Nutrigenomics and its Role in Male Puberty of Cattle: A Mini Review
Amit Kumar Verma,
Nutrigenomics a novel era in genomics research is based on
puzzling issue on how nutrition and genes re-interacts. Perusal of literature
reveals that very few information are available in this field and especially
when it is associated with puberty in cattle which is a multigenic trait of
great economic importance. Thus it opens a new area of research interest. Various
markers like-gonadotropin releasing hormone/GNRH (responsible for sexual differentiation
and reproduction), interstitial growth regulating factor/IGF1 (having signal
controlling reproduction function linked to somatic growth); circulating metabolic
hormones viz., leptin apart from GnRH and IGF1 (having impact on testicular
development in peripubertal bull) are proved to be associated with male puberty
in cattle. Various minerals (copper, selenium, manganese, zinc, chromium, iron
and molybdenum) and vitamins (Vit. A, D, E and C) are directly or indirectly
linked to male puberty. But no research till today initiated how the nutrients
effect on the transcriptome/proteome/ metabolome level of marker genes associated
with male puberty in cattle. Application of nanotechnology to make food safer
for promotion of good health has created much excitement and nanoparticles has
been developed against infectious diseases (e.g., Campylobacteriosis) affecting
puberty along with certain nanocarriers that can facilitate the uptake of essential
nutrients associated with puberty. Much of nutrigenomics research is however
in infancy and hence the present mini-review will allow building the concept
among researchers and scientists to initiate research in this interesting area.
Received: March 27, 2013;
Accepted: April 20, 2013;
Published: November 25, 2013
Increase in the demand of milk, meat and eggs globally, due to increased population
density and requirements of feeds including Genetically Modified Crops (GMO)
crops have also made pressure for enhancing the increase livestock population
(Tayo et al., 2011; Mahima
et al., 2012). With the advancement on genomics research various
novel omics research has been raised up (Deb
et al., 2012a, b). Gene expression is modified
by dietary components i.e., macrocomponents (includes carbohydrates, proteins,
fats and cholesterol), vitamins (e.g., A, B, E, D) minerals (e.g., Fe, Se, Ca)
and phytocompounds such as flavonoids, isothiocyanates and indoles (Kaput
and Rodriguez, 2004; Lander et al., 2001;
Venter et al., 2001; Boss
et al., 2012; Neibergs and Johnson, 2012).
This has laid to a new era in science so called nutrigenomics, literally
means interaction between nutrition and genomics (Kaput
et al., 2005). The primary focus of Nutrigenomics is on effect of
diet on health, altered gene expression by compounds present in feed (Neibergs
and Johnson, 2012). From a nutrigenomic point of view diet and nutrients
directly/indirectly influence primarily gene (transcriptomics) and protein expression
(proteomics) and ultimately metabolite production (metabolomics) (Muller
and Kerten, 2003). Nutrition research has conventionally decisive on the
fact that all individuals have the same nutritional needs, although nutritional
professionals do recognise that children differing needs compared with adults,
as well as males as compared with females. Advancement in nutritional science,
Mypyramid dietary tool (www.mypyramid.gov.com)
were established for individual dietary requirements which indicate that personal
eating plan can be prepared by entering physical activity along with age and
sex, height and weight (Mahima et al., 2013).
Puberty is an important factor for differentiating among cattle breeds (Casas
et al., 2007; Kumar et al., 2013).
Puberty is a mutagenic trait and the study on human /mouse puberty indicate
that there could be single genes with major effects involved for male puberty.
Even though its economic importance, there are very few markers associated with
male puberty. The association of receptor for Gonadotropin releasing hormone
(GNRHR) polymorphisms and first service period after calving has been proved
in dairy cattle (Derecka et al., 2010) and also
with the age of first CL in Brahman and Tropical cattle (Silveira
et al., 2010). Apart from this, other factors like cell adhesion,
axon guidance, ErbB signalling and glutamate activity are also affecting GnRH
release (Fortes et al., 2011). However, these
still remain to be investigated in bovine males which reinforce the importance
of identifying genes that regulate puberty and polymorphisms thereby explaining
these differences in bulls. Present mini-review, just a concept note for initiating
research on nutrigenomics study on male puberty in cattle.
