Scielo RSS <![CDATA[Austral journal of veterinary sciences]]> vol. 50 num. 2 lang. es <![CDATA[SciELO Logo]]> <![CDATA[Feed production: A collaborative challenge]]> <![CDATA[Drug resistance in parasitic helminths of veterinary importance in Chile: Status review and research needs]]> Abstract: The increasing development of anthelmintic resistance (AR) in parasites of livestock is threatening animal health and production worldwide. In Chile, studies evaluating the field efficacy of anthelmintics and the detection of AR have been performed since the 2000s, but until now, no previous attempt has tried to systematise the available information. This article reviews general concepts about AR in helminths of veterinary importance, methods for diagnosis of AR and summarises the published reports of AR in Chile. Anthelmintic resistance in Chile has been reported in gastrointestinal nematodes of horses (benzimidazole resistance) and ruminants (sheep and cattle, macrocyclic lactone and benzimidazole resistance). However, these cases involved a limited number of selected farms and no further conclusions can be made of the status of parasite drug resistance at a regional or national level. No published cases of AR in Fasciola hepatica have been reported in Chilean livestock, but human infections with triclabendazole-resistant F. hepatica have been described in patients with previous consumption of watercress or untreated water from marshes grazed by livestock. Given the zoonotic potential and endemic nature of F. hepatica in Chile, it is urgent to determine the extent of liver fluke resistance. Current research gaps of the situation of AR in Chile and suggestions for the performance of laboratory and field studies are further discussed. <![CDATA[Effect of immunocastration on behaviour and blood parameters (cortisol and testosterone) of Holstein bulls]]> Abstract: To evaluate the effect that immunocastration has on behaviour, testosterone and cortisol levels of feedlot Holstein bulls, 720 intact animals aged between 7 and 8 months, weighing 232±1.19 kg were randomly assigned to two treatments: immunocastration using the Bopriva vaccine and a placebo (360 animals per treatment). The bulls were slaughtered at day 239 of treatment. Animals were vaccinated on days 1, 21, 101, and 181, and on those same days testosterone levels were measured; while cortisol, glucose and creatin kinase measurements were done on day 181 and during exanguination at slaughter. Sexual, aggressive and social behaviours were evaluated and it was found that intact bulls showed a higher average of head butts, mounting, threats, flehmen sign and sniffing (P&lt;0.05), no differences were found for vocalisations, lowering of the head and grooming (P&gt;0.05). Testosterone levels in intact bulls remained at 0.47ng/mL throughout the study, however, by day 181 differences (P&lt;0.05) were observed in immunised bulls, with values of 0.22ng/mL. At slaughter, testosterone levels were 0.21 ± 0.06 ng/mL in immunocastrated bulls and 0.54 ± 0.06 ng/mL in the placebo group. The use of immunocastration with Bopriva has shown to be effective to reduce testosterone, sexual and aggressive behaviours on Holstein bulls. <![CDATA[Supplementing nursery pig feed with seaweed extracts increases final body weight of pigs]]> Abstract: Probiotics have been used as an alternative method to antibiotic treatment. In this study, we evaluated the effect of seaweed extracts, commercially named OceanFeed Swine® (OFS), on body weight, average daily weight gain (ADG) and feed efficiency (FE) in nursery and fattening pigs of terminal lines. The study was conducted with 1809 piglets from weaning age until the end of the fattening phase on a commercial farm, divided into two groups (control and OFS; 905 and 904 pigs, respectively). Three replicates were made during the 6 weeks of production. Food was elaborated in the same productive unit and was given to the animals in the form of flour. OceanFeed Swine® (5 g/kg of diet) was added to the diet of the OFS groups during the nursery period, from 21 to 55 days of age. The faecal microbial population was evaluated at 35 and 60 days of life. In this paper, we observed a positive effect of administering OceanFeed Swine® on the production parameters analysed in the fattening phase, showing an improvement of 26 g in ADG and FE of 0.07. It can be concluded that the use of OceanFeed Swine® in the diets of the piglets, aged between 21 to 55 days old, improves FE (Control 2.36, OFS 2.29) and ADG (control 0.798 kg, OFS 0.824 kg). Moreover, its use exhibited an increase in the slaughter weight, a reduction of E coli CFU, and an increase in Lactobacillus sp. in fattening animals. All these improvements have a major positive economic impact per pig at time of slaughter. <![CDATA[Effect of two oil types and energy levels on broiler performance, carcass quality and skin pigmentation]]> Abstract: This study evaluated different levels of metabolisable energy (ME) and two oil types: crude soybean oil (CSO) and acidulated soybean oil (ASO), in sorghum-soybean meal diets for broilers. One thousand and eight unsexed Ross 308 chicks aged 1 to 49 days old were used in a factorial arrangement design 2x3. The first factor corresponded to the oils (CSO and ASO) and the second factor corresponded to the ME levels (high, medium and low) in the initiation (1-10 days), growing (11-25 days) and finishing (26-48 days) feeds, with a 90 kcal/kg reduction. The treatments were as follows: (1) CSO with 3010, 3175 and 3200 kcal/kg; (2) CSO with 2920, 3085 and 3110 kcal/kg; (3) CSO with 2920, 3085 and 3200 kcal/kg; (4) ASO with 3010, 3175 and 3200 kcal/kg; (5) ASO with 2920, 3085 and 3110 kcal/kg; and (6) ASO with 2920, 3085 and 3200 kcal/kg. The treatments with high and medium levels of ME (P&lt;0.05) were higher. The carcass weight and skin pigmentation when cold were better in broilers fed with high and medium levels of ME (P&lt;0.05). No effect (P&gt;0.05) between oil types was found. It can be concluded that it is feasible to replace CSO by ASO and to reduce 90 kcal/kg of ME from the recommended amount for the breed during the initiation and growing stages, without affecting their performance. <![CDATA[Health status and productivity of sheep fed coffee pulp during fattening]]> Abstract: The objective of this study was to evaluate the productivity and health of fattening lambs fed different levels of coffee pulp in their diets. Thirty-five crossbred lambs with an average weight of 21.8 kg were fed isoproteic and isoenergetic diets with different percentages of coffee pulp (T0: control; T1: 7%; T2: 14%, T3: 21% and T4: 28%), the base diet was formulated with corn, soybean meal, alfalfa stubble, molasses, urea and mineral salt. The fattening period was 98 days. Productivity was measured by weight gain, feed intake and feed conversion. At the beginning and end of the study, blood samples were taken to determine the health status using a biochemical profile and blood count. Analysis of variance was performed using the initial weight as the covariate for the productive variables and the initial values of the analytes in the blood chemistry and hematological analysis tests. The coffee pulp did not affect productivity, although the amount of neutrophils decreased (P&lt;0.05) as the coffee pulp in the diet increased. In all treatments, urea exceeded the reference values, whereas creatinine was below the reference values. We concluded that the inclusion of up to 28% coffee pulp in the diet did not affect the productive parameters, decreases the neutrophil count without affect health status of lambs during fattening. <![CDATA[Humoral immune response of pregnant goats to two Corynebacterium pseudotuberculosis bacterin formulations]]> Abstract: Caseous lymphadenitis is a chronic suppurative bacterial disease caused by Corynebacterium pseudotuberculosis, and it has a high prevalence among small ruminants. Different vaccine preparations have been employed to control this disease. The adjuvant used in the formulation is a critical factor for the improvement of vaccine efficacy. No commercial vaccines are available in Argentina. The aims of the present work were to compare the specific antibody response against a C. pseudotuberculosis whole cell vaccine formulated with a classical and an immunoestimulant adjuvant in pregnant goats, and to assess the transfer of vaccine-specific antibodies from the goat to the offspring through colostrum. Twenty three pregnant goats were vaccinated. The animals were randomly allocated to three groups: control, aluminum hydroxide Al(OH)3 adjuvant and a new cage-like particle adjuvant (ISPA). Antibodies (IgG) against this antigen were measured by ELISA. A robust humoral immune response was detected in vaccinated animals, with production of specific IgG. No significant differences were found between the vaccines formulated with different adjuvants. High levels of specific antibodies were detected in colostrum samples from both immunised groups, which were passively transferred from goats to offprings. No adverse local reactions in the vaccines injection sites were detected. <![CDATA[Pyrrolizidine alkaloid toxicosis and hepatic encephalopathy in horses in Easter Island, Chile]]> Abstract: A group of horses died in Easter Island following anorexia, weight loss and neurological signs. Similar cases have occurred since the introduction of a plant containing pirrolizidine alkaloid to the island. This study describes the grazing behaviour of the horses and the potential correlation with the development of these horses clinical signs. <![CDATA[Association of acute equine leukoencephalomalacia (ELEM) with fumonisins concentrations in corn stover in an outbreak in the state of Jalisco, Mexico]]> Abstract: Fumonisins are mycotoxins responsible for equine leukoencephalomalacia (ELEM) and they are produced by Fusarium species of high incidence in corn crops. In Jalisco (Mexico), six cases were confirmed by histopathological and neurological findings and fumonisins analysis. This is the first report of fumonisins in corn stover associated to ELEM cases. <![CDATA[Molecular evidence for Mycobacterium bovis infection in wild Chilean hawk (Accipiter chilensis)]]> Abstract: The present study reports a case of tuberculosis in a juvenile Chilean hawk ( Accipiter chilensis ). Granulomas were identified in the liver, intestine and mesentery. Several of these granulomas contained acid-fast bacilli suggesting a mycobacterial infection through ingestion. Molecular diagnosis detected Mycobacterium bovis as etiological agent. Whether M. bovis infection in this Chilean hawk represents a risk for other wildlife, livestock or humans remains to be determined.