bluuebunny/crossref_metadata_2025 huggingface dataset:
Relationship between Prehardening, Photosynthetic Activity at Cold Acclimation Temperatures and Frost Tolerance in Winter Rape (Brassica napus var. oleifera). The Consequences for the Reliability of Frost Resistance Estimation under Controlled Conditions
Authors: Rapacz M. , Janowiak F.
Published: March 2003

The effect of prehardening (early stage of growth at moderate low temperatures (+12°C) during the day) on the reliability of frost resistance estimation in a controlled environment has been studied on three winter oilseed rape cultivars differing markedly in their field survival rate (Leo, Górczański and Idol). It has been also examined the relationship between the photosynthetic activity during the first stage of cold acclimation and the level of frost resistance observed in investigated cultivars. Presented results demonstrated that prehardening, which increases to a significant degree the effectiveness of the cold acclimation process, also increases the differences in cold hardiness between cultivars, and limits the magnitude of experimental errors made during frost resistance estimation under controlled conditions. In all studied cultivars, prehardening increases significantly the photosynthetic activity during cold acclimation. On the other hand, both in the prehardened and in the non‐prehardened plants, no relation has been found between either gas exchange rates or chlorophyll ‘a’ fluorescence characteristics at low temperatures and cultivar ability for acclimation. Neither the existing differences in photosynthetic activity, nor the degree of photosynthetic apparatus acclimation to cold, which occurs during prehardening, are the factors responsible for the frost resistance variation observed between studied cultivars.
Effect of Scheduling Irrigation at Different Phenophases of Sweet Corn (Zea mays saccharata) and Delineation of Critical Stages Based on Stress Day Index
Authors: Mallikarjunaswamy S. N. , Ramachandrappa B. K. , Nanjappa H. V.
Published: March 2003

A field experiment was conducted during the summer of 1996 at the Main Research Station, University of Agricultural Sciences, Hebbal, Bangalore to study the effect of phenophased irrigation schedules on green cob and fodder yield and to delineate critical stages based on Stress Day Index. There were seven irrigation schedules consisting of a combination of two IW/CPE ratios (irrigation water/cumulative pan evaporation), viz. 0.6 and 0.8 shuffled at three growth stages: 10–35 DAS (days after sowing), 36–65 DAS and 66 days to harvest in RCBD (randomized complete block design) with four replications. The investigations revealed that all yield attributing characters such as cobs per plant, cob weight, green cob and fodder yields were significantly higher under the irrigation schedule of 0.8 IW/CPE ratio throughout the crop growth. The reduction in green cob and fodder yields were 39 and 25 % respectively, when irrigations were scheduled at 0.6 IW/CPE ratio throughout as compared to 0.8 IW/CPE. Also, frequent irrigation at 0.8 IW/CPE ratio throughout maintained higher plant relative water content (86.90 %) and higher available soil moisture (59.95–81.51 %) before irrigation as compared to delayed irrigations at 0.6 IW/CPE ratio. The quality parameter viz. sucrose content (2900 μg g−1) in developed seeds was also higher under frequently irrigated treatment. The stress day index indicated that vegetative followed by silking and tasseling were the critical stages for moisture stress.
Effects of Tillage and Fertilization on Biomass, Roots, N‐Accumulation and Nodule Bacteria of Vetch (Vicia sativa cv. Alexander)
Authors: Sidiras N. , Avgoulas C. , Bilalis D. , Tsougrianis N.
Published: March 2003

Field experiments were conducted to determine the effects of tillage (ploughing followed by one rotary hoeing (CT), rotary hoeing (MT) and no‐tillage (NT)) and type of fertilization (NP 154/75 kg ha−1, digested farmyard manure 30 t ha−1) on growth (biomass and roots), N‐accumulation and nodulation of vetch plants (Vicia sativa cv. Alexander) at different stages. The highest dry matter yields and root weight were determined for the NT and the lowest for the CT systems. The NT system promoted nodulation of vetch plants to a higher degree than the MT and CT systems. At the time just before harvesting, the N‐accumulation in the above ground plants, was 54.3 for CT, 76.7 for MT, and 109.0 kg ha−1 for NT, and the corresponding values at roots were 73.3, 112.0 and 173.3 kg ha−1. Growth and nodulation of vetch plants was in general much better on farmyard manure plots than it was with the NP fertilization. The closest correlation coefficients between dry matter of biomass and roots on the one hand, and number of nodules and percentage N in roots on the other, were found with NT. The highest correlation between nodulation and percentage N in roots (r = 0.91***) was observed at the 128‐days‐old vetch plants. The highest correlation between the number of nodules and percentage N in biomass (r = 0.82**) was found at the beginning of the plants’ flowering period. *, **, *** indicate significance at P = 0.05, 0.01 and 0.001 respectively.
Cassava (Manihot esculenta Crantz) Growth Indices, Root Yield and its Components in Upland and Inland Valley Ecologies of Sierra Leone
Authors: Lahai M. T. , George J. B. , Ekanayake I. J.
Published: March 2003

