Estimates of inbreeding effects in a landrace are necessary in order to acquire information on the presence of different types of gene action for important traits. Twelve lines with different levels of inbreeding coefficients (F = 0, 0.25, 0.50 or 0.75) were developed from three phenotypically selected families of a winter squash landrace (Cucurbita moschata Duchesne) between 2000 and 2002 in the area of Thermi-Thessaloniki, Greece. During 2003, a field experiment was established at this location to evaluate the lines. The agronomical characters measured were: the number and weight of total commercial fruits, days to first female blossom, seed weight, size of pollen grains and water-stress tolerance. Comparisons were also made of morphological characters, the dry matter, the total soluble solids and the pH of fruits. Lines with inbreeding coefficient F = 0.50 were found to have the highest values for most of the measured characteristics. Significant family x inbreeding interactions were found, revealing different trends for the linear, quadratic and cubic components of each family with inbreeding coefficients. Three F = 0.50 lines selected from within each representative family were evaluated along with four winter squash landraces from the C. moschata collection of the Greek Gene Bank, during 2004 in the area of Thermi. These F = 0.50 lines showed a superior performance of three components contributing to yield, indicating that one generation of selfing improved the agronomic performance maintaining concurrently the substantial characteristics of the landrace.
A dynamic mathematical model of a closed mammary system in lactating cows was developed to incorporate the setpoint concept of tissue activity, using equations where nutrient supply and absorption are locally regulated so as to maintain a given rate of milk protein yield. The model consists of 12 differential equations, 11 of which are concerned with intracellular biochemical compartments and one describes the Volume of tissue actively perfused by blood (AP). The intracellular compartments are: amino acids (AAs), acetate, fatty acids (FAs), beta-hydroxybutyrate, glucose-6-phosphate, fructose-6-phosphate, phospho-glyceraldehyde, pyruvate, mitochondrial acetyl-CoA, adenosine triphosphate (ATP) and adenosine diphosphate (ADP). The model simulates mechanisms which are aimed at reproducing and, thereby, explain variations in mammary plasma flow (MPF) observed experimentally. The AP changes according to variations in the metabolic status or in the metabolic requirements of the gland. Should the tissue energy charge (i.e. ATP/ADP ratio) exceed a baseline ratio, then AP decreases and consequently MPF declines. Conversely, when milk protein yield increases, AP increases and MPF rises. In the present model, AA uptake by the mammary gland is inhibited by intracellular AAs. It is also assumed that, when milk protein yield diminishes, the respiratory chain and ATP synthesis become uncoupled and Consequently ATP yield is reduced. Model evaluation included behavioural analysis and sensitivity analysis. Behaviour analysis was conducted to test whether the model mechanisms reproduced the scenarios from which the model hypotheses were developed, and took into consideration: an increase in arterial glucose concentration (HIGLC), increases in arterial concentrations of non-esterified FAs, triacylglycerol and beta-hydroxybutyrate (HIFAT), a 50% reduction of arterial histidine concentration (LOHIS), and a hyperinsulinaemic euglycaemic clamp (HIINS). Both HIGLC and HIFAT resulted in a decrease in MPF and in milk protein yield; moreover, the scenario HIGLC also produced a notable decrease in the extraction of glucose. The scenario LOHIS resulted in increased MPF and extraction of His from plasma. However these responses were not sufficiently large to prevent a severe reduction of milk protein yield which was accompanied by a reduction in the extraction of other essential AAs. The scenario HIINS resulted in an increase or MPF and of milk protein yield, in the extraction of His and of other essential AAs. Model sensitivity analysis focused on variation of both affinity and inhibition constants of some of the Michaelis-Menten equations. Improvements in model Structure and directions for future research Suggested by the modelling analysis are discussed.
The aim of the current study was to compare three methods for determining the influence of different feeding strategies on the gut microbiota of piglets. Forty-eight weanling piglets were fed four different diets enriched with insoluble dietary fibre (wheat bran and pollen from Pinus massoniana). Starting from ileal and colonic samples, the total microbial DNA was isolated and bacterial parameters (lactobacilli, bifidobacteria, Bacteroides vulgatus and total bacterial Counts) were quantified using real-time polymerase chain reaction (PCR). The results for lactobacilli, bifidobacteria and total bacterial counts were compared with those obtained by fluorescence in situ hybridization (FISH) and cultivation method. No significant differences could be observed between dietary treatments with real-time PCR and FISH for all investigated parameters. Comparing the applied three methods no consistent results were achieved, whereas FISH usually showed lower values. It was shown that real-time PCR call be regarded as all alternative to conventional techniques and also as a complement to results obtained from conventional Culture method.
