Amino acid profiles of muscle and liver tissues of Australian Merino,Damara and Dorper lambs under restricted feeding

Seasonal weight loss (SWL) is a major constraint in extensive animal production systems in the tropics and Mediterranean. The objective of this study was to characterize the amino acid profile of muscle and hepatic tissues of Australian Merino, Damara and Dorper lambs under restricted feeding to evaluate the impact of SWL at the metabolic and physiological levels. SWL induced generalized muscle protein breakdown among restricted groups of all breeds, with varying intensity. Dorper breed mobilized less muscle amino acids when under these conditions, with the Damara having frequent significant differences, namely by having lower amino acid concentrations in the muscle of restricted lambs. Damara lambs showed greater ability to catabolize branched‐chain amino acids in the muscle tissue, which indicates yet another mechanism that provides the Damara with the necessary tools to endure harsh conditions. Overall, the Damara breed mobilized more muscle amino acids than the other breeds, with a better capacity to catabolize branched‐chain amino acids in the muscle, while maintaining muscle structural integrity.     

Wetting agent effect on physical properties of new and reused rockwool and coconut coir waste

Wettability of growing medium in horticulture is an important practical factor of this industry. With a proper choice and a right application, wetting agent in the nutrient solution would improve wettability and some other physical properties of growing media. The aim of this study was to evaluate the effects on some physical properties of new and reused rockwool and coconut coir dust substrates with different doses of wetting agent (2, 10, 20, 100, 200, 1000, 2000, 10,000 and 20,000 mg L⁻¹) applied to the nutrient solution and their effects measured by using bioassays. The wetting agent was ether poly-ethylene-glycol nonil-phenol with 20% (w/v) as an active ingredient of a non-ionic surfactant. Bioassay results showed differences among species. For this, the method can be suggested as a good tool to be utilized through fertigation in soilless crops; however, other studies should be proposed for each species in particular. Except to the 2 mg L⁻¹ wetting agent content in reused coir waste, the total water-holding capacity increased with the wetting agent. With 2 mg L⁻¹ wetting agent content there was an important and significant increase the easily available water (over 600%) in both substrates (including the reused ones), while higher doses show no significant differences. The effect of adjuvants added through fertigation is directly dependant on the substrate type evaluated. The substrate reutilized after one crop, reduces the air capacity and increases the easily available water and total water-holding capacity. 2 mg L⁻¹ is the wetting agent concentration more adequate in coir waste and rockwool.     

Effects of Heating Nutrient Solution on Water and Mineral Uptake and Early Yield of Two Cucurbits under Soilless Culture

Root temperature may affect the production of greenhouse vegetables under soilless culture. Four independent experiments were carried out over two consecutive crop cycles using two different substrates: rockwool and coconut coir waste. Three heating treatments were applied: non heating (T0), nutrient solution at 12–16°C (T1), and at 18–22°C (T2). The experiments were carried out in greenhouses in Almería (SE Spain) on cucumber and melon. Mean substrate and air temperature were not affected by the treatments. Under conditions of nutrient solution heating EC and percentage of drainage volume decreased, while water and mineral nutrient absorption increased. However, results showed great differences between both crops and substrates. A significant decrease in nitrate and phosphate emission from the substrates was also recorded, especially in rockwool substrate. Few effects were observed concerning yield and fruit quality parameters, but in rockwool-grown melon early yield was enhanced. It follows that nutrient solution heating is a low-cost and environmentally friendly method of increasing early melon yield.     

Estrus induction in anestrous mixed-breed goats using the “female-to-female effect”

A trial was conducted during the anestrous period in female goats to determine: (a) whether estrus can be induced in anestrous goats by administration of equine chorionic gonadotropic hormone (eCG) and PGF_2α under pen conditions and (b) whether these sexually active female goats can elicit sexual arousal in sexually inactive bucks. One hundred and fifteen pluriparous, nonlactating mixed-breed female goats were randomly assigned to one of four treatment groups: (1) administration of a single dose of 240 IU of eCG, 50 μg PGF_2α i.m., and 25 mg progesterone (P₄) (eCG; n?=?30); (2) administration of P₄ and exposure to female goats treated with eCG–PGF_2α (P₄; n?=?39); (3) administration of 0.5 ml saline and P₄ (Sal; n?=?23); and (4) P₄ plus exposure to female goats treated with saline (Con; n?=?23). After hormone administration, all goats were put together with adult sexually inactive bucks for 15 days. The percentage of goats in estrus during these 15 days was similar in eCG-treated animals and untreated animals exposed to the eCG animals (97 and 95 %). Pregnancy rate was also similar (63 vs. 64 %) between these two groups. eCG-treated goats exhibited estrus earlier (P?<?0.05) than the treated goats in contact with the eCG goats. Furthermore, eCG-treated goats had larger litters (1.9?±?0.2 vs. 1.6?±?0.1, P?<?0.05) than the untreated goats in contact with the eCG goats. These results show that fertile estrus can be induced in anestrous female goats by exposing them to female goats induced to estrus with eCG. This female–female interaction triggers the stimulation cycle leading to the sexual arousal of bucks.     