Genetic Markers and circulating hormones related to male puberty in cattle
GNRH: GNRH and its receptor having a major role for sexual differentiation
as well reproduction in mammals by stimulating the secretion of Luteinizing
Hormone (LH) and Follicle Stimulating Hormone (FSH) for regulating gonadal function
viz. steroid gametogenesis and synthesis of hormones. Fortes
et al. (2010) reported that genetic polymorphisms within GNRHR add
to the regulation of pubertal timing in human and mouse.
IGF1: Insulin like growth factor 1 (IGF1) has been reported as a signal
controlling reproductive function links to somatic growth primly during puberty
in mammals by influence on the activity of GNRH neurons, stimulating testicular
growth, development of seminiferous tubules as well as Leydig cells. Interestingly,
positive relations were observed in between serum concentrations of IGF1 and
serum LH and testicular LH receptor (LHR) concentrations in bull calves (Bagu
et al., 2010). Some evidence suggests that via direct actions at
the pituitary and gonadal levels, IGF1 can regulate the hypothalamic-pituitary-gonadal
axis (Daftary and Gore, 2005). In this context, serum
concentrations of pre-pubertal IGF-1 have been genetically correlated with the
adult scrotal circumference as well as sperm motility in bulls (Yilmaz
et al., 2004). IGF1-SnaBI SNP has been reported to associate with
IGF1 gene expression and IGF1 blood level in cattle (Maj
et al., 2008) and affect animal weight at different ages in cattle
(Siadkowska et al., 2006; Burns
et al., 2011) and with BMI in bovine and human (Elks
et al., 2010).
Circulating metabolic hormones: Brito et al.
(2007) reported that, circulating concentrations of leptin, IGF-I and insulin
associated with testes size, indicating their involvement in gonadotropin independent
mechanism for regulation of development of testes in peripubertal bulls. Leptin
is a recently discovered hormone produced by adipose tissue regulating feed
intake and energy balance and restores fertility exogenously (Barb
and Kraeling, 2004; Adam et al., 2003; Zieba
et al., 2005). The IGF system has an autocrine regulatory mechanism
in neuronal GnRH secretion. Treatment with IGF-1 increases GnRH secretion by
GT 1-7 cells in vitro and increases LH secretion in castrated males in vivo
(Adam et al., 1998; Anderson
et al., 1999). Moreover, insulin and IGF-I receptors have been identified
in leydig cells which causes proliferation of the leydig cells (Wang
et al., 2003; Wang and Hardy, 2004).
Nutrients and their effect on male puberty
Copper (Cu): Copper act as cofactors of many enzymes like Cytochrome oxidase,
which is necessary for electron transport in mitochondria for energy metabolism
of ATP dependent biosynthetic reactions. It is required in the body for production
of red blood cells, as it is essential for absorption as well as transportation
of iron necessary for haemoglobin synthesis (Tuormaa, 2000).
Deficiency of copper and cobalt may delay onset of puberty.
Selenium (Se): Selenium along with Vitamin E acts as antioxidant and
inactivate the peroxidase formed during cell metabolism (Hine
1992; Puertollano et al., 2011; Chaudhary
et al., 2010; Mahima and Mudgal, 2012; Mahima
et al., 2012). Testicular selenium is essential for testicular function.
Low selenium leads to lower sperm production and motility with flagella defects
localised primarily to the mid piece has been a consistent feature.
