Scientific Journals of INIA (Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria)
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Comparison of growth performance and immune responses of broiler chicks reared under heat stress, cold stress and thermoneutral conditions
Get PDFThis study was conducted to compare the effects of thermal stress on growth performance and some immunity variables of broiler chickens. Birds were randomly assigned to one of three thermal treatments as follows: cold stress (CS, 12±1°C), (b) heat stress (HS, 33±3 °C) and (c) thermoneutral (TN, 24±2 °C). Body weight gain (BWG), feed intake (FI), water intake (WI) and feed conversion ratio (FCR) were recorded. In order to evaluate the primary and secondary humoral immune responses, two birds per replicate were intravenously administrated with a suspension of 7% sheep red blood cell (SRBC) at 28 and 35 days. The heat-stressed broiler chickens had lower FI (-14.90%), BWG (-25.71%) and higher FCR (+13.06%) in comparison to broiler chickens reared under TN condition (p<0.001) from 1 to 42 days of age. The cold-stressed broiler chickens showed lower FI (-22.05%), BWG (-38.32%) and higher FCR (+22.47%) in comparison to birds reared under TN conditions (p<0.001). Stressed birds (CS and HS) showed decreased antibody titer against SRBC, lymphocyte count and the relative weights of lymphoid organs and increased heterophil count, heterophil to lymphocyte ratio and the serum concentration of corticosterone, in comparison to birds in TN group (p<0.001). In conclusion, HS and CS conditions have similar negative effects on performance and immunity of broiler chickens
Sperm quality and seminal plasma proteins in three sheep breeds under high altitude and tropical conditions
Get PDFWe tested the hypothesis that sheep breed can influence the sperm quality and seminal plasma (SP) composition and investigated any potential relationship between SP proteins and antioxidant enzyme activities (AO) with sperm quality. Ejaculates from twelve rams of three breeds were obtained during the rainy season at high altitudes, and sperm quality was automatically evaluated (CASA-Hamilton Thorne). The AO of superoxide dismutase, glutathione peroxide and glutathione reductase (GR) in SP was evaluated and total proteins were separated by SDS-PAGE. Comparative analyses of semen quality parameters between breeds revealed that Creole and Hampshire breeds had a higher sperm quality compared with Romney Marsh (p<0.05), although no difference in AO was found. GR activity was negatively correlated (p<0.05) with several kinematic variables and positively (p<0.05) with morphological abnormalities. The highest SP protein concentration was found in semen collected from Hampshire males compared with that from Creole and Romney Marsh (p<0.05). SDS-PAGE analysis showed the presence of 32 protein bands in SP with molecular weights between 334 and 10 kDa. Differences (p<0.05) between breeds in bands of 43, 25, 22 and 20 kDa were observed. These results evidence a relationship between the protective effect of the antioxidant enzyme system in SP of three ram types under high altitude and tropical conditions and semen quality. Our findings also suggest that the identified proteins might play an important role in sperm physiology and quality
Short communication: The percentage of egg yolk in the freezing media affects mouflon (Ovis musimon) epididymal sperm cryosurvival
Get PDFSperm cryopreservation protocols are not well defined in many wild species such as the mouflon. The aim was to study the effect of different concentrations of EY on mouflon epididymal sperm cryosurvival. Samples were collected by the flushing method and cryopreserved by the conventional freezing technique in straws using a TEST (TES, Tris, glucose) 5% v/v glycerol medium containing either 6% v/v (n=16) or 12% v/v (n=13) clarified EY. The membrane integrity, acrosome integrity, motility, and morphological abnormalities were assessed in fresh and frozen/thawed samples. Fresh sperm quality parameters did not differ between groups except for the acrosome integrity that was lower in the TEST-6% EY than in the TEST-12% EY group (88.9 ± 2.1% vs 94.7 ± 0.8%). Membrane integrity (31.6 ± 4.6% vs 11.6 ± 4.5%), total motility (32.8 ± 4.6% vs 17.2 ± 5.6%), progressive motility (13.3 ± 2.7% vs 6.1 ± 2.9) were higher in frozen-thawed sperm with TEST-6% EY than with TEST-12% EY (p<0.05). Other motility parameters such as curvilinear velocity, straight-line velocity, average path velocity and amplitude of lateral head displacement were also higher (p<0.05) in frozen-thawed sperm with TEST-6% EY. Frozen-thawed acrosome integrity (85.1 ± 3.3% vs 91.9 ± 2.3) and morphological abnormalities (34.0 ± 3.7% vs 29.1 ± 3.6%) did not differ between extenders. In conclusion, high EY concentration had detrimental effects on post-thaw quality parameters, therefore the use of TEST based extender containing 6% EY is recommended for the cryopreservation of mouflon epididymal sperm
