SIMILARITY INDICES OF A SARCOCAULESCENTE SCRUBLAND AND BROWSING GOATS DIET IN NORTHWEST MEXICO (original) (raw)
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SUMMARY The extent of vegetation used by free browsing goats on a rangeland is a practical measure to determine rangeland productivity and may be measured by the similarity indices between the botanical composition of diet and the rangeland. The aims of this study were to evaluate and compare, seasonally the similarity indices of forage species and goats diets under the Sonorant desert conditions. Samplings were carried out in summer and autumn of 2006, and winter 2007 in a 200-ha rangeland with an animal density of 0.13 to 0.36 individuals/ha. Twenty two fixed transects (30 m long) distributed randomly were used to measure the botanical composition and importance value (IV) for plant types by the line-intercept method. Identified species were classified as non legumes trees and shrubs (NLTS), legumes trees and shrubs (LTS), cacti, forbs, agaves and grasses. Five castrated Creole-Nubio goats (29 kg of BW) provided with esophageal fistula were used to obtain diet samples and determine botanical composition of diets by microhistological analyses. Botanical composition of diet (A) and IV values (B) were used to calculate the similarity indices (SI) according to S = 2(W)(100)/A+B, being W the lower value between A and B. Sixty plant species were founded in the study area, but only 23 species were in diet of goats. Similarity indices indicated that NLTS were more utilized in all seasons than other plant types. The SI between seasons indicated a gradient of forage utilization in the following order (P<.05): In summer; forbs (87.3) > NLTS (70.2) > LTS (39.1) > cactus (0.0) = grasses (0.0), in autumn; cactus (85.9) > NLTS (85.6) > forbs (77.1) > LTS (73.3) > grasses (6.9) and in winter LNTS (88.8) > LTS (88.0) > grasses (87.4) > forbs (70.8) > cactus (53.3). Goats utilized only 30% of the vegetation on rangeland in all seasons and showed light change in their forage utilization pattern because of the opportunistic feeding behavior of these animals; however they maintain a high utilization on shrubs and trees.
Preference Indices for Forage Species Grazed by Spanish Goats on a Semiarid Shrubland in México
Journal of Applied Animal Research
Forage intake and nutrition of range goats in a shrubland in northeastern Mexico 1991. 69:879-885. J Anim Sci http://jas.fass.org the World Wide Web at: The online version of this article, along with updated information and services, is located on www.asas.org ABSTRACT Voluntary intake and nutritive value of diets selected by goats grazing a shrubland at Marin county, N.L., Mexico were determined. Four esophageally cannulated Spanish female goats (average BW 35 kg), were used to collect extrusa samples monthly throughout 1 yr (June 1987 to May 1988). Organic matter intake (OM) was estimated by total fecal collections from four castrated Spanish male goats (average BW 42 kg). Diets selected by goats were high in CP throughout the year (Z = 18.9%). Available CP represented only about half the total CP. The ADF content of extrusa samples differed (P < .05) among months, with high ADF values during winter months. Dietary lignin followed a similar pattern during the year. Goats consumed forage with sufficient amounts of Ca, Na, K, Mg, Cu, ZN, Mn, and Fe to meet requirements. The OMI of goats was different (P < .05) among sampling periods. On the average, estimated OMI 6 = 878.7 g/d) compared well with results of other studies in the area. Amounts of DE consumed by goats (1.1 Mcal DE/d)
RESUMEN El agostadero sarcocaulescente es representativo del desierto Sonorense en Baja California Sur, México, de su flora, 92 % son arbustos y 23 % son especies endémicas, sin embargo, el impacto ecológico de la producción animal es desconocido. Los objetivos de este estudio fueron determinar y comparar durante dos años la preferencia y utilización de especies de plantas por caprinos en pastoreo. La colecta de datos de campo se llevó a cabo de junio de 2006, a junio de 2008. Los datos de composición botánica de la dieta y del área de estudio se emplearon para estimar los índices de preferencia y similitud. Se detectaron 78 especies, de las cuales los caprinos utilizaron 41; en cada muestreo, los animales utilizaron de 10 a 24 especies. El índice de similitud medio fue 26 % (16-32 %), la preferencia y la utilización fueron variables entre muestreos. La preferencia no estuvo acorde con la similitud. Este patrón de conducta alimenticia puede ser indicativo de una estrategia conserva-tiva de utilización del forraje por los caprinos. ABSTRACT Sarcocaulecent scrubland is representative of the Sonoran Desert of Baja California Sur, Mexico. In this area 92 % of its flora is shrubs and 23 % of these are endemic species, however, the ecological impact of animal production is unknown. The objectives of this study were to determine and to compare during two years the preference and use of plant species by grazing goats. Data field collections were done from June 2006 through June 2008. Botanical composition of diet and the study area data sets were used to estimate preference and similarity indices. In the studied site total plant species were 78 and goats utilized 41 throughout the study, in each collection date goats utilized 10 to 24 species. Mean similarity index was 26 % (16 to 32 %), both preference and utilization were highly variable between collection dates for each plant species. Preference by goats was not in accordance with similarity. This pattern of feeding behavior may indicate a conservative strategy of forage utilization by goats.