Manganese (Mn): Though the pathway of specific manganese involvement
in reproductive functions remains unknown, some evidence suggests that it plays
a role in the activity of certain endocrine organs. Mn functions as co factor
during cholesterol synthesis, necessary for the synthesis of steroids viz.,
progesterone, estrogens and testosterone (Keen and Zidenberg-Cherr,
1990). In males the dietary deficiencies of Mn may leads to absences of
libido, decreased motility of spermatozoa and reduced number of sperms in ejaculate.
Zinc (Zn): Zn deficiency has profound effect on reproductive cycle by
interfering prostaglandin synthesis and delayed puberty (Kreplin
and Yaremcio, 1992). Zn deficient male animals have lower FSH and LH (Boland,
2003). Zinc deficiency in male may leads to atrophy of semeniferous tubule,
reduced testicular size, lack of libido and can adversely affect spermatogenesis
Chromium (Cr): Naturally occurring chromium is crucial for carbohydrate
metabolism. Chromium supplementation may regulate the genes for insulin production
and may be helpful in diabetes or obesity management (Lau
et al., 2008). Lower sperm count associated with chromium deficiency.
Iron (Fe): Iron takes part in the function of transportation of oxygen
to tissues, maintenance of oxidative enzyme system and is concerned with ferretin
formation. All these are accomplished via haemoglobin and myoglobin as well
as many enzymes viz., cytochrome enzymes of electron transport chain forms (Khillare,
2007). Deficiency in adult animals is rare due to its ubiquitous presence
in the feed stuffs.
Molybdenum (Mo): Mo is interdependent with Cu with reference to body
system of ruminants and thus proper balance of Cu and Mo in soil is very much
essential for normal absorption (Randhawa and Randhawa,
1994). Molybdenum deficiency causes sex drive and spermatogenesis leading
to sterility in males and is responsible for delayed puberty, reduced conception
rate and anoestrous in females.
Vitamins: Some of the vitamins play role in puberty like vitamins E,
A and D. Vitamin A (retinol) is the vitamin most likely to be deficient in diets
of cattle. Normal vision, growth and reproduction along with maintenance of
skin tissue and body cavity lining cell and bone development are all influenced
by Vitamin A (Perrotta et al., 2003). The deficiency
of this vitamin shows up as night blindness and excessive tear production, reduced
feed intake and rough hair coat and even fluid accumulation in joints and brisket,
diarrhea, seizures, poor (and slow) skeletal growth, reproductive problems,
low quality semen and infections in cattle. Vitamin D is necessary for calcium
and phosphorus absorption required for normal bone mineralization and calcium
mobilization from bone and also it requires for puberty. Recent study demonstrated
that there is a significant inverse relationship between obese Asian-Indian
children between body fat indices and serum 25 (OH) D concentrations. Vitamin
E serves as an antioxidant and is particularly important in protecting the immune
system from damage during times of oxidative stress and infection of bacteria,
virus or parasite. Deficiency of this vitamin increases the susceptibility to
infections (Beck, 2007; Fondell
et al., 2011). Selenium is closely linked with this vitamin and helps
in testicular function. Vitamin C (L-ascorbic acid) an antioxidant; is present
in high concentrations in the plasma and leukocytes rapidly decline during infections
and stress and has got a significant impact on health status of bulls during
exercise (Schwager and Schulze, 1998; Castellani
et al., 2010; Puertollano et al., 2011;
Khadgawat et al., 2012; Holmannova
et al., 2012; Sahay and Sahaya, 2012; Braakhuis,
Nanofood and nanodelivery: Application of nanotechnology to make food
safer for promotion of good health has created much excitement. Nanoparticles
has been developed that latch on to Campylobacter a bacterium having
no harmful effect on chicken but causes illness in human beings leading to even
