Ewe reproductive traits of imported Merino local Ossimi and Barki, their first crosses, backcrosses to Merino and the interbred groups of the backcrosses, were considered in this study. Records of 2168 ewes born from 1960 through 1970 were used in the study; they totalled 6959 records.

Reproductive performance was different in the three purebred groups, with more multiple births but more lamb losses and abortions in Merinos. However, the three groups weaned similar numbers of lambs/ewe run with the rams (0·98). Merino × Ossimi ewes had the best performance, they lambed and weaned 27% more lambs than local Ossimi. They were followed by MB ewes weaning 0·96 lambs/ewe run with the rams. Reproductive performance of the backcross ewes was lower than that of the first cross, but still better than the purebred groups. Inter-breeding of back-crosses reduced their hybrid vigour markedly.

Non-maternal heterosis contributed greatly to the reproductive performance of cross-bred ewes, while the effect of maternal heterosis on reproductive traits was fairly small.

Multiple births showed least heterotic effect.

The yields of spring barley during a medium-term (7 years) compost and slurry addition experiment and the soil carbon (C) and nitrogen (N) contents, bacterial community structure, soil microbial biomass and soil respiration rates have been determined to assess the effects of repeated, and in some cases very large, organic amendments on soil and crop parameters. For compost, total additions were equivalent to up to 119 t C/ha and 1·7 t N/ha and for slurry they were 25 t C/ha and 0·35 t N/ha over 7 years, which represented very large additions compared to control soil C and N contents (69 t C/ha and 0·3 t N/ha in the 0–30 cm soil depth). There was an initial positive response to compost and slurry addition on barley yield, but over the experiment the yield differential between the amounts of compost addition declined, indicating that repeated addition of compost at a lower rate over several years had the same cumulative effect as a large single compost application. By the end of the experiment it was clear that the addition of compost and slurry increased soil C and N contents, especially towards the top of the soil profile, as well as soil respiration rates. However, the increases in soil C and N contents were not proportional to the amount of C and N added, suggesting either that: (i) a portion of the added C and N was more vulnerable to loss; (ii) that its addition rendered another C or N pool in the soil more susceptible to loss; or (iii) that the C inputs from additional crop productivity did not increase in line with the organic amendments. Soil microbial biomass was depressed at the highest rate of organic amendment, and whilst this may have been due to genuine toxic or inhibitory effects of large amounts of compost, it could also be due to the inaccuracy of the substrate-induced respiration approach used for determining soil biomass when there is a large supply of organic matter. At the highest compost addition, the bacterial community structure was significantly altered, suggesting that the amendments significantly altered soil community dynamics.

Previous research has suggested that fry colour of processed potatoes is inversely correlated with tuber reducing sugar content, and agronomic practice should therefore be tailored to minimize amounts of tuber sugars at harvest and during storage as a means of maximizing processing quality. A total of 30 experiments from three sites in England from 1985 to 1988 examined this hypothesis for two cultivars using a wider range of husbandry than that used in practice and long periods of storage. No tuber sugar value was sufficiently well correlated with fry colour for the relationship to be interpreted as causal and of use predictively, irrespective of whether it was measured early in growth, at harvest or at the time of processing. Fry colour at harvest was not correlated with fry colour after storage. No agronomic practice (variables used were physiological age, date of planting, irrigation or date of harvest) consistently caused fry colours to be darker than the acceptable colour limit, whether at harvest or after long term storage. Crops producing unacceptable fry colours early in storage generally improved to produce acceptable fry colours after long term storage. Agronomic practices within the range normally found in commercial production are therefore considered to have little effect on long-term processing quality, although harvesting, handling and transport operations were not investigated.

In 1974 three cultivars of barley of different straw lengths, Mazurka, Julia and Midas, were grown alone and with each of four cultivars of red and two of white clover in a split-plot randomized-block experiment of four replications. Although the barley cultivars differed significantly in yield the barley x clover interaction was not significant and yield of grain was not affected by the presence of the clovers.

In the following year the entire experimental area was sown with Mazurka barley. Significantly higher grain yields were obtained on those plots sown with clover in 1974 than in plots where no clover had been sown. In no case was the combined yield of barley from the 2 years on any treatment involving clover lower than that of the mean of the no-clover control plots, although the highest increase in yield, 11% from the S.123 red clover treatment, over the no-clover control was not shown to be significant.

