Use of sewage sludge in silvopastoral systems under Pinus radiata D. Don: soil,tree growth,and pasture production

Agroforestry Systems - Short-term production in silvopastoral systems is often limited due to inappropriate soil-fertility management. Sewage sludge fertilisation could enhance productivity of...     

Pigmentation, carotenoids, lipid peroxides and lipid composition of skin of red porgy (Pagrus pagrus) fed diets supplemented with different astaxanthin sources

A feeding experiment was carried out to determine the efficiency of different commercial sources, chemical forms and levels, of dietary astaxanthin, to appropriately pigment the red porgy (Pagrus pagrus) skin. According to this, total carotenoid content, profiles and chemical forms present in the skin were determined. In order to establish the potential for antioxidant protecting role of astaxanthin supplemented diets, peroxide levels and lipid composition of skin were also determined.

Red porgy alevins were fed six dietary treatments in triplicate; a basal diet (B) without carotenoids; two diets (N25 and N50) formulated to supply either 25 or 50 mg kg^− 1 of an esterified source of astaxanthin (Haematococcus pluvialis, NatuRose™); two diets (CP25 and CP50) with either 25 or 50 mg kg^− 1 of unesterified astaxanthin (Carophyll® Pink); and a positive control diet (B + S) proved as a successful pigmenting-diet in previous experiences (B + S, 88% basal diet:12% frozen shrimp) [Cejas, J., Almansa, E., Tejera, N., Jerez, S., Bolaños, A., Lorenzo, A., 2003. Effect of dietary supplementation with shrimp on skin pigmentation and lipid composition of red porgy (P. pagrus) alevins. Aquaculture 218, 457–469].

All fish fed carotenoid supplemented diets displayed a pink-coloured skin after 4 months of feeding in contrast to the greyish appearance displayed by fish fed the basal diet not supplemented with carotenoids (B). Furthermore, astaxanthin diesters were the major carotenoid in the skin of pink fish. A second carotenoid, tentatively identified as tunaxanthin diester, was also detected. The best results in terms of skin natural reddish hue, total carotenoid and astaxanthin contents were found by using the esterified forms of dietary astaxanthin (N25, N50 and B + S). Interestingly, the lowest levels of lipid peroxides were found in the fish fed these three treatments. However, no effect of treatment on lipid composition was found. In conclusion, red porgy alevins are able to efficiently utilise dietary natural or synthetic astaxanthin, and deposit this pigment in its esterified form to acquire an acceptable pink-coloured skin compared to that of the wild fish.     

Weight–length relationships of 33 demersal fish species from Azores archipelago

Weight–length relationships are presented for 33 fish species of Azores archipelago. This work is the first reference on weight–length parameters of 16 species. Samples were collected between the years of 1999 and 2003 using longline at depths ranging from a few meters to 1200 m. The parameters of a and b of the equation W = aL^b were estimated. The b values of the species caught ranged from 2.701 for Lepidopus caudatus to 3.677 for Centroscymnus crepidater. Whenever possible, the b values for the species obtained both in this study and some of the previously reported in the Portuguese waters were compared.     

Higher feeding diets effects on age and liveweight gain at puberty in crossbred Nelore × Hereford heifers

This study was conducted to determine the age and liveweight at puberty of 120 crossbred beef heifers submitted to four diets to achieve predetermined weight gains (kg/day): 0.5 (G500; n?=?32), 0.75 (G750; n?=?32), 1.0 (G1000; n?=?29), and 1.25 (G1250; n?=?27). Animals were classified depending on their level of crossing between Nelore (N) and Hereford (H): 25%N-75%H, 37.5%N-63.5%H, 43.7%N-56.7%H, 50%N-50%H, and 75%N-25%H. Reproductive evaluation was performed at the beginning and at the end of the experimental period by ultrasonography and hormone analysis. The average age and liveweight at puberty were 388.0?±?1.9 days and 331.4?±?1.3 kg, respectively. Animals from the 25%N-75%H group reached puberty earlier than heifers from other genetic groups supplemented with G1250 diet (P?<?0.05). Heifers with higher degree of Nelore (75%N-25%H) fed with G1000 diet showed estrus 42 days prior to mating, but only 57 % reached puberty at mating (P?<?0.05). Heifers with follicles of higher diameter reached puberty (P?<?0.05) earlier. Higher average daily weight gain showed a positive effect on follicular diameter and IGF-I level at puberty (P?<?0.01). Concentrations of GH were lower in heifers fed G1250 compared to G1000 diet (P?<?0.05). There was a significant interaction between nutritional level and insulin levels at puberty (P?<?0.01). We demonstrated the relationship between IGF-I and average daily gain on the onset of puberty in heifers. In conclusion, heifers submitted to the higher feeding level showed a higher follicular diameter and were younger at puberty.     

