1. NEJJAM Ibtissam
Title: partial substitution of alfalfa with corn silage in the irrigated perimeter of Tadla:
milk production, water efficiency irrigation and economic interest.
ABSTRACT
This present work, conducted in the irrigated area of Tadla in Morocco has the overall
objective of studying two forages (alfalfa and maize forage) in terms of valorization and their
role in the dairy cattle production system dairy cattle in this region. The specific objectives of
this work are to study the feeding management of dairy cows (sample of 27 farmers); the
effect of partial substitution of alfalfa or berseem by corn silage on daily milk production of
dairy cows; and to compare the amount of water consumed and the cost of production of
alfalfa and corn silage conducted on drip irrigation as well as the analyses of the quality of
corn silage stored in bags, horizontal silo or molehill.
The study showed the importance of forages in land use: 29% of the agricultural and cereals
occupy 30%. Forages consist mainly of alfalfa (69%), maize for silage (16%), berseem (12%)
and corn used as green forage (3%). The production of corn silage has some limitations
especially when it is sown in the summer, which has led most farmers to abandon the
production of this forage in summer. Cattle feeding is mainly based on alfalfa (hay or green)
with 96,2% of cases, the corn silage is used by 38,5% and concentrates supplementation is
primarily wheat bran (53,5%) and beet pulp (38,5%). In addition, 85% of rations studied have
an average excess energy compared to total needs (maintenance and milk production) of about
3,58 UFL and 100% of the rations have excess protein with an average of 598 g.
The partial substitution of alfalfa to corn silage with different ratios studied resulted in an
average increase in milk production of 2,8 (75:25 ratio) and 2,9 kg/cow/day (58:42 ratio) for
cross bred cattle, while it was 8,7 kg/cow/day in the case of a partial substitution of berseem
to corn silage in Holstein cows.
Comparison of alfalfa (4 first cuts considered in this study) and corn drip irrigated through
system has revealed that 1 m3
of water produce 2,65 and 4,22 kg DM, 1,97 and 3,77 UFL and
291 and 176 g of protein respectively for alfalfa and corn. From an economic point of view,
production cost for alfalfa was 17 776 DH/ha and it was 13 070 DH/ha for corn silage. The
cost of production was 0,89 and 0,73 DH / kg DM produced 1,15 and 0,81 DH / UFL, and
0,80 and 1,74 g DH/100 g PDI respectively for alfalfa and corn silage. Therefore, it appears
that corn valorizes better irrigation water with a production value of 12,5 DH/m3
, while with
alfalfa valorization of water is about 4,5 DH/m3
.
Corn silage studied has an average DM of 33,31%, and the quality is generally good to
excellent with good preservation.
Keywords: Tadla, alfalfa, berseem, silage, corn, valorization of the irrigation water, dairy
cows.