Agricultural activity involves direct interaction with the physical environment factors in the environmental context in which the activity is developed. Galicia, northwest Spain, is an environmentally heterogeneous region that encompasses territorial spaces with different levels Of Suitability for each agricultural activity. In barely 30 years, the production systems of the region have evolved from Self-sufficiency to commercial production; however, the requirements of production for each differ greatly. During Such a transformation, many farms have disappeared while other farms have conformed to the requirements of the Current production systems without changing location. Decision-making in rural planning requires knowing the spatial distribution of farms, the evolution of farm distribution and the relationship between the spatial location of farms (associated with some specific environmental characteristics) and the production systems used. The current paper describes a methodology for analysing the spatial distribution of farms and for determining the relationships between the spatial location of farms and the values of the physical environment factors that are characteristic of each spatial location. The methodology has been developed by using Agricultural Census data and is exemplified through the analysis of two crops (wheat and potato) and one farming activity (dairy farming). Results show the location of farms and the production systems used, and reveal different degrees of fit to the physical environment factors considered.
The aim of the Current study was to determine how cooling and Supplemental recombinant bovine somatotropin (rbST) affect body function with respect to digestion kinetics, digestibility and other variables relevant to milk production in cross-bred Holstein cattle. Ten primiparous cross-bred dairy cattle (0.875 Holstein Friesian x 0.125 Red Shindi) were used and divided into two groups of five animals each that were housed in a normal shaded barn (NS barn; non-cooled cows) and in,I shaded barn with mist-fan cooling (M F; cooled cows). The cows in each group were supplemented with rbST in early, mid and late stages of lactation with three consecutive subcutaneous injections of 500 mg rbST every 14 days. All cows were red the same total mixed ration twice daily at approximately 1.1 of assumed ad libitum intake and water was offered ad libitum. During the experimental periods, values of ambient temperatures and temperature humidity index (THI) in the NS barn were significantly higher than in the MF barn, whereas the relative humidity in the MF barn was significantly higher than in the NS barn (P<0.01). The respiration rate and rectal temperature were significantly higher for non-cooled cows than for cooled cows during the daytime whether there was or was not rbST supplementation. Supplementation of rbST for either cooled or non-cooled cows significantly increased dry matter intake (DMI), the efficiency of feed utilization and milk yields (P<0.05), Digesta kinetics using chromic oxide as an external marker showed I high digesta passage rate constant and low mean retention time of digesta in cows either by cooling or Supplementation of rbST, whereas no changes were seen for the digestibility of dry matter (DM), organic matter (OM), crude protein (CP), neutral detergent fibre (NDF) and acid detergent fibre (ADF). The half-time of Cr2O3 in the whole digestive tract of cooled cows was lower than those of non-cooled cows and significantly decreased (P<0.05) during rbST supplementation in both groups in all stages of lactation. The magnitude of responses for the digesta passage rate and efficiency of feed utilization were larger in animals supplemented with rbST than in animals under MF cooling only. The main effect of cooling and supplemental rbST was to improve digestion by an increase in the rate of passage of digesta and in turn an increase in feed intake. Digestibility was not influenced by changes in passage rate of digesta either by cooling or rbST supplementation. Milk production in response to rbST supplementation is probably enhanced with cooling. The increased milk production induced by rbST supplementation was mediated by increased efficiency of feed utilization without changes in diet digestibility.
This group, which represents the reformed Operational Research (OR) Society's Agriculture and Related Industries group (http://www.orsoc.org.uk), promotes the use of OR (or the application of the scientific method) in solving management and governance problems within this sector. The theme of this meeting was to look at models concerned with making better decisions for the management or governance of the agricultural and natural resource industries. This first one day meeting was at Reading University, Berkshire, UK on the 2 April when the following papers were read. [PUBLICATION ABSTRACT
SUMMARY Six pairs of isogenic lines of sorghum (Sorghum bicolor L. Moench) were sown in field plots in Montecillo, State of México (2240 m altitude), in 2005 and 2006. Crosses A ([female])xB ([male]) were done in each pair. In A-lines, the length of pistil, stigma, style and ovary, as well as the ovary width, were measured. In B-lines, pollen diameter, viability (cytoplasm density) and production were evaluated. Pollen germination and pollen tube growth in the pistils of the A-lines, were quantified in vivo with aniline blue and epifluorescence 18 h after pollination (HAP), while fertilized pistils were counted at 96 HAP. Histological studies on both pollinated and non-pollinated pistils were performed in one male-sterile line. Seed yield, mean-seed weight, seeds per panicle and seed set (SS; seeds/flower/panicle) were determined at harvest. Pollen viability was the variable most related to pollen germination and pollen tube growth. Stigma receptivity was not associated with its morphology. Growth of the pollen tube in stigma, style and ovary was observed in the transmitting tissue 18 HAP, running parallel to the vascular tissue. Yield under chilling field temperatures (minimum average of 6 and 8°C) prevailing during flower development and pollination ranged from 7 to 12 g/panicle. The differences in seed production and SS among AxB crosses did not depend on the amount and viability of pollen. [PUBLICATION ABSTRACT