scholarly journals Genetic parameters of growth traits and carcass weight of New Zealand white rabbits in a tropical dry forest area

2021 ◽  
Vol 8 (3) ◽  
pp. 471
Author(s):  
Donicer Vergara ◽  
Darwin Herrera ◽  
Naudin Lugo
Keyword(s):  
New Zealand ◽  
Genetic Parameters ◽  
Growth Traits ◽  
Tropical Dry Forest ◽  
Forest Area ◽  
Dry Forest ◽  
Carcass Weight ◽  
New Zealand White Rabbits

scholarly journals Estimates of (co)variance components and genetic parameters for body weights and growth efficiency traits in the New Zealand white rabbit

2017 ◽  
Vol 25 (4) ◽  
pp. 329 ◽  
Author(s):  
M. Sakthivel ◽  
D. Balasubramanyam ◽  
P. Kumarasamy ◽  
H. Gopi ◽  
A. Raja ◽  
...  
Keyword(s):  
Body Weight ◽  
New Zealand ◽  
Variance Components ◽  
Environmental Effect ◽  
Genetic Parameters ◽  
Growth Traits ◽  
Genetic Effect ◽  
Growth Efficiency ◽  
Body Weights ◽  
Heritability Estimates

The genetic parameters of growth traits in the New Zealand White rabbits kept at Sheep Breeding and Research Station, Sandynallah, The Nilgiris, India were estimated by partitioning the variance and covariance components. The (co)variance components of body weights at weaning (W42), post-weaning (W70) and marketing (W135) age and growth efficiency traits viz., average daily gain (ADG), relative growth rate (RGR) and Kleiber ratio (KR) estimated on a daily basis at different age intervals (42 to 70 d; 70 to 135 d and 42 to 135 d) from weaning to marketing were estimated by restricted maximum likelihood, fitting 6 animal models with various combinations of direct and maternal effects. Data were collected over a period of 15 yr (1998 to 2012). A log-likelihood ratio test was used to select the most appropriate univariate model for each trait, which was subsequently used in bivariate analysis. Heritability estimates for W42, W70 and W135 were 0.42±0.07, 0.40±0.08 and 0.27±0.07, respectively. Heritability estimates of growth efficiency traits were moderate to high (0.18 to 0.42). Of the total phenotypic variation, maternal genetic effect contributed 14 to 32% for early body weight traits (W42 and W70) and ADG1. The contribution of maternal permanent environmental effect varied from 6 to 18% for W42 and for all the growth efficiency traits except for KR2. Maternal permanent environmental effect on most of the growth efficiency traits was a carryover effect of maternal care during weaning. Direct maternal genetic correlations, for the traits in which maternal genetic effect was significant, were moderate to high in magnitude and negative in direction. Maternal effect declined as the age of the animal increased. The estimates of total heritability and maternal across year repeatability for growth traits were moderate and an optimum rate of genetic progress seems possible in the herd by mass selection. The genetic and phenotypic correlations among body weights and between growth efficiency traits were also estimated. Moderate to high heritability and higher genetic correlation in body weight traits promise good scope for genetic improvement provided measures are taken to keep the inbreeding at the lowest level.

Effects of hydric and light combined stresses on the morphological and plastic responses of Aspidosperma polyneuron Müll. Arg. Seedlings (Apocynaceae)

2021 ◽  
Author(s):  
Yelena S. Pájaro-Esquivia ◽  
Yamileth Domínguez-Haydar ◽  
Clara Tinoco-Ojanguren ◽  
Sergio E. Lozano-Baez ◽  
Mirko Castellini ◽  
...  
Keyword(s):  
Native Species ◽  
Growth Traits ◽  
Tropical Dry Forest ◽  
Field Capacity ◽  
Dry Forest ◽  
Plant Soil ◽  
Interdisciplinary Field ◽  
Light Gradient ◽  
Drought Conditions ◽  
Plastic Responses

