bluuebunny/crossref_metadata_2025_split huggingface dataset:
An evaluation of small seed for ware-potato production
Authors: Allen E. J. , O'Brien P. J. , Firman D. 
Published: March 2009

SUMMARYSixteen experiments over six seasons (1981–87) compared the growth and yield of up to 16 seed-tuber weights, ranging from 1–5 to 110–120 g, in one second-early and four maincrop varieties. Four of the experiments (1986–87) examined effects in seed tubers from seed crops planted in July; the remaining experiments used seed from crops planted at the normal time, April–May. Effects were similar for seed from the different planting dates. Plants from seed < 5 g (and occasionally up to 15 g) emerged slightly later and produced a smaller crop canopy that those from larger seed. The later emergence from the smallest seed was a consequence of a slower rate of sprout elongation. There were no effects of seed weight above 15 g on stem emergence or growth of the canopy. In 1982, a severe frost completely defoliated all plants in four experiments but within 2 weeks complete plant emergence was re-achieved from all seed weights except the smallest (1–5 g). The results suggest few differences between seed weights > 5 or 10 g in emergence from similar depths of planting or in recovery from frost damage.Tuber yields were little affected by seed weight > 5 or 10 g, even at constant within-row spacings. Consequently, seed rates from 0·59 to 5·4 t/ha produced similar yields and the results suggest considerable economic benefits and potential for using seed tubers of much smaller weight than may be sold under current legislation. The use of small seed tubers from late-planted crops may result in further economies in production costs and reduction in disease in seed tubers.
The effects of seed size and spacing on growth and yield of lesser yam (Dioscorea esculenta)
Authors: Enyi B. A. C. 
Published: March 2009

SUMMARYThe effects of seed size and spacing on growth, development and yield of lesser yam and the relationship between growth, development and yield in this yam variety were investigated in the 1967 and 1968 growing seasons. Larger seeds outyielded smaller ones both in the total and ware tuber yields. The seed size effect was associated with a difference in tuber number, leaf area duration and bulking rate. Mean tuber weight at harvest, decreased with the decrease in seed size. Total and ware tuber yields increased with the decrease in spacing distance. The spacing effect was associated with differences in leaf area duration and bulking rate per unit area. Final total dry matter produced per plant increased with the increase in both seed size and spacing distance but the dry matter produced per unit area decreased with the increase in spacing distance. Leaf area index and leaf area duration increased with an increase in seed size and decreased with increase in spacing distance. There was a greater positive relationship between total tuber yield and leaf area duration between tuber initiation and the final sampling period than that between it and absolute leaf area duration.
The effects of crossing Merino with Ossimi and Barki sheep on some productive traits
Authors: Aboul-Naga A. , Eltawil E. E. , Galal E. Salah E. , Labban F. , Khishest S. S. 
Published: March 2009

SUMMARYA total number of 5949 birth records collected over a period of 9 years from a crossbreeding experiment at Sakha Animal Research Station were used in this study. The following breeding groups were included: Fleisch Merino (M), native Ossimi (0) and Barki (B) breeds, MO, MB, ¾M ¼ O, ¾ M ¾ B and the inter se mating groups of the backcrosses (’¾ M ¼O’ and ‘¾ M ¼B’). Productive traits studied were birth, 4-month and yearling weight, lamb liveability at 4 months of age; and first fleece weight (at 10 months of age).Generally, the cross-bred lambs were heavier in body weights and sheared more wool than the pure breds, with the differences being almost significant. In liveability, native breeds showed significantly higher estimates than the cross-breds where the Merino breed was the poorest in this respect.Merino × Ossimi first cross was the best breed group showing a high heterosis estimate of 0·9, 5·2, 10·3, 7·6, 0·9 and 0·7 kg in birth, 4-month, yearling males and females body weights and first fleece weight, respectively. They were followed by ¾ M ¼ O with a corresponding heterosis value of 0·8, 3·9, 7·4, 4·2, 0·5 and 0·5 kg respectively. Merino x Barki and their backcrosses to Merino are ranked second to the Ossimi crosses. Heterosis in the Barki backcross was 0·8, 2·9, 4·8, 2·1, 0·4 and 0·4 kg compared with 0·5, 2·5, 3·1, 2·7, 0·5, 0·4 kg for MB, on different traits, respectively. The interbreeding of the backcrosses caused a diminishing in hybrid vigour. Heterosis estimates in ‘¾ M ¼ O’ were 0·3, 0·9, 4·6, 2·3, 0·3 and 0·3 kg, whereas it was 0·1, 0·3, –0·1, –0·3, 0·0 and 0·1 kg for ‘¾ M ¼B’, in different traits respectively. All cross-breds showed negligible or/and negative heterosis in lamb liveability up to 4 months.The effects of breed group, year of birth, age of dam, sex and type of birth were found to be highly significant on all traits except the effect of type of birth on lamb liveability.
Influence of air humidity on the partition of heat exchanges of cattle
Authors: McLean J. A. , Calvert D. T. 
Published: March 2009