death. Nano-sized self assembled liquid structures (incorporated with lycopene
as well as beta carotene and lutein); nanocochleates (containing vitamins and
omega fatty acids) have also been widely used to enhance male puberty (Roco
and Bainbridge, 2003; Wolbing, 2007; Maclurcan,
CONCLUSION AND FUTURE PERSPECTIVES
Puberty is a multigenic trait and endocrine patterns associated with puberty
in cattle are governed to a greater extent by the nutrient requirements. It
has been a prime focus of nutrition research to investigate how nutrition can
optimize and maintain tissue as well as organ and whole body integrity having
considerable effect on male puberty. In recent years it has shifted from epidemiology
and physiology to molecular biology and genetics. This has increased the importance
of nutrigenomics in the eye of the researchers as such dynamic arena of biological
science is able to demonstrate the effect of bioactive food compounds on puberty
and health status of bull affecting fertility. Study of genetic markers and
hormones along with kinetics of utilization of essential vitamins and minerals
that are essential to have better understanding of male puberty forms theme
of nutrigenomic research. Identification of polymorphism in genes regulating
puberty has also not been over looked. Nutrigenomics though is a rapidly developing
science but still is considered in its infancy as far as management of puberty
in bull is concerned. Uncertainty prevails regarding the use of the tools to
study protein expression profile and metabolite production to such point of
extent so as to enable efficient and reliable measurements. With the advent
of nanotechnology it is not only easier to deliver essential nutrients to the
animal in a better and safer way but also to prevent infectious diseases that
affect puberty. There is however considerable debate regarding whether nano
approaches will be used to increase the usability of the previously existing
approaches or whether these two will complement each others. Such advanced technologies
are still under development. Not only achieving success in the field of nutrigenomics
but also further integrations together to produce dietary recommendations will
be ultimately fruitful.
Adam, C.L., Z.A. Archer and D.W. Miller, 2003.
Leptin actions on the reproductive neuroendocrine axis in sheep. Reprod. Suppl., 61: 283-297.PubMed |
Adam, C.L., P.A. Findlay and A.H. Moore, 1998.
Effects of insulin-like growth factor-1 on luteinizing hormone secretion in sheep. Anim. Reprod. Sci., 50: 45-56.PubMed | Direct Link |
Anderson, R.A., I.H. Zwain, A. Arroyo, P.L. Mellon and S.S. Yen, 1999.
The insulin-like growth factor system in the GT1-7 GnRH neuronal cell line. Neuroendocrinology, 70: 353-359.PubMed | Direct Link |
Bagu, E.T., K.L. Davies, T. Epp, A. Arteaga and D.M. Barrett et al
The effect of parity of the dam on sexual maturation, serum concentrations of metabolic hormones and the response to luteinizing hormone releasing hormone in bull calves. Reprod. Domest. Anim., 45: 803-810.CrossRef | PubMed | Direct Link |
Barb, C.R. and R.R. Kraeling, 2004.
Role of leptin in the regulation of gonadotropin secretion in farm animals. Anim. Reprod. Sci., 82: 155-167.CrossRef | PubMed | Direct Link |
Beck, M.A., 2007.
Selenium and Vitamin E Status: Impact on viral pathogenicity. J. Nutr., 137: 1338-1340.PubMed | Direct Link |
Boland, M.P., 2003.
Trace minerals in production and reproduction in dairy cows. Adv. Dairy Technol., 15: 319-330.Direct Link |
Boss, D.L., M.F. Allan, K.A. Johnson, P.A. Lancaster, A.E. Wertz-Lutz and M.E. Branine, 2012.
Alpharma beef cattle nutrition symposium: Enhancing beef production efficiency with new knowledge and technologies: Building the bridges for future collaboration. J. Anim. Sci., 90: 2299-2300.CrossRef |
Braakhuis, A.J., 2012.
Effect of vitamin C supplements on physical performance. Curr. Sports Med. Rep., 11: 180-184.PubMed | Direct Link |
Brito, L., A. Barth, N. Rawlings, R. Wilde, D. Crews Jr., P. Mir and J. Kastelic, 2007.
