Replacement of corn with pre-dried cassava root silage in the diet for dairy goats

The objective of this study was to evaluate the effect of replacement of corn with pre-dried cassava root silage (CRS) on intake, ingestive behavior, production and composition of goat milk. Five lactating Saanen goats were used, with 42.5 ± 4.2 kg body weight and production of 2 kg milk day-1, distributed in a 5 x 5 Latin square with five treatments: 0, 28.6, 58.0, 81.6 and 100% replacement of corn with CRS in the diet dry matter. Goats were monitored for five periods of 15 days each. The intake of dry matter, crude protein and neutral detergent fiber decreased linearly (p <0.05) with the replacement of corn with CRS. Feeding (348.5 ± 62.1 min.) and rumination (468.8 ± 83.8 min.) times were not influenced (p >0.05) by the replacement of corn with CRS, but the ingestion and rumination efficiencies had a linear increase (p > 0.05). Milk production (2.17 ± 0.45 kg day-1), fat (3.49 ± 0.42%), protein (3.11 ± 0.13%) and lactose (4.47 ± 0,11%) of goat milk were not influenced (p >0.05) by the replacement of corn with CRS. Therefore, it is recommended the total replacement of corn with pre-dried cassava root silage in the diet for dairy goats with an average production of 2 kg day-1.(AU)

Cinética da degradação ruminal da matéria seca da haste, da raiz, do feno da parte aérea e da silagem de raiz de mandioca (Manihot esculenta Crantz) tratada com uréia / Kinetic of dry matter ruminal degradation of stem, root, aerial part hay and ureatreated-cassava root silage (Manihot esculenta Crantz)

O experimento foi conduzido na UESB, com o objetivo de se determinar a cinética da degradação ruminal da matéria seca, de alimentos obtidos da mandioca. Foram utilizadas duas vacas fistuladas no rúmen, incubando-se as amostras em sacolas de náilon por 2, 4, 8, 16, 24, 48, 72 e 96 horas, por quatro rodadas seqüenciais, dentro de um delineamento em blocos inteiramente cazualizados. Os alimentos testados foram a raiz (T1), a silagem de raízes tratada com 3% de uréia (T2), o feno da parte aérea da mandioca obtido aos 5 meses (T3) ou 14 meses após o plantio (T4) e as hastes de plantas de mandioca, colhidas aos 14 meses, plantadas em espaçamento contínuo (T5) ou de 0,6 metros entre plantas (T6). Os resultados dos percentuais de degradabilidade no rúmen (P), foram ajustados ao modelo matemático "P = a + b (1 - e-ct)". Os valores médios percentuais dos resultados encontrados foram comparados pelo teste de Student-Newman-Keuls, ao nível de 5% de probabilidade, como se segue para os tratamentos de 1 a 6, respectivamente: fração solúvel (74,8b; 80,9a; 26,3c; 23,6d; 22,4d; 22,3d), degradabilidade efetiva (90,7b; 92,0a; 65,4c; 62,4d; 41,8e; 40,9e), degradabilidade potencial (99,1a; 99,4a; 74,4b; 73,4b; 49,2c; 46,8d) e tempo de colonização em horas (0,4cb; 0,1c; 1,5ba; 1,5ba; 1,6ba; 1,8a). Os resultados indicam uma alta taxa de solubilidade ruminal da silagem de raiz de mandioca tratada com uréia e uma maior taxa de degradabilidade efetiva do feno obtido aos 5 meses em relação ao obtido aos 14 meses após o plantio.(AU)

This experiment was carried out at the Southwestern State University of Bahia (UESB), Bahia, Brazil, in order to verify the kinetic of dry matter ruminal degradation of cassava byproducts. Two cows, fistulated in the rumen, were used to incubate samples in nylon bags for 2, 4, 8, 16, 24, 48, 72 and 96 hours, in a completely randomized block design, resulting in four incubation periods for each sample. Tested feedstuffs were cassava root (T1), cassava root silage treated with 3% of urea (T2), cassava aereal part hay (CLH) harvested at 5 (T3) or 14 months of age (T4) and the stems of cassava plants, harvested at 14 months, planted in continuous rows (T5) or 0,6 meters between plants (T6) along the planting line. Percentual results of feed rumen degradabilities (P), were adjusted to the mathematical model "P = a + b (1 - e-ct)". Average percent results found in the treatments were compared using Student-Newman-Keuls test, at the level of 5% of probability. Results for treatments 1 to 6, were respectively: soluble fraction (74,8b; 80,9a; 26,3c; 23,6d; 22,4d; 22,3d), effective degradability (90,7b; 92,0a; 65,4c; 62,4d; 41,8e; 40,9e), potential degradability (99,1a; 99,4a; 74,4b; 73,4b; 49,2c; 46,8d) and lag time in hours (0,4cb; 0,1c; 1,5ba; 1,5ba; 1,6ba; 1,8a). These results indicate a high level of ruminal solubility of cassava root silage treated with urea and a higher degradation rate of CH harvested at 5 months compared to CH harvested at 14 months of age.(AU)