Silvopasture in the Caatinga biome of Brazil: A review of its ecology, management, and development opportunities
Get PDFAim of study: Silvopastoral system (SPS) involving numerous indigenous trees and shrubs is a traditional land-use system in the Caatinga, but it has little been studied scientifically. Given the importance of SPS as a sustainable land-use strategy in the drylands, this paper examines the attributes of the Caatinga SPS and their relevance to other arid and semiarid regions.Area of study: Caatinga biome, with an area of 0.9 million km2 and a population of 25 million, a unique dryland ecosystem of Brazil.Materials and methods: The paper reviewed the literature on the main characteristics of SPS management of the Caatinga biome and the global perspectives of silvopastoral land-management in semiarid regions.Main results: Guidelines for sustainable SPS management of the Caatinga include maintaining up to 400 trees/ha (40% tree cover) and allowing at least 40% of the available forage to dry up to provide mulch for soil protection. Opportunities for improving the low carrying capacity of the Caatinga are thinning, coppicing, and enrichment planting with desirable tree and understory species. Establishment of fodder banks, promotion of non-conventional feed sources such as cactus, and introduction of grazing animals to orchards and plantations are some other promising interventions.Research highlights: The review highlights the importance of initiating new studies on Caatinga SPS, focusing on the role and potential of various native species and the ecosystem services they provide, in conjunction with relevant social, economic, and policy aspects to better exploit the benefits of the system and facilitate its wider adoption
Modeling surface fire rate of spread within a thinned Anatolian black pine stand in Turkey
Get PDFAim of the study: To develop regression models for estimating the rate of surface fire spread in a thinned even-aged black pine stand (Pinus nigra J.F. Arnold subsp. nigra var. caramanica (Loudon) Rehder).Area of the study: The study was carried out within a thinned black pine forest located in the Kastamonu Forest District, northwestern Turkey. The study area is located at 546819, 4577880 UTM.Material and methods: A total of 33 small scale surface fires were ignited under varying weather and fuel conditions. Line ignition was used during the burnings. Surface fuels consisted generally of thinned material (needle+branches).Main results: Within the stand, surface fuel loading ranged from 3.0 to 10.2 kg/m2. Wind speed ranged from 0.3 to 8.4 km/h. Needle moisture content ranged from 8 to 15%. The rate of fire spread ranged from 0.47 to 6.92 m/min. Relationships between the rate of fire spread and fuel and weather conditions were determined through regression analyses.Research highlights: Wind speed was the most important factor on the rate of fire spread and explained 85% of the observed variation in the surface fire rate of spread within a stand
External validation of the GrazeIn model of pasture dry matter intake and milk yield prediction for cows managed at different calving dates and stocking rates
Get PDFThe aim was to evaluate the prediction accuracy of pasture dry matter intake (PDMI) and milk yield (MY) predicted by the GrazeIn model using a database representing 124 PDMI measurements at paddock level and 2232 MY measurements at cow level. External validation of the model was conducted using data collected from a trial carried out with Holstein-Friesian cows (n=72) while grazed 28 paddocks and were managed in a 2×2 factorial design by considering two calving dates (CD), with different number of days in milk (DIM), early (E, 29 DIM) vs. middle (M, 167 DIM), and two stocking rates (SR), medium (M, 3.9 cows ha-1) vs. high (H, 4.8 cows ha-1), under a rotational grazing system. Cows were randomly assigned to four grazing scenarios (EM, EH, MM and MH). The mean observed PDMI of the total database was 14.2 kg DM cow-1 day-1 while GrazeIn predicted a mean PDMI for the database of 13.8 kg DM cow-1 day-1. The mean bias was −0.4 kg DM cow-1 day-1. GrazeIn predicted PDMI for the total database with a relative prediction error (RPE) of 10.0% at paddock level. The mean observed MY of the database was 23.2 kg cow-1 day-1 while GrazeIn predicted a MY for the database of 23.1 kg cow-1 day-1. The mean bias was –0.1 kg cow-1 day-1. GrazeIn predicted MY for the total database with a mean RPE of 17.3% at cow level. For the scenarios investigated, GrazeIn predicted PDMI and MY with a low level of error which made it a suitable tool for decision support systems