Diet and nutrition of range goats on a sarcocaulescent shrubland from Baja California Sur, Mexico
Small Ruminant Research, 2008
Botanical composition of diets of range goats was studied to determine seasonal preference indices of forage species and nutritional quality of selected diets on a sarcocaulescent shrubland from the Sonoran desert in Baja California Sur, Mexico. Extrusas from five esophageal cannulated adult female goats (40kg of BW) were collected at the beginning and at the end of each season from
Diet selection by goats on a semi-arid shrubland in central Argentina
Ecologia Austral
The objective of this study was to determine diet selection by goats on a semi-arid shrubland in the central part of Argentina. Ten goats grazed on a pasture for 10-days periods in winter, spring, and summer. The botanical composition of the pasture was estimated by a combined measure of cover and biomass, whereas the botanical composition of the diet was determined by the microhistological technique complemented with direct observation. Two shrub species (Condalia microphylla and Prosopis caldenia) and five soft grasses (Piptochaetium napostaense, Poa spp., Stipa tennis, S. clarazii, and Pappophorum spp.) were highly selected by goats. Shrubs represented 32%, 40% and 74% of goat diets in winter, spring and summer, respectively. For each season, the rest of goat diets was composed by the soft grasses. Although coarse grasses represented most (> 80%) of the available biomass in all seasons, they were always highly avoided by goats. The results showed that goats behave as mixed-feeders (eat grasses and shrubs) on semi-arid shrublands in central Argentina.
Nutritive value of browse plants selected by range goats in the Mexican plateau
Journal of Applied Animal Research, 2011
The study was conducted in the south-west Tlaxcala, Mexico. Two simultaneous trials were carried out in range goats, during dry and wet seasons, to determine the nutritive value of selected forages and dry matter intake (DMI) using Cr 2 O 3 . The crude protein (CP) content varied from 2.89 to 19.8 g/100 g, and acid detergent fiber (ADF) from 23.4 to 67.7 g/100 g. The highest CP content was in the plants Simpsia amplexicahuale and Senecio salignus. The ADF and ash contents increased in dry season (p B0.05). Conversely, dry matter digestibility (DMD) increased in wet season (p B0.05). DMI of goats was 98.1 and 90.3 g/kg LW 0.75 (p B0.01) for dry and wet season, respectively. In dry season protein requirements of goats were fulfilled only by S. salignus. In wet season, all evaluated plants covered the requirements of CP for maintenance. Simpsia amplexicahuale and Bouvardia ternifolia showed outstanding CP and DMD.
Forage intake and nutrition of range goats in a shrubland in northeastern Mexico
Journal of Animal Science
1991, 69:879-885. J ANIM SCI http://jas.fass.org/content/69/3/879 the World Wide Web at: The online version of this article, along with updated information and services, is located on www.asas.org by guest on ABSTRACT Voluntary intake and nutritive value of diets selected by goats grazing a shrubland at Marin county, N.L., Mexico were determined. Four esophageally cannulated Spanish female goats (average BW 35 kg), were used to collect extrusa samples monthly throughout 1 yr (June 1987 to May 1988). Organic matter intake (OM) was estimated by total fecal collections from four castrated Spanish male goats (average BW 42 kg). Diets selected by goats were high in CP throughout the year (Z = 18.9%). Available CP represented only about half the total CP. The ADF content of extrusa samples differed (P < .05) among months, with high ADF values during winter months. Dietary lignin followed a similar pattern during the year. Goats consumed forage with sufficient amounts of Ca, Na, K, Mg, Cu, ZN, Mn, and Fe to meet requirements. The OMI of goats was different (P < .05) among sampling periods. On the average, estimated OMI 6 = 878.7 g/d) compared well with results of other studies in the area. Amounts of DE consumed by goats (1.1 Mcal DE/d)
Botanical composition and diet quality of goats grazing natural and grass reseeded shrublands
Small Ruminant Research, 1995
Botanical and chemical compositions and diet consumption of goats grazing on xerophyte shrubland communities with and without grass reseeding were estimated during March, July and November in three consecutive years. Botanical composition of the diet was determined by microhistology, digestibility in vitro and consumption of nutrients. Forage samples were obtained from esophageal fistulated animals and feces collection from intact animals. Of the species identified in the diet, 93% were shrubs and herbaceous plants, these being more abundant in esophageal samples of animals on no-reseeded sites. Correlation upon time of these two groups of plants was inverse (P < 0.05) for both types of shrublands, just as the correlation between shrubs and gramineous plants. It was observed that as the dry season advanced, the herbaceous plants (after being the predominant species of the esophageal samples) and gramineous plants diminished in the diet and the only relevant species were shrub-like plants. Functional relationships to predict the chemical composition of the diet from its botanical components or from the characteristics of feces, as well as to predict consumption from components of the feces are discussed. The botanical composition changed between year and seasons within years. Nutritious characteristics of the ingesta, with exception of lignin concentration, did not show real differences (P > 0.05) between shrublands with and without reseeding.
COMPOSITION AND ANIMAL PREFERENCE FOR PLANTS USED FOR GOAT FEEDING IN SEMIARID NORTHEASTERN MEXICO
Journal of Animal and Plant Sciences
Arid and semiarid zones of Northeastern Mexico are characterized as regions with high variation in their climatic conditions but rich in drought-tolerant botanical species which are potentially useful for grazing and pastoral activities. Feeding habits and voluntary intake from a total of 100 grazing goats were determined through identification of the plants that make up their diet, their availability in the rangeland, preference index, browsing height and their chemical composition during a 10-month growing period. Four heights of browsing were determined in the different vegetative strata. Climatic factors were determinant in the height of grazing and the availability of forage. Shrub species constituted 78% of the animal diet during the growing season followed by herbs (12-18%) and grasses (6-10%). The species with higher index of preference offered high availability in the rangeland with proper content of crude protein (10.7-24%), crude fiber (12.2-24.5%), cellulose (5.9-20.6%) ...