Cassava is predominantly an upland crop that is also cultivated in inland valley swamps (IVS). Identifying physiological traits that can withstand excess moisture stress can aid in the selection and use of stable cassava cultivars in IVS. Three cassava cultivars were evaluated for growth and yield in the upland and IVS ecologies in the 1993–94 crop seasons using a randomized complete block design. In the upland, 80/40 outyielded 87/29 and ‘coco’, while in the IVS, 87/29 had the highest yield. Highest yielding cultivars in each ecology also had the highest tuberous root bulking rate (TBR), dry matter (DM) production, crop growth rate (CGR), relative growth rate, net assimilation rate (NAR), leaf area index, leaf production rate and leaf life. Positive correlations between these parameters and tuberous root yield were noted. High yield of 87/29 in IVS was partly due to its low tuberous root rotting. High root rotting in 80/40 was partly as a result of the greater depth of tuberous roots in the soil (0.3–0.6 m) as compared to the other cultivars (0.15–0.3 m) where roots were in contact with stressful water levels earlier than others. The yield and yield components, growth and leaf characters were all drastically reduced when the cultivars were grown in IVS as compared to upland. For example, root yields of ‘coco’, 87/29 and 80/40 were reduced by 53 %, 60 % and 92 %, respectively, in IVS. Selection of cassava cultivars with longer leaf life and leaf area maintenance leading to high CGR, TBR, NAR and harvest index (in IVS and upland), coupled with a shallow tuberous root formation zone (in IVS) can give higher root and leaf yields in the two ecologies.
Endophyte Infection May Affect the Competitive Ability of Tall Fescue Grown with Red Clover
Authors: Malinowski D. P. , Belesky D. P. , Fedders J. M.
Published: March 2003

Cool‐season grasses infected with Neotyphodium endophytes may be more persistent and competitive than non‐infected plants. In a greenhouse experiment, two tall fescue (Festuca arundinacea Schreb.) cloned genotypes (DN2 and DN11) with different growth characteristics and endophyte status (E−, non‐infected; E+, infected) were grown in monocultures and in full competition with red clover (Trifolium pratense L.) cv. Reddy Red for 20 weeks. When grown in monoculture, endophyte infection reduced the root dry matter (DM) of DN2 (16 %) and DN11 (5 %) when compared to E− plants, while shoot DM was not affected. In full competition with red clover, root and shoot DM of tall fescue were not influenced by endophytes, but cumulative herbage DM yield was less in E+ than in E− plants. Root growth of red clover was significantly depressed (22 %) in competition with E+ plants of DN2 compared to E− plants, but was not affected when plants were grown in competition with DN11. The relative yield total (RYT) did not differ from 1.0 in red clover mixtures with E− plants of DN2 and DN11, and with E+ plants of DN11, indicating competition between the competitors for the same resources. In contrast, RYT was less than 1.0 in the red clover/DN2 E+ mixture, suggesting a negative interaction between the competitors. Endophyte infection increased the competitive ability of DN2 but reduced that of DN11 when compared to E− plants. Because the concentration of pyrrolizidine alkaloids in roots of E+ plants of DN2 was twice that found in roots of DN11 (1083 and 536 μg g−1, respectively), we suggest that pyrrolizidine alkaloids might influence the competitive ability of some endophyte–tall fescue associations through a possible allelopathic effect on companion species.
Nitrogen Nutrition of Potato Cultivars Differing in Maturity
Authors: Saluzzo J. A. , Echeverría H. E. , Andrade F. H. , Huarte M.
Published: March 2003

In potato, dry matter (DM) production and partitioning between plant organs and N accumulation are affected by N application; however, since cultivars differ in these processes, N fertilization must be adjusted to each cultivar. This paper studies the response of potato cultivars differing in maturity to N fertilization in the south‐east of the Buenos Aires Province (37°45′S, 58°18′W) in two growing seasons. Treatments combined four N doses (0–180 kg ha−1) and four cultivars: Jaerla (early), Spunta (mid‐early), Mailén INTA (medium late) and Huinkul MAG (late). DM and N content were measured in leaves, stems and tubers throughout the growing season and intercepted photosynthetically active radiation was regularly assessed. There was an increase in tuber yield up to intermediate N doses (60 kg ha−1 in 1990 and 120 kg ha−1 in 1991). Tuber yield was similar for Spunta and Huinkul MAG. There was no interaction between cultivar and N fertilization for tuber dry matter yield. DM partitioning to leaves and tubers during the growing season differed among cultivars, but N availability affected partitioning similarly for all cultivars. Jaerla had a high and Huinkul MAG had a low radiation use efficiency between plant emergence and the beginning of tuber formation. Jaerla, Spunta and Mailén INTA reached maximum N content in foliage at ≈60 days after emergence and Huinkul MAG 20 days later. Total N content at maturity varied between 120 and 250 kg ha−1 and was affected by cultivar and N dose. The results will help to improve N fertilization recommendations and management practices as related to each cultivar under the environmental conditions of this region.
Physiological Genetics of Salt Tolerance in Wheat (Triticum aestivum L.): Performance of Wheat Varieties, Inbred Lines and Reciprocal F1 Hybrids under Saline Conditions
Authors: Salam Abdus , Hollington P. A. , Gorham J. , Jones R. G. Wyn , Gliddon C.
Published: March 2003

