Evaluation of Monongo Nut meals as a source of protein in broiler rations
Date
2011-03-16
Authors
Mwangala, Sicecani, Justin
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Abstract
The potential of Mongongo (Ricinodendron rautanenii schinzj as a source of protein
in broiler rations was investigated. In the first trial, Soybean-based and Mongongobased
diets were formulated and fed ad libitum to broilers for six weeks. The
treatments were: SOY (Soybean alone); SOY + A (Soybean + methionine + lysine);
MG (Mongongo alone); MG + A (Mongongo + methionine + lysine); MG + A + T
(Mongongo + methionine + lysine + tryptophan). In the second trial the first three
treatments in the first trial (SOY, SOY + A and MG) were reformulated, while three
other treatments; HMG (Heat treated Mungongo alone), HMG + A (Heat -treated
Mongongo + methionine + lysine), and HMG + A + T (Heat-treated Mongongo +
methionine + lysine +tryptophan) were also formulated and fed for another six-week
period. Mongongo meal was heated to 125°C for 15 minutes in an attempt to
deactivate the supposedly present antinutritional factor, ricin. A Completely
Randomized Design (CRD) with 5 treatments in the first trial, and 6 treatments in the
second trial replicated 3 times was used. There were no significant differences in feed
intake between birds on SOY and those on SOY + A in both trials. However, feed
intake, live, dressed and carcass weights for birds on Soybean-based diets were
higher than those for birds on Mongongo-based diets. Addition of amino acids, lysine
and methionine, increased intake and improved the performance of birds on
Mongongo diet in terms of live, dressed and carcass weights more when Mongongo
was untreated by 502%, 507% and 571% respectively, while when heat-treated the
performance was improved by 149%, 203% and 239% respectively.Addition of the
amino acid, tryptophan, increased the performance of birds on Mongongo diet in
IV
terms of live, dressed and carcass weights by 15%, 15% and 16% respectively, only
when Mongongo was heat-treated, but reduced the performance of birds on
Mongongo diet when it was untreated by 6%, 7% and 5%, respectively. Heat treating
Mongongo increased the performance of birds in terms of live, dressed and carcass
weights by 95%, 92% and 105% respectively. Feed Conversion Ratios (FCRs) for the
treatments were in the order: MG > SOY > SOY +A > HMG > HMG +A + T > HMG
+ A during the second trial, while during the first trial the order was MG > SOY >
MG + A + T > SOY + A > MG + A. Liver and gizzard weights expressed as
percentages of carcass weights were higher in birds on Mongongo-based diets than
those on soybean-based diets. Carcass crude protein percentages differed in the order:
SOY + A > SOY > HMG + A + T > HMG + A >MG >HMG, whereas carcass fat
percentages were in the order: MG > HMG > HMG + A > HMG + A + T > SOY >
SOY +A. Mongongo-based carcasses had higher (P<0.05) fat percentages. Carcass
calcium and phosphorus percentages were in the same order: SOY + A > SOY >
HMG + A + T > HMG + A >MG > HMG. Carcasses of birds fed Mongongo-based
diets had lower (P<0.05) ash percentages than those for birds fed Soybean-based
diets. The order of carcass ash percentages was: SOY + A > SOY > HMG + A + T >
HMG -f A > HMG > MG. Mongongo nut meal can be used as a source of protein in
broiler rations when it is untreated and supplemented with amino acids lysine and
methionine (MG + A). However the performance of birds fed this diet in terms of
live, dressed and carcass weights is not as good as that for birds fed Soybean based
diet supplemented with the same amino acids lysine and methionine. Heat treating
Mongongo and supplementing with amino acid tryptophan increased the performance
of birds fed Mongongo diet in terms of live, dressed and carcass weights, although
this increase was not as good as the overall performance of birds fed untreated
Mongongo supplemented with amino acids lysine and methionine and those fed
Soybean based diets.
Description
Keywords
Protein In Broiler Rations , Mongongo Nut Meal