Effects of Underfeeding on Semen Quality of Rhode Island Cocks
Fifty Rhode Island chickens were randomly assigned to
five treatments with ten cocks in each treatment. Group I cocks (full
fed control) received 140 g of a 16% CP growers ration per cock per day.
Cocks in Group II, III, IV and V received 98, 70, 42 and 28 g of the same
ration per cock per day, representing 70, 50, 30 and 20% of Group I intake,
respectively. The feeding trials lasted for 8 weeks during which one ejaculate
per day was collected from each cock using the massage technique. The
ejaculated semen samples were subjected to both physical and biochemical
evaluations. Results showed that cocks that were severely underfed (i.e.,
Groups IV and V) took significantly longer time (p<0.01) to ejaculate.
In addition, ejaculation failures were encountered more frequently with
the severely underfed cocks than in cocks that were moderately underfed
(i.e., Groups II and III). There were however, no significant differences
in most of the biochemical parameters between cocks I all the treatment
groups. Ejaculate volume, progressive sperm motility and sperm concentration
were significantly depressed (p<0.01) in the severely underfed cocks
than in the moderately underfed cocks. Thus, this study revealed that
providing Rhode Island red and white cocks with one-half to three-quarter
(i.e., 50-70%) of their normal daily ration would neither undermine their
semen producing ability nor affect their semen quality adversely.
Feed has been implicated by some workers (Hocking and Bernard, 1997)
as one of the factors known to affect semen production and quality in
the male bird. Studies by Boone and Hughes (1969) showed that starvation
of cocks for six days led to a marked reduction in semen production, but
the condition was reversed after 14 days of resumption to normal feeding.
With intensive production and improved feeding, Nwosu (1979) reported
a remarkable improvement in the reproductive traits of local chickens.
This therefore shows that adequate nutritional environment is essential
to maintain the breeding flock in good reproductive condition. Pana et
al. (2000) reported that Cornish broiler cocks whose daily feed consumption
was limited to 130 g produced ejaculates whose concentration did not differ
significantly from their full-fed counterparts. According to Ezekwe et
al. (2003) the effects of underfeeding on semen quality traits appeared
to be more severe on the physical rather than biochemical characteristics,
which implies that the spermatogenic functions of the testes are more
responsive to underfeeding than the secretory activities of the reproductive
Dietary crude protein and food intake were reported to affect semen production
of broiler breeder males (Hocking and Bernard, 1997). Moderate underfeeding
was reported to affect semen production and semen quality attributes of
local cocks whereas volume, motility and concentration were significantly
depressed by severe underfeeding (Ezekwe et al. 2003). It is of
interest to evolve a feeding programme for breeding birds that will reduce
the high cost of feeding under intensive production system without inflicting
serious damage to their reproductive functions.
Thus, the sole objective of this research was to evaluate the effect
of under feeding on the semen production and quality of Rhode Island red
and white chickens.
MATERIALS AND METHODS
The study was conducted at the poultry breeding unit of the National
Animal Production Research Institute Shika, Zaria. Shika is geographically
situated between latitude 11°12` N and longitude 7°33` E at an
altitude of 640 M above sea level (Akpa et al., 2002). It is located
22 km northwest of Zaria City and is vegetationally in the northern guinea
savannah zone of Nigeria. The Shika climate is characterized by a well
defined dry and wet seasons. The dry season lasts from mid-October to
April and consists of a period of low relative humidity with strong, cold
and dry northeast harmattan winds.
A total of fifty Rhode Island cocks aged between 28-32 weeks old and
ranging in body weight from 1.562±0.224 to 1.839±0.325 kg
were used. Cocks were housed in individual wire cages and fed growers
ration containing 16% CP and 2737 Kcal ME kg-1. Prior to the
commencement of the work, a one-week pre-experimental trial was observed
during which the average daily feed intake of the cocks was found to be
140 g/cock/day. This was considered necessary in order to calculate the
quantity of feed required for the different levels of underfeeding the
cocks would be exposed to. In addition, the pre-experimental period also
allowed the birds to be trained how to ejaculate and emit semen once every
morning, by the massage technique described by Hafez (1990). Thereafter,
the cocks were randomly assigned to five treatment groups of ten cocks
per treatment as follows:
Group I 140 g/bird/day:(100% full-fed control)
Group II 98 g/bird/day: (70% of group I intake; i.e., mild feeding)
Group III 70 g/bird/day: (50% of group I intake; i.e., moderate underfeeding)
Group IV42 g/bird/day: (30% of group I intake; i.e., severe underfeeding)
Group V28 g /bird/day: (20% of group I intake; i.e., very severe underfeeding)
The entire daily ration was fed to every cock once at 0900 h, while clean
drinking water was provided ad libitum. The feeding programme
lasted for eight weeks during which each cock was ejaculated every morning.
Ejaculation time for each cock was recorded using a stop watch. The ejaculates
were then subjected to both physical evaluation and biochemical analysis.
The physical evaluation involved determination of semen volume, semen
progressive motility and sperm concentration as described by Lake (1966).
The biochemical analysis involved determination of the electrolyte concentrations
of the pooled weekly semen samples for cocks in each treatment group,
which was stored frozen until required for analysis. The atomic absorption
spectrophotometry of Quinn et al. (1966) was used for the analysis.
The mean weekly body weight changes of the cocks were recorded to monitor
body weight changes during the experimental period. One-way analysis of
variance was used to test for the significance of treatment means while
Duncan`s Multiple Range Test (DMRT) was used for the separation of significant
treatment means (Steel and Torrie, 1980).