Four bread wheat cultivars were studied at two salinity levels. Tobari 66 had the lowest uptake of Na+ and Cl−, and the highest K+/Na+ ratio; Pato had the highest uptake of these ions and Lyallpur 73 was intermediate. Intervarietal differences were greater at higher salinity, suggesting that they were not caused by variation at the Kna1 locus. There were significant differences between inbred lines for Na+, particularly in Blue Silver, suggesting the possibility of selecting genotypes with enhanced tolerance from within existing cultivars. Pato, Tobari 66 and their reciprocal F1 hybrids were further evaluated at four salinity levels. The hybrids exhibited similar relative grain yield to Tobari, with better Na+ and Cl− exclusion and higher K+/Na+ ratios than Pato. Overall, Tobari had the highest absolute yield under salinity, and the hybrids were closer to Tobari than to Pato. Tiller and grain numbers, 100‐grain weight and yield were more affected by salinity than were height, spike length and spikelet number. We conclude that intervarietal variation for salt tolerance in wheat is controlled by genes which could be transferred to sensitive genotypes to improve their tolerance, and that the K+/Na+ ratio of the youngest leaf could be used to screen for salt tolerance.
Nutrient Use Efficiency as a Factor Determining the Structure of Herbaceous Plant Communities in Low‐Nutrient Environments
Authors: Koutroubas S. D. , Veresoglou D. S. , Zounos A.
Published: March 2003

We tested the hypothesis that, in competition for nutrients, the plant species using more efficiently the limiting nutrient will tend to dominate in plant communities. Two experiments were conducted. In the first, plant communities consisting of perennial herbaceous species were grown in large boxes filled with soil enriched with all necessary nutrients, except for nitrogen (N) in half of the boxes and phosphorus (P) in the other half. It was expected that N or P, respectively, would become progressively limiting. In the second experiment, five perennial species, in monocultures and in mixtures of the five species, were grown in nutrient solutions of the combination of 3 levels of potassium (4, 16 and 64 µg ml−1) × 2 levels of phosphorus (1 and 4 µg ml−1) with all the other necessary nutrients at adequate concentrations for plant growth. In the first experiment, changes of the proportions of species biomass duration to community biomass duration between the second and the third years of the experiments were negatively related to species P shoot concentrations, but they were not related to species N shoot concentrations, probably because N did not become limiting. The second experiment showed that the species use efficiency of a particular nutrient (measured as the quantity of dry matter produced per g nutrient) was highest when the availability of this nutrient was lowest; the species with the highest use efficiency of a particular nutrient tended to have the highest relative abundance when this nutrient was limiting. The results of both experiments suggest that nutrient competition is important in low‐nutrient environments and the species that use more efficiently the limiting nutrients have a competitive advantage and tend to dominate in the plant community.
Morphological and Yield Traits of Wild Legume (Tetragonolobus palaestinus Boiss) Populations
Authors: Al‐Karaki G. N.
Published: March 2003

Through the process of domestication, cultivated crops have been selected from their wild ancestors for various anthropocentrically important characteristics. Tetragonolobus palaestinus Bioss is a wild grain legume species which grows naturally on the plains and hilly areas of north Jordan and neighbouring countries. In a study of agronomic and morphological traits of wild populations of T. palaestinus at two locations, the following variables were evaluated: number and dry weight of nodules per plant, plant height, number of branches and pods per plant, pod length, number of seeds per pod, 100‐seed weight, and seed weight per plant. Positive and significant correlations between 14 pairs of variables were noted, including number and dry weight of nodules per plant, plant height, number of branches and pods per plant, pod length, and seed weight per plant. The wild populations of T. palaestinus studied here appeared to be homogenous, although some of the observed variation could have arisen from variation of the environmental conditions among locations.
Influence of Seeding Density on Contents and Uptake of N, P and K in Linseed (Linum usitatissimum L.)
Authors: Hassan F. U. , Leitch M. H.
Published: March 2003

Field experiments were conducted at the University of Wales, Aberystwyth, UK to evaluate the effects of seeding density and row spacing on the contents and uptake of N, P and K in linseed during 1993 and 1994. The contents of all three nutrients decreased with age of the plants up to the start of flowering, but N and P slightly increased at maturity in both the experiments. The increase of N and P at maturity could be the result of greater accumulation of these elements in the seeds. The uptake of all three elements (N, P and K) increased progressively with age of the plants, with a peak at maturity, but the level of K decreased by almost half in both experiments between flowering and maturity. The progressive increase of uptake with age of the plants may be related to total dry matter production. The decrease of K at maturity indicated that lower plant parts (stem and leaves) accumulated a higher percentage of K than seeds. The senescence of leaves at maturity might also have contributed to the decrease of K at maturity. The characteristics of the crop were in general quite similar in 1993 and 1994. The small variations found in the contents and uptake of N, P and K could be due to variation in weather conditions and the total length of the growth period. In 1993, the weather was moist and relatively cool, while in 1994 it was dry and relatively hot.
Effects of Benzyl Adenine and Abscisic Acid on Grain Yield and Yield Components in Triticale and Wheat
Authors: Sivakumar T. , Virendranath  , Srivastava G. C.
Published: March 2003