SUMMARYThe balance between heat production and heat loss and the partition of heat exchanges of cattle in relation to air humidity has been studied at two different air temperatures using a direct (gradient-layer) calorimeter.Increasing humidity at 35 °C air temperature caused no significant change in heat production or in the level of total heat loss finally attained, but body temperature and respiratory activity were both increased.Increasing humidity at 15 °C air temperature caused a small reduction in heat loss by evaporation but had no effect on sensible heat loss, body temperature or respiratory frequency.Heat loss by evaporation amounted to 18% of the total heat loss at 15 °C and to 84% at 35 °C.Heat loss by respiratory evaporation amounted to 54% of the total evaporative heat loss at 15 °C and to 38% at 35 °C.
Intravaginal stilboestrol-progestagen treatments in the induction of early breeding in sheep
Authors: Gordon I. , Maher P. G. 
Published: March 2009

SUMMARYNinety-eight sheep in three farm flocks were treated in July (period of late anoestrus) with intravaginal sponges impregnated with 30 mg ‘Cronolone’ (9α-fluoro-11βhydroxy 17α-acetoxy-progesterone; G. D. Searle) or ‘Cronolone’ plus 400 mg progesterone and incorporating doses of 0–800 μg diethyl stilboestrol. Treatment was for 12 days; a single dose of 500 i.u. PMS (Burroughs Wellcome) was injected at pessary withdrawal. Ten rams bred the ewes at the induced and subsequent heats.Of the ninety-five ewes retaining pessaries, ninety-three (98%) were bred in the 3 days following treatment. Sixty-three sheep (68·5%) conceived at the controlled oestrus, producing an average of 1·54 lambs/conception. In the thirty-four ewes failing to conceive at that time, twenty-seven (80%) showed oestrus after one cycle interval; twenty of these (74%) conceived and produced 1·3 lambs/conception. Lambing outcome toservices at the controlled oestrus was lowest in sheep treated with 800 μg stilboestrol, but the reduction was not significant.
Effects of defoliation on populations of Festuca arundinacea Schreb. sown in spring and autumn
Authors: Thomas W. D. , Lazenby Alec 
Published: March 2009

SUMMARYThe effects of defoliation regime on seasonal and total yields of spring- and autumnsown material of three populations Festuca arundinacea(syn. 1 and syn. 2 from North Africa and the British cultivar S. 170) were examined at Cambridge from the period June 1963 to April 1965.A micro-plot technique was used in which defoliation treatments were defined by vertical height above soil level. The vertical growth intervals between successive defoliations were, for the summer cutting regimes 7.5–25 cm and 2.5–12.5 cm, and for the winter regimes 7.5–20 cm, 2.5–20 cm, 7.5–12.5 cm, and 2.5–7.5 cm.In summer 1963 mean yields of all populations were very similar, being equivalent to approximately 12000 kg/ha. Mean population yields for the following three 6-month periods were equivalent to (in kg/ha): syn. 11519, 14740, 3385; syn. 2 2194,17669, 5523; S. 170 1656, 19832,3696.Variety x treatment interactions were found in every season. In particular, S. 170 winter production was reduced by severe defoliations in the preceding summer, and syn. 1 and syn. 2 summer production by severe defoliations in the preceding winter. It is suggested that such interactions may have been responsible for conflicting assessments of the relative potential production of these populations.Syn. 1 appeared to offer no advantage over S. 170, and syn. 2 only to outyield S. 170 where spring sowing was followed by infrequent or lax defoliations in all seasons. Agronomic implications are discussed.
Ileal apparent digestibilities of amino acids, growth and tissue deposition in growing pigs fed low glucosinolate rapeseed meals
Authors: Rowan T. G. , Lawrence T. L. J. 
Published: March 2009

