Effect of formic acid on performance, digestibility, intestinal histomorphology and plasma metabolite levels of broiler chickens

1. The effect of dietary formic acid on performance, digestibility, intestinal histomorphology and plasma metabolite levels of broiler chickens was studied. 2. An experiment with 120 Ross male broiler chickens was conducted from 1 to 42 d of age at the laboratory. There were 4 treatment groups: control (C), 10 mg/kg feed avilamycin (AV) and formic acid at two concentrations, 5 and 10 g/kg feed (FA5 and FA10, respectively). 3. No differences in weight gain, feed intake or feed conversion ratio were observed in male broiler chickens fed on the different diets. 4. An effect of the additives on ileal dry matter (DM) digestibility at 42 d of age was detected with the finisher diets; AV and 10 g/kg of feed formic acid slightly improved ileal DM digestibility compared to the other treatment groups. 5. Jejunum pH was not affected when 5 or 10 g/kg formic acid was added, and the results do not clearly show a positive effect of formic acid on the intestinal histomorphology. 6. No differences were noticed for blood metabolites in the different diets, and the levels of calcium and phosphorus in the plasma were not altered by formic acid addition. 7. In conclusion, when using broiler chickens under conditions of good hygiene, dietary formic acid did not have a clear positive effect on performance, intestinal histomorphology or plasma metabolite levels; however, there was a slight positive effect on the ileal digestibility of nutrients.     

Effects of long-term dietary supplementation of monensin or saccharomyces cerevisiae on blood acid-base and productive performance in growing feedlot steers

The aim of this study was to evaluate the effects of two dietary supplements (monensin and a live yeast culture) on acid-base balance in steers maintained in a commercial feedlot system, considering effects over the growing period (14 to 23 weeks of age). A 63-day feedlot study was performed using 42 double-muscled Belgian Blue steers. Steers were allotted randomly to one of the three study groups: (1) control group [no supplementation, C], (2) monensin supplementation [MON] at a concentration of 30 mg/kg (DM basis), and (3) live Saccharomyces cerevisiae strain supplementation [SACC] at a dose of 500 mg/kg (DM basis).Venous blood samples were collected for the measurement of acid-base parameters and L-lactate. Production parameters were also used as a complementary tool for understanding the internal changes associated with supplementation. Our results show that during the study period no statistical differences were observed between supplemented and control steers, although non-supplemented animals tended to gain more efficiently than those fed monensin or yeast. Nevertheless, taking into account blood parameters, these control animals showed a greater risk of acid overload due to a more marked decline in blood buffer levels over time in comparison with supplemented steers although no differences were observed between monensin or yeast supplemented animals. Additionally, significant effect of supplementation was observed in packed cell volume (PCV) values.     

Monthly variation of fertility and oestrus frequency in crossbred dual-purpose cows in three agroecological areas of the South American tropics

The aim of this study was to examine the monthly variation of the first service conception (FSC) and oestrus frequency (OF) from 8308 artificial inseminations (AI) of 2960 crossbred dual-purpose cows on three commercial farms with improved management located in the Maracaibo Lake Basin, Venezuela. The effects of month of the year, agroecological area (from dry tropical forest to sub-humid tropical forest on the three farms), predominant breed (BT, Bos taurus; BI, Bos indicus), and season (December–April}; May–August; and September–November) were considered. Data were analysed using logistic regression (FSC) and GLM (OF) from SAS. The mean FSC was 55.4% overall and 48.7%, 57.0% and 58.3% for farms A, B and C, respectively (p < 0.01). Within the three agroecological areas (farms A, B and C), the FSC was highest during the cooler and drier months of the year (season 1), while the lowest FSC was obtained during the months of highest rainfall and humidity (season 3) (53.3% vs 37.4%; 58.5% vs 49.0% and 63.0% vs 52.3% on farms A, B, C, respectively; p < 0.01). In the three studied farms, OF was higher during the first 4 months of the year; with a diminishing trend towards the end of the year (p % 0.05). In general, BI cows had a higher FSC than BT cows, especially during the second half of the year, when environmental conditions were characterized by higher rainfall and humidity with lower wind velocity (58.8%^a 55.5%^b and 46.4%^c in season 1, 2 and 3 respectively; ^{a, b, c} p < 0.01).     

