Spanish Journal of Agricultural Research
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Comparison of growth performance and immune responses of broiler chicks reared under heat stress, cold stress and thermoneutral conditions
No full textThis 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
Detection of Bactrocera oleae (Diptera: Tephritidae) DNA in the gut of the soil species Pseudoophonus rufipes (Coleoptera: Carabidae)
No full textPest control service provided by natural enemies of Bactrocera oleae, the key pest of the olive tree, is nowadays recognized as fundamental. B. oleae has developed resistance to common insecticides, and negative effects both on consumers’ health and non-target species are the major drawbacks of conventional control strategies. Carabid beetles are potential B. oleae pupae predators, but their predation on field still need to be assessed. We tested adult Pseudoophonus rufipes, a species known to be active in olive orchard when pest pupae are abundant in the soil, in order to detect B. oleae pupae consumption at different post feeding times for both male and female carabids. An already existing protocol was used for detecting B. oleae mtDNA sequences of the cytochrome oxidase subunit I gene in carabids’ gut, and its versatility improved. B. oleae mtDNA was detected up to 20 h after pupa ingestion with a high percentage of success, without significant differences between sexes and pair primers used. Prey DNA extraction was tested from both dissected and non-dissected carabids, obtaining comparable results. The trapping system used to collect carabids for molecular assays and the new elements introduced in the protocol represent cost-effective solutions that may be beneficial for future laboratory trials and, mostly, for the analysis of field-collected predators. Fostering the investigation of soil predators in olive orchard may increase the design of conservation control strategies against B. oleae
Differences in nutritional characteristics of three varieties of sorghum grain determine their in vitro rumen fermentation
No full textThe effect of phenolic compounds and protein matrix on microbial fermentation of three sorghum grains (S1, S2 and S3) were studied in vitro. Total phenolics and total tannins concentration (g/kg dry matter, DM) were 1.5 and 0.2 for S1, 19.3 and 8.1 for S2 and 2.6 and 1.3 for S3. Protein enzymatic digestibility was 0.614, 0.226 and 0.454, respectively. Trial 1 was conducted for 24 h, without or with polyethylene glycol (PEG) to determine the effect of phenolic compounds on fermentation. Without PEG, gas production for S1 was the highest after 24 h (257, 237 and 238 mL/g organic matter, for S1, S2 and S3; p<0.05), and higher proportion of propionate at the expense of acetate was recorded with S3 after 6 h. Gas produced with S1 and S3 remained unaffected (p>0.10), but increased in S2 by 0.21 to 0.30 with vs. without PEG. No differences in gas production between S1 and S2 were observed with PEG, S3 recording the lowest (p<0.05) values from 8 h onwards. Addition of PEG reduced proportion of butyrate (p<0.05) and increased three-fold lactate (1.62 vs. 4.98 mM; p<0.001). In Trial 2 (12 h) gas production followed a similar pattern. Without PEG, starch disappearance was the highest in S1 (0.356, 0.231 and 0.216, respectively), but no differences were recorded with PEG. Considering differences in protein digestibility and the effect of phenolic compounds, the effect of starch nature and structure on fermentation is apparently minor. Colour of grain is not necessarily related to phenolic compounds proportion or rumen utilization
Valuation of small to medium sized companies using spatial information: An empirical example from the fruit subsector
No full textThe Discounted Cash Flow (DCF) model, similar to other firm valuation models, uses temporal information for a firm to forecast future results. However, the lack of temporal information for many companies hinders the application of the DCF model. To overcome this limitation, we proposed an approach based on the spatial information of the analysed companies. In particular, to get firms’ valuation our approach combined both data from companies that are geographically proximal to the analysed company and data from the analysed company. Based on this approach, we provided an empirical example to demonstrate that the economic value computed with our proposal, the Spatial-Firm Economic Value, was consistent with the traditional economic value after application of the DCF model. In particular, we found a minimal difference in terms of absolute deviations between our proposal and the firm’s valuation applying traditional valuation techniques. Thus, this study demonstrated the relevance of considering the spatial dimension as an additional source of information to determine firms’ value in the Fruit subsector when there is not available temporal information to apply traditional valuation methods
Influence of density on growth and survival of freshwater prawn Macrobrachium americanum (Bate, 1868) (Caridea: Palaemonidae) cultured in a cage-pond system
No full textThe domestication and culture of freshwater shrimp native of tropical and subtropical American Pacific zone requires the study and development of technologies in open systems where their response to types of farming, feeding and management strategies generate practical information for the production of this species. The aim of this study was to evaluate the effect of stocking density on growth and survival in M. americanum juvenile-adult, cage-cultured and to determine the optimal density for grow-out production. The caridean shrimp Macrobrachium americanum was cultured for 152 days in a 16 cage-culture (3 m3 each) at densities of 1, 3, 6 and 9 org / m3, respectively, with stocking sizes from 12.1 ± 1.7 to 13.5 ± 2.3 g. The prawns were fed twice daily with Camaronina 35%. Water quality parameters were within standard range for caridean shrimp culture. There was a significant effect of density on final weight, growth rate, specific growth rate, K condition and survival, and an inversely proportional relationship with the feed conversion ratio. The growth was affected by density, resulting to a maximum increase of 6 org / m3 in the asymmetry of the prawn and also increasing the number of small organisms by 9 org / m3. However, it is necessary to study such aspects as the rate and frequency of feeding, the initial size-grade and the implementation of shelter, among others
