Scientific Journals of INIA (Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria)
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Short communication: Genetic parameters for post-weaning visual scores and reproductive traits in Suffolk sheep
Get PDF The aim of this study was to estimate the coefficients of heritability and genetic correlations among visual scores (conformation, CPW; precocity, PPW; musculature, MPW) and reproductive traits: age at first lambing (AFL) and scrotal circumference (SC) evaluated at 180 days of age in Suffolk lambs. In the statistical model only the additive genetic effect was considered as random effect. The heritability estimates by univariate analyses for CPW, PPW, MPW, AFL and SC were 0.08, 0.12, 0.09, 0.20 and 0.22, respectively. The genetic correlations among AFL and CPW, PPW, MPW were -0.26, 0.19, and 0.08, respectively. The genetic correlation among SC and CPW, PPW, MPW were, respectively, 0.54, 0.88 and 0.86, and between AFL and SC was 0.26. The direct selection for conformation, precocity and musculature at 180 days of age and age at first lambing will provide slow genetic progress due to low heritability estimates. It is possible to obtain genetic gain in sexual precocity through selection on scrotal circumference in Suffolk rams. The favorable genetic correlation among visual scores and SC and between CPW and AFL, indicated the possibility to gain in genetic progress for reproductive traits through indirect selection of the visual scores in Suffolk sheep
Short communication: The main factors affecting somatic cell count in organic dairy farming
Get PDFPreventive management practices are essential for maintaining acceptable udder health status, especially in organic farming, in which the use of antimicrobials is restricted. The contribution of the following factors to somatic cell count (SCC) was assessed in 788 cows from 15 organically reared herds in northern Spain: milk production, lactation number, treatments applied, selective dry cow therapy and teat dipping routines. The data were examined by linear logistic regression. Lactation number was the main factor affecting logSCC (β= 0.339, p<0.001) followed in order of importance by milk production (β= -0.205, p<0.001), use of alternative treatments (β=0.153, p<0.001), selective dry cow therapy (β=0.120, p=0.005) and teat dipping routines (β=-0.076, p=0.028). However, the model only explained 17.0% of the total variation in SCC. This variable depends on factors other than those considered here, amongst which udder infection is probably one of the most important. Nonetheless, the study findings enabled us to determine the contribution of the main management factors that should be taken into account to improve udder health status on organic farms
Multi-criteria decision-making model in the strategic planning of table egg production in the Republic of Croatia
Get PDFUntil 2012, egg production in Croatia was mostly in cages, which was not in accordance with the European Union standards on the welfare of laying hens. Therefore, producers of table eggs could not continue their current practice and had to use those systems permitted in the EU member countries, such as organic, free-range, indoor or enriched cages. The aim of this study was to analyse and evaluate various systems of table-egg production using a method of multi-criteria analysis called the Analytic Hierarchy Process (AHP). Thus, the aim was to determine scientifically which production system was the favoured option for the Croatian poultry sector. According to the results, production of eggs using an indoor system for housing hens was the best option (priority 0.317). This was followed by a free-range system (priority 0.242). The third-ranked alternative egg production system was in cages (priority 0.237), while the fourth and the least acceptable alternative refers to egg production according to organic principles (priority 0.202). Based on the results of the multi-criteria analysis and respecting the worldwide trends that reflect changes in consumers’ habits and their concerns for food safety and quality, as well as their preference for local markets and local products, it is recommended that eggs be produced in an indoor system of keeping laying hens. In this sense, egg production on small farms provides the possibility of self-employment and creation of additional income to contribute towards overall economic and social development of rural areas
Non-phytate phosphorus requirement for male broilers subjected to two calcium supply regimens from 8 to 21 days of age under thermoneutral environment conditions