The addition of supplementary fat to pig diets above current dietary recommendations has generally been viewed in a negative manner because it is considered that the surplus energy will be deposited into adipose tissue, and may therefore be detrimental to carcass value. The current study sought to investigate the effects of adding supplementary fat, in place of starch, to increase the energy density of male and female pig diets on growth performance and carcass quality. A total of 288 Large White × Landrace male and female pigs (boars and gilts) were randomly allocated to pens of 12 pigs each. The effects of (i) sex (gilts v. boars), (ii) added dietary fat level (as tallow; 0 v. 40 and 80 g/kg) and (iii) within added dietary fat level (40 v. 80 g fat/kg), were tested for a 5-week period (Period 1) (n = 4). These diets were formulated to contain 13·5, 14·3 and 15·2 MJ digestible energy/kg for 0, 40 and 80 g added fat/kg, respectively; the calculated standardized ileal digestible lysine content was kept constant at 8·8 g/kg of diet. Thereafter the experiment was designed to test for the same effects over a second 5-week period (Period 2), during which pigs from the initial three treatments were offered the diets with 0 and 40 g added fat/kg. Treatment effects were also assessed over the whole 10 weeks of the study. There was a positive linear effect of dietary fat supplementation in Period 1 on average daily weight gain, whereas dietary fat level in Period 1 had no effect on performance in Period 2, overall, or on carcass weight and P2 backfat thickness (i.e. thickness of fat at 65 mm down the left side from the midline, at the level of the head of the last rib) at 10 weeks. In contrast, supplementation of the diet with 40 g fat/kg during Period 2, regardless of the diet offered in Period 1, increased ADG in the second period and over the entire experiment. There were minimal effects of supplementary fat on feed intake in the entire experiment; however feed conversion ratio (FCR) was influenced by sex over the entire study and tended to be reduced by dietary fat supplementation in Period 2. The diet with 40 g added fat/kg fed in Period 2 increased carcass weight by an average of 2·8 kg and P2 backfat thickness by 1·2 mm. Collectively, the data from the current study suggest that dietary fat supplementation is more effective in finisher pigs than in grower pigs in terms of growth rate, FCR and carcass weight.

A comparison was made of the development of acid and alkaline phosphatase, invertase, lactase and leucine aminopeptidase specific activities in the small intestines of two groups of neonatal pigs. The groups consisted of two litters of suckling pigs and two litters of pigs that were delivered by hysterectomy and reared in incubators on a diet based on cow's milk. In the unsuckled pigs there was retardation of the development of invertase and leucine aminopeptidase. The unsuckled animals grew slowly and were affected by diarrhoea, and it is possible that enteric disease may have affected the development of the brush border of the intestinal epithelial cells, or enzymes specifically associated with the microvilli.

All the pods on pigeon-pea plants were removed after 1, 2 or 3 weeks of flowering in a pot experiment and in one field trial, in order to evaluate the compensatory ability of the crop under humid tropical conditions.

Pod removal after 1 or 2 weeks of flowering led to an immediate significantly higher vegetative development and dry-matter accumulation compared with the control. Subsequent flowering led to greater pod production and pod yield than the control with seed yield increased by 21 and 50%, respectively, in the pot experiment while pod removal after 1 week of flowering increased seed yield by 15% in the field. The removal of pods after 3 weeks of flowering was detrimental to subsequent pod development and seed yield which was decreased by 56 and 34% in the pot and field experiments, respectively.

It would seem that the loss of pods produced soon after flowering starts, before active pod filling begins, can be tolerated by pigeon peas, whereas the loss of fully elongated and actively filling pods would significantly reduce seed yield in the crop.

The evaluation of the genetic potential of cereal varieties in variety trials will be accurate only if compensation can be made for all the variables known to influence the results, or if those variables are controlled. The influence of one such variable, seed size, on subsequent performance of crop plants, is well documented (wheat, Kittock & Law, 1968; beans, Ries, 1971; barley, McDaniel, 1969). McFadden (1963), working with barley, felt that seed size was such an important determinant of subsequent plant performance that he suggested that seed used in comparative testing systems should all be processed to the same seed range.