Effect of the type of silage on milk yield,intake and rumen metabolism of dairy cows grazing swards with low herbage mass

The aim of this study was to evaluate the effect of herbage allowance (HA) and type of silage supplemented (TS) on milk yield, dry matter intake (DMI) and metabolism of dairy cows in early lactation. Thirty‐six Holstein‐Friesian dairy cows were allocated to four treatments derived from an arrangement of two HA (LHA = 17 or HHA = 25 kg of DM/cow/day) and two TS (grass (GS) or maize (MS)). Herbage allowance had no effect on DMI or milk yield. Rumen pH and NH₃‐N concentration were not affected by HA. The efficiency of microbial protein synthesis in the rumen (microbial protein (MP)) was affected by HA with 21.5 and 23.9 g microbial nitrogen per kg ruminal digestible organic matter for LHA and HHA, respectively (P < 0.05). Supplementation with MS showed higher values of milk yield by 2.4 kg/cow/day (P < 0.001), milk protein content by 0.10 % (P < 0.023) and herbage DMI by 2.2 kg/cow/day, and showed lower values for milk urea compared to GS (P < 0.001). The former results suggest that TS had a greater effect on milk yield, total feed intake and energy intake than increase in herbage allowance; however, increase in HA had greater effects on MP than TS.     

Reproductive performance of seasonally anovular mixed‐bred dairy goats induced to ovulate with a combination of progesterone and eCG or estradiol

Adult goats (n = 32) were randomly assigned to one of four treatments (n = 8, each): (i) progesterone (P₄) + equine chorionic gonadotropin (eCG), treated with 25 mg progesterone intramuscularly (i.m.) + 250 IU eCG 24 h later; (ii) cronolone + eCG, treated with vaginal sponges ‐ 20 mg cronolone × 7 days + 250 IU eCG at pessary removal; (ii) P₄ + estradiol (E₂), treated with 25 mg progesterone i.m. + 1 mg estradiol 24 h later; (iv) cronolone + E₂, treated with vaginal sponges ‐ 20 mg cronolone × 7 days + 1 mg of estradiol i.m. at pessary removal. Goats were tested for estrus throughout the presence of a buck. Seven days prior and after treatment, an ovarian ultrasonographic scanning was performed to determine ovarian function and structures. An ultrasonographic pregnancy diagnosis was performed on day 30 post‐service. In all groups, 100% estrus response was observed within 96 h post‐treatment. While ovulation occurred in 100% of P₄ + eCG and cronolone + eCG treated goats, the other groups only depicted 50% ovulatory activity (P < 0.05). Pregnancy rate was higher (P <0.05) in the P₄ + eCG and cronolone + eCG groups (88 and 100%, respectively), compared with 38% in P₄ + E₂ and cronolone + E₂ groups. The best treatments were those in which eCG was applied. The P₄ + eCG treatment was a pessary‐free, cheaper and effective protocol to induce ovulation in goats during the seasonal anovulatory period.     

Can anthropogenic linear gaps increase plant abundance and diversity?

Context

Seed-dispersing animals often move along “linear gaps” (linear anthropogenic features such as roads and trails that contain little vegetation), especially in densely-vegetated landscapes. As a result, linear gaps and their verges may receive more seeds than adjacent habitats. In addition, linear gap verges may provide more suitable conditions for plant establishment than neighboring habitats. In this way, linear gaps may increase plant abundance and diversity, and facilitate connectivity of native and non-native plant populations, ultimately increasing plant diversity in the landscape.

Objectives

We reviewed current evidence for the potential of anthropogenic linear gaps to increase plant abundance and diversity, and for the mechanisms involved.

