May the force be with you: an investigation into logging methods using donkeys

Working equids represent major sources of energy worldwide, and assume an increasingly important role in line with increasing requirements for sustainable energy. The effectiveness of their contributions relies on welfare, especially in the case of donkeys that, due to their size, face more adverse working conditions compared to larger equids. In this study, heart rate and force exerted were monitored while logging using three methods: direct pull, sled, and vehicles. A swingle tree incorporating a dynamometer and data logger was developed for this project, allowing continuous recording of forces. It was hypothesized that logging techniques that suspend (partially or totally) the load from the ground, reduce the force exerted, thus reducing physical effort. This study also aimed to understand if heart rate can be used as an alternative proxy measure when pulling different loads using different methods. Results showed that the greatest force was measured during direct pull (369.66 N), requiring 20% greater force compared to the sled (299.10 N, P <0.001), and 60% greater force than the vehicle (125.11 N, P <0.001). The sled required an additional 58% of force compared to the vehicle (P <0.001). This determines vehicles are the best option for reducing the force exerted by donkeys. Affordability and skills needed to work with this technique, however, are important considerations. Sleds represent a user-friendly solution; reducing the force needed when compared to direct pull, requiring less skills and equipment. The dynamometer proved an excellent method for force monitoring. Heart rate as a proxy measure for force didn’t provide accurate data for lighter loads. Increasing load weight, followed by the increasing force requirements, correlation and explanatory power became greater, indicating that with heavier logs, or methods that display greater force requirements, heart rate may be used as a proxy method for force, but further studies are needed.Keywords: Working donkeys, dynamometer, logging techniques, heart rate, animal welfare

Special Issue: Working Equids

Editorial (January 2023) Vol. 55 Nº 1 Special Issue of Austral Journal of Veterinary Sciences gathers several studies regarding the critical contribution working equids have made throughour history developing societies, which leads us to encourage its health and welfar

Neosaxitoxin, a Long-Lasting Local Anesthetic and its Potential Clinical Applications in Horses

Neosaxitoxin (NeoSTX) is a toxin that binds to the voltage-gated sodium channels therefore, inhibiting the neuronal impulse. The present study was conducted to explore the properties of NeoSTX and to evaluate its effects when injected as a perineural nerve block in horses. A group of five client-owned mature Warmblood horses exhibiting clinical signs of unilateral foot pain were enrolled in the study. For inclusion, lameness should subside after a palmar digital nerve block using 2 mL of 2% Lidocaine administered over the medial and lateral palmar digital nerves of the affected limb (day 0). Lameness was assessed using the AAEP scale and skin sensitivity was judged objectively using a pressure algometer. On day 1, 5µg of NeoSTX was injected. On day 4, 10µg of NeoSTX was administered. Lameness examination and skin sensitivity were evaluated at 3, 5,10, 15,30, 60, 90 minutes, and every hour until the effect of the injection wear off. When 10µg of NeoSTX was compared with lidocaine 2% the results showed no statistical differences in the onset of the anesthetic effect, measured as the time of start of desensitization of the skin and the time of complete desensitization or lameness resolution, nonetheless there was a significant difference in the return of skin sensation and lameness, showing a clear long-lasting nociceptive blocker effect of NeoSTX. In conclusion, this study suggest that NeoSTX can be used as a better alternative to conventional local anesthetics when a long-lasting effect is desired, for example as a part of a multimodal approach for pain management, as a local anesthetic for surgical procedures or to control chronic pain in some musculoskeletal diseases

Vertebral osteomyelitis associated with Enterococcus faecalis in Broiler Breeders in Chile

Vertebral osteomyelitis is a re-emerging disease characterized by inflammation and necrosis of the thoracic vertebral body, caused by Enterococcus cecorum.  Here, we report the first case of vertebral osteomyelitis caused by Enterococcus faecalis in Broiler Breeders, in Chile, which also causes infections in humans and is resistant to multiple antimicrobials, representing a risk to public health

Locomotor injuries morbidity data analysis in Chilean sport horses: a retrospective study (2016-2021)