Grain yield and yield components (grains per ear, grain weight, 1000‐grain weight, ear weight, ear seed ratio and dry matter partitioning between ear and seed) were examined in a wheat genotype (PBW‐343) with well‐filled grains and a Triticale genotype (DT‐46) with poorly filled grains (showing grain shrivelling) grown in pots. Six days after anthesis (DAA), benzyladenine (BA) @2 µg ear−1 and abscisic acid (ABA) @4 µg ear−1 were injected at the base of the mother shoot ear in both species. It was observed that, in both wheat and Triticale, BA increased the grain weight, grain number and partitioning of dry matter between ear and seed, whereas ABA decreased the grain weight, grain number and dry matter partitioning between ear and seed. However, these decreases were slower in Triticale than in wheat. BA treatment increased the grain dry matter accumulation, which in turn resulted in better filling of grains and increased the grain weight in both wheat and Triticale. The average grain weight of Triticale was lower than that of wheat. Thus, it appears that variation in grain weight between wheat and Triticale might be due to different availabilities of growth‐promoting phytohormones such as cytokinins and assimilates.
Response of Corn Hybrids Differing in Canopy Architecture to Chemical and Mechanical (Rotary Hoeing) Weed Control: Morphology and Yield
Authors: Begna S. H. , Hamilton R. I. , Dwyer L. M. , Stewart D. W. , Cloutier D. , Liu A. , Smith D. L.
Published: March 2003

Weed interference with the growth and yield of corn plants is affected by both mechanical and chemical means of weed control. Recently, corn hybrids accumulating more leaf area, maturing earlier, yielding better in narrower row spacings and tolerating higher plant populations better than conventional hybrids have been developed. Because of more rapid leaf area accumulation during the earliest stages of canopy development and overall canopy architecture, they may be more susceptible to damage due to mechanical weed control. The objective of this study was to assess the response of corn hybrids with a wide range of canopy architectures to chemical and mechanical (rotary hoeing) weed control, with an emphasis on quantifying morphology and grain yield responses. Field experiments were conducted in 1997 and 1998 at Ste. Anne de Bellevue, Quebec. Three hybrids were tested: leafy reduced‐stature (LRS1 and LRS2), and the conventional hybrid Pioneer 3979 (P3979). Rotary hoeing alone had very little effect, while herbicide application reduced the interference of weeds with growth and grain yield of all hybrids. Hybrid P3979 had more total leaf area than LRS1 and LRS2, but the percentage of leaf area above the ear was much higher for LRS hybrids (70 %) than for P3979 (51 %). Generally, LRS hybrids were much shorter with more leaf area above the ear than P3979, contributing to the large differences in canopy architecture between the LRS hybrids and P3979. However, morphology and grain yield response of hybrids to rotary hoeing and herbicide weed control was not different, indicating that the new hybrids were not more susceptible to damage caused by mechanical weed control than a corn hybrid with a conventional canopy architecture.
Contributions to the Analysis of Genotype × Environment Interactions: Theoretical Results of the Application and Comparison of Clustering Techniques for the Stratification of Field Test Sites
Authors: Hühn M. , Truberg B.
Published: March 2003

For an analysis of cross‐classified data sets with rows = genotypes and columns = environments (locations and/or years), existing genotype × environment interactions are of major importance. Differential responses of genotypes (environments) across environments (genotypes) are expressed by these effects. To reduce the impact of these genotype × environment interaction effects, one commonly stratifies genotypes or environments by cluster analysis techniques into homogeneous groups so that interactions within groups are minimized. The present paper presents a comprehensive overview of the numerous procedures for stratification of genotypes or environments by cluster analysis which have been proposed in the literature. In these studies, two different concepts of interaction have been used: the crossover concept of interaction [different rank orders of genotypes (environments) within environments (genotypes)] or the usual statistical concept of interaction (deviations from additivity of main effects in the linear model). For a quantitative characterization of cluster techniques and for a comparison of two different clustering procedures, two parameters are introduced and discussed: measure of resemblance for two classifications and cluster size for one classification.
Allelopathic Effect of Conyza albida on Avena sativa and Spirodela polyrhiza
Authors: Economou G. , Tzakou O. , Gani A. , Yannitsaros A. , Bilalis D.
Published: March 2003

The allelopathic influence of four plant tissues of Conyza albida (stems, leaves and inflorescences) on oat growth were investigated using in vivo tests. Oat growth (fresh and dry weights of above and underground parts) was inhibited from phytotoxic activity of upper leaves and inflorescence tissues of C. albida in pot studies. The inhibition was significantly higher than in the other tissues studied. The inhibiting action of crude extracts and volatile compounds from young plants (rosette) and mature plants were examined using two bioassay methods: (a) seed germination and radicle growth of oat and (b) fresh weight of duckweed plants. Both bioassayed species exhibited greater phytotoxic response from the young plants, collected in winter, than from the mature ones.
Effects of Hail on Evapotranspiration and Plant Temperature of Maize
Authors: Anda A. , Burucs Z. , Lõke Z. , Decsi É. K.
Published: March 2003

The effect of natural and artificial hail on the evapotranspiration of maize (Zea mays L.) was studied. In 1998, observations were made after a natural hailstorm, while in 1999 hail was simulated by lacerating the leaves parallel with the leaf veins. Plants of one treatment were grown in a lysimeter. In addition to evapotranspiration, measurements were also made on plant temperature. Among physiological processes, the modifications occurring in evapotranspiration could be divided into two distinct phases. On the days immediately following the damage the raised plant temperature caused by the wounds indicated a reduction in evapotranspiration leading to less efficient plant cooling. Later, in both the natural and artificial hail treatments, changes in evapotranspiration depended on the weather. The changes in evapotranspiration and plant temperature after natural and artificial hail injury were similar in nature. The yield loss was less than 10 %, in agreement with data in the literature on the effect of simulated hail injury. However, it can be expected that further study of simulated hail injuries will lead to a better understanding of the changes in plant water balance caused by hail.
Spring Cereals for Forage and Grain Production in a Cool Maritime Climate
Authors: Todd A. G. , Spaner D.
Published: March 2003