Influence of Grain Processing on Acid–Base Balance in Feedlot Steers

Grain processing (e.g. grinding, steaming, pelleting, flaking) has been reported to modify the incidence of ruminal disturbances in feedlot cattle. This study investigated the effects of two grain processing methods widely used in Spanish feedlots (grinding and pelleting) on animal performance, blood acid–base balance, blood electrolyte levels and serum lactate in a 140-day feedlot experiment with double-muscled Belgian Blue steers. The main aim of the study was to evaluate the way in which these two feeds modify blood acid–base balance, which is closely associated with ruminal pH. In light of our results we conclude that the animals that received the pelleted feed showed a more stable acid–base balance over time than those fed a ground feed. Nevertheless, higher levels of L-lactate and lower base excess (BE) and HCO₃ ⁻ values for cattle fed pelleted grain reflect a greater risk of grain-acid overload.     

Influence of climatic and management factors on Eimeria infections in goats from semi-arid zones

A survey of Eimeria infections was performed in dairy goats and kids (<6 months old) of six farms from a dry desert area of Gran Canaria Island (Spain). The number of oocysts per gram of faeces (OPG) was determined by a modified McMaster technique over a total of 2,616 individual faecal samples taken from the rectum in monthly intervals. Eimeria oocysts were found in 96.1% of the samples with OPG ranging from 1 x 10(2) to 1.4 x 10(6). Kid goats had significantly (P < 0.001) higher OPG counts (46,496 +/- 5,228) than dairy females (2,225 +/- 287). Eight Eimeria species were identified, with Eimeria ninakohlyakimovae (30.0%), Eimeria arloingi (28.6%) and Eimeria alijevi (20.5%) being the most frequent species followed by Eimeria caprina (9.1%), Eimeria christenseni (4.5%), Eimeria jolchijevi (3.4%), Eimeria caprovina (3.2%) and Eimeria hirci (0.7%). Although significant differences were observed among goat groups and herds, the eight species were present in the six farms in both dairy goats and kids. The intensity of oocysts shedding was related to some factors such as the size of the herd and was further influenced by the prevailing climatic conditions of the area. The highest OPG counts were recorded during the hot season in dairy goats and close to weaning time in kids reared in small farms having no prophylactic treatments against eimeriosis.     

Bacterial pseudomycetoma in dwarf hamster, Phodopus sungorus

A case of a dwarf hamster with two progressively growing nodules on the right fore limb is described. These were excised following ineffective medical treatment and were submitted for histopathological examination, which revealed bacterial pseudomycetoma in both nodules. To the authors' knowledge this is the first reported case of bacterial pseudomycetoma in a dwarf hamster.     

Use of stakeholder analysis to inform risk communication and extension strategies for improved biosecurity amongst small-scale pig producers

Extension and communication needs amongst small-scale pig producers, described as pig producers with less than 100 sows, have been previously identified. These producers, who are believed to pose a biosecurity risk to commercial livestock industries, are characterized by a lack of formal networks, mistrust of authorities, poor disease reporting behaviour and motivational diversity, and reliance on other producers, veterinarians and family for pig health and production advice. This paper applies stakeholder identification and analysis tools to determine stakeholders' influence and interest on pig producers' practices. Findings can inform a risk communication process and the development of an extension framework to increase producers' engagement with industry and their compliance with biosecurity standards and legislation in Australia. The process included identification of stakeholders, their issues of concerns regarding small-scale pig producers and biosecurity and their influence and interest in each of these issues. This exercise identified the capacity of different stakeholders to influence the outcomes for each issue and assessed their success or failure to do so. The disconnection identified between the level of interest and influence suggests that government and industry need to work with the small-scale pig producers and with those who have the capacity to influence them. Successful biosecurity risk management will depend on shared responsibility and building trust amongst stakeholders. Flow-on effects may include legitimating the importance of reporting and compliance systems and the co-management of risk. Compliance of small-scale pig producers with biosecurity industry standards and legislation will reduce the risks of entry and spread of exotic diseases in Australia.     

