2.2.2. Chilean Journal (Ex- Agricultura Técnica)
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- Changes in the milk response to different herbage mass of dairy cattle in a tropical climate
Institución: Instituto de Investigaciones Agropecuarias
Serie Documental: Chilean Journal of Agricultural Research
N° Documento: v. 84(2) p. 225-235
Objetivos de desarrollo sostenible
The interaction between pasture and supplementation in dairy production systems constitutes a very important part of the efficiency of dairy. This study evaluated the effect of the herbage mass (HM) on the milk production and solid concentration. Twenty Holstein cows were distributed into two groups, 10 assigned 2200 kg DM ha-1 (low herbage mass, LHM) and 10 with 2800 kg DM ha-1 (medium herbage mass, MHM). Herbage mass was measured above 5 cm. The experiment lasted 8 wk. The variables evaluated were DM intake (DMI), milk production and composition (fat and protein concentration). Effects of treatments on variables were evaluated using a repeated measure analysis over time. The results showed nonsignificant differences in the pasture DMI between LHM and MHM for weeks 1, 2, 3 and 5 (P > 0.05). During week 4, pasture DMI was 3 kg greater for LHM than MHM (P < 0.05). The milk production did not differ between treatments per week, but the average was 2.4 kg greater for LHM compared to MHM (P < 0.05). In conclusion, changes in the pasture availability increased milk production at LHM, but not enough to cause changes in solids concentration. This clearly shows that, LHM can increase milk and solids production.Calvache, Iván, Beltran, Ignacio, Balocchi, Oscar, Venegas, Luz A., Navas, Alexander , (2024-04) - Citrus volatiles induced by herbivory of Aleurothrixus floccosus (Hemiptera: Aleyrodidae) elicit attraction to the exotic ladybird Clitostethus arcuatus (Coleoptera: Coccinellidae)
Autor: Rioja, Tommy; Ceballos, Ricardo
Institución: Instituto de Investigaciones Agropecuarias
Serie Documental: Chilean Journal of Agricultural Research
N° Documento: v. 84(2) p. 181-194
Objetivos de desarrollo sostenible
Plants undergoing insect infestation release herbivore-induced plant volatiles (HIPVs) into their environment, which are then used by natural enemies for their benefit. The pest Aleurothrixus floccosus, which affects citrus orchards in northern Chile, specifically at Pica Oasis, poses a year-round threat. Recently, the introduction of the exotic ladybird Clitostethus arcuatus has been noted as a predator of A. floccosus. This study delved into how HIPVs emitted from tangelo (Citrus reticulata × C. ×paradisi Macfad.) and lime (C. ×aurantifolia (Christm.) Swingle) infested-shoots impact the behavioral responses of C. arcuatus. The volatile compounds were collected using the headspace technique, revealing notable qualitative changes after herbivory. In two-choice bioassays, the HIPVs elicited an attractive response in C. arcuatus compared to A. floccosus. At concentrations of 10 and 100 μg mL-1, the predators displayed a distinct preference for methyl salicylate (MeSA). These findings underscore that C. arcuatus exploits the HIPVs emitted from citrus infested-shoots, fostering tritrophic interactions. Exploring the impact of whitefly attacks on other fruit trees, emerges as a significant avenue for future investigation.Rioja, Tommy, Ceballos, Ricardo , (2024-04) - Do root interactions between wheat and non-mycorrhizal ancestral plants influence fungal activity and soil quality in an Andisol?
Autor: Castillo, Claudia; Solano, Jaime; Aguilera, Paula; Sacha, Debouzy; Catalán, Rocío; Ruiz, Antonieta; Souza C., Pedro de; Sieverding, Ewald; Borie B., Fernando
Institución: Instituto de Investigaciones Agropecuarias
Serie Documental: Chilean Journal of Agricultural Research
N° Documento: v. 83(5) p. 589-601
Objetivos de desarrollo sostenible
Cover crops in sustainable agrosystems are becoming more and more applied. However, legacy effects on the growth of companion plants or following crops in rotation systems are still poorly understood, especially when Andean and ancestral crops are involved. In this work, two wheat (Triticum aestivum L.) cultivars differing in P efficiency (Kirón higher than Chevignon) were cropped together with two non-mycorrhizal plants, quinoa (Chenopodium quinoa Willd.) and amaranth (Amaranthus spp.), to study the interactions and the effects produced in the wheat rhizosphere, plant growth and mycorrhizal parameters at harvest. The plants were grown in a three-compartment plexiglass rhizobox containing an Andisol. The central compartment separated by a nylon mesh was used for the cover crops, and wheat was sown on each side. A habitual pre-crop rapeseed (Brassica napus L.), also non-mycorrhizal, was used as control. At harvest, soil (pH, available P, acid phosphatase, microbial-P), plant (phytomass, organic acid exudation, P uptake efficiency, Zn and Mn in shoots), and mycorrhizal properties (root colonization, glomalin, spore number, and hyphal density) were measured in both wheat rhizospheres. Results show that wheat cultivars differed in soil and plant characteristics affected by non-host plants being the most efficient one, better. Surprisingly, mycorrhizal propagules were not depressed, and even fungal spores with amaranth (10543 spores 100 g-1) increased 2.6-fold than control (3910 spores 100 g-1) in the P-efficient cultivar. Data obtained suggest being cautious in selecting the best wheat cultivar when using these ancestral crops, especially for wheat natives’ smallholders working in this type of soil.Castillo, Claudia, Solano, Jaime, Aguilera, Paula, Sacha, Debouzy, Catalán, Rocío, Ruiz, Antonieta, Souza C., Pedro de, Sieverding, Ewald, Borie B., Fernando , (2023-10) - Use of spent brewer’s yeasts as an additive of pasture silages and its effects on nutritional quality and pH
Autor: Daza C., José; González, Verónica; Moldenhauer, Rodrigo; Reyes S., Camila; Rivas, Jorge; Solís, Carolina; Muñoz, Francisco; Carvajal, Adriana; Saldivia, Viola; Urrejola, José Luis
Institución: Instituto de Investigaciones Agropecuarias
Serie Documental: Chilean Journal of Agricultural Research
N° Documento: v. 84(2) p. 260-266
Objetivos de desarrollo sostenible
Livestock systems at Region Aysén del General Carlos Ibáñez del Campo depend on forage conservation during the spring-summer season, generally with low nutritional quality to animal requirements. To reduce nutrient loss, additives are commonly used, being spent brewery yeast a potential additive. Therefore, a study was carried out with the inclusion of two spent brewer’s yeast (Lager and Ale) as an additive in pasture mini silos compared to two commercial additives (SiloSolve MC™ and Josilac grass™) and mini silo without additive. It was observed that spent brewer’s yeast has a negative effect on crude protein and metabolizable energy, contents that decreased to 9.8% and 2.5%, respectively, compared to control. However, Ale yeast declined faster and maintained lower pH levels below 4.1. Spent brewer’s yeast do not improve nutritional quality, however decreased pH levels of pasture silage. Therefore, it should be noted that the effect of spent brewer’s yeasts has been insufficiently evaluated. Thus, is still a lack of trials within large scale of silage conservation and its effects on animal feed performance.Daza C., José, González, Verónica, Moldenhauer, Rodrigo, Reyes S., Camila, Rivas, Jorge, Solís, Carolina, Muñoz, Francisco, Carvajal, Adriana, Saldivia, Viola, Urrejola, José Luis , (2024-04)