Evidence is presented, based on feeding tests, that vitamin A metabolism is adversely affected when meat meal having a vitamin A consuming power in vitro is included in the diet of chicks.

Evidence is presented, based on feeding tests, that when fish meal having no vitamin A consuming power in vitro is fed to chicks in a basal ration which produces negligible mortality, the addition of such fish meal to the ration does not appreciably increase mortality.

Evidence is presented, based on feeding tests, that when fish meal having a vitamin A consuming power in vitro is fed to chicks in a basal ration which produces negligible mortality, the addition of such fish meal to the ration causes appreciable mortality.

1. Twelve pony mares were inseminated at various intervals (18 days to within 24 hr.) before ovulation with spermatozoa which had been concentrated by centrifugation and stored for 24 hr.

2. Of fourteen inseminations, only two, both within 24 hr. of ovulation, produced pregnancies.

3. The survival time of the stored spermatozoa within the female tract was concluded to be somewhat less than 24 hr.

4. It is suggested that successful inseminations with stored spermatozoa could be made 24 hr. after the injection of prolan.

This work was carried out while holding the Miss Aleen Curt Memorial Veterinary Research Scholarship from the Royal College of Veterinary Surgeons.

My thanks are due to Dr J. Hammond and Dr A. Walton for their help and encouragement and to Mr F. T. Day for the loan of the ponies and for his help and instruction in the technique of examination.

Pyrethrum flowers are widely used in different insecticidal formulations for controlling household insects and crop pests. The quick knock-down effect on insects, the low mammalian toxicity and the rapid decomposition of pyrethrins in the soil make it an ideal and safe insecticide. The flower yield in pyrethrum is influenced by plant population density and phosphate fertilizer application (Nair, 1955; Kroll, 1962, 1963; Parlevliet, Muturi & Brewer, 1968a, b). Parlevliet et al.(1968a, b) recommended a spacing of 60 × 30 cm whereas Nair (1955) suggested a spacing of 75 × 60 cm for obtaining higher flower yields in this crop. The present investigation was made to compare the effects of different spacings and rates of nitrogen application on the flower and pyrethrin yields of pyrethrum.

The water balance and urinary parameters of lambs fed diets containing cactus cladodes varieties were evaluated. Thirty-six uncastrated male Santa Inês lambs (22.0 ± 2.9 kg initial body weight) were distributed in a completely randomized design, with three treatments and 12 replicates. The animals were fed a control diet (Tifton-85 hay as exclusive roughage), Miúda or Orelha de Elefante Mexicana (OEM) cactus-based diets. Urine samples were collected 45 days after the introduction of the tested diets, and voluntary water intake was measured over 10 days, during the experimental period. Diets containing Miúda or OEM cactus caused a reduction of 68.35 and 77.03% in voluntary water intake, respectively. In addition, the Miúda cactus cladodes caused urinary alkalinization (pH = 8.14) and reduction in the urinary excretion index (UEI) and on the fractional excretion rate (FER) of total calcium (Ca). The diets with OEM cactus cladodes caused higher oxalates intake (6.21 g/day) and increase in urinary volume. Regardless of the variety, there was a reduction in the urinary concentrations of urea, creatinine, total proteins, Ca, phosphorus (P), UEI of urea and P, as well as in FER of P, compared to the control diet. Urinary Mg content and UEI of uric acid and Mg increased and FER of P decreased by diets supplemented with different varieties of cactus cladodes. In conclusion, the cactus cladodes increased water intake and retention, and diuresis in lambs, altered urine parameters, without compromising kidney function.

The present paper deals with the composition and nutritive value of the following by-products of the pea-canning industry: (1) green pea pods; (2.) pea-pod meal resulting from the artificial drying of pea pods; (3) pea-pod silage as made in a tower silo; (4) molassed silage made in a sisalkraft silo from pea haulms with pods.

Pea pods give rise to an excellent silage provided they are tightly trampled and a means for draining off the effluent is supplied. The silage is pale yellowish green in colour and has a pleasant, vinegary smell with little or no suggestion of the presence of butyric acid. It is much relished by sheep and cattle. It is superior in digestibility to ‘green fruity’ oat and vetch silage and contains, per 100 lb., 27·5 lb. of dry matter, including 15·9 lb. of starch equivalent and 2·3 lb. of digestible crude protein. No molasses need be added during filling, since the sugar naturally present in the pods ensures a favourable fermentation.

