Tropical animal health and production最新文献

There are concerns about residues of drugs in meat that are used to prevent coccidiosis in chickens. Natural compounds are an alternative to drugs. Two studies investigated the effect of an extract of Enterolobium cyclocarpum fruits (EEC) in the feed of male Leghorn chickens exposed to Eimeria spp. In the first experiment, the administration of EEC after infection with Eimeria spp. was investigated over 16 days. One thousand chickens were randomly housed in 20 pens of 1 m² each. The pens were randomly assigned to each treatment. Five treatments were administered, containing 150, 300 and 450 mg/kg of EEC in the feed, the fourth treatment (C) contained 0.5 g/kg of a commercial anticoccidial, and the fifth treatment provided no treatment (WA). The second experiment lasted 18 days. Administration of the EEC began five days before the chickens were infected with Eimeria spp. Four hundred and eighty chickens were randomly allocated to 24 pens of 1 m². The pens were randomly assigned to each treatment. In the second experiment, the same five treatments were tested and one additional treatment containing 300 mg EEC plus 1 g of polyethylene glycol (PEG)/kg of feed (E300PEG). In the experiment one chickens in the EEC treatments had lower faecal oocyst excretion (OE) on day 14 post infection with Eimeria spp., than chickens in the WA treatment (P < 0.05). A reduction in live weight gain (LWG) was observed in the EEC treatments (P < 0.05). In the second experiment, the excretion of oocysts in chickens from the EEC and E300PEG treatments on day 13 post-infection with Eimeria spp. was the same as in the C treatment and lower than in the WA treatment (P < 0.05). LWG was lower in the EEC treatments than in the C treatment (P < 0.05). However, the Chickens in the E300PEG and C treatments had similar LWG (P > 0.05) suggesting that PEG inhibits the negative effect of EEC tannins on LWG. In conclusion, the addition of EEC to chicken feed reduced both OE and LWG. Treatment with EEC and PEG (E300PEG) reduced the excretion of oocysts without negative effects on LWG.

Our aim was to evaluate a whole-grain diet containing 0 (T1) and 60% (T2) waste papaya silage in vitro, in situ and in vivo. In vitro, biogas, methane and dry matter degradation (DMDiv), neutral detergent fiber (NDFDiv) and crude protein (CPDiv) were determined at 72 h; in situ, DM (DMDis), NDF (NDFis) and CP (CPDis) digestibility was determined at 72 h; in vivo, consumption and apparent digestibility of DM (DMI and DMD) and NDF (NDFI and NDFD), daily weight gain (DWG), rumen characteristics (pH, bacterial and protozoan counts) were determined. In addition, we performed coproparasitoscopic analysis and interviews with producers. Biogas production, methane, DMDiv, CDPiv, DMDis, DMD, NDFD, pH, bacterial and protozoan counts, and parasite load of nematodes and coccidia were not different between treatments (p > 0.05). T2 showed more NDFDiv, CPDis, DMI, NDFI, DWG than T1, while T1 was higher than T2 in NDFDis (p < 0.05). The results obtained from in vitro, in situ and in vivo techniques indicate that the diet with 60% waste papaya silage (T2) showed a similar response to the control diet (T1). Therefore, waste papaya silage is a non-conventional feeding alternative for weaned calves in the Costa Chica region of the state of Guerrero, Mexico.

Supplementation with insulin-like growth factor type 1 (IGF-1) during in vitro culture of bovine embryos has yielded mixed results, likely due to genetic variability among embryos. This work aimed to evaluate the effect of IGF-1 at two concentrations on the development speed embryos from primary F1 crossbreeds used in dual-purpose cattle farming in the Colombian low tropics. Specifically, we investigated the influence of IGF-1 and embryo breed on the blastocyst formation rate. Oocytes were sourced from non-pregnant cows: Bos taurus indicus (20 Brahman and 14 Gyr) and Bos taurus taurus (12 Holstein and 28 Romosinuano). Oocytes were fertilized with semen from specific bulls (Recoil for Holstein, Gabinete for Gyr, and UBER POI 1490 for Brahman). The resulting embryos from each crossbreed group were randomly distributed in three different cultured media with 50 ng/mL IGF-1, 100 ng/mL IGF-1, or no IGF-1 (control) for 7 days. Results showed that 50 ng/mL IGF-1 significantly increased embryo production by day 6 (25.9%±14.56%) compared to control (20.5%±11.84%) and 100 ng/mL IGF-1 (23.0%±9.54%) (p < 0.05). By day 7, both 50 ng/mL (42.6%±26.55%) and 100 ng/mL (49.7%±21.98%) IGF-1 groups exhibited significantly higher production rates compared to the control group (p < 0.001). The embryo breed also influenced development, with Gyr-Holstein (GxH) crossbreeds showing the highest production rates (p < 0.001). In conclusion, IGF-1 supplementation enhances in vitro embryo production, with the effect influenced by both breed and IGF-1 concentration. These findings suggest that breed-specific optimization of IGF-1 conditions is necessary to maximize embryonic development outcomes.