Methods

We reviewed peer-reviewed literature published up to December 31st, 2014.

Results

Most (69.2 %) studies found significantly higher plant abundance and/or diversity in linear gap verges than in adjacent habitats. This suggests that linear gaps can increase plant abundance and diversity, and possibly facilitate population spread. However, there was a strong bias toward the study of exotic species. In addition, there were few mechanistic studies to allow estimation of the relative contributions of dispersal and post-dispersal mechanisms operating in linear gaps.

Conclusions

Future studies should focus on entire plant communities, not just exotic species, and should allow identification of the mechanisms by which linear gaps increase plant abundance and diversity. With this knowledge in hand, we will be in a better position to understand whether the net benefit of linear gaps for plant diversity in general outweigh their facilitation of the spread of exotic species.

     

Evaluation through a simulation model of nutrient exports in fast-growing southern European pine stands in relation to thinning intensity and harvesting operations

The effects on nutrient exports of a range of thinning regimes for maritime pine and radiata pine plantations in northern Spain were simulated in this study. Growth models, tree biomass equations and nutrient concentration in tree fractions were used simultaneously to calculate the amounts of N, P, K, Ca and Mg removed and left in the logging residues for five thinning intensities, five site indexes and four harvesting scenarios for each species, considering the whole rotation. A more intense thinning regime decreases the total amount of nutrients exported and increases the proportion of nutrients returned to the soil before the clearfell, being a more progressive system of extracting nutrients from the ecosystem. A substantial amount of nutrients are located in the crown fractions and the bark, making desirable the harvesting of debarked logs. The results allow the calculation of fertilization needs to avoid the depletion of soil nutrient capital in a variety of silvicultural situations.     

Effects of Topography and Surface Soil Cover on Erosion for Mining Reclamation: The Experimental Spoil Heap at El Machorro Mine (Central Spain)

Mining reclamation tries to reduce environmental impacts, including accelerated runoff, erosion and sediment load in the nearby fluvial networks and their ecosystems. This study compares the effects of topography and surface soil cover on erosion on man‐made slopes coming from surface mining reclamation in Central Spain. Two topographic profiles, linear and concave, with two surface soil covers, subsoil and topsoil, were monitored for two hydrologic years. Sediment load, rill development and plant colonization from the four profiles were measured under field conditions. The results show that, in the case of this experiment, a thick and non‐compacted topsoil cover on a linear slope yielded less sediment than carbonate colluvium or topsoil cover on a concave slope. This study also shows that vegetation establishment, which plays an important role in erosion control, depends on topography. Plant cover was more widespread and more homogeneous on linear profiles with topsoil cover. On concave slopes, plant establishment was severely limited on the steepest upper part and favoured in the bottom. This study suggests that management of topography and surface soil cover should be approached systematically, taking three outcomes into consideration: (i) topsoil can lead to a successful mining reclamation regardless of topography, (ii) created concave slopes can lead to a successful mining reclamation and (iii) topography determines the vegetation colonization pattern. Copyright © 2013 John Wiley & Sons, Ltd.     

Flow and Sediment Connectivity in Semi‐arid Landscapes in SE Spain: Patterns and Controls

Much of the water and sediment fluxes in semi‐arid catchments are found to be highly concentrated in localized pathways. Identifying the location of these pathways in the landscape is important for management and restoration. Measures can then be targeted so as to minimize the potential for erosion and sediment flux along these pathways. A method of repeat field mapping of flow and sediment pathways suitable for Mediterranean catchments is presented. Several small catchments in Cárcavo basin, SE Spain, differing in topographic and land use characteristics, were monitored under several events. Morphometric properties of pathways were analysed and compared with rainfall characteristics. Number and length of pathways varied with rainfall characteristics and also antecedent conditions. In low rainfall events, runoff sources and main pathways were disconnected, but in a larger event, the network of pathways became fully connected. The pathway patterns showed that man‐made lines such as terrace embankments and tracks have a major influence on sediment connectivity. Micro‐topographic factors, soil moisture and the presence of vegetation are highly influential on pathways and the frequency of water and sediment fluxes. Runoff and erosion hotpots for the development of pathways were identified, which should be targeted for mitigation and restoration measures using vegetation. The relevance of local scale factors emphasizes the importance of repeat field observations to understand connectivity and pathways development in the landscape. Copyright © 2015 John Wiley & Sons, Ltd.