Results are reported of sixteen replicated experiments on spring-sown barley and oats in south-east England to compare fertilizer sown in the drills with fertilizer broadcast. In thirteen of the experiments, fertilizer in the drills gave significantly greater yields of grain and straw than fertilizer broadcast, in two of the experiments the differences between the two were not significant; in only one experiment was the grain yield significantly greater where the fertilizer was broadcast.

Fertilizers were twice as effective when sown in the drills as when broadcast. On an average, broadcast fertilizer increased the yields of grain and straw by 4·0 and 6·3 cwt. per acre respectively. Drilling the fertilizer with the seed gave over double these increases, viz. 8·0 cwt. grain and 14·6 cwt. straw per acre.

Drilling the fertilizer with the seed tended to delay brairding. The crop on the fertilizer-drilled plots soon caught up and overtook that on the fertilizer-broadcast plots. Drilling the fertilizer with the seed increased tillering and decreased weed-growth.

Not more than about 3 cwt. of a soluble fertilizer per acre should be sown in the drills or the stand of plant may be poor. For the same amounts of soluble plant food, the higher the analysis of the fertilizer the less is the delay in brairding.

The possibility of obviating the delay in brairding by sowing the fertilizer near, but not in contact with, the seed is briefly considered.

Phosphate-potash fertilizer was drilled in bands 20 in. apart and 3 in. below the soil surface and compared with similar dressings broadcast on the surface for established crops of sainfoin. On unmanured plots yields were not reduced by cutting grooves for the fertilizer bands. Broadcasting fertilizer on the surface produced consistently more sainfoin hay than dressings placed in bands. In similar experiments on permanent grass broadcast fertilizer also gave consistently more hay than bands of fertilizer placed 10 in.apart. Intheabsence of fertilizer small decreases in yields of grass were caused by cutting grooves. The advantages of an equal supply of nutrients to all the plants in an established sward, obtained by broadcasting fertilizers, outweighs any disadvantage from confining the application to the soil surface.

Two experiments on lucerne in 1950–51 compared broadcast dressings of phosphate-potash fertilizer harrowed into the seed-bed with the same quantities of fertilizer placed in one band 2 in. to the side of the seed. Side-band placement did not give better early growth than broadcasting. Broadcast fertilizer gave higher yields of hay than placed fertilizer at one centre in the first year. There were no significant differences at either centre between yields of hay given by broadcast and placed fertilizer in the second year. When the dressings were divided, half being applied at sowing-time and the remainder in the spring of the following year, slightly lower yields were obtained than from dressings applied wholly at sowing.

A further experiment on lucerne was laid down in spring 1952. Superphosphate, muriate of potash and a mixture of the two fertilizers were compared both when broadcast and ploughed in and when broadcast on the seed-bed. All the dressings of broadcast fertilizer were tested in the presence and absence of a ‘starter-dose’ of superphosphate drilled directly beneath the seed. The ‘starter-dose’ gave much better early growth and higher yields of lucerne than any of the dressings of broadcast phosphate and potash. Broadcast fertilizer ploughed in tended to give higher yields at the first cutting than seedbed dressings. At the second cutting there was little difference between yields given by ploughed-in dressings and dressings broadcast on the seed-bed.

There is no case for introducing special equipment to place fertilizer in bands below the surface of established swards. For establishing lucerne and other ley crops, where fertilizers may be applied at or before sowing, there are no advantages from using special drills to place the full dressing of fertilizer at a safe distance to the side of the seed. Where combine-drills are used for sowing herbage crops they should be modified to place a small quantity of superphosphate directly beneath the seed and the remainder of the fertilizer should be broadcast before sowing.

1. Five varieties of thousand-headed kale, grown in singled and unsingled plots, were sampled three times during the winter at monthly intervals. The plants were divided into leaf, top half of the stem and bottom half. Dry matter, the proximate constituents and minerals were determined in the samples.

2. The differences in the composition of the leaf and stem of the plant were similar to those found previously and the top half of the stem was intermediate in composition between the leaf and the bottom half of the stem for all the constituents except potassium.

3. The proportions of the various constituents occurring in the three portions of the plant were calculated and considered in terms of the incomplete utilization of the crop by grazing animals.