This study assessed the prevalence and risk factors associated with gastrointestinal parasite infection in goats in Ayacucho, Peru. Fecal samples were collected from a total of 254 goats from four districts of Ayacucho: Ocaña (89), Colca (76), Pacaicasa (64), and Luricocha (25) during the dry season; recording the location, sex, and age of the animals. The fecal samples were analyzed using the flotation technique in salt and sugar solution, and modified McMaster egg counting techniques for eggs/oocysts (epg/opg) of gastrointestinal parasites. The associations between location, sex, and age with the prevalence of gastrointestinal parasites were analyzed using the chi-square test. Fecal samples showed an overall parasite prevalence of 87.80%. The identified parasites were Eimeria spp. (86.22%), Strongyle type eggs (STE) (65.75%), Skrjabinema spp. (7.87%), Trichuris spp. (3.15%) and Moniezia spp. (3.15%). There was a significant association between the location and the presence of parasites (p < 0.05); where STE was more prevalent in the district of Colca (98.68%); Trichuris spp. in Pacaycasa (9.38%); Skrjabinema spp. (48.00%), Moniezia spp. (12.00%) and Eimeria spp. (100%) were more prevalent in Luricocha. Sex had a significant association with the prevalence of Eimeria spp., Skrjabinema spp. and Moniezia spp. (p < 0.05); while age had a significant association with parasitosis only for Trichuris spp. and Moniezia spp. (p < 0.05). The epg/opg values revealed a higher parasite burden in goats from Colca compared to the other locations (p < 0.05). There was also no statistical relationship between fecal egg/oocyst counts and sex or age, nevertheless, there were moderate and high parasitic burdens. The high prevalence of parasites such as nematodes, cestodes, and coccidia suggests the need to implement strategic control and prevention programs in free-grazing goats. Location and sex were the most relevant risk factors for parasitosis in Ayacucho, Peru.

African swine fever (ASF) is endemic to Uganda and causes annual outbreaks. Some pigs survive these outbreaks and remain asymptomatic but are African swine fever virus (ASFV) positive. The potential heritability and genetic disparities in disease susceptibility among Ugandan pigs are not fully understood. In a 12-year study, whole blood and tissue samples were collected from 212 pigs across 19 districts in Uganda. Polymerase chain reaction (PCR) assays were used to determine ASFV infection status and genotyping was completed using a commercial porcine array. The point prevalence of ASF was calculated for each district, and breed composition origins were quantified for the sampled pigs by implementing established ancestry analyses. Genome-wide associated studies (GWAS) were conducted using all available domestic swine samples (full study population; n = 206) as well as a reduced dataset (farm-level study population; n = 129). This study revealed a greater number of ASFV-positive pigs in border districts than in non-border districts, a high level of admixture among domestic pigs sampled from Ugandan smallholder farms, and 48 loci that were associated with ASFV infection status. The discovery of 48 significant SNPs and 28 putative candidate genes may imply the possibility of heritability for resistance to ASFV. However, additional investigations in ASFV-endemic regions are required to fully elucidate the heritability of ASFV susceptibility among surviving pigs in Uganda.

Brazil is among the world's top beef producers and exporters, and the Montana breed of livestock has gained popularity due to its exceptional meat quality and ability to adapt to the tropical climate. This differentiates it from other breeds, such as the Zebu and Taurine. A methodology that mapped sixteen farms across five Brazilian states was adopted to investigate the link between SNP genetic data and animal collection location. The data was georeferenced using the Geographic Information System and the ArcGIS 10.3 software, considering a geographic coordinate system and the WGS 84 datum. The Alleles in Space (AIS) software was used to study the relationship between the SNP genetic data and the animal collection location. Various analyses were conducted, including the Mantel correlation, genetic barrier identification, and spatial autocorrelation. The results suggest that there is a correlation between genetic and geographical distances, supporting the idea that geographical distance can affect genetic diversity. This information is vital to understand the genetic structure of populations concerning geographical space and is crucial for optimizing Brazilian agricultural production.

In this study, we analyzed the effects of including açaí kernel, in the experimental diets fed to horses on the intake and digestibility of their nutrient and the resultant effects on the behavior of horses. The experiments were conducted in Federal Rural University of Amazonia. Five mares with no defined breeds, were allocated to five treatments (the replacement of Mombaça grass (Megathyrsus maximus) with crushed açaí kernel at 0, 18.75, 37.50, 56.25, and 75% levels of dry matter), in a 5 × 5 Latin square design. The animals were housed in covered stalls with concrete floors, equipped with individual troughs and drinkers, and fed 80% roughage and 20% concentrate. The inclusion of açaí kernel altered the intake and digestibility of a few nutritional components and the feeding behavior of mares. Increasing levels of the substitution of Mombaça grass with crushed açaí kernel in the experimental diets increased the nutrient intake and digestibility of neutral detergent fiber, total carbohydrates, and non-fibrous carbohydrates (P < 0.05) while reducing the time spent on feeding by the animals. Crushed açaí kernel can, therefore, be included as a substitute for Mombaça grass at up to 37.5% in equine diets.

