object of these investigations was to form a list of the different varieties of swedes in order of merit. Incidentally other points of interest have arisen, and are dealt with in the following pages. The results of these experiments have been published each year in the Annual Report of the Agricultural Department of the College, but a review of the work done seems of sufficient general importance to prove interesting to a larger circle of readers.

1. Emergence and dry-matter production of largeand small seeds of two varieties of broad beans (Beladi and Rebaya 34) were studied.

The fertility of a number of ejaculates from normal dairy bulls in regular service is found to be positively correlated to the light-reflecting capacity, NE, of the spermatozoa in the ejaculates.

In the course of determinations of organic carbon in soils, some unexpectedly high figures suggested the possibility that free carbon in the form of fragments of coal or cinder might affect appreciably the results obtained. The soils in question were from the Coal Measure district of Flintshire, and the presence of notable amounts of coal was not surprising. Even in soils from other districts, however, it is not unusual to find small carbonaceous fragments, which are generally noticeable in the coarse sand separated in mechanical analysis. Their presence is not difficult to explain, for domestic ashes containing unburnt coal or cinders are often thrown on to the manure heap, and thus get carted on to the soil where they persist unaltered. The highest proportions of elementary carbon may be expected in heavily manured soils such as those of gardens.

The close-grazing or rotational system of pasture management has received wide attention in recent years, not only from the agricultural chemist but in one or other of its various modifications from the farmer and dairyman. Its underlying principles have been found to be sound and its main features capable of practical application. Given a fertile soil, suitable fertilisation and favourable seasonal conditions, it serves to furnish a highly digestible, high-protein herbage throughout the season.

Factors influencing potato virus X (PVX)-induced resistance to Alternaria solani in potato leaves are reported. The inhibition of fungal infection was dependent on the time interval between viral and fungal inoculations, fungal inoculum load, age of the host, virus strain and host cultivar. The maximum reduction in fungal infection was observed when a gap of 120 h occurred between PVX and A. solani inoculations. The clearest interactive effect in terms of reduced susceptibility to A. solani infection was seen at a fungal spore concentration of 1000 spores/ml in 20-day-old plants. This effect was gradually reduced following an increase in inoculum load and age of the host.

The extent of pathogen interaction was also affected by different virus strains and host cultivars. Maximum inhibition of fungal disease occurred with the PVX-ring spot strain. Of five potato cultivar tested, the maximum inhibition occurred in Kufri Chandramukhi and Kufri Sindhuri, the cultivars most susceptible to A. solani.

1. Several authors have previously reported that the sulphuric acid treatment of the cotton seed resulted in: (a) earlier germination, (b) higher percentage of seeds germinating, (c) higher yield of seed cotton per acre, and (d) better and more uniform planting (this paper is not concerned with the disinfecting effect of this process).

2. A series of experiments, both in the laboratory and under field conditions have been carried out to determine whether the above statements are in agreement with actual experimental data.

3. In so far as the rate of germination is concerned, it was found that: (a) untreated seeds often show a smaller percentage of germination than seeds treated with sulphuric acid for various time-intervals, particularly when tested in the laboratory; (b) cotton seed treated with the reagent for from 5 min. to 2 hr. or even 5 hr. in some cases, does not show any decrease in its germinative value as determined by laboratory tests. In field trials seeds treated for 5 or 12 hr. practically do not germinate at all, whereas the 2 hr. treatment often shows a small decline in germination; (c) an enormous difference in the rate of germination has been revealed between the laboratory determinations on the one hand and the field determinations on the other.

1. Wheats from manurial trials, whose nitrogen contents differed by reason of the fertilizer treatment applied, have been used as the sole source of protein in rat-feeding experiments.

2. Pairs of rats given such diets have shown increased growth when fed wheat of higher nitrogen content.

3. Measurement of the ratio of growth rate to nitrogen ingested, suggests that the difference obtained is due, not to increase in the acceptability of the diet, but to the greater nutritive value of the grain from the manurial plots.

This research paper addresses the effect of different grouping strategies of fresh cows on total lactational and reproductive performance. Hundred-sixty multiparous Holstein cows were enrolled in a completely randomized design and assigned to one of following treatments: 21 days in fresh pen with 12.5 kg/day concentrate (C21, n = 60), 10 days in fresh pen with 12.5 kg/day concentrate (C10, n = 50) and 10 days in fresh pen with 10 kg/day concentrate (L10, n = 50). Although there were no differences among treatments within the first 10 days in milk (DIM), C10 and L10 cows tended to produce more milk than C21 from 10 to 21 DIM. In addition, greater milk yield was obtained in C10 and L10 cows during 22–28 DIM and 29–70 DIM. Higher production in early lactation resulted in a tendency for greater milk production for C10 and L10 cows throughout a 305 days lactation. There was no difference in productivity between C10 and L10 groups at any time point. No blood metabolites (Ca, P, non-esterified fatty acids and β-hydroxy butyrate) were affected by treatments. Pregnancy at first, second and third service was 38, 39 and 40%, respectively, which were not influenced by the days in fresh pen or concentrate allowance. Collectively, our results for the first time suggest that fresh cow grouping strategy has a long-term effect on productivity but that adding 2.5 kg/day concentrate has no effect on milk yield in fresh pen.