Multifocal cutaneous histiocytic sarcoma in a young dog and review of histiocytic cell immunophenotyping

A 9‐month‐old male Great Dane had progressive generalized nodular dermatopathy for several months. There were > 100 raised, alopecic, firm, painful nodules throughout the skin. Aspirates from several lesions yielded moderate numbers of irregularly round or polygonal to spindle‐shaped cells with mild to moderate anisocytosis and few inflammatory cells, and the cytologic interpretation was proliferation of mesenchymal or histiocytic cells. On histopathologic examination, nodules were composed of densely packed sheets of round to spindle‐shaped cells with mild anisokaryosis and low mitotic activity. Multifocal histiocytic sarcoma with a spindle‐cell pattern was diagnosed based on morphologic features and intense expression of CD18. Additional immunophenotypic analysis on frozen sections of tissue confirmed the diagnosis of histiocytic sarcoma; expression of CD18, CD45, CD1a, CD11b, and CD11c, limited expression of Thy‐1 (CD90) and CD80, and lack of expression of CD4, CD11d, and CD86 indicated that the cells were likely interstitial dendritic cells; a review of reactive and neoplastic dendritic cells is provided. Based on staging, internal organs were not affected. Sequential treatment with lomustine and doxorubicin failed to prevent progression of the cutaneous lesions, and the dog died 3 months after initial diagnosis. At necropsy, a focus of neoplastic cells was present in one lymph node, but except for skin other organs were not involved. The clinical presentation of histiocytic sarcoma may be unusual, and neoplastic cells may lack overt features of malignancy on cytologic and histopathologic examination. In some instances, immunophenotyping is required to differentiate histiocytic sarcoma from other histiocytic disorders.     

Deep planting with shelters improves performance of different stocktype sizes under arid Mediterranean conditions

New Forests - Increasing plant size has been considered a way to improve survival and growth of planted containerized stock under dry conditions. Additionally, deep planting provides advantages to...     

In vivo anthelmintic activity of Phytolacca icosandra against Haemonchus contortus in goats

Two separate controlled and blinded studies were conducted to confirm the dose and non-interference of spinosad and milbemycin oxime (MO) administered orally in combination or alone to dogs for the treatment and control of experimentally induced flea infestations (Ctenocephalides felis) and adult hookworm infections (Ancylostoma caninum). For each study, dogs were allocated randomly based on pre-treatment adult flea and hookworm egg counts to one of four treatment groups of 10 animals each. In each study, spinosad and MO in combination, using the lower half (30-45 mg/kg spinosad; 0.5-0.75 mg/kg MO) of the US commercial dose band (30-60 mg/kg spinosad; 0.5-1.0mg/kg MO) of each active ingredient, or individually alone using the full dose range, were given orally to dogs on Day 0 using a tablet formulation. A placebo control was treated similarly. In one study, on Days -1, 5, 12, 19, 28 and 35 each dog was infested with approximately 100 unfed adult C. felis obtained from the investigator's established flea colony. All dogs were infested via the same method. Forty-eight hour post-infestation flea comb counts were conducted on Days 1, 7, 14, 21, 30 and 37 and were used to determine the knockdown and residual flea activity. In the second study, on Day -27 each of 48 dogs were experimentally inoculated with 100 third-stage infective larvae of the hookworm, A. caninum. Dogs were treated on Day 0 and necropsied on Day 7 or Day 8. All nematodes in the intestinal tract were collected on Day 7 or Day 8, identified and counted by species and stage. Post-treatment, the geometric mean live flea counts were significantly different (p-value<0.0001) between the spinosad/MO combination and the spinosad only treatment groups as compared to the vehicle control group. The flea counts in the MO only group and the control group were not statistically different. The spinosad and MO combination group and the spinosad only treatment group demonstrated significantly different knockdown (100%) and post-treatment residual flea efficacy at Day 30 was 100% for both groups as compared to the vehicle control. The presence of MO in combination with spinosad did not interfere with the flea efficacy of spinosad as compared to the spinosad only group. MO alone did not demonstrate any flea efficacy. Post-treatment, the geometric mean A. caninum worm counts were significantly different (p-value<0.0001) between the spinosad and MO combination group as compared to the vehicle control group. The worm counts in the MO only group and the combination group were not statistically different. The spinosad and MO combination group (99.8% reduction) and the MO only treatment group (99.5% reduction) both demonstrated significantly different hookworm efficacy as compared to the vehicle control group. The presence of spinosad in combination with MO did not interfere with the hookworm efficacy of MO as compared to the MO only group. Spinosad alone did not demonstrate any hookworm efficacy. In summary, flavored spinosad and MO combination tablets administered orally to dogs at the lower end (30-45 mg/kg spinosad; 0.5-0.75 mg/kg MO) of the US commercial tablet unit dose range (30-60 mg/kg spinosad; 0.5-1.0mg/kg MO) were both safe and highly efficacious delivering 100% knockdown and 30 days of residual adult flea control on experimentally infested dogs as well as >99% adult hookworm efficacy evaluated under laboratory conditions. Interference between either drugs was not demonstrated for both of these dose limiting parasites.