The equine industry in Chile is small but constantly growing, being the Chilean Rodeo the most important discipline. Problems associated to the musculoskeletal system are the most frequent condition in the equine veterinary practice. Economic losses for the equine industry associated to injuries related to the locomotor system are significant and have been estimated in different parts of the world. Five hundred and eighty-one (581) Chilean purebred horses (Caballo Raza Chilena) performing or training for Chilean Rodeo discipline fulfilled the inclusion criteria. Results showed that in Chilean purebred horses, forelimbs injuries were recorded in 73.1% and hindlimbs 26.9% being a statistically significant difference (P = 0.001). Unilateral lameness was the most frequent situation seen in 74.9% (n=424), bilateral lameness was observed in 21.7% (n=102) and lameness in 3 or more areas was recorded in 9.5% of horses (n=55). When comparing frequency of distribution between right and left sides, no differences were observed between forelimbs (P = 0.645) or hindlimbs (P = 0.853). The forelimb digit (hoof, pastern, and fetlock) had a prevalence of 59.6%. When specific diagnoses were recorded the most prevalent causes of lameness in Chilean purebreds were navicular disease (12.9%), fetlock osteoarthritis (11.9%) and distal tarsal joints osteoarthritis (11.7%). In conclusion, due to the activity and specific physical demands suffered by Chilean Rodeo horses, veterinarians must be familiar with injuries affecting Chilean sport horses, as the morbidity of musculoskeletal injuries varies drastically between different disciplines

Effects of the inclusion of brown seaweed (Macrocystis pyrifera) additive in the diet of grass-fed steers on carcass performance, meat quality, and nutrient composition

The objective of this study was to evaluate the inclusion of a brown seaweed additive (SWA; Macrocystis pyrifera) in the diet of grass-fed steers on carcass performance, beef quality, and nutrient composition. A total of 20 Holstein-Friesian steers were randomly distributed into two groups: Control group (a basal diet without supplementation of SWA) and SWA group (2%-SWA) with basal diet + 30 g/day/animal of SWA during the breeding phase (11 months) and 48 g/day/animal of SWA during the fattening phase (4 months). Steers fed with 2%-SWA were not different (P>0.05) in final body weight, carcass weight, carcass dressing, fat thickness, ribeye area, and marbling score than those from the Control group. Likewise, no effects of 2%-SWA supplementation were detected (P>0.05) for beef quality traits, glycolytic potential, or their metabolites (muscular glycogen, glycose+glucose-6-phosphate, and lactate), evaluated in longissimus lumborum (LL) samples. Sensory evaluation showed a slight preference for Control group samples rather than those from the 2%-SWA group (58.93% and 41.07%; P=0.06). Regarding, proximal composition, the inclusion of SWA only affected the total lipids present in the LL samples, which decreased significantly (P=0.01) in LL samples of grass-fed steers fed with 2%-SWA. The composition of macro (Ca, Na, Mg, P, and K) and micro (Mn, Fe, Cu, and Zn) minerals in LL samples were not affected (P>0.05) by the inclusion of SWA in the diet. The inclusion of the additive based on brown seaweed had not a detrimental effect on carcass performance, beef quality, and mineral content, however, it reduced the total lipids content in the LL muscle

Frequency distribution of polymorphisms on k-casein and DGAT1 genes in dairy cattle used in Chilean milk production

Milk solids are very important to transform milk in dairy products like cheese. Several genes and polymorphic variants had been associated with this process, increasing the milk fat and/or protein content or regulating the coagulation milk properties. In the present study, we evaluate the frequency distribution of two major polymorphisms present in DGAT1 and CSN3 genes in 6 dairy biotypes commonly used in southern Chile: Holstein-Friesian (HF), Jersey (JE), Montbeliarde (MB), Overo Colorado (OC), Frisón Negro (FN) and hybrids (HYB). For CSN3 the results revealed that the A variant was predominant (0.57 to 0.71) in all breeds except Jersey which showed a high frequency of the B variant (0.73), one that favors milk transformation, and in MB (0.58). For DGAT1 a similar trend was seen. The A variant predominated (0.64 to 0.96) in all populations except Jersey, which displayed a high frequency (0.70) of the K variant that favors milk solids. The analysis of FIS for both markers gave negative and non-significant values in all populations some exception of OC and HYB, which are not in Hardy-Weinberg equilibrium, suggesting an excess of heterozygotes. By another hand, FST analysis suggest a high genetic structure for Jersey. The simultaneous analyses of both markers produced 16 combined genotypes with hybrid animals displaying the highest number (11) whereas Jersey showed a favorable combination (DGAT1 KK and CSN3 BB) renewing their productive orientation to transform milk to cheese. Also, some Holstein animals displayed a heterozygous combined genotype (DGAT1 A/K–CSN3 AB). For decades, Holstein-Friesian has been an important breed used for milk production in southern Chile and during the last time, several farmers have introduced Jersey in order to improve milk quality. In this sense, our results show the presence of potential favorable genotypes for the transformation of milk to dairy products

Effects of plant extracts on the growth of beneficial indigenous lactic acid bacteria (BLAB) for their potential use in preventing bovine reproductive tract infections