Evaluation in mice of Brucella ovis attenuated mutants for use as live vaccines against B. ovis infection

Brucella ovis causes ram contagious epididymitis, a disease for which a specific vaccine is lacking. Attenuated Brucella melitensis Rev 1, used as vaccine against ovine and caprine brucellosis caused by B. melitensis, is also considered the best vaccine available for the prophylaxis of B. ovis infection, but its use for this purpose has serious drawbacks. In this work, two previously characterized B. ovis attenuated mutants (Δomp25d and Δomp22) were evaluated in mice, in comparison with B. melitensis Rev 1, as vaccines against B. ovis. Similarities, but also significant differences, were found regarding the immune response induced by the three vaccines. Mice vaccinated with the B. ovis mutants developed anti-B. ovis antibodies in serum of the IgG₁, IgG_2a and IgG_2b subclasses and their levels were higher than those observed in Rev 1-vaccinated mice. After an antigen stimulus with B. ovis cells, splenocytes obtained from all vaccinated mice secreted similar levels of TNF-α and IL12(p40) and remarkably high amounts of IFN-γ, a crucial cytokine in protective immunity against other Brucella species. By contrast, IL-1α -an enhancer of T cell responses to antigen- was present at higher levels in mice vaccinated with the B. ovis mutants, while IL-10, an anti-inflammatory cytokine, was significantly more abundant in Rev 1-vaccinated mice. Additionally, the B. ovis mutants showed appropriate persistence, limited splenomegaly and protective efficacy against B. ovis similar to that observed with B. melitensis Rev 1. These characteristics encourage their evaluation in the natural host as homologous vaccines for the specific prophylaxis of B. ovis infection.     

Relationship of Progesterone,Bovine Pregnancy-Associated Glycoprotein-1 and Nitric Oxide with Late Embryonic and Early Fetal Mortalities in Dairy Cows

The aim of the present study was to determine the relationship of progesterone (P4), bovine pregnancy-associated glycoprotein-1 (bPAG-1) and nitric oxide (NO) levels with late embryonic (LEM; day 28 to day 42) and early fetal mortalities (EFM; > day 42 to day 56) in dairy cows. Transrectal ultrasonography (6–8 MHz) was performed in 100 Holstein-Friesian cows at days 28, 42 and 56 after artificial insemination (AI; day 0) to diagnose pregnancy and to monitor the fate of the embryo. After ultrasound scanning of each cow, a milk sample was collected for assessment of P4 by an ELISA test and a blood sample was collected for assessment of bPAG-1, by using a double-antibody radioimmunoassay, and serum NO metabolites (nitrate + nitrite). Based on ultrasonographic examinations and bPAG-1-RIA, 41 of 100 inseminated cows were confirmed pregnant at day 28 after AI. Nine cows suffered of LEM, and 6 cows suffered of EFM and the overall pregnancy loss rate was 36.6% (15/41) between days 28 and 56 of pregnancy. By logistic regression analysis, there were no significant relationships between the level of P4 and bPAG-1 at day 28 after AI and the occurrence of LEM and EFM. Also, there were no significant relationships between the levels of P4 and bPAG-1 at day 42 and the occurrence of EFM. On the other hand, a significant relationship (P<0.05) was found between NO level at day 28 and the occurrence of LEM. In conclusion, measurement of the serum NO concentration at day 28 of pregnancy might help to predict the outcome of pregnancy by day 42 in dairy cows but further studies are needed to confirm this.     

Hyaluronic Acid as Capacitation Inductor: Metabolic Changes and Membrane‐Associated Adenylate Cyclase Regulation

The aim of this research was to study the effect of hyaluronic acid on bovine cryopreserved spermatozoa compared with heparin as regards the variation of capacitation induction, cellular oxidative metabolism and intracellular signal induced by membrane‐associated adenylate cyclase to propose hyaluronic acid as a capacitation inductor. Heparin or hyaluronic acid and lysophosphatidylcholine were used to induce sperm capacitation and acrosome reaction, respectively. 2′,5′‐dideoxyadenosine was used as a membrane‐associated adenylate cyclase inhibitor. The highest percentages of capacitated spermatozoa and live spermatozoa with acrosome integrity were obtained by incubating sperm for 60 min using 1000 μg/ml hyaluronic acid. In these conditions, capacitation induced by hyaluronic acid was lower compared with heparin; nonetheless both glycosaminoglycans promote intracellular changes that allow true acrosome reaction in vitro induced by lysophosphatidylcholine in bovine spermatozoa. Oxygen consumption in heparin‐capacitated spermatozoa was significantly higher than in hyaluronic acid‐treated spermatozoa. With all treatments, mitochondrial coupling was observed when a specific uncoupler of the respiratory chain was added. The inhibition of membrane‐associated adenylate cyclase significantly blocked capacitation induction produced by hyaluronic acid, maintaining a basal sperm oxygen uptake in contrast to heparin effect in which both sperm parameters were inhibited, suggesting that the membrane‐associated adenylate cyclase activation is involved in the intracellular signal mechanisms induced by both capacitation inductors, but only regulates mitochondrial oxidative phosphorylation in heparin‐capacitated spermatozoa.     

