Feed supplementation improves estrus response and increases fertility of sheep induced to breed out of season

Tropical Animal Health and Production - To test the efficacy on reproductive performance of nutritional supplementation in an out-of-season mating system, 66 adult prolific Barbarine ewes were...     

Reproductive response of fat‐tailed Barbarine ewes subjected to short‐term nutritional treatments including spineless cactus (Opuntia ficus‐indica f. inermis) cladodes

Reproductive outputs in fat‐tailed Barbarine sheep in central Tunisia are often low because of feed shortage and the low nutritive value of diets. Supplementation with conventional concentrates is economically unsuitable in central Tunisia, so more cost‐effective and sustainable alternative feeding strategies need to be developed. We tested effects of short‐term nutritional treatments including cactus cladodes during the induction of ‘male effect’ on fertility and prolificacy parameters (follicular growth, ovulatory response and early embryo losses). One hundred and twenty ewes were distributed in 4 equal groups balanced for live weight grazed natural pastures and were supplemented for 21 days, starting day 10 after introduction of rams, with cactus cladodes (CA), cactus cladodes and soybean meal (CAS), concentrate (CC) or only soybean meal (S). Nutritional treatment did not affect live weight in this experiment. Ewes receiving cactus had higher number of large pre‐ovulatory follicles (≥6 mm; 1.08 ± 0.05), between days 14 and 19 after introduction of rams, than females in the CC and S ewes (0.64 ± 0.06; p < 0.05). However, there were no differences in the onset of oestrous behaviour in response to ‘male effect’ or in the number of corpora lutea. Average ovulation rates were 1.42 ± 0.16 for CC, 1.47 ± 0.13 for CAS, 1.31 ± 0.15 for CA and 1.31 ± 0.13 for S groups respectively. Finally, reproductive wastages at day 35 after mating were not different between groups being 0.33 ± 0.19 for CC, 0.60 ± 0.17 for CAS, 0.43 ± 0.16 for CA and 0.31 ± 0.15 for S groups respectively. It is concluded that Barbarine ewes fed nutritional treatments including cactus performed similarly to those receiving diets including conventional concentrate feeds.     

围封对藏北高寒草原土壤矿质元素和群落特征的影响

围栏封育是退化草地生态恢复的常见措施之一.土壤矿质元素含量影响植物个体生长发育和群落结构功能演替.为评价围栏封育对高寒草原土壤矿质元素和植物群落特征的影响,本研究于2010–2013年夏季对班戈县北拉镇和普保镇2块样地(围栏内外)进行植物和土壤采样,测定群落水平植物物种多样性、地上生物量以及表层土壤Ca、Cu、Fe、M...     

Regional and maturational effects on essential oils yields and composition of coriander (Coriandrum sativum L.) fruits

The composition of volatile components of the essential oils extracted from fruits of coriander (Coriandrum sativum L.) growing in two different Tunisian regions in both Menzel Temime and Borj El Ifaa was studied by GC and GC–MS. The highest oil yields were observed at final stages of maturity: 0.324 ± 0.09% and 0.327 ± 0.08%, in Menzel Temime and Borj El Ifaa, respectively. Essential oil yields were highly (P < 0.001) affected by the growing region, stages of maturity and their interaction. Essential oil composition changed significantly (P < 0.05) among the different stages of maturity and growing region. Linalool and geranyl acetate were the main compounds at full fruit maturity in the two studied regions. Growing region, stages of maturity and their interaction had a strong effect (P < 0.001) on 35 compounds. α-Pinene, sabinene, limonene, γ-terpinene, cis-dihydrocarvone and geranial were insensible to the regional factor.     

Response to drought of two olive tree cultivars (cv Koroneki and Meski)

The effect of water deprivation on plant water status, photosynthetic gas exchange and fluorescence parameters in two different olive tree varieties (Olea europaea L. var. ‘koroneiki’, ‘Meski’) was studied. Two-year-old olive trees, grown in pots in greenhouse, were subjected to one of three drought treatments (i.e., mild, moderate and severe drought stress) and compared to control trees. Both the leaf water potential (Ψ_w) and the relative water content (RWC) of the two varieties decreased with increasing levels of drought stress. Koroneiki showed higher (less negative) values of Ψ_w and lower values of RWC than the Meski, particularly during severe drought stress.