Circulating metabolic hormones during the peripubertal period and their association with testicular development in bulls. Reprod. Domest. Anim., 42: 502-508.CrossRef | PubMed | Direct Link |
Burns, B.M., C. Gazzola, R.G. Holroyd, J. Crisp and M.R. McGowan, 2011.
Male reproductive traits and their relationship to reproductive traits in their female progeny: A systematic review. Reprod. Domest. Anim., 46: 534-553.CrossRef | PubMed | Direct Link |
Casas, E., D.D. Lunstra, L.V. Cundiff and J.J. Ford, 2007.
Growth and pubertal development of F1 bulls from Hereford, Angus, Norwegian Red, Swedish Red and White, Friesian and Wagyu sires. J. Anim. Sci., 85: 2904-2909.PubMed | Direct Link |
Castellani, M.L., Y.B. Shaik-Dasthagirisaheb, D. Tripodi, A. Anogeianaki and P. Felaco et al
Interrelationship between vitamins and cytokines in immunity. J. Biol. Regul. Homeostat. Agents, 24: 385-390.PubMed | Direct Link |
Chaudhary, M., A.K. Garg, G.K. Mittal and V. Mudgal, 2010.
Effect of organic selenium supplementation on growth, se uptake and nutrient utilization in guinea pigs. Biol. Trace Elem. Res., 133: 217-226.CrossRef | Direct Link |
Daftary, S.S. and A.C. Gore, 2005.
IGF-1 in the brain as a regulator of reproductive neuroendocrine function. Exp. Biol. Med., 230: 292-306.PubMed | Direct Link |
Deb, R., U. Singh, S. Kumar and A. Sharma, 2012.
Exploring Cattle Genome, Livestock Update. Satish Serial Publishing, New Delhi, India, ISBN: 9789381226308
Deb, R., S. Chakraborty and U. Singh, 2012.
Molecular markers and their application in livestock genomic research. J. Vet. Sci. Technol., Vol. 3, No. 5.CrossRef | Direct Link |
Derecka, K., S. Ahmad, T.C. Hodgman, N. Hastings, M.D. Royal, J.A. Woolliams and A.P. F. Flint, 2010.
Sequence variants in the bovine gonadotrophin releasing hormone receptor gene and their associations with fertility. Anim. Genet., 41: 239-331.CrossRef | PubMed | Direct Link |
Elks, C.E., J.R.B. Perry, P. Sulem, D.I. Chasman and N. Franceschini et al
Thirty new loci for age at menarche identified by a meta-analysis of genome-wide association studies. Nat. Genet., 42: 1077-1085.CrossRef | PubMed | Direct Link |
Silveira, L.F.G., E.B. Trarbach and A.C. Latronico, 2010.
Genetics basis for GnRH-dependent pubertal disorders in humans. Mol. Cell. Endocrinol., 324: 30-38.CrossRef |
Fondell, E., O. Balter, K.J. Rothman and K. Balter, 2011.
Dietary intake and supplement use of vitamins C and E and upper respiratory tract infection. J. Am. Coll. Nutr., 30: 248-258.PubMed | Direct Link |
Fortes, M.R., A. Reverter, S.H. Nagaraj, Y. Zhang and N.N. Jonsson et al
A single nucleotide polymorphism-derived regulatory gene network underlying puberty in 2 tropical breeds of beef cattle. J. Anim. Sci., 89: 1669-1683.CrossRef | Direct Link |
Fortes, M.R., A. Reverter, Y. Zhang, E. Collis and S.H. Nagaraj et al
Association weight matrix for the genetic dissection of puberty in beef cattle. Proc. Natl. Acad. Sci., 107: 13642-13647.CrossRef | Direct Link |
Hine, R.S., 1992.
Oxford Concise Veterinary Dictionary. CBC, India
Holmannova, D., M. Kolackova and J. Krejsek, 2012.
Vitamin C and its physiological role with respect to the components of the immune system. Vnitr. Lek., 58: 743-749.PubMed | Direct Link |
Kaput, J. and R.L. Rodriguez, 2004.