Comprehensive understanding of reproductive hormones and environmental cues with their relationship is essential for efficient production in livestock sectors involving either assisted or natural reproductive methods. This study evaluated the effects of age and seasonal-associated changes in the blood concentrations of testosterone and follicle stimulating hormone (FSH) of male Kalahari Red (KR) and Kalawad (KW)-crossbred goats. Based on a 2 × 3 × 4 factorial arrangement, a total of 42 bucks (KR n = 21 and KW n = 21) were allotted into three age groups (> 1 ≤ 2 years, > 2 ≤ 3 years and > 3 ≤ 4 years) with seven KR bucks and seven KW bucks each per age group; reared under different seasons (early rainy, late rainy, early dry and late dry). The animals were managed semi-intensively, kept in an open-ventilated pen and subjected to same nutritional regime throughout the one-year experimental period. Follicle stimulating hormone and testosterone concentrations were analyzed in serum samples. Data obtained reproductive hormones were subjected to three-way Analysis of Variance using SAS 1999. Results show that breed had a significant effect (p < 0.05) on both serum FSH and testosterone concentrations. The highest FSH (0.49 ± 0.02 ng/mL, 0.45 ± 0.01 ng/mL, 0.41 ± 0.1 ng/mL and 0.47 ± 0.07 ng/mL) mean values (P > 0.05) were observed in KR in September, October, November and May, respectively while the highest (2.6 ± 0.02 ng/mL) testosterone concentration in KW (p < 0.05) was obtained in December. Testosterone had irregular patterns between breeds and months of sampling. FSH was at peak (p > 0.05) in KR during the late rainy season at all ages while the values of FSH concentration in KW were not significantly different at all ages and seasons. The highest (2.05 ± 0.11 ng/mL) serum testosterone mean value in KW peaked (p < 0.05) age > 3 ≤ 4 years during the late rainy season. Testosterone concentration was lower and steady at all ages during rainy seasons in KR but started fluctuating during the early dry season. The least mean (0.62 ± 0.07 ng/mL and 0.68 ± 0.05 ng/mL) were recorded (p > 0.05) in KW during the late dry season at age > 2 ≤ 3 and > 3 ≤ 4 years respectively. In KR and KW goat breeds raised under tropical condition, the high seasonal variations were responsible for the fluctuations in the reproductive hormones which resultantly altered or lowered the sexual activity of the animals at certain season(s).

Avian metapneumovirus (aMPV) poses a significant global threat to the respiratory and reproductive systems of poultry, yet its prevalence and impact in specific regions, such as northern Thailand, remain understudied. This study is the first comprehensive assessment of aMPV seroprevalence among layer hens in the region. By the application of Enzyme-Linked Immunosorbent Assay (ELISA), our findings reveal a high overall seroprevalence of 60.78%, with significantly higher rates among post-laying hens (70.87%) compared to pre-laying hens (47.02%). Regional variations were noted, Uttaradit province showing the highest seroprevalence at 74%. Factors such as overcrowded conditions and poor farm hygiene were implied as contributors to increased seropositivity. Comparison with global studies highlights aMPV's endemicity and emphasizes the need for targeted surveillance and biosecurity measures. Migratory birds were inferred as potential vectors, contributing to the spread of aMPV across different regions. This study provides crucial epidemiological data essential for optimizing vaccination strategies and enhancing disease management practices to safeguard poultry health and sustainable production in northern Thailand.

The drive to hasten the development of smallholder livestock farming through research-extension-farmer-input linkage systems (REFILS) is being promoted in African countries. Resource-constrained smallholders face various challenges including poor access to timely and relevant research-based innovations. Weak research-extension-farmer-input linkages exacerbate this issue. This review explores the evolution of Knowledge Transfer and Agricultural Extension Theories, emphasising the shift from centralised top-down dissemination to participatory and user-driven models. The paper characterises "research", "extension", "farmer", and "input" as the main pillars of agricultural knowledge systems and how their lack of interconnectedness impacts their effectiveness. Examining the dynamics of these pillars provides a comprehensive rationale for strengthening REFILS. Also, REFILS adoption disparities such as limited funding and investment, institutional and organisational inefficiencies, and social and cultural factors were discussed. The identified key challenges form an intricate web of interconnected issues which should not be addressed in isolation but collectively. The proposed measures for REFILS enhancement include building strong public-private partnerships, full participation and collaboration by all key actors including farmers, digitalisation of smallholder agriculture, and policy and institutional reorganisation towards a stronger REFILS. Moreover, the study acts as a foundational guide for strengthening REFILS at national, regional, and continental levels to foster economic, environmental, and social sustainability in Africa's livestock industry.