Milk production and quality from Holstein cows in two arrangements of acacia and alder related to kikuyo grass

Abstract

The evaluated treatments were two arrangements of silviculture and pastureland, T1: Alnus acuminata in association with Pennisetum clandestinum (SSPS), T2: Acacia decurrens + A. acuminata in association with P.clandestinum (SSPSR), compared to T3: Pennisetum clandestinum pastures. Nine Holstein cows with an average weight of 450 kilograms, with two or three lactation periods and an average production of 12 l/cow/day were used. Initial forage production was 1.500, 2.000 y 2.500 kg/DM/ha in SSPS (T1); SSPSR (T2) and control treatment (T3) respectively. Forage production on second period for T2 was similar to T3 with 2.500 kg/DM/Ha, exceeding T1 by an estimated 25% (2.000 kg/DM/ ha). Forage production for the third period on T2 was outstandingly superior with 3.500 kg/DM/ha, exceeding by an estimated 16,6% and 25% for T3 and T1 respectively. Dairy production on SSPS and SSPSR was higher (P<0,01) with 14,38 and 13,38 l/ cow/day respectively, surpassing (P<0,05) control treatment (T3) with 12.76 l/cow/day. This response is possibly due to the increased protein levels, lower percentages of FDN (Spanish initials for Neutral Detergent Fiber) and FDA (Spanish initials for Acid Detergent Fiber) in the pastures, which was reflected in better DIVMS values and inferior Lignin levels. These increments are closely associated to forage quality offered by both treatments (T1 and T2). This forage had greater concentrations of protein (15,61% and 15,89%), FDN (46,46% and 46,53%) and minerals, the tree factor improved the deposition of protein fractions such as B2 (31,82% and 42,89%) and B3 (32,10 y 25,18%) on the P. clandestinum, fractions that directly affect on DIVMS and animal response