SUMMARYA factorially designed growth and carcass dissection experiment was made in which a low glucosinolate rapeseed meal (cv. Tower, TRSM) was compared with soya-bean meal (SBM) as the sole protein supplement in simple diets, containing barley and a vitamin and mineral supplement (to give 18 mg copper/kg air-dry diet) only, which were fed individually on a restricted scale of feeding to 72 pigs. The diets were of similar digestible energy (DE) content and were formulated to contain in each kg of air-dry matter 150, 170 and 190 g crude protein. In each crude-protein level the total lysine content was similar. Also experiments using 35 pigs were made to determine the ileal apparent digestibilities of amino acids in barley-based diets containing SBM, the low glucosinolate rapeseed meals Erglu (ERSM) and TRSM and a high glucosinolate British rapeseed meal (BRSM) and either 20 mg or 200 mg copper/kg air-dry diet.In the growth experiments there were no significant interactions for the variables considered. Pigs given TRSM diets, compared with those given SBM diets, had significantly poorer growth rates, conversion efficiencies and killing-out proportions but the proportions of lean and fat in carcasses and the backfat thicknesses (P2) were similar. There were no significant differences between protein levels in the killing-out proportions, the proportions of fat in carcasses and backfat thicknesses (P2) but pigs given diets containing 150 g, compared with 170 and 190 g, crude protein/kg air-dry diet had significantly lower growth rates and proportions of lean in the carcass and significantly poorer efficiencies of food conversion. The quantities of dietary crude protein used to produce units of live-weight gain, carcass weight and lean tissue increased progressively from the diets containing 150 to 170 to 190 g crude protein in each kg air-dry diet.In the ileal digestibility studies the results indicated that amino acids were of a lower digestibility in the rapeseed meal diets than in those based on SBM and that the copper content of the diet may have been important in this context.
Growth, tissue deposition and metabolism studies in growing pigs given low glucosinolate rapeseed meal diets containing different amounts of copper and polyethylene glycol
Authors: Rowan G. , Lawrence T. L. J. 
Published: March 2009

SummaryIn three factorial growth experiments and a metabolism experiment pigs of approximately 25 kg initial live weight were given on a restricted scale of feeding simple diets, based on barley, a vitamin and mineral supplement and either soya-bean meal (SBM) or a low glucosinolate rapeseed meal (cv. Tower; TRSM). Variations in these two basic diets were produced by adding different quantities of tannic acid, polyethylene glycol (PEG) and copper (Cu).Diets based on soya-bean meal were used in the first experiment. There were no significant interactions. Tannic acid added at 3·75 and 7·50 g/kg air-dry matter was without significant effect on performance compared with no tannic acid addition, but PEG at 17 g/kg air-dry matter significantly improved growth rate compared with no PEG addition to the diet (P < 0·05). In the second experiment TRSM-based diets were used. There were no significant interactions and no significant effects on performance from adding 0, 8·5 and 17·0 g PEG/kg air-dry matter. Increasing Cu from 17 to 54 mg/kg air-dry diet significantly improved growth rate (P < 0·05). In the third experiment TRSM and SBM based diets, of similar digestible energy (DE), crude protein and lysine content, and containing either 19 or 202 mg Cu/kg air-dry matter, were used. Pigs were slaughtered at 87·5 kg live weight and hand joints dissected. Pigs given the TRSM diet containing 19 mg Cu/kg grew significantly more slowly than pigs given the three other diets between which there were no significant differences. There were no other significant interactions and no significant differences between Cu concentrations for the growth, carcass and efficiency of conversion results. Compared with TRSM diets, SBM diets at similar slaughter weights gave significantly greater carcass weights, killingout proportions and backfat thicknesses. Also the efficiencies with which dietary protein and DE were used to promote units of carcass growth were significantly better for the SBM diets, but there were no significant differences in the estimated weights of lean in carcasses.In the metabolism experiments the effects of adding PEG to diets similar to those used in the growth experiments were examined. The apparent digestibilities of dry matter, gross energy and nitrogen and the nitrogen retentions were significantly greater for the SBM diets than for the TRSM diets. The addition of PEG to the SBM and TRSM diets significantly decreased the apparent digestibilities of dry matter and gross energy, and significantly increased the apparent digestibility of nitrogen in the SBM diet but not in the TRSM diet.
The effect of density and nitrogen fertilizer on the growth and yield of maize (Zea maysL.) in Nigeria
Authors: Lucas E. O. 
Published: March 2009

