Nutrient intake of horses in Thoroughbred and Standardbred stables

SUMMARY Twenty-five Thoroughbred (TB) and 25 Standardbred (SB) stables were visited to determine their feeding practices. The ingredients of the main feed of the day for a mature gelding of average size in full training were weighed at each stable. Nutrient content of diets was calculated using published data for the individual ingredients. Results are expressed as mean±sd. The estimated body weight of TB horses was 493±34 kg and 437±32 kg for SB horses. There was considerable variation in diet composition and nutrient intake between stables. The TB trainers fed 11.0±2.4 kg and SB trainers 11.8±2.5 kg per day. The concentrate component of the diet weighed 7.8±1.6 and 7.7±2.3 kg for TB and SB stables, respectively, and the roughage component for TB horses 3.3±1.4 and SB horses 4.1±1.4 kg per day. The digestible energy intake of horses at TB stables was 129±29 MJ per day and at SB stables 132±31 MJ per day. Crude protein intake of TB horses was 1452±363 g and SB horses 1442±338 g per day. There were differences in some feeding practices at TB and SB stables. Standardbred trainers fed more roughage than TB trainers. Standardbred trainers fed chaffed lucerne (alfalfa) and cereal hays as the major roughage, whereas TB trainers fed more hay. The major hay type fed by TB trainers was lucerne, whereas many SB trainers preferred clover hay. Both trainers fed oats as the major grain, but TB trainers fed slightly more maize (corn) than SB trainers. The SB trainers fed barley as part of the concentrate component of the diet, whereas TB trainers usually fed boiled barley and linseed oil in winter only. Although many trainers used vitamin and mineral supplements, this appeared unnecessary in many Instances, especially with respect to Iron. Calcium and NaCI supplementation was necessary for some diets. We concluded that while there was a wide range in feed intake and diet composition for both TB and SB horses, average nutrient intakes were similar to National Research Council (1989) recommendations for horses performing intense work.     

Detection and genetic diversity of porcine rotavirus A,B and C in eastern Australian piggeries

Rotaviruses (RV) have a high prevalence in piggeries worldwide and are one of the major pathogens causing severe diarrhoea in young pigs. RV species A, B, and C have been linked to piglet diarrhoea in Australian pig herds, but their genetic diversity has not been studied in detail. Based on sequencing of the structural viral protein 7 (VP7) RVA G genotypes G3, G4 and G5, and RVC types G1, G3, G5, and G6 have been identified in Australian piggeries in previous studies. Although occurrence of RVB was reported in Australia in 1988, no further genetic analysis has been conducted. To improve health management decisions in Australian pig herds, more information on RV prevalence and genetic diversity is needed. Here, 243 enteric samples collected from 20 pig farms within Eastern Australia were analysed for the presence of RV in different age groups using a novel PCR-based multiplex assay (Pork MultiPath™ enteric panel). RVA, RVB, and RVC were detected in 10, 14, and 14 farms, respectively. Further sequencing of VP7 in selected RV-positive samples revealed G genotypes G2, G5, G9 (RVA), G6, G8, G14, G16, G20 (RVB), and G1, G3, G5, G6 (RVC) present. RVA was only detected in young (<10 weeks old) pigs whereas RVB and RVC were also detected in older animals (>11 weeks old). Interestingly, RVB and RVC G-type occurrence differed between age groups. In conclusion, this study provides new insights on the prevalence and diversity of different RV species in pig herds of Eastern Australia whilst demonstrating the ability of the Pork MultiPath™ technology to accurately differentiate between these RV species.     