Get PDFThe purpose of this study was to determine the non-phytate phosphorus (nPP) requirement for male broiler subjected to two calcium supply regimens from 8 to 21 d of age, based on performance and bone mineralization. Birds were distributed in a complete randomized 4 × 2 factorial design with four nPP concentrations: 0.25, 0.35, 0.45 and 0.55%, and two Ca supply regimens: Ca fixed at 9.0 g/kg of diet (CaF) or varying together with the nPP concentrations tested keeping a fixed Ca:nPP ratio (CaV), with 8 battery cages/treatment and 9 birds/battery cage. Feed intake (FI), body weight gain (BWG) and Ca:P ratio deposited in the dry defatted tibia (TibCa:TibP) were quadraticaly increased by the increasing nPP concentrations, regardless of the Ca supply regimen adopted (p<0.01). The nPP levels tested also influenced FCR and TibAsh, which presented a quadratic and linear response when CaF and CaV diets were used, respectively, and TibP and TibCa, which presented a quadratic response with both Ca supply regimen, CaF and CaV diets. Also, CaV diets provided a 2.86 and 5.02% higher FCR (p<0.05) and TibCa (p<0.01), respectively, when compared to CaF diets. Therefore, nPP nutritional requirement for male broilers reared at thermoneutral conditions from 8 to 21 d of age that provided better performance and bone mineralization were, respectively, 0.480 and 0.459% with CaF and 0.550% with CaV diets, indicating that, under thermoneutral conditions, CaV diets negatively affected growth performance of broilers, while positively affecting bone mineralization especially when low nPP levels are applied
Evaluation of a local goat population for fertility traits aiming at the improvement of its economic sustainability through genetic selection
Get PDFThe study aims to determine the environmental and genetic components for the reproductive performance of a Tunisian local goat population to set up the basis for the future improvement of this important component of efficient production. The reproductive traits considered were kidding interval (KI) and litter size at birth (LSB). Records of 462 kiddings belonging to 185 dams and 11 sires were collected over a period of 22 years in the caprine herd of the Arid Areas Institute of Médenine. Significance of environmental effects was tested with ANOVA techniques. Genetic parameters were estimated using restricted maximum likelihood fitting an animal mixed model. Mean KI and LSB were 13.85 ± 5.20 months and 1.33 ± 0.49 kids, respectively. The effect of parity number and the interaction between year and month of kidding were significant for LSB and KI. Trait LSB increased with parity number up to the fifth parity while KI decreased with parity number indicating that young females show compromised reproductive performance probably because of growth requirements and scarcity of food resources. A detrimental effect for kiddings occurring during winter (matings in summer) was observed from estimates of the year by month of kidding effect. Heritability estimates for KI and LSB were 0.13 and 0.08, respectively. A moderate repeatability estimate of 0.31 was obtained for LSB while 0.17 was obtained for KI. The low estimates of heritability obtained for reproductive traits indicated that accurate selection based on the doe’s own performance will require large amounts of data. However, the estimated genetic variability was substantial, providing the grounds for the genetic improvement of the reproductive parameters in this population
A biotic strategy to sequester carbon in the ornamental containerized bedding plant production: A review
Get PDFIdentifying options of climate change mitigation is of global interest to researchers. Whereas wide range of techniques of reducing greenhouse gas (GHG) emissions and carbon sequestration have been studied in row crops and forest systems, little research has been done on the ornamental horticulture. The ornamental industrial sector has indeed some negative impacts on the global environment, but also presents opportunities to reduce GHG emissions and increase C sequestration. Thus the objective of this study was to synthesize the potential contributions of some substrates used in the horticultural sector to carbon sequestration. The specific focus of the review is on the possible use of compost, vermicompost and biochar as soilless substrate substitutes for containerized ornamental plants production. Around 11 million kilograms of sphagnum peat moss are used annually in the world for horticultural production. Therefore, the potential of using compost, vermicompost and biochar as growing media is assessed on the basis of data from greenhouse studies. Peat-based substrate can be substituted up to 30% to 35% by compost or vermicompost and up to 20% to 25% by biochar. Some examples from field studies are included to conduct the life cycle assessment of using these growth media. An estimate of C storage on the long-term basis in soil indicates up to 3 million tons of CO2 equivalent as the maximum C potential storage per year in the global productive sector if the peat-based growing media are substituted by compost/vermicompost and biochar at the ratios mentioned above. Finally, synergies between compost vermicompost and biochar are discussed when these materials are combined as growing media additives and research gaps in this area of activity have been identified for further research