MALDI‐MS Lipid Profiles of Oocytes Recovered by Ovum Pickup from Bos indicus and 1/2 indicus × taurus with High vs Low Oocyte Yields

The aim of the present study was to compare the lipid profile in oocytes of indicus and 1/2 indicus × taurus cows with high and low antral follicle count (AFC)/oocyte yields. After an OPU procedure (D0), antral follicles ≥3 mm were counted by ultrasonography (D4, 19, 34, 49, 64), and cows were assigned to groups with either high AFC (≥30 follicles; indicus, NH group; 1/2 indicus × taurus, AH group) or low AFC (≤15 antral follicles; indicus, NL group; 1/2 indicus × taurus, AL group). The lipid profiles of the oocytes were determined by MALDI‐MS. For GI, GII and GIII oocytes, the indicus samples tend to cluster separately from the 1/2 indicus × taurus samples. The lipid species [PC (P‐38:5) + H]⁺ and/or [PC (P‐36:2) + Na]⁺, [PC (38:2) + H]⁺, [PC (38:5) + Na]⁺ and [TAG (60:8) + NH⁴]⁺ were more abundant in indicus (NH and NL groups) than 1/2 indicus × taurus. The higher lipid content in the indicus oocytes likely reflects differences in the rate of lipid metabolism and may contribute to oocyte competence and embryo development.     

Content of plasmatic glycerol and activity of hepatic glycerol kinase in broiler chickens fed diets containing different sources and concentrations of glycerine

The objective of this study was to evaluate the effect of three sources of glycerine (crude glycerine from soya bean oil – CGSO, mixed crude glycerine from frying oil and lard – MCG, and a semipurified glycerine from soya bean oil – SPGSO) in four concentrations in the diet (17.5, 35.0, 52.5 and 70.0 g of each type of glycerine per kg of feed) on the levels of plasmatic glycerol and the activity of the hepatic enzyme glycerol kinase in broilers of 22–35 days old (experiment I) and 33–42 days old (experiment II). The highest (p < 0.05) plasmatic glycerol level was detected in broilers fed diet containing CGSO. Independent of the source, increasing the concentration of glycerine led to a linear increase (p < 0.05) in the plasmatic glycerol concentration. In experiment I, all the diets containing glycerine resulted in increased concentrations of plasmatic glycerol, in relation to the control diet without glycerine. However, in experiment II, only the diet containing 17.5 g of CGSO per kg of feed and the diets formulated with any of the three types of glycerine in the inclusion concentrations of 35, 52.5 and 70 g/kg of feed resulted in higher plasmatic glycerol levels than those observed in the control broilers. The source of glycerine influenced the glycerol kinase activity only in experiment II, where the use of CGSO in the diet increased the enzyme activity. For both experiments, the glycerol kinase activity increased with the inclusion of glycerine in the diet. In conclusion, based on the absence of saturation of the glycerol kinase activity for the three glycerine sources and for both rearing periods evaluated, the broilers can metabolize the glycerol (at the level of the phosphorylation of the glycerol to glycerol‐3‐phosphate in the liver) present in the glycerine when the diet is supplemented with up to 70 g of glycerine per kg of feed.     

Nitrogen fertilization of black walnut (Juglans nigra L.) during plantation establishment. Physiology of production

Physiological mechanisms by which nitrogen (N) fertilization affects growth and development in temperate deciduous forest trees are not clearly understood, especially under intensive silvicultural systems. Grafted, Tippecanoe 1 cultivar black walnut (Juglans nigra L.) trees were grown in an intensively managed plantation in west-central Spain and subjected to six, fixed-nutrient-ratio complete fertilizer treatments (defined as 0, 25, 50, 75, 150, and 300 g N tree^?1) delivered via daily fertigation. Leaf chemistry and morphology were evaluated from June to September, and gas exchange was measured in July. Specific leaf mass, leaflet nitrogen (N), and chlorophyll concentrations varied over the course of the growing season, yet consistently increased with increasing fertilization. Net photosynthesis at ambient (A _net) and light-saturated (A _max) conditions increased from the unfertilized control to lowest treatment (25 g N) but did not increase at higher fertilizer rates. Photosynthetic N and chlorophyll use efficiencies decreased with increasing fertilization, but photosynthetic phosphorus and water use efficiencies increased. Transpiration rates and dark respiration were not significantly affected by treatment. Overall, the lowest fertilizer treatment (25 g N) had the greatest photosynthetic efficiency. Interactions between N and other nutrients with increasing fertilizer application suggested potential for nutrient imbalances at high fertilization rates. Our results provide a physiological justification for the use of low-to-moderate fertilization as an efficient strategy to promote black walnut plantation establishment under intensive cultural systems.