SummarFARZ 27, a high-yield maize variety, was grown in 1984 and 1985 over a wide range of density treatments (1·9– 11·1 plants/m2) and with four rates of nitrogen application (0, 75, 100 and 150 kg N/ha) in Ibadan. south-western Nigeria.There was no significant density or fertilizer effect on morphological characters of number of leaves per plant, height or stem diameter. For total dry-matter yield, the highest density of planting gave the highest yield although less dry matter was obtained in the 1985 experiment than in the 1984 experiment. Optimum density for grain production in both years was 8·8 plants/m2. There is an indication that there is no need to increase density of planting of maize beyond 80000 plants/ha in the south-western part of Nigeria. Plants without applied nitrogen fertilizer gave significantly lower total dry-matter and grain yields than plants with applied nitrogen. Highest grain yield was obtained with 150 kg N/ha in both years. By doubling the nitrogen application rate from the present recommended level of 75 kg N/ha to 150 kg N/ha an average increase of 0·42t/ha of maize was obtained in both years. With the present prices of fertilizer and maize, this increase is economical. It seems therefore that more revenue would accrue to the farmers by using 150 kg N/ha on the ‘FARZ series’ of maize instead of the present recommendation of 75 kg N/ha.
Endogenous losses of phosphorus by sheep
Authors: Ternouth J. H. 
Published: March 2009

SUMMARYTwelve sheep were fed semisynthetic roughage diets at three rates to study the effects of intake of dry matter, concentration of phosphorus and the physical form of two low-P barley straws upon the faecal losses of P. The sheep were in negative P balance throughout the experiement. The absorption of dietary P increased with P intake and was unaffected by differences in the physical form of the roughage. For each barley straw diet, endogenous faecal P increased with dry matter intake, and was higher when the roughage was ground than chopped. Over the whole experiment, daily endogenous faecal P ranged from 8·5 to 31·5 mg/kg live weight. Endogenous faecal P was related to P intake or to dry matter intake and plasma inorganic P. The concentration of faecal endogenous P was negatively related to the intake of each diet. It is concluded that the concentration of inorganic plasma P and the rate of salivary secretion are responsible for the endogenous faecal excretion of P and the regulation of P balance in sheep fed low-P diets.
Effects of chlormequat chloride on yield and components of yield in six cultivars of spring barley (Hordeum vulgare)
Authors: White E. M. 
Published: March 2009

SUMMARYThe effects of chlormequat chloride on grain yield and its components in spring barley (Hordeum vulgare)cultivars were studied in five field experiments conducted at two sites near Belfast over 3 years (1982–84). Grain yield was significantly increased by chlormequat chloride treatment in only one experiment, where ear loss was less in the treated plots. Number of ears per plant was increased by treatment in another experiment but yield was unaffected. It was concluded that chlormequat chloride applications are unlikely to produce consistent yield increases in field crops of spring barley.
Effect of acidification with sulphuric acid on the volatilization of ammonia from cow and pig slurries
Authors: Stevens R. J. , Laughlin R. J. , Frost J. P. 
Published: March 2009

SUMMARYPig and cow slurries were applied to bare soil surfaces in the laboratory. Volatilization of NH3 was measured using ventilated enclosures for 3·25 days after slurry application. Slurries were acidified to pH values between 7 and 4 with 5 M H2SO4. Lowering cow slurry pH to 5·5 decreased NH2 volatilization by 95%, while lowering pig slurry pH to 6·0 decreased NH3 volatilization by 82%. A field experiment, measuring the volatilization of NH3 for 2 h after application to grassland stubble of slurry acidified to pH values between 7·5 and 5, gave similar results to the laboratory study.Titration curves were constructed within the pH range of 9 to 4 with cow and pig slurries. There was a significant (P < 0·05) positive correlation between the NH4+-N content of the slurries and the volume of acid required to attain a target pH of 6·0 for pig slurries and a pH of 5·5 for cow slurries. One litre of slurry containing 2 g of NH4+-N required c. 20 ml of 5 M H2SO4 for acidification.
Performance of morphologically divergent plant types in dried peas (Pisum sativum)
Authors: Stelling D. 
Published: March 2009