<p>There is a lack of knowledge on the grow requirements for most endangered plant species in tropical ecosystems. The interdisciplinary field of the “critical zone” provides an opportunity to understand the plant-soil interactions, allowing the development of strategies for species propagation and restoration. Aspidosperma polyneuron is a Tropical Dry Forest native species, currently categorized as “endangered” in Colombia and the neotropics.  In this study, we evaluated the intrapopulation differences in the morphological and plastic responses of A. polyneuron seedlings along an experimental gradient of light and water. We collected seedlings from two locations of the same population at the department of Atlántico (Colombia) and exposed them to three levels of light (100, 55 and 10%) and two different levels of water (field capacity, 60% and dry conditions, 20%). We allowed these seeds to grow for six months in an experimental 3 x 2 x 2 m random factorial design. In addition, we measured 16 morphological and growth traits associated to their performance.<strong> </strong>Results showed that medium-light treatment produced the most favorable outcome when facing drought conditions, while low light aggravated negative performance effects when facing drought conditions. The seedlings origin was a significant factor influencing the morphological responses of most traits. Regarding plasticity, there were differences in the pattern and magnitude of the traits according to the locality they were collected from. The influence of water gradient prevailed over the light gradient in the phenotypic responses. The results showed differences in the response mechanism of the two groups of seedlings, indicating intrapopulation differentiation processes between both groups.</p>

Growth performance, carcass traits, behaviour and welfare of New Zealand White rabbits housed in different enriched cages

2017 ◽  
Vol 57 (8) ◽  
pp. 1759 ◽  
Author(s):  
Hesham Mohammed ◽  
Mohammed Nasr
Keyword(s):  
New Zealand ◽  
Feed Intake ◽  
Average Daily Gain ◽  
Carcass Traits ◽  
Carcass Weight ◽  
Control Group ◽  
Abnormal Behaviour ◽  
Total Weight Gain ◽  
New Zealand White Rabbits ◽  
Daily Gain

The present study investigated the effect of gnawing sticks as environmental enhancers on the performance, carcass traits and behaviour of individually housed growing rabbits. Two batches of weaned New Zealand White (NZW) rabbits were used, each consisting of 135 animals. Rabbits were homogeneously classified into the following three groups, each consisting of 45 rabbits: rabbits housed individually in cages without enrichment (control), rabbits housed individually in cages enriched with wooden sticks from apple tree and rabbits housed individually in cages enriched with wooden sticks from willow tree. Rabbits reared in enriched cages with apple or willow sticks showed a significantly (P < 0.0001) better performance (live bodyweight at slaughter 2526 and 2591 g, total weight gain 1620 and 1683 g, average daily gain 21.04 and 21.87 g and daily feed intake 78.57 and 74.89 g respectively), and had a higher carcass weight (1648.39 and 1750.26 g respectively, P < 0.0001) than did the control group. Rabbits in apple-stick group had a higher daily feed intake (78.57 g, P < 0.0001) and lower carcass weight (1648.39 g, P < 0.0001) than did those in the willow-stick group. The cortisol concentration was significantly (P < 0.0001) lower in apple and willow groups (9.44 ± 0.02 and 9.35 ± 0.02 nmol/L respectively) than in the control group (17.24 ± 0.03 nmol/L). Moreover, cage enrichment with apple or willow sticks improved the duration of feeding (7.08 and 7.39 min/3 h respectively, P < 0.0001) and drinking (2.54 and 2.67 min/3 h respectively, P < 0.0001) time, and reduced abnormal behaviour (biting the bars of the cage 0.24 and 0.34 min/3 h respectively, P = 0.001) when compared with the control group. Overall, the current results indicated that cage enrichment (with wooden sticks from apple or willow trees for gnawing) increased the final bodyweight and some carcass traits, reduced abnormal behaviour and potentially improved rabbit welfare during intensive rabbit breeding.

Germination and seedling growth of five tree species from tropical dry forest in relation to water stress: impact of seed size

2004 ◽  
Vol 20 (4) ◽  
pp. 385-396 ◽  
Author(s):  
Ekta Khurana ◽  
J. S. Singh
Keyword(s):  
Water Stress ◽  
Leaf Area ◽  
Seed Size ◽  
Seedling Growth ◽  
Tree Species ◽  
Growth Traits ◽  
Tropical Dry Forest ◽  
Dry Forest ◽  
Terminalia Arjuna ◽  
The Impact