4. There were significant increases in the percentage of dry matter in all three portions of the plant as the season advanced. The only other significant changes in composition with advancing season were in the leaf in which the levels of crude protein, crude fibre, ash, calcium, phosphorus and sulphate varied.

5. Singling the crop had no significant effects on its composition, but there was a tendency for the stems of the singled crop to be lower in crude fibre and higher in crude protein and several of the minerals.

6. There were very few differences in the composition of the varieties. They were mainly due to the higher mineral levels in one variety.

7. Samples of the two halves of the stem of thousand-headed kale were divided into their main tissues, e.g. rind, xylem and marrow. These were analysed in the same manner as the samples in the main investigation. The results were used in an attempt to explain the effects of singling, advancing season and variety in terms of different ratios of these tissues.

Field experiments with chick peas (Rawat & Sanoria, 1977) and peas (Sanoria & Ram, 1979) showed a synergistic effect of a particular Rhizobium and Azotobacter on yield and quality of seed. Isolates of R. leguminosarum revealed differences in the yield and quality of lentil grown in pots and in the field (Mallik & Sanoria, 1980). As there is no evidence in the literature regarding the simultaneous use of Rhizobium and Azotobacter on lentil (Lens esculenta), this study was undertaken to assess their effect on the yield and quality of lentil in field.

In order to quantify the radiation hazard to humans through food, both migration and distribution of 95Zr in Chinese cabbage/soil system were examined by using the radioisotope tracer technique. When 95Zr was administered with simulated irrigation or simulated rainfall, 95Zr was detected in every part of Chinese cabbage, which indicated that 95Zr could be translocated to above-ground parts. Although concentrations of 95Zr in different parts of Chinese cabbage were different in the two treatments used in the present study, the patterns of 95Zr distribution in different parts of the plant were similar. Concentration of 95Zr in each part of Chinese cabbage followed the order of root>leaf>lower part of petiole>upper part of petiole>bud in the case of simulated irrigation. Moreover, the 95Zr could be accumulated in leaves after being taken up by roots. In the simulated irrigation treatment, 95Zr concentrations were 1·7 and 2·9 times higher in the leaf than in the petiole and bud, respectively. In the case of simulated rainfall, a portion of applied 95Zr precipitated on the above-ground parts of Chinese cabbage, which led to a higher concentration here than in the case of simulated irrigation. The results of the present study clearly indicate that there is a distinct possibility that foodstuffs produced in the 95Zr-contaminated area are radioactively contaminated. More than 90% of total 95Zr in soil was retained in the upper layer (0–8 cm), which indicated 95Zr could not easily move downwards because of strong adsorption to soil.

Linear measurements of the length and maximum width of terminal leaflets of mungbean (Vigna radiata (L.) Wilczek) were made to estimate the whole trifoliate leaf area. The linear measurements were compared with the areas of leaflets and whole trifoliate leaves, determined using a leaf area meter. Five varieties were used in the study. Varieties differed in leaf shape and size, and equations were generated for each of the varieties to estimate the leaf area as a function of the product of the length and maximum width of the terminal leaflets, thus providing a means of nondestructive estimation of leaf area.

The effects of food restriction on the growth and distribution of bone and on the relation between changes in long bone lengths and changes in limb muscle proportions were studied in 32 Duroc Jersey barrows. Sixteen pigs were fed ad libitum (H group) whilst the other 16 received the same diet on a restricted scale related to live weight.

Animals in each group were slaughtered at times such that the weights of bone in their half carcasses were spread evenly over the range 1·5–4·O kg. The right half carcasses were completely dissected using strictly anatomical criteria.

The results on the relative growth of bone were examined by covariance analysis using the allometric equation.

After adjusting for equal weight of total bone in the side L pigs had heavier femur, tibia-fibula, humerus and radius-ulna and lighter scapula and ribs than H pigs.

Relative to their weights all appendicular long bones were longer in L pigs than in H ones, while there was no such effect on spinal column length.

The effects of the treatment on fore limb muscle proportions relative to total muscle were significantly correlated (P < 0·01) with the changes observed in the lengths of the long bones forming their osseus bases. However, in the case of the hind limb the regression and correlation coefficients were not significantly different from zero.