Four experiments investigated some of the factors affecting the digestion of whole maize grain in non-lactating cows and yearling steers. With steers, but not cows, maize in diets containing small amounts of hay (14%) and large amounts of whole grain were better digested than those with 37 or 48% hay. The higher digestibility of maize in steers was associated with a greater time spent ruminating per kg feed and a longer retention time of maize in the gut than in cows. Replacing long roughage with ground and pelleted roughage in diets for steers improved the digestion of whole maize but not as well as reducing the hay to 14% of the diet. Finely grinding the maize produced a large increase in digestibility of the feed in cows and steers and both digested it to the same extent. It was concluded that the motility of the reticulo-rumen during eating and ruminating largely determines the extent of the digestion of whole maize grain.

A radiography unit was developed with which two technicians and two assistants were able to diagnose number of foetuses in 400–600 ewes per day on farms. Diagnoses made between 100 and 120 days of gestation in flocks where weekly mating records were made were 95–98% accurate as judged by lambing records. In most flocks more than 90% of twin pregnancies were correctly diagnosed. Agreement between diagnoses and lambing records was reduced when weekly mating records were not available. The radiographic examination had no detrimental effects on ewes or lambs.

Split-plot (or split-block) analyses are commonly applied to experimental results where several successive observations of the same variable have been recorded on each experimental unit. The assumptions required for such analyses receive scant attention and it often seems unlikely that these assumptions would be satisfied in experimental situations. Five sets of results are presented to support this proposition. An alternative analytical approach is suggested in which contrasts over time are analysed; such a method is always valid, computationally simple, and readily interpretable, and may also be used to gauge the validity of the split-plot analysis.

Effect of 24 h and 48 h of water deprivation on glomerular filtration rate (GFR), and on blood and urine electrolyte levels in Marwari sheep of the Rajasthan desert, India, have been recorded. Body weight, urine volume, GFR and erythrocyte sodium concentration in these animals registered considerable decreases due to dehydration. Both plasma sodium and urinary potassium concentrations remained unaffected. While plasma potassium was somewhat reduced, the potassium in red blood cells increased after 48 h of water deprivation. The most remarkable response was in the concentration of urinary sodium which rose to more than double the normal level.

The possibility of a sub-clinical state of thiamine deficiency in young cattle and sheep is discussed. A trial was carried out on six MAFF experimental husbandry farms in which groups of animals were given 100 mg of thiamine per day orally throughout the rearing period. Measurement of erythrocyte transketolase showed that the dosed group gave a significantly lower percentage thiamine pyrophosphate effect than the control group. There was no difference in weight gain of the two groups during the limited period of the trial.

The effects on the body composition of Corriedale wethers of weight loss, compensatory gain and constant body weight are described. Three groups of sheep were grown from 35–63 kg by different paths. The first grew continuously (fed ad libitum). The second and third groups lost 20% and 28% of body weight (restricted intake), respectively, from 48 kg and were then fed ad libitum until they reached 63 kg. Pairs of animals were slaughtered at intervals in each group. A fourth group of sheep was maintained at 48 kg. Analyses of covariance comparing regression equations were used to determine differences in body composition between the first three groups.

The compensatory growth rates of both groups which had lost weight were 1·5–2 times those during continuous growth. These increases were associated with an increased gut content of these animals and a concomitant reduction in the proportion of empty body weight (EBW) and carcass weight (CW) in t he full body weight (FBW). Thus, the apparent dressing percentage (CW/FBW x 100) was reduced by 2% during compensatory growth. The carcass length was not reduced during weight loss and its growth in relation to the CW was not affected by treatment. Thus compensatory growth animals had longer carcasses. Similar increases in gut contents and carcass length were found for animals maintained at constant body weight.

During developmental growth the proportions of the external offals, organs and gut tissue decreased in relation to the EBW; notable exceptions were the large intestine and caul fat where the proportions remained constant and increased, respectively.

The growth of the CW, lungs, large intestine and head were not reversed during weight loss whilst the liver, heart, hide and gut tissues (except the large intestine) all lost more weight during weight loss than they had gained during the growth phase. The proportions of these latter components were increased in relation to the EBW during the ensuing compensatory growth.

In general, the composition of animals held at constant body weight was similar to that of animals experiencing compensatory growth at the same weight and age.