Net photosynthetic assimilation and stomatal conductance declined with drought. This inactivation of photosynthetic activity was accompanied by changes in the fluorescence characteristics. The PSII maximal photochemical efficiency (F_v/F_m), the intrinsic efficiency of open PSII reaction centres (F_v′/F_m′), the photochemical efficiency of PSII (Φ_PSII) and the total electron flow (J_t) decreased during the development of drought stress.

The non-quenching photochimique (q_N) showed an increase in the response to water deficit. These observations are discussed in relation to the strategies developed to grow drought-resistant olive trees in arid areas.     

Comparison of three pea cultivars (Pisum sativum) regarding their responses to direct and bicarbonate-induced iron deficiency

The aim of this work was to explore leaf characteristics underlining the difference in the sensitivity of pea cultivars (cv. Kelvedon, Douce and Lincoln) to Fe deficiency. Plants were grown in a greenhouse under controlled conditions in continuously aerated solution. Three treatments were used: 30 μM Fe (+Fe), 0 μM Fe (−Fe); direct deficiency and 30 μM Fe + 10 mM NaHCO₃ (+Fe+Bic); indirect deficiency for 12 days. Growth parameters, iron status, potassium content, chlorophyll fluorescence and photosynthetic capacity were studied. Our results showed that Fe deficiency led to a significant decrease of chlorophyll index (SPAD readings) and bivalent iron content in all Pisum sativum cultivars. The lower reduction was observed in Fe-deficient plants of Kelvedon and Douce. In addition, shoot length and whole plant dry weight were not affected by Fe deficiency in the latter cultivars. Both tolerant cultivars showed higher accumulation of potassium content in their leaves compared with the sensitive one. Moreover, both chlorophyll fluorescence ratios (F_v/F_m and F_v/F₀) were significantly decreased in all cultivars under both Fe deficiency treatments. The photosynthetic electron transport activity was reduced in the sensitive cultivar, especially in the absence of iron. The adverse effect of bicarbonate-induced Fe deficiency on the above mentioned parameters were more pronounced than that of the direct one. The capacity of both tolerant cultivars to preserve adequate chlorophyll synthesis, photosynthetic capacity and plant growth under iron-limiting conditions is related to the suitable nutrition of their leaves in ferrous iron, due to (at least partially) their higher potassium content.     

Chemometric Multivariate Analyses of Kernel Biometric Techniques and Shell Morphological Attributes for Analyzing Pistacia vera L. Genotypes Variability

In this study, the corresponding correlations, interdependencies, and relationships of nine traits of pistachio (Pistacia vera L.) kernels were established. Here, the percentage of dehiscent shells, shell homogeneity, shell apex, position of suture opening, suture opening, number of pistachio kernels/100?g, (length/width) pistachio kernel ratio, pistachio kernel flavour and fat content of pistachio kernel were studied.

The evaluation of experimental data was performed by applying a chemometric approach: Principal Component Analysis (PCA), Bayesian Networks method and Network Meta-Analysis. In this regard, based on PCA the first principal component of shell and kernel had high loadings for shell homogeneity. By using Bayesian Networks method, dendrogram of selected pistachio varieties demonstrate a high similitude existing between varieties. Furthermore, the of shell and kernel dendrogram of studied pistachio varieties demonstrated that all studied accessions could be separated into four distinct groups. Based on cluster analysis, a detailed comparison between the varieties demonstrated that the accession named ‘KERMAN’ showed a significant similarity with the Tunisian genotype ‘ELGUETAR’. In this line, Network Meta-Analysis exhibited the different interdependencies between morphological parameters, and the hierarchical clustering via heat maps displayed relationships between studied factors.

These results showed a potential use of desired characteristics at least in some infra-specific studies in Pistacia vera L. The findings of this study will help plant growers by highlighting hidden and eventual relationships between Pistacia vera L. varieties.

     

Ultrahigh strength in nanocrystalline materials under shock loading

Molecular dynamics simulations of nanocrystalline copper under shock loading show an unexpected ultrahigh strength behind the shock front, with values up to twice those at low pressure. Partial and perfect dislocations, twinning, and debris from dislocation interactions are found behind the shock front. Results are interpreted in terms of the pressure dependence of both deformation mechanisms active at these grain sizes, namely dislocation-based plasticity and grain boundary sliding. These simulations, together with new shock experiments on nanocrystalline nickel, raise the possibility of achieving ultrahard materials during and after shock loading.