The current study was conducted to compare the responses of broiler chicks (average daily gain (ADG) and feed efficiency (FE)) raised before and after 2000 to dietary protein and lysine through neural networks (NN). The available lysine dose-response data were extracted from the literature and arbitrarily divided into two sets of before and after 2000. The training and testing data sets derived from each group were used to develop the NN models. The developed models were subjected to a sensitivity analysis test to assess the relative importance of dietary protein and lysine on chicks’ responses. An optimization algorithm was used to find the dietary protein and lysine required for maximum ADG and FE, based on each dataset. The results showed that the NN models developed could predict ADG and FE efficiently in broiler chicks of before and after 2000, and the higher accuracies of prediction were attained by these models compared to those of regression models. Sensitivity analysis indicated that ADG and FE were more sensitive to dietary lysine, compared to protein, in both time periods. Based on the optimization results, the protein and lysine requirements for maximum ADG or FE for birds reared after 2000 were lower and higher, respectively, compared to those reared before 2000. The protein requirements for maximum ADG and FE for birds reared before 2000 were 241·3 and 247·0 g/kg diet and for lysine 10·76 and 11·18 g/kg diet, respectively. In birds reared after 2000, maximum ADG was obtained when the diet contained 224·30 g protein/kg diet and 11·75 g lysine/kg diet, whereas maximum FE was achieved with a diet containing 228·3 g protein and 13·1 g lysine.

When water and nutrients are not limiting, and pests and disease are effectively controlled, crop growth and yield is determined by weather conditions such as temperature and solar radiation. To determine the relationship between weather indices and crop yield, multiple wheat varieties were sown at two sowing times, for five sowing seasons and at two locations. The following weather indices around the 50% anthesis stage were recorded and analysed: mean temperature (Tmean), maximum temperature (Tmax), number of days with temperature >30°C (T30), vapour pressure deficit (VPD), photosynthetically active radiation, photothermal quotient (PQ) and photothermal quotient corrected for vapour pressure deficit (PQvpd). Overall, for every 1°C rise in temperature, crop yield decreased by 370 kg/ha. For every 1°C rise in temperature, normal sowing window yield decreased by 360 kg/ha while late-sown wheat yield decreased by 640 kg/ha. Correlation analysis was conducted between the weather indices and grain number, grain yield and grain protein. There was a significant positive correlation between PQ and PQvpd and grain number and grain yield. There was a significant negative correlation between Tmean, Tmax, T30 and VPD and grain number and grain yield. Grain protein content showed a positive correlation with maximum air temperature and a negative correlation with the weather indices PQ and PQvpd. PQ and PQvpd can be used to predict grain number and grain yield potential. This study showed that grain number and grain yield predicted using PQ and PQvpd are more reliable than using temperature and radiation individually.

Analysing the stability and adaptation of cultivars to different environments is always necessary before recommending them for planting on large areas. Additive main effects and multiplicative interaction (AMMI) models have been used to analyse genotype-by-environment interactions (G × E). AMMI models require data with homogeneous variance, normal errors and additive effects. However, agronomic data do not always conform to these statistical assumptions. The objective of the present study was to analyse G × E interactions for severity and incidence of grey leaf spot, a foliar disease in maize caused by Cercospora zeae-maydis, using a generalized AMMI model. Data were collected and evaluated for 36 maize cultivars from experiments carried out in nine Brazilian regions in 2010/11 by the Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA – Milho e Sorgo). Only two of three stable genotypes defined by a quasi-likelihood model with a logistic link function could be recommended for their desirable agronomic characteristics. Four growing locations in which the genotypes were stable were identified, but in only one of these was stability associated with very severe grey leaf spot disease. Cultivars adapted to specific locations with low percentage disease severity were also identified.

Milk records and records of farm and herd management collected over a 2-year period have been used to study the effects of seasonal changes in climate, feeding and management in each of four Dairy Shorthorn herds.

Differences in climatic conditions and management between the four farms appeared to be reflected in mean lactation yields, herd D having a slightly higher, and herd C a considerably lower average than the other two herds.

In each herd, mean yields in each week were corrected for the effects of potential productivity and mean stage of lactation of the cows to give a weekly value designated the yield index. Variations in this quantity were used as a measure of the effects of seasonal changes in climate, feeding and management upon milk yields.