Detection of Ureaplasma diversum in the upper airways of Australian feedlot cattle

Bovine respiratory disease (BRD) exerts a major impact on the beef cattle industry nationally and worldwide, with a range of aetiological factors impacting its pathogenesis. Previous research has focussed on an increasing number of bacteria and viruses that have been shown to play a role in eliciting disease. Recently, additional agents have been emerging as potential contributors to BRD, including the opportunistic pathogen Ureaplasma diversum. To determine if U. diversum was present in Australian feedlot cattle and if that presence was linked to BRD, nasal swabs were collected from a cohort of 34 hospital pen animals and compared to 216 apparently healthy animals sampled contemporaneously at feedlot induction and again after 14 days on feed at an Australian feedlot. All samples were subjected to a de novo polymerase chain reaction (PCR) assay targeting U. diversum in combination with other BRD agents. U. diversum was detected at a low prevalence in cattle at induction (Day 0: 6.9%, Day 14: 9.7%), but in a significantly greater proportion of cattle sampled from the hospital pen (58.8%). When considering the presence of other BRD-associated agents, co-detection of U. diversum and Mycoplasma bovis was most common in hospital pen animals receiving treatment for BRD. These findings suggest that U. diversum may be an opportunistic pathogen involved in the aetiology of BRD in Australian feedlot cattle, in combination with other agents, with further studies are warranted to identify if a causal relationship exists.     

Assessment of the socio-economic impacts associated with the arrival of apple snail (Pomacea canaliculata) in Mwea irrigation scheme,Kenya

Background

In Kenya, rice (Oryza sativa L.) is mainly produced under irrigation by small-scale farmers. Mwea irrigation scheme (MIS) in Kirinyaga County accounts for 80–88% of rice production. Here, rice is the main source of livelihood and a source of revenue generation for the county. However, a recently established invasive freshwater snail, Pomacea canaliculata (Lamarck) (family: Ampullariidae), a species of apple snail, presents a serious threat to rice production.

Results

Household surveys, focus group discussions and key informant interviews highlight apple snail as a serious problem in MIS. Households that observed at least a moderate level of infestation (>20% of cultivated area) experienced significant reductions in rice yield (~14%) and net rice income (~60%). Farmers reported increased use of chemical pesticides for management of apple snail. In addition, the cost of hired labor for physical removal of egg masses and snails is resulting in substantial negative effects on net income. Farmer age, area of land owned, responsibility for decision-making, receipt of extension advice, training, and membership of a farmer organization, were all statistically significant variables to explain farmers awareness of the need for area-wide apple snail management.

Conclusion

Strategies to limit the spread of apple snail are urgently needed. A Multi-Institutional Technical Team (MITT) has been established to spearhead management efforts and consolidate advice to farmers on how to manage apple snail. However, without action to mitigate spread, the consequences could be disastrous for rice production and food security in Kenya, and for other rice growing regions across Africa. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.     

Foliar lifespan,phenology and seasonal dynamics of the invasive shrub Schinus terebinthifolia

Schinus terebinthifolia is a dioecious tree native to South America that has become an invasive weed in Florida, southern California, southern Arizona, Texas and Hawaii and has been naturalised in over 20 countries. Biological control is considered a viable long-term control option for S. terebinthifolia because release from natural enemies appears to be at least partly responsible for its success in Florida. We examined leaf phenology of S. terebinthifolia over a period of 15 months at five sites in central and southern Florida to provide information that may help in predicting the impacts of potential biocontrol agents for this weed. We documented leaf lifespan, the seasonality of leaf development and abscission and the survivorship of leaves that emerged during either spring, summer or autumn. Average leaf lifespan was >4.5 months at all sites, and leaf phenology followed the seasons closely. Although S. terebinthifolia possesses leaves throughout the year, leaf production was greatest from April to September, and most leaves were abscised in February and March. Spring- and summer-emerging leaves were also longer-lived than leaves produced during autumn. These results suggest that leaves of S. terebinthifolia would be most vulnerable to herbivory during the spring and summer months when newly growing leaf tissue is most plentiful. Biocontrol agents capable of damaging these tissues during spring/summer might be an effective means of controlling this invasive weed.     