Short communication: Use of a new form of protected sodium butyrate to control Salmonella infection in fattening pigs
No full textA field trial on a commercial pig farm was carried out to assess the efficacy of the addition in the diet of fattening pigs of a new form of sodium butyrate protected with a sodium salt of coconut fatty acid distillate (3 kg/ton of feed) to control Salmonella spp. infection. Around 50 pigs were assigned to treatment group and 50 kept as controls. During the fattening period pigs were monthly sampled (serum and feces), and after slaughter fecal and mesenteric lymph nodes samples were collected. No differences in the proportion of shedders were observed between the sodium butyrate and the control groups, but a significant reduction in the number of infected pigs (61% vs. 4%; p<0.01) and in the median ELISA Optical Density percentage values (55.9% vs. 19.4%; p<0.01) at slaughter was observed in pigs under treatment compared to the controls. In addition, an overall significant association between seropositivity and Salmonella shedding and infection was detected. Results from this study add more evidences on the positive effect of butyrate on the control of pig salmonellosis
Using manure as fertilizer for maize could improve sustainability of milk production
No full textThis study evaluated the effect of organic or chemical fertilization of maize on cow performance, economic outcomes, and greenhouse gas emission. Each type of maize silage according its different fertilization was used in two rations offered to two different groups of nine Friesian-Holstein cows throughout 4 months. The production cost of the maize silage was 8.8% lower for organic than for chemical fertilization. Both silages had similar nutritive value, except a higher concentration of starch in maize with organic fertilization, which allowed a reduction in the proportion of concentrate in the ration, saving 25.3 eurocents per cow in the daily ration, generating a positive balance of 21.8 eurocents per cow and day. The milk yield and composition were unaffected depending on the type of fertilization, whereas the estimation of CH4 and N2O emissions with chemical fertilization was higher than emissions with organic fertilization. As a result, it is possible to increase the sustainability and profitability of dairy production with reuse and recycling of manure
Protective effect of mangrove (Rhizophora apiculata) leaves extract in shrimp (Penaeus monodon) larvae against bio-luminescent disease-causing Vibrio harveyi bacteria
No full textApplication of chemicals for monitoring if Vibrio outbreaks can enhance resistance in mangrove (Rhizophora apiculata) leaves extract was tested against bioluminescence disease-causing Vibrio harveyi bacteria. An inhibitory zone of 12 mm was observed at 350 µg/mL The growth of V. harveyi was decreased from 0.783 to 0.533 (OD600) as compared to control (0.970 to 1.031 OD) against R. apiculata extract. The extract was treated against virulence produced by V. harveyi, the crude bacteriocin values decreased from 1.653 to 1.574 OD as compared with control. Further, extract 200 mg/mL was challenged against V. harveyi (10 mL at 1.8 OD600) during larviculture of Penaeus monodon for 30 days. The mortality increased from 9.0 to 68.5% in the control, but in the treatment the mortality varied from 0 to 57.8% till 30th day. The difference in the decrease of mortality in the treatments was 10.6%. V. harveyi count was decreased from 1.46 × 105 to 3 × 103 cfu/mL, respectively in the treatment for the 30th day as compared to control (1.33×105 to 9.2×103 cfu/mL). R. apiculata leaves extract was reported to have various functional groups of compounds as determined by Fourier Transform Infrared Spectroscopy (FTIR). The GC-MS analysis revealed that the R. apiculata extract contains compounds such as 1, 2-diacetate, cyclododecane, 2-chloropropionic acid and squalene. These compounds might be responsible for the antagonism against V. harveyi. Hence, crude extracts of R. apiculata can be used as a non-antibiotic agent to control shrimp disease caused by V. harveyi during larviculture
Effect of breed and finishing diet on growth performance, carcass and meat quality characteristics of Mos young hens
No full textMos breed is a Spanish authoctonus breed linked to raising and natural food, with a growing market niche in the restoration due to their meat is associated with high quality products. The effect of breed (Mos and Sasso X44) on growth performance, carcass characteristics and meat quality of breast and drumsticks was examined in young hens reared 20 weeks in free-range system. The effect of finishing feeding (fodder, corn and linseed) was also evaluated on the aforementioned parameters. The Sasso group grew faster and the maximum weights were higher (p<0.001), but there was no effect of genotype or feed on final weight or growth efficiency. With the exception of breast piece, the highest percentages of commercial cuts were achieved in Mos birds, when breed was the studied effect. On the other hand, color parameters were not affected by breed. However, significant differences were found among feeding, since animals fed with corn achieved the highest redness values in drumstick (11.94 vs. 10.09 for corn and fodder, respectively; p<0.05). Regarding chemical composition, intramuscular fat (IMF) displayed significant differences between breeds (p<0.05), showing higher values in Sasso X-44. On the contrary, with the exception of IMF, significant differences (p<0.05) on chemical composition were observed among feeding groups. Finally, fatty acid profile was significantly affected by breed and feeding since animals fed with linseed presented better nutritional indices (lower SFA, n-6/n-3 ratio and higher PUFA and P/S ratio). The results show the suitability of Mos breed to produce high quality poultry products