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Simple Summary: Under field conditions, interactions occur between animals, parasites and the environment. Usually, only 30% of goats (over a dispersed distribution) display high gastrointestinal nematode (GIN) burdens. Hence, focusing on individual infection would allow better management of the impact of GINs. As acclaimed evolutionary biologist and natural historian S.J. Gould (1941–2002) once emphasized: "The Median Isn't the Message". The relationship between individual and herd GIN infection levels, nutritional and productive performance and anemia parameters in a tropical farm context were evaluated. Fifty-four female goats browsing the tropical forest (supplemented with balanced feed and chopped grass) were used. Measurements were obtained every 15 days (six samplings during the study); likewise, in each sampling time, the fecal samples were obtained in the morning [AM] and afternoon [PM] to assess the GIN burdens (eggs per gram of feces). The individual AM and PM values were similar and highly correlated at each sampling time. The nutritional and productive status fluctuated over time, although the median GIN burden of the flock was relatively constant. Nevertheless, the individual GIN burden differed when assessed at 30 d intervals; thus, these sampling points can be considered independent. Higher GIN burdens were associated with low body condition and low hematocrit. Moreover, the marked fluctuation of live weight should warn that nutrition is highly dynamic and could have a more important effect than GIN burden on the performance of goats under farm conditions in the tropics. We evaluated the relationship between individual and herd GIN infection level, nutrition, production performance and anemia parameters in a tropical farm context. Fifty-four female goats were monitored to assess their body condition score (BCS, nutritional status indicator), live weight (LW) and LW gain (LWG, both used as production level indicators), FAMACHA© and hematocrit (HT, both used as anemia indicators). Goats browsed for 4 h in a tropical forest and received balanced feed and chopped grass. The eggs per gram of feces (EPG) indicated the GIN burden, with fecal samples obtained at 7:00 (AM) and 15:00 h (PM.) from each goat at six sampling points during the study. The variables and their relationship with GIN burdens were analyzed using Kruskall–Wallis, ANOVA and Friedman tests and Spearman correlations. The fecal samples obtained in the AM and PM can be equally representative of parasitic burdens (similar and highly correlated). However, the EPG of individual goats from periods of 30 days apart can be considered independent. The BCS and LWG varied between sampling times (p < 0.05), whereas EPG, LW and HT did not (p > 0.05). The GIN burden was negatively correlated with HT and BCS (−0.21, p = 0.01 for each one). The individual pattern of infection demonstrates the true impact of GINs on their hosts. Additionally, feeding and nutritional status may present important variations influencing the performance of the goats more than the impact of GINs under the farm conditions of the present study. However, GIN infection contributed to the variation in goat health and productivity in this tropical farm. [ABSTRACT FROM AUTHOR]

Simple Summary: Grazing/browsing goats ingest a diverse diet selected from the forage resources available in the range/paddock intending to meet their nutritional requirements. Intake and selection of any given forage can be modified by several factors, such as its nutrient content, including secondary compounds, as well as its biomass availability in the environment. The animal's previous browsing experience can also be an important factor driving intake and selection. Therefore, the present study evaluated all these factors as well as their interaction. The results showed that the goats' browsing experience guided the selection and intake towards those forage resources of better nutritional quality when there was no restriction in forage supply, as is the case for cafeteria trials. Goats with browsing experience showed their ability to limit secondary compounds and optimize their selection and intake for plants with better digestibility. This cafeteria protocol made it possible to identify the selection and consumption pattern of plant species with limited availability in the natural vegetation. This methodology could help identifying the forage resources that may be useful for small ruminant feeding, versus those resources that are not consumed by goats despite having a suitable chemical composition and in vitro digestibility or a high abundance. We evaluated the effect of browsing experience, nutritional quality and secondary compounds of forage resources, and the interaction between these factors on the selection and intake of goats in a cafeteria trial. Twelve juvenile Criollo goats from 7 to 9 months of age, weighing 22 ± 3 kg, were divided into two groups: (a) browser goats group (n = 6, BG), and (b) naïve goats group (n = 6, NG), formed according to their previous browsing experience (with and without, respectively). Animals were housed in individual pens. The cafeteria experiment lasted 21 days considering pen adaptation, foliage adaptation, and measurements, which included the selection index (SI) of experimental forage resources (Chesson's alpha) and their dry matter intake (DMI/Kg0.75), using a multiple Latin square design. Furthermore, correlation and regression analyses were used to assess the relationship between the aforementioned factors. The NG did not show any selection pattern, while the BG selected Piscidia piscipula and Senegalia gaumeri (p = 0.0002). The BG consumed smaller amounts of secondary compounds compared to NG (p = 0.0001). In the BG, the flavonoids affected negatively their selection (R2 = 97.51, p = 0.0001), while the DMI was affected by in vitro DM digestibility and flavonoids (R2 = 99.85; p = 0.0001). For the NG, the crude protein and organic matter contents were associated with DMI, but none had a significant relationship with SI. The BG selected and consumed forages with suitable nutritional quality avoiding those with high content of secondary compounds such as flavonoids. Conversely, NG did not show a clear pattern for their selection or intake. [ABSTRACT FROM AUTHOR]

Simple Summary: The low deciduous forest is an ecosystem covering 8% of México's surface and is present in 15 of the 32 states of the country. It has been observed that sheep and goats feeding in this high biodiverse biome can consume up to 80 plant species. In addition, the low deciduous forest biomass is frequently used to feed small ruminants in cut and carry systems. However, there is not enough information to provide guidelines for its sustainable use by ruminant livestock. In the present review, we present an interdisciplinary approach aimed at identifying the nutraceutical properties of this native vegetation system, involving disciplines like botany, ecology, agronomy, ethology, ethnoveterinary, nutrition, parasitology and chemistry. Nutraceuticals are defined as livestock feeds combining nutritional value with beneficial effects on animal health and productivity. The identification of nutraceutical properties amongst plant species of the low deciduous forest may contribute to the revalorization of this native vegetation system and provide information enabling the design of sustainable livestock feeding/management systems that benefit the nutrition and health of small ruminants, and ultimately human health through the consumption of animal products produced in this native vegetation system. The plant kingdom can influence the productivity and health of herbivores at different levels. However, demonstrating this process in a scientific manner entails substantial endeavors from different disciplines. In the present review, we will describe the features of a native vegetation system traditionally used by small ruminants and use its particularities to build an interdisciplinary approach to evaluate the nutraceutical properties of plants. Initially, we will establish the context of the low deciduous forest (LDF), considering some botanical and nutritional aspects, as well as the presence of plant secondary compounds (PSC) and gastrointestinal nematodes (GIN). Furthermore, we will focus on coevolutionary aspects that undoubtedly shaped the plants–nutrients–PSC–GIN–herbivore relationship. In addition, the concept of nutraceutical will be discussed to provide clarity and aspects to be considered for their evaluation. Then, ethological, agronomical, nutritional, PSC, parasitological and animal species issues are deepened placing emphasis on methodological approaches. Special focus is given to condensed tannins, as they are the fourth largest group of PSCs and the most studied in livestock sciences. Validation of the nutraceutical properties of plants from native vegetation systems should be seen as a process derived from many scientific disciplines that feed into each other in a cyclic manner. [ABSTRACT FROM AUTHOR]