Issue |
Reprod. Nutr. Dev.
Volume 46, Number 6, November-December 2006
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|
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Page(s) | 663 - 675 | |
DOI | https://doi.org/10.1051/rnd:2006041 | |
Published online | 15 December 2006 |
DOI: 10.1051/rnd:2006041
Effect of different levels and sources of zinc supplementation on
quantitative and qualitative semen attributes and serum testosterone level
in crossbred cattle (Bos indicus
Bos taurus) bulls
Nishant Kumara, Ramesh Prashad Vermaa, Lallan Prasad Singha, Vijay Prakash Varshneyb and Ram Sharan Dassc a Animal Reproduction Division, Indian Veterinary Research Institute, Izatnagar, 243 122, India
b Division of Veterinary Physiology and Climatology, Izatnagar, 243 122, India
c Division of Animal nutrition, Izatnagar, 243 122, India
(Received 30 August 2005; accepted 7 July 2006; published online 15 December 2006)
Abstract - An experiment was conducted on 16 crossbred bulls (about
2 years of age,
kg average body weight), divided into groups
I, II, III and IV to study the effect of different levels of Zn
supplementation from inorganic and organic sources on semen quality. The
animals in the first 3 groups were supplemented with 0, 35 and 70 ppm Zn from
Zn sulfate, respectively and the animals in-group IV were supplemented with
35 ppm Zn as Zn propionate. Semen collection and evaluation was done in the
first month (to assess semen quality at the start of the experiment) and
7th, 8th and 9th month of experimental feeding to evaluate the effect of
supplemental Zn on semen attributes. We gave 6 months for Zn feeding, so
that 3 sperm cycles of spermatogenesis had passed and the collected semen
reflected the complete effect of Zn supplementation. Six ejaculates from
each bull were collected and evaluated for semen quantitative (ejaculate
volume, sperm concentration and sperm number per ejaculate) and qualitative
characteristics (semen pH, mass motility, individual motility, sperm
livability percent and abnormal sperm percent, percent intact acrosome,
bovine cervical mucus penetration test, hypo-osmotic sperm swelling test)
and activity of seminal plasma enzymes i.e., alkaline phosphatase, acid
phosphatase, GOT and GPT. Testosterone level in the blood serum of crossbred
bulls was also estimated. Mean values of semen quantitative and qualitative
characteristics at the start of the experiment were statistically non
significant (P > 0.05) in all the crossbred cattle bulls, however, there
were statistically significant differences among the bulls of different
groups after 6 months of zinc supplementation. Mean ejaculate volume (mL)
was 2.37, 4.70, 5.86 and 6.38, respectively in groups I to IV, indicating a
statistically significant (P < 0.05) higher semen volume in Zn-supplemented
groups as compared to the control group of bulls. Similarly, sperm
concentration (million.mL-1), live sperm (%) and motility (%)
were significantly (P < 0.01) higher in Zn-supplemented groups as
compared to the control group. The results of BCMPT and HOSST revealed a
significant improvement in sperm functional ability in all the groups
supplemented with Zn as compared to the control group. The activity of
alkaline and acid phosphatase in seminal plasma was significantly (P <
0.05) higher in the Zn-supplemented groups, whereas GOT and GPT activities
in seminal plasma were significantly (P < 0.05) lower in the Zn propionate
supplemented group as compared to the control group. Testosterone concentration
(ng.mL-1) in blood serum was significantly higher in animals of groups
III and IV, as compared to control group. It may be concluded that Zn
supplementation either in the inorganic or organic form in the diet of
crossbred bulls improved the qualitative and quantitative attributes of
semen; however, the number of sperm per ejaculate, mass motility and semen
fertility test like bovine cervical mucus penetration was significantly
higher in bulls given Zn in an organic form (Zn propionate) as compared to
an inorganic form (Zn sulfate).
Key words: zinc / crossbred bulls / semen / sperm / testosterone / seminal plasma enzyme
Corresponding author: rsd@ivri.up.nic.in
© INRA, EDP Sciences 2006