There is a renewed interest in products based on phytocompounds, prebiotics and probiotics in recent years, applied to different hosts to exert a wide variety of effects. The microbiome of the bovine reproductive tract can become unbalanced for many reasons, favoring the entry and proliferation of pathogenic microorganisms, currently treated with antibiotics that exert adverse effects and generate antimicrobial resistance. To deal with this situation, "phytobiotic" formulas are proposed that combine phytocompounds and probiotics. This study aims to determine the compatibility of beneficial autochthonous lactic acid bacteria (BALB) with plant extracts, prebiotics and vitamins, to incorporate them into intravaginal formulas with therapeutic activity. Nine beneficial strains isolated from different bovine ecosystems were evaluated against nine phytocompounds, two prebiotics and five vitamins. Compatibility was assayed using the diffusion technique on agar plates, and the effect of the phytocompounds on the growth of lactic acid bacteria by microplates. The growth of all the strains was affected by some plant extracts, showing a stimulating or inhibitory effect. By the qualitative method, only vitamin A affected the viability of Lactobacillus johnsonii CRL1702 at concentrations higher than 7.5 mg/ml, however, when studying the growth kinetics of the strains with the phytocompounds, the results show that the effect was different in each of one the associated strains + plant extracts, indicating a strain specific effect of plant extacts on each BALB strain. Lapacho and Malva have a stimulating effect on most of the microorganisms, while Garlic and Belladonna inhibited the growth of all of them. Plant extracts at different concentrations did not inhibit the growth of most of the pathogens responsible for endometritis. On the other hand, the highest concentrations of phenolic compounds were detected in Echinacea, Lapacho and Llantén; and the best percentages of antioxidant activity were evidenced in Garlic, Blueberry and Chamomile (<60%). The results obtained in this stage are original, since the combination of natural extracts with lactobacillus strains for veterinary application was not studied previously

Working equids presented at a veterinary reference center in southern Chile (2015-2021)

In Chile many families still rely on working equids as a fundamental source of income. Their use is particularly important for harnessing and transport of people and goods, in agriculture as well as in the leisure industry. Information on common emergency and clinical conditions in working equids is important to identify foci for owner education and to guide action towards disease prevention and animal welfare. The aim of the report was to highlight details about the clinical presentation of working equids at a veterinary reference center in southern Chile.Hospital records from working equids presented pro bono from 2015 to 2021 at the Equine Clinic of the Veterinary Teaching Hospital of the Universidad Austral de Chile were evaluated and included.A total of 107 working equid cases were recorded. The age range went from 1 day of age to 19 years (8.2±5.19 years). Most cases were not hospitalized and discharged on the same day of presentation (n=52). Horses were presented for evaluation of reproductive status (23%), lameness (15%) and castration (13%). Common reproductive diagnoses were uncomplicated castration (13%), barren (9%) and pregnant (8%) mares. Causes of lameness included laceration and wounds (40%), distal limb fractures (15%) and foot abscesses and/or poor foot care (10%). Only 4 cases of colic (3.7%) were presented over the years. Transrectal ultrasonography was the most used imaging tool, followed by radiography and endoscopy. Laboratory analysis was only performed in 15% of all cases.This is the first report on clinical presentation of working equids at a veterinary care reference center in southern Chile. Most working equids seek veterinary care to aid reproduction and treat conditions related to their use. Findings suggest that animal use, husbandry and welfare can be improved

Diagnostic value of patellofemoral parameters in small breed dogs with medial patellar luxation: a tangential X-ray study

Knowing the diagnostic value of radiological patellofemoral parameters is important for evaluating the status of small-breed dogs with medial patellar luxation (MPL). This retrospective survey was conducted in four small dog breeds (Mini Pinscher, Pomeranian, Chihuahua, and Yorkshire terrier) on 46 healthy stifle joints and 72 joints with grade II and III MPL. The following morphometric parameters were measured on tangential radiographs: trochlear sulcus angle, lateral and medial trochlear inclination angles, trochlear depth, horizontal and vertical patellar diameters, length of the lateral and medial patellar facets, lateral and medial facet angles, Wiberg angle, congruence angle, and axial linear patellar displacement. Receiver operating characteristic (ROC) analysis was performed to evaluate the cut-off values, sensitivity, and specificity of the parameters associated with MPL. The trochlear sulcus angle and trochlear depth were capable of consistently identifying the MPL-affected joints (AUCs > 0.9). The parameters describing the position of the patella within the trochlear groove (congruence angle and axial linear patellar displacement) were found to be the most accurate, with an AUC of over 0.990 and a sensitivity/specificity of over 94%. The patellar morphology parameters had no diagnostic value in distinguishing between healthy and MPL stifles