Newfoundland's climate is marginal for agricultural production. The availability of locally grown cereal grain and high‐quality forage are major limitations to successful animal agriculture in this region. Here, our overall objective was to compare several spring cereal species for both annual forage and grain production in Newfoundland's cool Maritime climate. Several varieties of barley (Hordeum vulgare L.), wheat (Triticum aesitivum L.), oats (Avena sativa L.) and pea (Pisum sativum L.)–cereal mixtures for forage yield and quality, as well as grain yield and maturity, were compared in field trials on the east and west coasts in both 1999 and 2000. Barley headed earliest, yielded greatest forage dry matter, had lowest forage protein and acid detergent fibre (ADF) percentages, and had neutral detergent fibre (NDF) mean values greater than those of pea–cereal mixtures, but less than those of oats and wheat. Forage harvested from pea–cereal mixtures was similar to that of barley for yield, ADF and NDF, while P and protein percentage were much greater. Barley matured 10–15 days earlier than both wheat and oats. In general terms, all three spring cereals exhibited similar grain yield potential. Oats tillered less, but compensated by producing more kernels spike−1. Days to maturity for cereal grains in western Newfoundland were roughly similar to those reported for the Maritime provinces of Canada. Yield and maturity results for both forage and grain production suggest that eastern Newfoundland is a unique agro‐ecoregion in North America, and agronomic recommendations specific to other regions may not be applicable in this region.
Associations between the c‐myc proto‐oncogene and carcass quality traits in the pig: evidence for epistasis with the Ryr1‐gene
Authors: Reiner By G. , Moser G. , Geldermann H. , Dzapo V.
Published: March 2003

The nucleotide sequence data referred to in this paper have been submitted to GenBank and have been assigned the accession number X97040.

c‐myc is an ubiquitous nuclear phosphoprotein involved in the regulation of cell‐growth, differentiation and apoptosis. Higher nuclear levels of c‐myc block adipogenesis and trigger the onset of myogenesis and folliculogenesis. The c‐myc proto‐oncogene has the potential of a mediator between second messengers such as calcium and cAMP and gene expression. As both are involved in stress‐susceptibility and carcass quality in the pig, this study investigates associations between c‐myc genotypes and carcass quality traits as well as interactions with the Ryr1 genotype in this species. An association between c‐myc and carcass fat traits was evident, but did not reach genome‐wide significance levels. Significance niveaus, explained variance and mean differences between the homozygotes of the Ryr1‐gene which clearly decreased from the AA‐genotype to the BB‐genotype of c‐myc are indicating a gene interaction between both genes. Mean differences in lean percentage (expressed in SD) decreased by 89.2% in ME × PI and by 86.3% in WS × PI. The existing but weakly developed significances of the association between c‐myc and carcass fat traits are discussed under the aspect of epistatic nullification.
Genetic aspects of productive and reproductive traits in a Murrah buffalo herd in São Paulo, Brazil
Authors: Tonhati H. , Vasconcellos F. B. , Albuquerque L. G.
Published: March 2003

This study investigated genetic trends of some productive and reproductive traits in a herd of Murrah buffalo raised in São Paulo, Brazil. Variance components for milk production (MP), length of lactation (LL), calving interval (CI) and age of first calving (AFC) were estimated by the restricted maximum likelihood method, using an animal model. Estimated heritability values were 0.38; 0.01; 0.10 and 0.20 for MP, LL, CI and AFC, respectively. Estimated repeatability values were 0.50, 0.13 and 0.20 for MP, LL and CI, respectively. Means of predicted breeding values for cows, dams and sires according to calving year and the genetic correlations were presented.
Genetic diversity among some cattle breeds in the Alpine area
Authors: Del Bo L. , Polli M. , Longeri M. , Ceriotti G. , Looft C. , Barre‐Dirie A. , Dolf G. , Zanotti M.
Published: March 2003

Seven autochthonous Italian cattle breeds bred in the alpine area (Aosta Black Pied, Aosta Red Pied, Aosta Chestnut, Oropa Red Pied, Grey Alpine, Rendena and Burlina) were investigated in order to characterise their genetic structure and to study their phylogenetic origin. Two cattle breeds from Germany (Original German Brown and Holstein) and four from Switzerland (Simmental, Herens, Evolene and Brown Swiss) were included in the study in order to determine the genetic diversity existing among Italian local breeds, similar breeds bred on the other side of the Alps and in the well known Holstein.

Seventeen microsatellites, of the internationally accepted panel for the study of cattle biodiversity, were used for the analysis.

