Tropical pastures alone do not provide sufficient protein and growth energy to cover for the maintenance and production needs of dual purpose cows, leading to low milk production per surface unit. Thus, farmers add different forages of improved nutritional quality, including tropical leguminosae. The present work studies the effect of feeding on milk production and lactation requirements of crossbred cows, whilst evaluating possible contributions towards sustainability. Three systems were compared: (1) intentsive silvopastoral (iSPS) comprising Leucaena leucocephala plus Panicum máximum var. Tanzania, as an agroecological alternative, vs (2) free roaming on mountaneous pasture (FMR) with native vegetation including the highest diversity in forage species, and (3) a confined system with controlled feeding consisting of chopped grass Pennisetum purpureum ad libitum (CCF). The study was conducted on a farm in the tropical southeast of Mexico (n = 15, Bos Taurus x Bos indicus), keeping animals under iSPS and FMR first (20 hrs/d), followed by CCF. Each treatment lasted 21 days, manual milking conducted once a day, supplementing with 3 kg of fresh, chopped Brosimum alicastrum and 1 kg of a 2:2:1 mixture of Enterolobium cyclocarpum ground fruits, maize pericarp and wheat bran whilst sampling individually every 7 days. Chemical composition was analysed using a Lactoscan Milkanalyzer; energy of lactation was calculated according to literature; covariance analysis was conducted (proc PRINT GLM); for differences the Tukey test was applied (P<0.05). Net milk production and lactation energy intake were highest in iSPS and FMR (4.7 and 4.8 kg/cow/d; 14.9 y 15.9 MJ/cow/d, respectively). There were no statistically significant differences in the chemical composition of milk (P<0.05); however, total fat contents confirm a product of high quality with values between 45 and 50 g/kg in all cases. The higher values in iSPS and FMR (as opposed to CCF) suggest that animals are consuming a higher ratio of more digestible plant fibres in ecosystems where they can develop a more natural nutrient selectiveness. L. leucocephala in iSPS seems to be a viable alternative in dual purpose production systems, as partial substitute of protein, thus reducing costs of production and maintenance during the seasonally critical dry periods. The results support the assumption that the expression of the animal’s natural behaviour (pasture feeding) not only improves animal welfare but also productivity in terms of quantity and quality, in this case, of milk.
|Publication status||Published - Sep 2016|
|Event||World Silvopastoral Congress - Universidade de Évora, Évora, Portugal|
Duration: 27 Sep 2016 → 30 Sep 2016
|Conference||World Silvopastoral Congress|
|Period||27/09/16 → 30/09/16|