Animal and vegetal production of a Cynodon pasture managed under different forage allowance by wethers of two breeding groups/Producao animal e vegetal em pastagem de Cynodon manejada sob diferentes ofertas de forragem por ovinos de dois grupos geneticos

• Published in: Ciência rural Vol. 43; no. 1; p. 145
• Main Authors: Soriano, Vanessa de Souza, Kozloski, Gilberto Vilmar, de Quadros, Fernando Luiz Ferreira, Pires, Cleber Cassol, Griebler, Letieri
• Format: Journal Article
• Language: Spanish
• Published: Universidade Federal de Santa Maria 01.01.2013
• Subjects: Sheep
• ISSN: 0103-8478; 1678-4596

The productive potential of a Cynodon dactylon var.dactylon pasture managed under continuous stocking with wethers was evaluated. The effect of three (3, 6 or 9kg of dry matter (DM) 100[kg.sup.-1] of body weight (BW)) green leaf allowances (GLAL) on pasture attributes and animal performance of two genetic groups (Texel x Ile de France and Lacaune x Texel x Ile de France) was tested. Experiment was carried out through a 53 days period with 1 8 wethers of each genetic group randomly distributed in nine pasture plots (three pasture plots per treatment). Actual GLAL were near to those planned for each treatment (i.e. 3.2, 6.7 e 9.5% of BW). Forage mass (mean of 3474kg of DM [ha.sup.-1]) and the content of DM, neutral detergent fibre and crude protein of samples taken through grazing simulation (mean of 49.4, 76.1 and 12.9%, respectively) were not affected by treatments. The green leaf growth rate increased (P < 0.05) from 12.1 to 20.5kg of DIM [ha.sup.-1][day.sup.-1] and stocking rate decreased (P < 0.05) from 1178 to 609kg of BW [ha.sup.-1] when GLAL increased from 3.2 to 9.5% of BW. Animal production per area was in average negative (mean BW gain of -551g [ha.sup.-1][day.sup.-1]), highly variable (variation coefficient of 280%) and not affected by treatments. Individual animal performance was affected by interaction between treatments and animal breed (P < 0.05). Daily BW gain by Lacaune-crossed wethers was positive (34g [day.sup.-1]) and higher (P < 0.05) for the highest allowance, null for the lowest allowance and negative (-62g day1) for the intermediary allowance treatment. Differently, the daily BW gain by Texel x Ile de France wethers was negative and similar for all treatments (mean of -18g [day.sup.-1]). Independently of animal breeding, the daily grazing time was similar for the lowest and highest forage allowance treatments whereas it was lower for the intermediary level of forage allowance (P < 0.05). In conclusion, the Cynodon dactylon var. dactylon pasture showed a low productive potential, mainly when the GLAL was similar or lower than 6% of animal BW. However, results also indicate that pasture structure and animal breed interact with forage allowance to determine animal performance.