Microsatellites were highly polymorphic with a mean number of 5,5 alleles (ranging from 2 to 12 per locus). For each locus, allelic frequencies, heterozygosity (H) and the Polymorphism Information Content (PIC) were computed. The genetic equilibrium according to Hardy–Weinberg was calculated for each population and for each locus. Allele frequencies were used to estimate genetic distances and to draw a phylogenetic tree. The two closest breeds were Aosta Red Pied and Aosta Black Pied, while the two genetically most different were Holstein and Aosta Chestnut. Aosta valley breeds, Evolene and Herens constituted a tight cluster in the phylogenetic consensus tree. Principal component analysis showed a similar pattern for all the alpine breeds, while Holstein and Original German Brown were far away. The genetic differences among breeds were in accordance with their geographical and historical origins.
Estimates of environmental effects and genetic parameters for body measurements and weight in Brahman cattle raised in Mexico
Authors: Magnabosco C. D. U. , Ojala M. , De Los Reyes A. , Sainz R. D. , Fernandes A. , Famula T. R.
Published: March 2003

A Derivative Free Restricted Maximum Likelihood (DFREML) algorithm was used with single trait and two traits animal models to estimate the variance and covariance components and thus, heritabilities and phenotypic, genetic and environmental correlations among nine different body measurements and weights of Brahman cattle raised in Mexico. The following measurements were considered: hip width, pin width, hip‐pin width, anterior height, posterior height, body length, thorax perimeter, scrotal circumference and weight. The analysis was based on a total of 1018 animals, born between 1992 and 1995, from 17 herds in the Mexican States of Chiapas, San Luis Potosi, Tabasco, Tamaulipas and Veracruz. The model included the following fixed effects: herd, year‐season of birth, sex, age of the animal and feed management. The only random effect was the direct additive genetic contribution of each animal. All fixed effects in the model were significant for all traits (p < 0.05). Estimated heritabilities for the traits were: hip width 0.57, pin width 0.32, hip‐pin width 0.41, anterior height 0.56, posterior height 0.54, body length 0.32, thorax perimeter 0.49, scrotal circumference 0.02 and weight 0.66. The magnitude of the heritabilities was medium to high, with the exception of scrotal circumference. The genetic correlations among all body measurements were consistently positive and high, ranging from 0.64 to 1.00. Although other measures showed higher genetic correlations with weight, thorax perimeter combines a high value (0.70) with ease and repeatability, making it a useful field measurement to estimate body weight when scales are not available.
Fat deposition in tropical sheep as adaptive attribute to periodic feed fluctuation
Authors: Ermias E. , Yami A. , Rege J. E. O.
Published: March 2003

Ruminants adapt to periodic fluctuation in feed resources by accumulating fat stores during favourable periods. Thus, genetic variations, among ruminant genotypes, in the capacity to deposit fat could be exploited through breeding to improve animal productivity in traditional tropical production systems. Based on this premise, breed differences among weights of principal adipose depots and total body fat were estimated in Menz (n = 303) and Horro (n = 151) sheep of Ethiopia. Animals were kept on supplemental feeding, for about 3.5 months, until slaughter at about 17 months of age and pre‐slaughter live weight of 25 kg. Except the combined weight of tail and rump fat (TRF) which was similar (p > 0.05) in the two breeds, weights of subcutaneous and intermuscular fat (SIF), internal fat (IF) as well as total dissected body fat (TotDF), total ether‐extracted body fat (TotEE) and TotFAT (TotDF plus ‘residual’ fat, fat recovered by ether‐extraction from non‐adipose tissues) were significantly (p < 0.01) higher in the Menz. TotDF, TotEE and TotFAT were 1.91 ± 0.04, 2.05 ± 0.06 and 2.64 ± 0.06 kg, respectively, in the Menz and 1.50 ± 0.05, 1.44 ± 0.06 and 2.02 ± 0.07 kg, respectively, in the Horro. Implications of breed differences in fat distribution among depots, and possible consequences of genetic improvement of some of the depots on adaptation to climatic and nutritional stresses as well as some production objectives are discussed.
Genetic conservation of five endangered Spanish donkey breeds
Authors: Aranguren‐Mendez J. , Jordana J. , Gomez M.
Published: March 2003

The genetic diversity of most livestock species is being reduced, and it is not possible to preserve all of these livestock breeds. In order to preserve as much of the genetic diversity as possible, we must first have a robust method of measuring genetic diversity among breeds. Three different methods of study that graphically represent relationships among breeds are presented; Weitzman's method, principal component analysis (PCA) and a neighbour‐joining tree with allele sharing. Diversity was evaluated on the basis of 15 microsatellite markers typed over a total of 513 DNA samples collected from five Spanish donkey breeds. Breed differentiation was confirmed by the clustering based on the genetic distances between individuals, which essentially grouped all individuals in discrete clusters. The genetic distance among breeds was used to measure the global diversity of the set in breeds considered, and to evaluate the marginal loss of diversity attached to each breed. The Catalana breed appeared to be the most ‘unique’ in the set considered. In addition to this, the usefulness of global evaluations of diversity using molecular markers to choose breeds is worthy of conservation.
Gene expression in different tissues of lactating cows of differing metabolic type: 1. Comparison of mRNA patterns by the differential display method
Authors: Schwerin M. , Voigt J. , Wegner J. , Kühn Ch. , Ender K. , Hagemeister H.
Published: March 2003