The impact of seed size on germination and seedling growth, as affected by water stress, was studied for five tree species from tropical dry forest of India, viz. Albizia procera, Acacia nilotica, Phyllanthus emblica, Terminalia arjuna and Terminalia chebula. Germination tests were conducted under five osmotic potential levels. Seedlings from large (LS) and small (SS) seeds were grown at four soil moisture levels. Observations were made on height, leaf area, biomass and other growth traits such as relative growth rate (RGR), net assimilation rate (NAR), specific leaf area (SLA), and root:shoot (R:S) ratio. Seeds of pioneer species and large seeds, within species, germinated earlier, and with increasing water stress, per cent germination and germination velocity declined. RGR was inversely related with drought tolerance. R:S ratio increased, RGR and SLA declined, but NAR increased with water stress. Notwithstanding successional status, the slow-growing species registered minimum reduction in biomass due to water stress. The response of LS and SS seedlings also differed for some of the growth variables. Increase in NAR could be a compensatory response to water stress, and the marked allocational plasticity could help maximize capture of the limited resource. Seedlings from smaller seeds, particularly of fast-growing species, would be able to cope with mild drought by morphogenetic and physiological plastic response in a better way than those from large seeds. However, seedlings from large seeds had greater survival than those from smaller seeds under intense water stress.

scholarly journals GENETIC ASPECTS OF POST-WEANING FOR GROWTH TRAITS IN NEW ZEALAND WHITE RABBITS.

2017 ◽  
Vol 27 (2) ◽  
pp. 507-521
Author(s):  
Amira El-Deighadi ◽  
Ibrahim Ibrahim
Keyword(s):  
New Zealand ◽  
Growth Traits ◽  
New Zealand White Rabbits

scholarly journals Mapping soil carbon, particle-size fractions, and water retention in tropical dry forest in Brazil

2016 ◽  
Vol 51 (9) ◽  
pp. 1371-1385 ◽  
Author(s):  
Gustavo Mattos Vasques ◽  
Maurício Rizzato Coelho ◽  
Ricardo Oliveira Dart ◽  
Ronaldo Pereira Oliveira ◽  
Wenceslau Geraldes Teixeira
Keyword(s):  
Particle Size ◽  
Soil Properties ◽  
Ordinary Kriging ◽  
Water Retention ◽  
Tropical Dry Forest ◽  
Forest Area ◽  
Dry Forest ◽  
Organic Carbon Content ◽  
Size Fractions ◽  
Particle Size Fractions

Abstract The objective of this work was to compare ordinary kriging with regression kriging to map soil properties at different depths in a tropical dry forest area in Brazil. The 11 soil properties evaluated were: organic carbon content and stock; bulk density; clay, sand, and silt contents; cation exchange capacity; pH; water retention at field capacity and at permanent wilting point; and available water. Samples were taken from 327 sites at 0.0-0.10, 0.10-0.20, and 0.20-0.40-m depths, in a tropical dry forest area of 102 km2. Stepwise linear regression models for particle-size fractions and water retention properties had the best fit. Relief and parent material covariates were selected in 31 of the 33 models (11 properties at three depths) and vegetation covariates in 29 models. Based on external validation, ordinary kriging obtained higher accuracy for 21 out of 33 property x depth combinations, indicating that the inclusion of a linear trend model before kriging does not necessarily improve predictions. Therefore, for similar studies, the geostatistical methods employed should be compared on a case-by-case basis.

scholarly journals Effect of temporal variation in precipitation on the demography of four herbaceous populations in a tropical dry forest area in Northeastern Brazil

2015 ◽  
Vol 63 (4) ◽  
pp. 903 ◽  
Author(s):  
Kleber Andrade da Silva ◽  
Juliana Ramos de Andrade ◽  
Josiene Maria Falcão Fraga dos Santos ◽  
Clarissa Gomes Reis Lopes ◽  
Elba Maria Nogueira Ferraz ◽  
...  
Keyword(s):  
Temporal Variation ◽  
Tropical Dry Forest ◽  
Forest Area ◽  
Dry Forest ◽  
Northeastern Brazil ◽  
Modelo Lineal