Antioxidant activity of Trifolium resupinatum L. exposed to different extracts from leaves, flowers and shoots of Prangos ferulacea
Get PDFPrangos ferulacea is a member of Apiaceae family, is a popular fodder for livestock production and an important species in rangeland restoration. The objectives of the research are the comparative phytotoxic activity of aqueous and hydroalcoholic extracts obtained from different organs (flower, shoot and leaf) of P. ferulacea on antioxidant response of Trifolium resupinatum was investigated in a laboratory bioassay. Antioxidant enzyme activities including catalase (CAT), peroxidase (POD), ascorbic peroxidase (APX), and superoxide dismutase (SOD), in line with content of malondialdehyde (MDA) and hydrogen peroxide were measured. Results indicated that hydroalcoholic extract of P. ferulaceae flower possess the highest total phenolic content as well as highest phytotoxic effect on T. resupinatum. The highest antioxidant enzyme activity belonged to hydroalcoholic treatment. The treated T. resupinatum seedlings experienced lipid peroxidation at high extract concentrations (12% of hydroalcoholic and 100% of aqueous extract) as evidenced by increased concentration of MDA. In response to this, the activities of SOD, CAT, POD and APX increased at lower extract concentrations but significantly dropped as concentrations increased. According to results of this study, rehabilitation of T. resupinatum sites through the use of P. ferulaceae will probably not be successful
Fatty acid profile as a tool to trace the origin of beef in pasture- and grain-fed young bulls of Retinta breed
Get PDFThis research explores the possibility of using the fatty acid profiles of intramuscular fat to authenticate the origin of Retinta breed meat according to different feeding regimes based on the combined use of concentrate and grass or forage (GP, grass pasture; MC, medium concentrate; HC, high concentrate). Young bulls from GP (n=30) were reared on grass pasture and supplement with concentrate in controlled feeders; MC (n=30) and HC (n=15) were reared in farm buildings using 40 and 80% concentrate of total dry matter from diet, respectively. The stepclass function in R was used to perform a stepwise linear discriminant analysis including thirty fatty acids from intramuscular fat. Two fatty acids, 9c18:1 and 22:5 n-3 were selected as discriminators of the meat origin. Meat from the GP and MC was characterized by higher 22:5 n-3 (p<0.05), while HC meat showed higher 9c18:1 (p<0.05). The use of 9c18:1 and 22:5 n-3 fatty acids from intramuscular fat resulted in a correct assignation of 100% of beef samples to each of the feeding regimes. Therefore, in addition to serving as an effective tool for discriminating between feeding regimes in the origin of the beef, the fatty acid profile of intramuscular fat could help companies to check the authenticity of the meat origin
Autopolyploids in fodder grass breeding: induction and field performance
Get PDFDoubling of chromosome set directly affects plant performance through increase of organ size, higher feeding value and increased resistance to adverse environmental factors. Therefore efficient methods of polyploid induction are needed in order to develop new varieties of naturally diploid fodder grass species. The efficiency of antimitotic agents as colchicine, amiprophos-methyl, trifluralin and oryzalin was compared in a series of tetraploid induction experiments in Lolium multiflorum, L. perenne and Festuca pratensis, while newly developed tetraploid plants were compared to standard tetraploid varieties in the field trials. Colchicine treatment proved to be the most efficient method for in vitro cultured embryos in comparison with the other agents. Induced tetraploids of F. pratensis produced higher dry matter and seed yield and could be used for the development of new varieties. Induced tetraploid plants of Lolium spp. were equal to the standard varieties in field trials, therefore they could be used as parental genotypes in crosses. Induced tetraploids of F. pratensis produced higher dry matter and seed yield and could be used for development of new variety