Ingestive behaviour, performance, and methane emissions of pregnant alpacas grazing cultivated pastures in the high Peruvian Andes

• Autores: Gualdron Duarte, Laura Bibiana; Loza, Cecilia; Gere, José Ignacio; Huanca Marca, Nancy Frinee; Franco, Francisco E.; Uscamayta, Yemi Sanca; García Ticllacuri, Rubén; Orellana Ligas, Guadalupe; López, Diannett Benito; Rivera Pachiño, Feliciano; Moscoso Muñoz, Juan E.; Díaz Céspedes, Medardo A.; Collazos Paucar, Lizbeth L.; Pinares Patiño, César S.; Vélez Marroquín, Víctor M.; Cabezas Garcia, Edward H.
• Año de publicación: 2025
• Idioma: inglés
• Tipo de recurso: artículo
• Materia: Methane emissions; Forage quality; Rotational grazing; South American camelids
• Institución: Consejo Nacional de Investigaciones Científicas y Técnicas

This study compares grazing patterns, animal performance, and enteric methane emissions (CH4) of female alpacas (Huacaya and Suri) at two periods of their late pregnancy. Animals were rotationally grazed on a mixed sward at high Peruvian Andes conditions. This study involved two experimental periods (P1 and P2), each lasting 26 days. P1 took place in November 2021, corresponding to the end of dry season (‘Transition period’), whereas P2 was conducted in January 2022, with this coinciding with the beginning of rainy season (‘Wet period’). Forage selectivity was measured using hand plucking of forage harvested, whereas grazing behaviour was recorded by visual observation. Dry matter intake (DMI) was estimated from total faecal collection and in vitro forage digestibility. Fleece characteristics were measured following standard procedures adopted by the local industry. The sulphur hexafluoride (SF6) gas-tracer technique was used to estimate CH4 emissions. Data were analysed by a repeated measures model including both alpaca variety and period as fixed effects, whereas alpaca within variety was considered as random. No differences were detected among alpaca varieties either in terms of forage selectivity, grazing behaviour (except for biting rate) or feed intake. Regardless of period, grasses were the main dietary components (≥ 78 %). The proportion of leaves consumed lowered from 84 to 70% and presence of both legumes and herbs increased during P2. Increased nutritional requirements prior to parturition in conjunction with reduced forage quality and DMI (P = 0.004) during P2 led to negative energy and protein balances. This was aligned with increases in fibre growth and diameter, prior to parturition (P ≤ 0.035). Suri displayed faster fibre growth than Huacaya (P = 0.005). Although Huacaya females tended to emit more enteric CH4 per unit of metabolic live weight than Suri (P = 0.056), this was not reflected either on variety differences in emissions per unit of intake or fleece produced. On average, CH4 intensity decreased from 0.805 (P1) to 0.530 g/kg clean fleece at P2 (P = 0.032). Results are valuable towards fine-tuning the effect of pregnancy for sustainable alpaca farming.
Fil: Gualdron Duarte, Laura Bibiana. Universidad Nacional Mayor de San Marcos; Perú. Instituto Nacional de Tecnología Agropecuaria; Argentina
Fil: Loza, Cecilia. Universidad de la República; Uruguay. Universidad Nacional Mayor de San Marcos; Perú
Fil: Gere, José Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Tecnológica Nacional. Facultad Regional Buenos Aires. Unidad de Investigación y Desarrollo de las Ingenierías; Argentina
Fil: Huanca Marca, Nancy Frinee. Universidad Nacional Mayor de San Marcos; Perú. Universidad de Zaragoza; España
Fil: Franco, Francisco E.. Universidad Nacional Mayor de San Marcos; Perú
Fil: Uscamayta, Yemi Sanca. Universidad Nacional Mayor de San Marcos; Perú
Fil: García Ticllacuri, Rubén. Universidad Nacional Mayor de San Marcos; Perú
Fil: Orellana Ligas, Guadalupe. Universidad Nacional Mayor de San Marcos; Perú
Fil: López, Diannett Benito. Universidad Nacional Mayor de San Marcos; Perú
Fil: Rivera Pachiño, Feliciano. Universidad Nacional Mayor de San Marcos; Perú
Fil: Moscoso Muñoz, Juan E.. Universidad Nacional San Antonio Abad del Cusco; Perú
Fil: Díaz Céspedes, Medardo A.. Universidad Nacional Agraria de la Selva; Perú
Fil: Collazos Paucar, Lizbeth L.. Universidad Nacional Mayor de San Marcos; Perú
Fil: Pinares Patiño, César S.. Universidad Nacional Mayor de San Marcos; Perú
Fil: Vélez Marroquín, Víctor M.. Universidad Nacional Mayor de San Marcos; Perú
Fil: Cabezas Garcia, Edward H.. Universidad Nacional Mayor de San Marcos; Perú