SUMMARYIn 1991 and 1992, four sets of isogenic lines and eight released cultivars of pea (Pisum sativum L.) differing at the loci af (normal leaflets are converted to tendrils) and st (reduced stipule size) were grown in conventional plot stands at Göttingen, Germany. Crops were either supported by wire netting, to avoid the negative effects of lodging on yield, or were unsupported, thus permitting natural lodging, in order to study the effect of both genes on yield.The conventional, normal-leafed plant type (AFAF STST) exhibited the highest yield potential, but also the largest yield reduction due to natural lodging. Yield potential of the ‘semi-leafless’ plant type (afaf STST) was less than that of the conventional type but, due to its better standing ability, the yield of the unsupported, ‘semi-leafless’ crop, on average, was less reduced by lodging than was the yield of the conventional one. With the additional reduction in stipule size by the gene st, the decrease in yield potential was too large to be counterbalanced by the positive effects of an improved standing ability. For the released cultivars, the effects of both genes on crop performance were smaller than for the isogenic lines.
Forage mixtures for dairy cows: the effect on dry matter intake and milk production of incorporating different proportions of maize silage into diets based on grass silages of differing energy value
Authors: Phipps R. H. , Weller R. F. , Rook A. J. 
Published: March 2009

SUMMARYDuring weeks 3–23 of lactation, 63 multiparous and 28 primiparous Friesian cows were offered ad libitum access to grass silage of either average (A)(ME 10·6 MJ/kg DM; CP 158 g/kg DM) or low (L)(ME 9·9 MJ/kg DM; CP 154 g/kg DM) energy value, either alone or in mixtures consisting of one of these grass silages with 25, 50 or 75% of the forage DM as maize silage. In addition, all cows received 7·2 kg DM/day of concentrate (ME 12·9 MJ/kg DM; CP 202 g/kg DM). There was a significant (P < 0·001) linear relationship between silage DM intake and percentage maize inclusion with grass silage. For grass silage A, DM intake of the mixture of grass and maize in a 1:1 DM ratio was significantly (P < 0·001) higher that at other inclusion levels. There was a significant (P < 0·05) overall linear effect of proportion of maize on milk yield, with a regression coefficient of 0·022 ± 0·009 kg/day per percentage maize proportion. Although milk composition was unaffected by treatment, there was a significant (P < 0·01) linear effect of maize proportion on protein yield for grass silage L, the regression coefficient being 0·8±0·03 g/day/percentage maize proportion. The mixture of grass silage A and maize silage in a 1:1 DM ratio produced the highest yield of milk protein.
Effect of sward height on herbage intake and production of ewes of different rearing rank during lactation
Authors: Parker W. J. , McCutcheon S. N. 
Published: March 2009

SUMMARYGroups of six single- and six twin-rearing ewes were continuously stocked on five pastures with sward surface heights (SSHs) of 3·5, 5·0, 6·0, 7·0 and 8·5 cm from week l until week ll of lactation. Herbage intake, estimated from faecal chromium concentrations and thein vitrodigestibility of herbage samples collected from oesophageal-fistulated wethers, was lowest on the 3·5 cm sward but was not significantly different between SSH treatments during weeks 5, 8 and 9 of lactation. Twin-rearing ewes consumed 0·9–17·6% more herbage than single-rearing ewes did. By week ll, ewe liveweights showed increases of 2–4 kg/ewe on all except the 3·5 cm sward, where the ewes lost a similar amount of liveweight. From week 4 of lactation, twin-rearing ewes had a lower body condition than ewes raising a single lamb on all except the 3·5 cm sward, where the body condition of both rearing ranks was similar. Lamb growth rates during the first 6 weeks were similar for each SSH treatment but from days 46–76 of lactation, lambs on the 5·0 cm and longer swards grew faster (240 g/day) than those on the 3·5 cm sward (197 g/day). Lamb weight on day 76 ranged from 21·5 kg on the 3·5 cm sward to 23·0 kg on the 5·0 cm sward, but was not significantly affected by SSH. Similarly, midside wool growth of ewes and lambs was not significantly influenced by SSH during the period of continuous stocking. The results indicate that farmers should aim to provide swards of 5–7 cm height during lactation to maximize production in both single- and twin-rearing ewes.