Soil fungal population levels in cotton fields fertilized with poultry litter and their relationships to soil nutrient concentrations and plant growth parameters

Application to land of large quantities of waste materials from concentrated animal production, without causing environmental pollution, presents a major challenge to agriculture in the 21st century. Effects of land-applied animal wastes on chemical contents of soil are well documented, but less is understood of their effects on microbial populations in soil. This study was undertaken to evaluate effects of commercial application of poultry litter (PL), as a fertilizer, on soil fungal population levels and components on cotton farms in Mississippi, and to determine relationships of fungal population levels to soil nutrient contents and cotton growth and yield. On each of two farms, soil fungal population levels were estimated by dilution plating from samples of soil collected at two sampling times during 2 years from replicated plots of four fertilization treatments: 0 fertilizer, conventional mineral fertilizer (CF), low PL, and high PL. Soil fungal population levels differed significantly (P = 0.05) according to years or seasons and fertilization treatments on both farms. Population levels often were higher in soils amended with low or high PL, or with CF, than in unfertilized controls. On one farm where PL was tilled into soil, fungal population levels increased significantly during the course of the experiment in PL and CF treatments, but not in unfertilized controls, as determined by linear regression. No such increases were observed on the second farm where PL was applied no-till. Population levels of Fusarium semitectum and Penicillium purpurogenum were significantly higher in PL-treated soils than in unfertilized controls in 1 or 2 of 4 sampling events at both farms, while levels of four other species or groups of fungi usually did not differ. Fungal population levels were significantly correlated (P = 0.05) with N concentrations of soils in 1–4 sampling events on each farm and less frequently correlated with concentrations of nine other elements. In 4 of 24 instances, soil fungal population levels were significantly correlated with leaf area index, chlorophyll content, or yield of cotton, and correlation coefficients with these plant parameters were always positive. Major conclusions derived from this study are (1) no deleterious effects on population levels of total or select soil fungi were observed with use of PL as a fertilizer for commercial cotton production; and (2) soil fungal population levels may increase over time in association with greater fertility and plant growth that is induced by both mineral fertilizer and PL applications.     

Intake and digestion of barley straw by sheep given expelled groundnut meal with different amounts of calcium

Summary Six wether sheep were used in a 6×6 latin square experiment to study the effect of calcium intake on intake and digestibility of barley straw fedad libitum with low and high oil groundnut meal. The level of added calcium ranged from 1.6 to 3.0 g/day for the low oil and 6.4 to 10.4 g/day for the high oil diet. Each experimental period was of 21 days duration which comprised 14 days for adaption to the diet followed by a sevenday collection. The amount of added calcium had a significant effect only with the high oil groundnut meal. The digestibility of crude fibre in diets which contained this meal was significantly increased (p<0.05) when the amount of added calcium was raised from 6.4 to 8.0 g/day. The sheep showed a marked adaptation to the diets which was manifested as a highly significant increase (p<0.001) in straw intake as the trial progressed. There was a significant difference (p<0.05) between animals in intake and digestibility of some dietary constituents. This was shown particularly by one animal whose intake was substantially greater but whose digestive ability was appreciably less than the other five. The nitrogen retention by the sheep on the six diets differed considerably between the two types of groundnut meal. It was higher when the high oil meal was fed and this difference was mainly due to a smaller excretion of urea.

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Sumario Los ensayos de digestibilidad y pruebas de balance fueron llevadas a cabo en 6 ovinos castrados con el fin de estudiar el efecto del suplemento de calcio sobre la ingestión y digestibilidad dela paja dela cebada con dietas de harina de maní altas y bajas. El incremento en la digestibilidad de la fibra cruda con la harina de maní en dosis altas se atribuyó al calcio suplementado. La adaptación de los ovinos a las dietas fue notada conforme progresaba el experimento junto con una amplia variación entre los animales en ingestión y digestibilidad de algunos constituyentes de la dieta. La retención de nitrógeno fue mas alta en aquellos animales alimentados con niveles altos de harina de maní, y debido a una mas peque?a excreción de urea.

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Résumé Des essais de digestibilité et de bilan ont été effectués sur six moutons pour étudier l’influence d’un complément de calcium sur la consommation et la digestibilité de paille d’orge avec une proportion faible ou élevée de tourteau d’arachide. Une augmentation de la digestibilité de la cellulose brute de ce dernier a été attribuée à l’addition de calcium. L’adaptation des moutons aux rations a été progressive mais une grande variation de la consommation et de la digestibilité de quelques constituants alimentaires a été constatée entre les animaux. La rétention d’azote était plus élevée chez les animaux ayant re?u une proportion élevée de tourteau d’arachide, par suite d’une excrétion plus faible d’urée.