Among other factors the nutrient utilization of a cow is influenced by its individual physiological and genetic predisposition. There are large differences within cows in the manner of partition of the nutrients that may affect the size and activity of the individual organs and the whole body composition. High genetic merit dairy cows have a higher potential rate of protein excretion than medium genetic merit dairy cows even when energy and protein intake are equal. Medium genetic merit dairy cows show higher potential rates of protein and fat deposition of the body. This phenomenon was partly explained by the regulatory functions of the hormone insulin (see Brockman and Laarveld 1986; Broucek et al. 1991; Wylie et al. 1998). Additionally, it is widely considered that the somatotropic axis [growth hormone, growth hormone releasing factor and insulin‐like growth factor I (IGF‐I)], could be involved, as one of the key control and balance mechanisms which regulate the partition of nutrients (Breier and Sauerwein 1995; Schams 1995; Knight 1997). Several studies have provided insights into the physiological action of these and further hormones, transport proteins and enzymes, e.g. the erythrocyte‐type glucose transporter, the insulin‐responsive glucose transporter or the glycerol‐3‐phosphate dehydrogenase, and indicate that these molecules may affect nutrient repartitioning and utilization as well as milk yield, growth and fat accumulation (Mathews et al. 1988; Bauman and Vernon 1993; Burton et al. 1994; Girard et al. 1994; Binelli et al. 1995; Zhao et al. 1996; Abe et al. 1997). However, the mechanisms of regulation of most of these processes are insufficiently known.

This paper presents a comparison of mRNA patterns of tissues potentially associated with protein and energy turnover in lactating cows of different metabolic types. The technique of differential display of messenger RNA species originally described by Liang and Pardee (1992), has already been applied as a powerful tool for cloning genes that are differentially expressed in various tissues or under altered conditions in the same tissue (e.g. Liang et al. 1993; Aiello et al. 1994; Li et al. 1994; Nishio et al. 1994). This method was applied to characterize the expression patterns in 12 tissues of three cows with divergent metabolic types (milk type, meat/milk type, and meat type) by the display of differentially and identically expressed cDNA bands. The aims of this exploratory study were first to indicate which of the 12 tissues analysed are mainly involved in trait differentiation according to their differentially displayed mRNA patterns. Secondly, the results of this study represent the prerequisite for the identification of tissue‐specific expressed sequence tags in general, and individual or type‐dependent differentially expressed sequence tags in particular.
Untersuchungen zur prophylaktischen Wirkung der Verfütterung eines Probiotikums und von erregerspezifischen Kolostrum‐ und Dotterantikörpern bei neugeborenen Kälbern
Authors: Von Erhard M. H. , Leuzinger K. , Stangassinger M.
Published: March 2003

Studies on the prophylactic effect of feeding probiotics, pathogen‐specific colostrum antibodies or egg yolk antibodies in newborn calves

The prophylactic efficacy of feeding probiotics, specific egg yolk antibodies and specific colostrum antibodies on neonatal diarrhoea was investigated in a field trial with calves, grouped (n = 39/40 per group) according to the following treatments: Group I: feeding no additive; Group II: feeding probiotics (5 g powder/day with Bacillus cereus var. toyoi); Group III: feeding egg powder (10 g/day with specific egg yolk antibodies against rotavirus, coronavirus and Escherichia coli F5); Group IV: feeding colostrum antibodies (10 ml/day containing 1 g bovine immunoglobulins with specific antibodies against rotavirus, coronavirus and E. coli antigens); Group V: feeding egg powder together with probiotics (according to group II and III). The additives were given twice daily with the meal from day 2 to day 14 post‐natum. The presence of infectious agents was proved in fecal samples of all calves. Intestinal infections with rotavirus (30.8% of the calves) predominated compared to those with coronavirus (7.1%), E. coli F5 (1.5%) and cryptosporidia (24.2%). In contrast to earlier studies, the manifestation of diarrhoea did not differ significantly between the five groups. Only the growth rate of the calves between day 2 and day 14 of life as a measure of their welfare showed treatmentFspecific differences. The control group (I) showed the lowest body weight gain of about 5.8 kg (SD 5.0), whereas in the treated groups it averaged 6.3 kg (SD 4.1, p = 0,60; group II), 6.8 kg (SD 4.3, p = 0.36; group III), 6.9 kg (SD 4.7, p = 0.61; group IV) and 7.7 kg (SD 4.9, p = 0.08; group V). Considering only the rotavirus‐positive calves the body weight gain of the control group (I) was 3.5 kg (SD 4.8) and of the treated groups was 3.8 kg (SD 3.3, p = 0.65; II), 5.0 kg (SD 3.5, p = 0.54; III), 6.6 kg (SD 4.5, p = 0.05; IV) and 6.1 kg (SD 5.0, p = 0.13; V). Obviously, the feeding of antibodies from colostrum or from egg powder does increase the mean body weight gain. The feeding of probiotics alone has nearly no effect. However, in the combination with specific egg antibodies probiotics seem to have a synergistic effect. In serum from the 198 newborn calves the IgG concentration averaged 4.9 mg/ml serum (SD 3.3). From 93 dams of these calves a sample of the first colostrum could be obtained showing a mean IgG concentration of 22.0 mg/ml (SD 11.0). IgG levels in the colostrum and in the serum have been positively correlated (r = 0.37, p < 0.05). Calves with a high intensity of diarrhoea had a significantly (p = 0.01) lower mean IgG serum level (3.7 mg/ml; n = 36; SD 2.5) than calves without diarrhoea (5.6 mg/ml; n = 75; SD 4.0).
Effects of potassium diformate (Formi® LHS) in combination with different grains and energy densities in the feed on growth performance of weaned piglets
Authors: Paulicks B. R. , Roth F. X. , Kirchgessner M.
Published: March 2003

