ABSTRACT:Mycotoxins are commonly present in feed for farm animals. Sows and gilts are highly susceptible to mycotoxins. This article presents a review describing the main mycotoxins encountered in pig feed which have a negative impact on sow fertility and reproduction. Consumption of feed that is contaminated with these mycotoxins may cause a variety of symptoms, depending on the type of mycotoxin, quantity and duration of exposure, as well as the health status and condition of the animal at the time of exposure. Two types of fungi are recognized, field fungi and storage fungi. Field fungi such as Fusarium spp., Aspergillus spp. and Claviceps spp. may produce toxins that lead to disturbed reproductive performance. Storage fungi occur if the humidity during storage is too high. In daily practice, the symptoms related to mycotoxicosis can occur at toxin concentrations below the detection limit. Knowledge of the effects of mycotoxins is expanding rapidly. Mycotoxins may still be present in feedstuffs despite negative analytical findings and because of the presence of hot spots in feed and or feedstuffs. Clinical symptoms can be very pronounced, making the diagnosis for the practitioner quite easy but in many cases the symptoms are vague and not at all present at herd level on a regular basis. The practitioner is in the first line of raising awareness in all parties whenever the first indication exists of a possible mycotoxicosis problem causing reproductive failure in breeding pigs. The problems can be resolved only if all parties involved in pig herd health take the necessary preventive measures and actions. The main toxins causing reproductive failure discussed in this article are aflatoxins, ergot alkaloids, trichothecenes and zearalenone.

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Synchronization of the oestrous cycle of gilts using altrenogest treatment has been found to increase ovulation rate. The current experiment investigated if the increase in ovulation rate after altrenogest treatment is related to increased follicle size at the end of altrenogest treatment compared with late luteal phase follicles. Crossbred gilts (n = 15) received altrenogest during 18 days [20 mg Regumate (Janssen Animal Health, Beerse, Belgium)], starting 5-7 days after onset of first oestrus. Control gilts (n = 15) did not receive altrenogest. At days 10-12 of the oestrous cycle [i.e. in the presence of corpora lutea (CL)], average follicle development was 2.51 +/- 0.20 mm (assessed with ultrasound) in altrenogest-treated gilts and 2.58 +/- 0.16 mm in control gilts (p > 0.10). During the last days of altrenogest treatment (i.e. when CL had gone into regression), average follicle size had increased to 3.01 +/- 0.31 mm (p < 0.05). Subsequent ovulation rate was 16.6 +/- 1.7 in altrenogest treated gilts and 15.1 +/- 1.2 in control gilts (p < 0.05). Altrenogest treatment resulted in increased follicle size after regression of the CL, showing that suppression of follicle growth by altrenogest alone is less severe than suppression by endogenous progesterone (either with or without altrenogest). Altrenogest treatment also resulted in a higher ovulation rate. However, it is unclear if the increased follicle size and higher ovulation rate after altrenogest treatment are causally related, as the relation between the two on an animal level was not significant.

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This paper upgrades generic and partial information from parasitological research for farm-specific decision support, using two methods from managerial sciences: partial budgeting and frontier analysis. The analysis focuses on strategic deworming in pig finishing and assesses both effects on economic performance and nutrient efficiency. The application of partial budgeting and frontier analysis is based on a production-theoretical system analysis which is necessary to integrate parasitological research results to assess aggregate economic and environmental impacts. Results show that both statistically significant and insignificant parasitological research results have to be taken into account. Partial budgeting and frontier analysis appear to be complementary methods: partial budgeting yields more discriminatory and communicative results, while frontier methods provide additional diagnostics through exploring optimization possibilities and economic-environmental trade-offs. Strategic deworming results in a win-win effect on economic and environmental performances. Gross margin increases with 3 to 12 € per average present finisher per year, depending on the cyclic pig price conditions. The impact on the nutrient balance ranges from +0.2 to -0.5 kg nitrogen per average present finisher per year. The observed efficiency improvements are mainly technical and further economic and environmental optimizations can be achieved through input re-allocation. A user-friendly spreadsheet is provided to translate the generic experimental information to farm-specific conditions. Keywords: partial budgeting; frontier analysis; pig finishing; strategic deworming Supported by the Institute for the Promotion of Innovation by Science and Technology in Flanders (IWT Vlaanderen).Endoparasites in livestock cause discomfort, physical damage and economic losses (Stewart and Hale, 1988;Corwin, 1997;Vercruysse and Dorny, 1999;Jaeger et al., 2005;Kemper and Henze, 2009). Many efforts are made by scientists and veterinary pharmaceutical companies to develop anti-parasitic products and/or strategies (e.g. Murrell, 1986;Roepstorff and Jorsal, 1989;Roepstorff and Nansen, 1994;Williams, 1997;Nansen and Roepstorff, 1999;Vercruysse and Dorny, 1999;Joachim et al., 2001;Beloeil et al., 2003;Jaeger et al., 2005;Kemper and Henze, 2009). In order to get adopted by farmers, these strategies must guarantee net improvements in economic farm results. As long as parasitological research outcomes demonstrate significant improvements in key performance indicators such as productivity, quality or mortality, traditional techniques like partial budgeting (see e.g. Dijkhuizen and Morris, 1997) suffice for aggregating these outcomes to assess net economic effects and for extrapolating results to a larger set of farms. In its most simple form, aggregation and extrapolation can even be done with rough back-of-the-envelope simulations.