Field experiments were conducted at the International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria, for four seasons to evaluate the effect of harvest interval on yield, quality and viability of indeterminate cowpea (Vigna unguiculata (L.) Walp.) seeds. Decreasing harvest frequency from every week to every 4 weeks reduced seed yield, quality and viability. Rate of yield losses was highest at close spacing and intermediate at wide spacing during the first rainy season, and lowest at wide spacing with supplementary irrigation during second rainy season. Time of harvest study conducted with six cultivars indicated that these yield losses were attributable to reduced seed weight and increased pod losses after mature pods were exposed to weathering for more than 1 week. The reduction in seed quality and viability was associated with a high degree of fungal and bacterial infection in the seed. Varietal differences in resistance to weathering were noted among the cultivars tested. TVu 2616 P-O1D, that has thick, leathery pods and smooth, tan seed coat was the most resistant to weathering.

Output from grazing animals in Britain could be increased by extending the growing season of grasslands. In particular the growth of hill pasture species is highly seasonal with 75% of annual production occurring in three summer months (Newbould, 1974). Stocking rates, limited by winter carrying capacity, are therefore low and summer leaf production is undergrazed. The consequent accumulation of mature senescing herbage seriously reduces pasture quality (Eadie, 1968). As a result of this and lack of grass growth, ewes are often poorly nourished prior to mating (November) and throughout pregnancy and early lactation. Hence fertility levels and lamb birth weights and growth rates are low, and mortality rates high (Gunn, 1967).

The mean total yield and mean fresh weight of seven swede varieties and their F1 hybrids was increased primarily by nitrogen and also by phosphorus fertilizer. There was no evidence of genotype × environment interaction for characters concerned with yield except for dry-matter content where two varieties, Best-of-All and Reform, were less stable to fertility environments than the others. Heterosis was common amongst F1 hybrids and this suggests their use in swede improvement: the inheritance pattern of root weight showed overdominance, shoot weight showed partial dominance and drymatter content showed additivity, with no evidence of gene interaction. Segregation for root fresh weight and dry-matter content occurred in F2 populations and although an overall negative correlation was found there was evidence that progeny from certain crosses gave reasonable prospects of combining both characters.

In a 7×7 diallel-cross experiment utilizing parents with varying resistance to mosaic virus disease and of different horticultural types significant heterosis over the better parent was found in number of days between sowing and flowering and over the mean of the two parents in other characters. The combining ability analysis revealed that genetic control of most character variation was due to additive effects.

It is suggested that pedigree and/or backcross methods are most appropriate for improving this chilli population.

Grain yield, plant height, spike length, grain weight per spike, 100-kernel weight, protein quantity and quality of Mexipak wheat grown with four rates of applied nitrogen (0, 75, 150 and 225 kg N/ha) and five rates of applied zinc (0, 1·25, 2·5, 5·0 and 7·5 kg Zn/ha) were measured. All these attributes were affected significantly by nitrogen fertilization in a linear manner. Differences among rates of applied zinc were significant for grain weight per spike, 100-kernel weight, grain yield and protein quantity and quality.

The possibility of using sustained lactation as a maternal character for the enhancement of lamb growth has been suggested by Doney & Peart (1976). Horák & Jakubec (1964) shows that Improved Valachian ewes had a relatively sustained pattern of lactation when lambs were suckled. This breed was developed by cross-breeding between the Texel breed and the original Valachian, a coarsewoolled, mountain breed used to produce milk for cheese. The process of breed development has been described by Laurinčík (1964).

Stem-rot, caused by Magnaporthe salvinii (Catt.) Krause & Webster, is a major rice disease in the Punjab. Varieties of the ‘Basmati’ group, especially Basmati-370, widely grown for its quality, have long been reported resistant to stem-rot (Paracer & Luthra, 1944; Srivastava, Maheshwari & Saini, 1971). Its cultivation in stem-rot-prone areas have been recommended (Grewal, 1975). Recently, however, the authors observed severe stem-rot on Basmati-370 and recorded the variety susceptible (Rattan & Mayee, 1975). Investigation into the causes of breakdown revealed that, wherever the variety had node infection by Pyricularia oryzae Cav., to which it is known to be susceptible, stemrot damage was exaggerated. In the present note, the analysis of breakdown is described.

Kalla & Ghosh (1975) and Hopkins, Roberts & Evans (1975) recently reported finding a negative correlation between wool production and the erythrocyte concentration of reduced glutatione. Both groups also found a higher rate of wool production in GSH-low type animals than in GSH-high types. Because erythrocyte GSH types are genetically controlled and the GSH concentration within these types is highly heritable (Board, Roberts & Evans, 1974), Hopkins et al. (1975) concluded that selection for GSH-low type sheep may provide a method for manipulating wool production.