En los bosques tropicales secos, la dinámica de las poblaciones herbáceas están fuertemente influenciadas por la variación estacional y anual de la precipitación total. Por otra parte, los acontecimientos presentes y pasados de anomalía climática (por ejemplo, años de sequía y lluvia errática antes de la temporada de crecimiento) pueden causar reducciones drásticas de tamaño de la población, lo que lleva a la desaparición temporal de algunas especies. Por lo tanto, este estudio tiene como objetivo evaluar, durante três años, la dinámica de <em>Delilia biflora</em> (Asteraceae), <em>Commelina obliqua</em> (Commelinaceae), <em>Phaseolus peduncularis</em> (Fabaceae) y <em>Euphorbia heterophylla</em> (Euphorbiaceae). El estudio se realizó en una zona de bosque seco tropical conocida como Caatinga, situado en la estación experimental del Instituto Agronómico de Pernambuco (IPA), en Caruaru, Pernambuco, Brasil. La Caatinga tiene un clima semiárido y fuerte variación estacional y anual de la precipitación total. Durante este estudio, hubo un evento de anomalía climática llamado la sequía de 2006 y la lluvia errática en la estación seca. El nacimiento, la muerte y la supervivencia fueron monitoreados mensualmente en 105 parcelas de 1 × 1 m. Las diferencias en densidad entre años y estaciones se evaluaron mediante la prueba de Kruskal-Wallis. El poder explicativo de la precipitación del presente y del pasado sobre la densidad se evaluó utilizando el Modelo Lineal Generalizado. En este estudio, fue el primer registro de <em>Euphorbia heterophylla</em> en el área de estudio. Las poblaciones estudiadas fueron mayores en los años más húmedos y durante la temporada de lluvias, y se redujeron drásticamente en el año más seco y en las estaciones secas. <em>Commelina obliqua</em> fue la menos sensible a la variación de la precipitación total. Con respecto a la densidad, las cuatro especies estuvieron presentes durante los tres años. Las tasas de natalidad fueron mayores durante la temporada de lluvias y las tasas de mortalidad fueron mayores en la estación seca. Lluvias esporádicas en la estación seca causado pronunciado reclutamiento de plántulas seguida de muerte y tuvo un fuerte impacto en la dinámica de <em>D. biflora</em>, <em>E. heterophylla</em> y <em>P. peduncularis</em>. La precipitación del año en curso explica entre el 3 % y 18 % de la variación interanual de la densidad y el poder explicativo de la precipitación del año anterior en la densidad de las poblaciones varió de 32 % a 67 %. Por lo tanto, los fenómenos climáticos del pasado también tienen una consecuencia significativa para las cuatro poblaciones. En conclusión, la drástica reducción de la precipitación total entre años podría ser un parámetro predictivo para el tamaño de la población de plantas herbáceas (en el momento presente y futuro) en una área de bosque tropical seco en el Noreste brasileño.

A Cytochemical Study of Glucose-6-Phosphatase (G-6-PASE) in Cells Participating in Atherogenesis of Rabbit Aorta

1975 ◽  
Vol 33 ◽  
pp. 460-461
Author(s):  
Sidney D. Kobernick ◽  
Edna A. Elfont ◽  
Neddra L. Brooks
Keyword(s):  
Lipid Metabolism ◽  
New Zealand ◽  
Aortic Wall ◽  
Rabbit Aorta ◽  
Plaque Formation ◽  
Metabolic Changes ◽  
Atherosclerotic Plaques ◽  
Cytochemical Study ◽  
Cellular Alteration ◽  
New Zealand White Rabbits

This cytochemical study was designed to investigate early metabolic changes in the aortic wall that might lead to or accompany development of atherosclerotic plaques in rabbits. The hypothesis that the primary cellular alteration leading to plaque formation might be due to changes in either carbohydrate or lipid metabolism led to histochemical studies that showed elevation of G-6-Pase in atherosclerotic plaques of rabbit aorta. This observation initiated the present investigation to determine how early in plaque formation and in which cells this change could be observed.Male New Zealand white rabbits of approximately 2000 kg consumed normal diets or diets containing 0.25 or 1.0 gm of cholesterol per day for 10, 50 and 90 days. Aortas were injected jin situ with glutaraldehyde fixative and dissected out. The plaques were identified, isolated, minced and fixed for not more than 10 minutes. Incubation and postfixation proceeded as described by Leskes and co-workers.

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