Nutritional genomics: The next frontier in the postgenomic era. Physiol. Genomics, 16: 166-177.CrossRef | Direct Link |
Kaput, J., J.M. Ordovas, L. Ferguson, B. van Ommen and R.L. Rodriguez et al
The case for strategic international alliances to harness nutritional genomics for public and personal heath. Br. J. Nutr., 94: 623-632.PubMed | Direct Link |
Keen, C.L. and S. Zidenberg-Cherr, 1990.
Manganese. In: Present Knowledge in Nutrition, Brown, M.L. (Ed.). International Life Sciences Institute, Nutrition Foundation, Washingoton, DC., ISBN-13: 9780944398050, pp: 279-286
Khadgawat, R., T. Thomas, M. Gahlot, N. Tandon, V. Tangpricha, D. Khandelwal and N. Gupta, 2012.
The effect of puberty on interaction between vitamin D status and insulin resistance in obese Asian-Indian children. Int. J. Endocrinol., Vol. 2012.CrossRef |
Khillare, K.P., 2007.
Trace Minerals and and therapeutic approaches to metabolic and deficiency. Reprod. Anim. Intas Polivet., 8: 308-314.
Kreplin, C. and B. Yaremcio, 1992.
Effects of nutrition on beef cow reproduction. Agdex, 420/51-1. http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/agdex3527.
Lander, E.S., L.M. Linton, B. Birren, C. Nusbaum and M.C. Zody et al
Initial sequencing and analysis of the human genome. Nature, 409: 860-921.CrossRef | PubMed | Direct Link |
Lau, F.C., M. Bagchi, C.K. Sen and D. Bagchi, 2008.
Nutrigenomic basis of beneficial effects of chromium(III) on obesity and diabetes. Mol. Cell. Biochem., 317: 1-10.CrossRef | PubMed | Direct Link |
Maclurcan, D.C., 2005.
Nanotechnology and developing countries part 2: What realities? AZoNano Online J. Nanotechnol.Direct Link |
Mahima, A.K. Garg and V. Mudgal, 2012.
Influence of sodium selenite on growth, nutrient utilization and selenium uptake in Cavia porcellus
. Pak. J. Biol. Sci., 15: 448-453.CrossRef | Direct Link |
Mahima, A.K. Verma, A. Kumar, A. Rahal, V. Kumar and D. Roy, 2012.
Inorganic versus organic selenium supplementation: A review. Pak. J. Biol. Sci., 15: 418-425.CrossRef | Direct Link |
Maj, A., M. Snochowski, E. Siadkowska, B. Rowinska and P. Lisowski et al
Polymorphism in genes of growth hormone receptor (GHR) and insulin-like growth factor-1 (IGF1) and its association with both the IGF1 expression in liver and its level in blood in Polish Holstein-Friesian cattle. Neuro. Endocrinol. Lett., 29: 981-989.PubMed | Direct Link |
Muller, M. and S. Kerten, 2003.
Nutrigenomics: Goals and strategies. Nat. Rev. Genet., 4: 315-322.CrossRef | PubMed | Direct Link |
Neibergs, H.L. and K.A. Johnson, 2012.
Alpharma beef cattle nutrition symposium: Nutrition and the genome. J. Anim. Sci., 90: 2308-2316.CrossRef | Direct Link |
Puertollano, M.A., E. Puertollano, G.A. de Cienfuegos and M.A. de Pablo, 2011.
Dietary antioxidants: Immunity and host defense. Curr. Top. Med. Chem., 11: 1752-1766.CrossRef | Direct Link |
Randhawa, S.S. and C.S. Randhawa, 1994.
element imbalances as a cause of infertility in farm animals. Proceedings of the Summer Institute on Recent advances in Animal Reproduction and Gynaecology, July 25-August 13, 1994, Ludhiana, India, pp: 103-121
Roco, M.C. and W.S. Bainbridge, 2003.
