Use of Fecal Indices as a Non-Invasive Tool for Nutritional Evaluation in Extensive-Grazing Sheep

Supplement Type Impact on the Performance and Nutrient Dynamics of Nursing Does and Kids Raised in Woodlands

The influence of different supplement types on the performance and nutrient dynamics of goats stocked in woodlands is not known. The objective of this study was to evaluate the effect of supplement type on the performance and the concentration of fecal nutrients of nursing does and the performance of kids raised in woodlands. One group of goats (SG, 9 does; 18 kids) was allowed supplemental grazing in adjacent silvopasture plots for 3-4 h daily and another group (SF, 8 does; 15 kids) was supplemented with corn (0.5% of metabolic weight) and ad libitum hay. Vegetation samples were collected and analyzed for productivity and quality (crude protein, CP; acid detergent fiber, ADF; neutral detergent fiber, NDF). The quality of the hay (N, ADF, NDF) and fecal samples (N, P, Ca) was analyzed. The animals' live weight, FAMACHA score, and body condition score were collected. The browsing height for does consuming woodland vegetation was measured. Data were analyzed using the GLM procedure, Mixed procedure, and MEANS procedure in SAS 9.4. SG does showed better FAMACHA scores vs. SF does (p < 0.05). Fecal N and ADF were greater (p < 0.0001) in SG does vs. SF does. The findings showed a better performance and greater concentration of fecal nutrients in SG does vs. SF does, suggesting grazing quality pastures is a better option than using feedstuffs to supplement nursing does in woodland.

Use of Fecal Indices as a Non-Invasive Tool for Ruminal Activity Evaluation in Extensive Grazing Sheep

Simple Summary

The main objective of this work was to evaluate the degree of association that exists between three fecal indices (concentrations of 2,6 diaminopimelic acid, nitrogen, and phosphorus) and biomarkers of ruminal activity, as a non-invasive way to estimate the nutritional status in sheep grazing on annual rangeland. It was possible to establish that fecal indices, and especially fecal nitrogen and phosphorus, were linearly and positively correlated with the ruminal concentration of some volatile fatty acids, especially branched-chain, and rumen ammonia. Due to the above, these fecal indices could be used to evaluate the ruminal activity and the nutritional status of grazing sheep, with minimal manipulation of the animals.

Abstract

For a simple, non-invasive evaluation of nutritional status of sheep kept under extensive grazing conditions on annual rangeland, fecal indices (2,6 diaminopimelic acid, nitrogen, and phosphorus) obtained during the vegetative, reproductive, and dry grassland phenological stages, were correlated with ruminal physiological biomarkers (volatile fatty acids and ruminal ammonia). Through correlation analysis and linear regressions, the degree of association between the variables studied was established. The fecal indices that presented the highest degree of association with ruminal variables were FN and FP, being highly correlated with the production of branched-chain volatile fatty acids (isobutyrate and isovalerate) and with ruminal ammonia (r ≥ 0.65), establishing simple linear regression equations of high significance (p ≤ 0.05). Therefore, fecal indices, especially fecal concentrations of N and P, could reflect the metabolism at the ruminal level and with it the availability of compounds for microbial growth, which would help to establish the nutritional status of sheep herds under extensive grazing conditions.

Diet Selection by the Italian Hare (Lepus corsicanus de Winton, 1898) in Two Protected Coastal Areas of Latium

Simple Summary

In order to better understand the ecological niche of the Italian hare, we evaluated the diet selection of the species in two protected areas of the Latium coastal environment. The main results emerging from our study were: the wide feeding spectrum of the Italian hare; the high incidence of grasses in dry and in wet season diets; the low number of plant species ingested at relatively high rates; the plastic feeding behaviour of this hare, as diet preferences changed with the variety and abundance of food species. These results highlighted the great adaptability of the species to different niches and the influence of the floristic composition on its feeding habits. In the Italian hare, the assessment of habitat suitability is of strategic importance for its conservation. In particular, feeding preferences of the species may lead to defining some food items as key plant species for identifying its elective habitat and, hence, planning effective re-introduction initiatives.

Abstract

This study was focused on the diet and feeding behaviour of Lepus corsicanus in two protected coastal areas of Latium, Castelporziano Presidential Estate (CPE) and Circeo National Park (CNP). Plant frequency was assessed by the quadrat method, while diet composition was determined by microhistological analysis of faecal samples. Over the year, the Italian hare fed on 185 of the 229 plant species identified in vegetation, with most of them ingested in low percentages (≤1%). During the dry season (DS), in both areas, Brachypodium sylvaticum, Cynodon dactylon, and Avena fatua were among the most consumed species. In the wet season (WS) the most common plant species in diet were B. sylvaticum, Poa trivialis, and Carex distachya in CPE and Dactylis glomerata, Cynosurus echinatus, and Spartium junceum in CNP. In both sites, considering the annual selection of life forms, grasses and leguminous forbs were preferred, while non-leguminous forbs and shrubs were used less than expected according to their availability. ANOSIM analysis showed significant differences between sites in DS and WS diets. Our study evidenced that the Italian hare behaved as generalist, revealing its capability for exploiting several plant species and to adapt its diet preferences to space-time variation of food availability.

Botanical Composition and Diet Quality of the Vicuñas (Vicugna vicugna Mol.) in Highland Range of Parinacota, Chile

Simple Summary

For the proper management of grazing wild ungulates, it is very important to know the botanical composition and quality of their selected diets. In the case of the vicuña, a wild camelid that lives in the Chilean highlands, there is little information related to these aspects. Therefore, in this work, the variations in the botanical composition and quality of their diets throughout the year were studied, which were estimated by analyzing the plant fragments found in the feces and the concentration of nitrogen within them. The vicuña mainly selects grasses from dry and wet grassland but is also capable of selecting other species, such as graminoids and dicotyledonous herbs. These plants contribute to obtaining a diverse and high-quality diet, this being an efficient foraging strategy to be able to consume a good quality diet, mainly in the months of high nutritional demand, which coincides with the summer rainy season.

Abstract

Understanding the botanical composition of herbivores’ diets and their nutritional quality is an important question in the development of sustainable strategies for the management of natural resources. In Chilean highland vicuña-grazed grasslands, there is little information in this regard and, therefore, this study aimed to determine the year-round profile of the diet’s botanical composition and quality. In highland grasslands, on an area of 21.9 ha, continuously grazed for 3.06 VU/ha/year (18°03′ S, 69°13′ W; 4425 m.o.s.l), twelve feces piles were sampled monthly and were analyzed through microhistology, and the nitrogen concentration [NF, OM basis] was determined. The botanical composition, diversity (J) and selectivity index (E_i) of the main species were estimated. Diets were composed of dry–grassland grasses (37.7%), wet–grassland grasses (36.6%), graminoids (14.3%) and forbs (10.2%). The diet diversity ranged from 0.79 (dry–winter) to 0.87 (wet–summer). The main dominant grassland species obtained negative E_i values. The annual mean value of [NF] was estimated as 1.82%, with a higher value in summer months (2.21%), which coincides with the physiological states of higher nutritional demand. The vicuñas behave like generalist ungulates, having a high degree of selectivity towards grass species, which mostly fulfill a nutritional role in subsistence and a functional role in survival, applying foraging strategies that allow them to obtain a better quality diet during the season of greatest nutritional demand.