To examine the effects of Formi®LHS (Norsk Hydro a.s., Oslo, Norway)on growth and health performance of weaned piglets fed on diets at different energy levels, three experiments were conducted. Experiment I comprised 48 weaned crossbred (German Landrace × Pietrain) piglets (7 kg live weight) in single rearing battery cages in a metabolism barn, experiment. II with 72 weaned piglets (German Landrace, 9 kg live weight) in groups of three animals kept in flat‐deck boxes on an experimental farm and experiment III with 96 weaned crossbred (German Landrace × Pietrain) piglets (8 kg live weight) again in single cages. In experiments I and II the animals were equally allotted to four treatment groups receiving a complete feed (type starter feed) containing either 13 MJ ME/kg or 14 MJ ME/kg feed with or without supplementation of 1.8% Formi®LHS. In experiment III four diets based either on barley, wheat, corn, or a mixture of them were prepared and applied without or with 1.8% Formi®LHS resulting in eight treatments. Feed intake, weight gains, feed conversion (kg feed/kg weight gain), and occurrence of diarrhoea were recorded. In experiments I and II on the low‐energy level Formi®LHS improved final weights by 5 and 12%, respectively, daily weight gains by 8 and 18%, respectively, and feed conversion by 6% each, with the feed intake being higher by 1 and 8%, respectively. With 14 MJ ME/kg feed final weights were up to 10%, daily weight gains up to 14%, and feed conversion up to 11% higher than in the unsupplemented low‐energy group, but particularly in group feeding, these performance data were lower than those of the Formi®LHS‐supplemented low‐energy group. Formi®LHS did not improve performance with 14 MJ ME/kg feed. In experiment III there were no differences in weight gains, feed consumption or feed efficiency between the different grains. Formi®LHS increased daily weight gains and feed consumption in all types of diets up to 14 and 9%, respectively, but significantly only in combination with wheat. Feed efficiency was significantly improved by Formi®LHS supplementation in the barley, wheat, and barley–wheat–corn diet (6, 4 and 7%, respectively) but not in the corn diet. Occurrence of diarrhoea was reduced markedly by Formi®LHS in all of the three experiments.
Effect of dietary copper and vitamin E supplementation, and extensive feeding with acorn and grass on longissimus muscle composition and susceptibility to oxidation in Iberian pigs
Authors: Rey A. I. , López‐Bote C. J.
Published: March 2003

The objective of this study was to assess the effect of dietary copper and/or vitamin E supplementation on composition and oxidation of M. longissimus in Iberian pigs and to compare it with meat samples from pigs produced extensively and fed with acorn and grass. Grass had the highest α‐tocopherol content (> 150 mg/kg DM), while acorns had the highest copper concentration (78.1 mg/kg DM). Dietary treatment did not affect copper composition in muscle and no interactions were detected between copper and α‐tocopherol. The α‐tocopherol content in muscle from pigs fed diets supplemented with α‐tocopheryl acetate (100 mg/kg feed) was 1.5 times greater (p < 0.0001) than those from pigs receiving a basel diet. M. longisssimus dorsi from pigs fed extensively had a higher concentration of α‐tocopherol than those fed in confinement with the basel level of α‐tocopheryl acetate, but lower values than pigs fed supplemented levels. Total n‐3 fatty acids (p < 0.02) and hematin (p < 0.0001) concentrations were significantly higher in muscle from pigs fed extensively than when fed in confinement. Muscle homogenates from Iberian pigs fed in extensive conditions showed significantly (p < 0.02) higher susceptibility to oxidation than those from pigs fed mixed diets. Dietary α‐tocopheryl acetate supplementation (100 mg/kg feed) significantly (p < 0.05) reduced lipid oxidation of muscle, while dietary copper concentration did not modify susceptibility to lipid oxidation.
Study on the performance enhancing effect of rare earth elements in growing and fattening pigs
Authors: He M. L. , Ranz D. , Rambeck W. A.
Published: March 2003

A feeding study was performed to investigate possible performance enhancing effects of rare earth elements (REE) in growing and fattening pigs, as well as their influence on the blood serum biochemical changes and the accumulation of REE in the organs of pigs treated with a REE diet for a longer time period. Fourteen crossbred piglets (Deutsche Landrasse × Piétrain) were allotted to two dietary treatments: a control group and the REE‐treated group which was supplemented with 300 mg of an REE mixture per kg feed. The REE mixture contained mainly chlorides of lanthanum (La), cerium (Ce) and praseodymium (Pr). The whole feeding period consisted of a 2 monthsad libitumfeeding period M‐I and a 1 month restricted feeding period M‐II. It was found that in comparison with the control group, the REE group had a better daily body weight gain of 19% (p < 0.05) in the period M‐I and 12% in the period M‐II; the REE group also had a better feed conversion ratio of 11% in period M‐I and 3% (p > 0.05) in the period M‐II. The REE had no significant (p > 0.05) influence on blood serum thyroxine (T4), aspartate‐amino‐transferase (AST), alanine‐amino‐transferase (ALT), alkaline‐phosphatase (AP), total cholesterol, triglyceride, total protein, albumin, glucose, Ca, P, Na, K and Cl. However, serum triiodothyronine (T3) in the REE group was significantly (p < 0.01) lower than that in the control group. The accumulation rate of La and Ce in the muscle, liver and kidneys was very low after feeding the REE diet for 3 months. The study indicates the possibility of using rare earth elements as safe and inexpensive alternative performance enhancers for pig production.