Converging technologies for improving human performance: Nanotechnology, biotechnology, information technology and cognitive science. NSF/DOC-Sponsored Report.
Sahay, M. and R. Sahaya, 2012.
Rickets-vitamin D deficiency and dependency. Ind. J. Encrinol. Metab., 16: 164-176.CrossRef | PubMed | Direct Link |
Kumar, S., 2003.
Management of infertility due to mineral deficiency in dairy animals. Proceedings of the ICAR Summer School on Advance Diagnostic Techniques and Therapeutic Approaches to Metabolic and Deficiency Diseases, July 15-August 4, 2003, I IVRI, Izatnagar, India, pp: 128-137
Schwager, J. and J. Schulze, 1998.
Modulation of interleukin production by ascorbic acid. Vet. Immunol. Immunopathol., 64: 45-57.CrossRef | PubMed | Direct Link |
Siadkowska, E., L. Zwierzchowski, J. Oprzadek, N. Strzałkowska, E. Agnicka and J. Krzyzewski, 2006.
Effect of polymorphism in IGF-1 gene on production traits in Polish Holstein-Friesian cattle. Anim. Sci. Pap. Rep., 3: 225-237.
Perrotta, S., B. Nobili, F. Rossi, D. Di Pinto and Cucciolla et al
Vitamin A and infancy. Biochemical, functional and clinical aspects. Vitam. Horm., 66: 457-591.Direct Link |
Tuormaa, T.E., 2000.
Chromium, selenium, copper and other trace minerals in health and reproduction. J. Orthomol. Med., 15: 145-157.Direct Link |
Venter, I.C., M.D. Adams, E.W. Myers, P.W. Li and R.J. Mural et al.
The sequence of the human genome. Science, 291: 1304-1351.CrossRef | Direct Link |
Wang, G. and M.P. Hardy, 2004.
Development of leydig cells in the insulin-like growth factor-I (IGF-I) knockout mouse: Effects of IGF-I replacement and gonadotropic stimulation. Biol. Reprod., 70: 632-639.CrossRef | PubMed | Direct Link |
Wang, G.M., P.J. O'Shaughnessy, C. Chubb, B. Robaire and M.P. Hardy, 2003.
Effects of insulin-like growth factor I on steroidogenic enzyme expression levels in mouse leydig cells. Endocrinology, 144: 5058-5064.PubMed | Direct Link |
Wolbing, G., 2007.
Social and ethical issues of different nanoproducts and nanoprocesses. J. Int. Organiz. Stand. ISO Focus, 4: 40-42.
Yilmaz, A., M.E. Davis and R.C.M. Simmen, 2004.
Estimation of (co)variance components for reproductive traits in Angus beef cattle divergently selected for blood serum IGF-I concentration. J. Anim. Sci., 82: 2285-2292.PubMed | Direct Link |
Zieba, D.A., M. Amstalden and G.L. Williams, 2005.
Regulatory roles of leptin in reproduction and metabolism: A comparative review. Domest. Anim. Endocrinol., 1: 166-185.CrossRef | PubMed |
Tayo, T., N. Dutta and R. Deb, 2011.
Feeding of Canola Meal on Lactating Cows: Sustainable Production of Milk. LAP Lambert Academic Publishing, Germany, ISBN: 978-3844390650, Pages: 92
Kumar, S., U. Singh, R. Deb and A. Sharma, 2013.
Biomarkers for Semen Quality in Bull. In: Advances in Cattle Research, Singh, U., S. Kumar, A. Kumar, R. Deb and A. Sharma (Eds.). Satish Serial Publishing House, New Delhi, India, ISBN: 9789381226551
Mahima, A.K. Verma, R. Tiwari, K. Karthik, S. Chakraborty, R. Deb and K. Dhama, 2013.
Nutraceuticals from fruits and vegetables at a glance: A review. J. Biol. Sci., 13: 38-47.CrossRef | Direct Link |