Performance and nutrients utilization of broilers.
period of 0-40 days, the percentage of retention was only
reared on metabolic cages to avoid coccidial threat for a
10%. They also suggested that nutritional approaches such
total duration of 6 weeks divided in two phases viz. 0-4
as reduction in dietary trace mineral supplementation may
weeks (Starter phase) and 4-6 weeks (Finisher phase). The
alleviate the risks of phytotoxicity in the soil. Cao et al.
birds were duly vaccinated against Ranikhet disease (at 7
(1996) supplemented 400,600 or 800 mg/kg added Fe as
ad 21 day) and for IBD (at 14 day). During the experiment,
reagent grade FeSO 4 .7H 2 O to chicks of 1, 2 or 3 weeks
no antibiotics were provided. Only medication provided
of age along with basal corn: soy diet. They reported that
to birds are Zeetress and Liver tonic. Daily weighed
excess Fe depressed (P<0.01) feed intake and body weight
amount of feed was offered and leftover and body weight
gain at 3 weeks.
gain was recorded on weekly basis. The Feed Efficiency
The requirement of copper, being 8 mg/kg DM of feed as
Ratio (FER) and Performance Index (PI) were calculated
per NRC (1994) is generally supplied by dietary sources
as per formulae of Bird (1955). At the end of 4 th week a
and thus do not require supplementation (Underwood
3 day metabolic trial was conducted to asses the nutrient
and Suttle, 1999). Johnson et al. (1985) suggested that
balance. The feed and feces were analyzed for nitrogen
broiler performance may be independent of dietary copper
by method prescribed by AOAC (1990) and for energy by
content. Mohanna and Nys (1998) reported retention
method of O’Shea and Maguire (1962). Calculation for
of copper in broiler chicken by 6% and suggested for a
energy retention and ME values were done as per Hill
modified supplementation strategy either by excluding
and Anderson (1958). The design of experimentation was
the minerals or by lowering the safety margin of
completely randomized design as prescribed by Snedcor
supplementation. Latymer and Coates (1981) studied the
and Cochran (1962).
effects of incorporation of copper sulphate supplying 250
mg copper/kg semi purified diet with graded amounts of
RESULTS AND DISCUSSION
calcium pantothenate in chicks. They suggested that high
The data on performance and nutrient utilization are
dietary supplements of CuSO 4 induce pantothenic acid
presented in Table: 1.
deficiency through interference in the biosynthesis of
CoA.
Nutrient utilization and performance at 0 - 4 weeks
Thus, keeping in view all the facts and possibilities, a study
The feed intake ranged from 1463.44 ± 2.53 (T 2 ) to 1412.99
was planned in broilers to asses the effect of exclusion of
± 42.59 g (T 1 ). The feed intake did not differ significantly
Cobalt, Iron and Copper from mineral premix of broilers
among the treatments.
on their performance and nutrient utilization.
The body weight gain ranged from 799.28 ± 9.33 (T ) to
2
726.17 ± 21.89 g (T 1 ). Non significant differences were
MATERIALS AND METHODS
observed between T 2 , T 3 , T 4 and T 5 . Similarly, body weight
gain of T and T did not differ. However, significant (P <
Ninety day old vencobb broiler chicks were randomly
1
4
0.5) difference was observed between weight gain of T
divided in 5 dietary treatments (T1, T2, T3, T4 and T5),
1
compared to T , T and T (726.17 ± 21.89 vs. 799.28 ±
having 3 replicates with 6 birds each. The basal diet
2
3
5
9.33, 774.56 ± 5.22, 785.10 ± 11.24).
was common to all and contained 2800 kcal ME/kg and
22% CP (Starter diet) and 20% CP (finisher diet) as per
The feed efficiency ratio ranged from 0.5498 ± 0.0175 (T 5 )
recommendation of ICAR (1998). Dietary treatment T1
to 0.5138 ± 0.0002 (T 1 ). The feed efficiency ratio did not
was fed commercial mineral mixture while laboratory
differ significantly between T 2 , T 3 , T 4 and T 5 . Similarly,
reagent grade mineral mixture was offered to broilers
no significant (p < 0.05) difference was observed between
of dietary treatment T2. The broilers of T3 groups were
broilers of T 1 compared toT 3 and T 4 . However, significant
offered lab reagent grade mineral premix without Cobalt
difference (p < 0.05) was observed between FER of group
(Co), while those of T4 received lab reagent grade mineral
T 1 and T 2 (0.5138 ± 0.0002 vs.0.5461 ± 0.0060) and
premix without Iron (Fe). Birds of T5 group received
between group T 1 and T 5 (0.5138 ± 0.0002 vs. 0.5498 ±
mineral premix without Copper (Cu). All the premix was
0.0175).
added at the rate of 2.5% of basal diet. The broilers were
The performance index ranged from 431.77 ± 16.08 (T5)
Journal of Animal Research: v.5 n.1. April 2015
63