RESULTS AND DISCUSSION
Table 1 shows the mean weekly body weight changes
of cocks in the five treatment groups. Cocks in Groups I-III recorded
slight weight increase during the experimental period while members of
Groups IV-V progressively lost weight within the same period. Non-significant
difference was observed in the body weight changes of cocks in Groups
II and III, while highly significant decrease in the body weights of cocks
I Groups IV and V (p<0.01) was obtained. However, cocks in Group III
were significantly lighter (p<0.05) than cocks in Group I. It can be
deduced from these results that reducing the daily feed consumption of
Rhode Island cocks by 50% would not have adverse effect on their body
Table 2 shows the average ejaculation time and other semen quality traits
of the Rhode Island cocks. A total of 348 semen samples were collected
over the eight-week experimental period. Ejaculation failures were encountered
more in the severely underfed cocks (Groups IV and V) than in cocks in
Groups I, II and III. Similarly, the severely underfed cocks were slower
(p<0.01) to respond to manipulation for ejaculation. Generally, ejaculation
time increased as the level of underfeeding increased.
Semen quality traits of cocks in Group I and II did not differ significantly.
Boone et al. (1967) reported that reducing either total feed or
calorie intake to 15% resulted in loss of body weight and very poor quality
semen and decreased fertility. The cation concentrations (electrolytes)
of the semen of cocks in all the treatment groups lie within the range
reported for normal cock semen (Lake et al., 1958). The semen
of cocks in Groups I-III did not differ significantly in their biochemical
constituents. This implies that the secretory ability of structures responsible
for contributing the biochemical constituents of semen were not adversely
affected when the feed intake of the cocks was reduced by half (i.e.,
The physical quality traits began to fall as the level of underfeeding
increased from 70 to 50%, but this trend was unobserved in the biochemical
constituents. The explanation to this was that the spermatogenic functions
of the testis can be said to be more responsive to underfeeding than the
secretory activity of the reproductive tract. This supports the findings
of Davies et al. (1957) that underfeeding diminishes the ability
of the gonads to respond to gonadotropin stimulation.
Mean weekly body weight (kg) of Rhode Island cocks
Levels of feed restriction
||Average ejaculation time, semen traits and semen cation
concentrations of Rhode Island cocks exposed to restricted feed consumption
|**Means in the same row with different superscripts
are significantly different (p<0.01)
In conclusion therefore, it can be said that moderate underfeeding (i.e.,
reducing the daily feed intake by 30 to 50%) was found not to adversely
affect semen production and semen quality attributes of Rhode Island cocks.
Instead, a substantial saving I terms of cost of feeding would be achieved
by the farmer.
The authors acknowledge with gratitude the technical assistance
of Messrs S. Agbonika, B. Mathias, K. Deshi, B. Phillip and Mal. Sale
Magaji. The kind permission of the Director, NAPRI, to publish this work
is also acknowledged.
1: Akpa, G.N., J.O. Ifut and F. Mohammed, 2002. Indigenous management of dystocia in ruminant livestock of Northern Guinea Savannah of Nigeria. Nig. J. Anim. Prod., 29: 264-270.
2: Boone, M.B., B.L. Hughes and B.D. Barnett, 1967. Starvation and its effects on semen quality. Poult. Sci., 46: 251-254.
3: Boone, M.A. and B.L. Hughes, 1969. Starvation and its effect on semen quality. Poult. Sci., 48: 1723-1729.
4: Davies, D.V., T. Mann and L.E.A. Rowson, 1957. Effect of nutrition on the onset of male sex hormone activity and sperm formation in monozygous bull calves. Proc. Roy. Soc. London Series, B147: 332-351.
5: Ezekwe, A.G., I.J. Udozor and C.O. Osita, 2003. Effect of quantitative feed restriction on the semen quality of Nigerian Local Cocks. Nig. J. Anim. Prod., 30: 127-132.
6: Hafez, E.S.E., 1990. Artificial Insemination in Reproduction in Farm Animals. 5th Edn., Lea and Febiger, Philadelphia, pp: 481-497
7: Hocking, P.M. and R. Bernard, 1997. Effect of dietary crude protein content and food intake on production of semen in two lines of broiler breeder males. Brit. Poult. Sci., 38: 199-202.
8: Lake, P.E., E.J. Butter, J.W. McCallum and J.J. Machtyre, 1958. A chemical analysis of the seminal and blood plasma of cocks. Quart. J. Exp. Physiol., 43: 309-313.
9: Lake, P.E., 1966. Physiology and Biochemistry of Poultry Semen. In: Advances in Reproductive Physiology, L. Mc (Ed.), Academic Press, New York, pp: 93-123
10: Nwosu, C.C., 1979. Characterization of the local chicken of Nigeria and its potential for egg and meat production. Poultry production in Nigeria. Proceedings of the 1st National Seminar on Poultry Production in Nigeria, December 11-13, 1979, Ahmadu Bello University, Zaria, pp: 87-210
11: Pana, C.I., D. Stoica, E.P. Dregotoiu, E.P. Midosanu and M. Stanescu, 2000. Influence of quantitative and qualitative feed restriction on sperm quality and fecundity of broiler breeder males. Abstr. 14th Int. Cong. Anim. Reprod., 1: 89-89.
12: Quinn, P.J., I.G. White and B.R. Wirrick, 1966. The effect of dilution on the concentration of Na+, K+, Ca2+ in Ram and Bull semen. J. Reprod. Fert., 12: 131-139.
13: Steel, R.G.D. and J.H. Torrie, 1980. Principles and Procedures of Statistics: A Biometrical Approach. 2nd Edn., McGraw Hill Book Co., New York, USA., ISBN-13: 9780070609266, Pages: 633
Direct Link |