The success of a fixed-time artificial insemination (FTAI) program depends on a high ovulation rate during a short interval. Equine chorionic gonadotropin (eCG) has been used in FTAI protocols to improve follicular growth and thereby to produce larger, more responsive follicles for ovulation with increased pregnancy rates. The aim of the present study was to evaluate the effects of eCG on concept...

The objective of this study was to determine the effects of two different time of GnRH injection after artificial insemination (A.I) (d 6 and d 12) on reproductive performances of Holstein cows during the warm season.  Cows randomly assigned to treatments 1) No GnRH injection (control, n = 300),2) GnRH injection at day 6 after A.I (G6, n=300) and 3) GnRH injection at day 12 after A.I (G12, n=30...

F OR profitable milk production the dairy cow must reproduce regularly. An interval of i~ to 13 months between calves usually is considered satisfactory. Cows calving every i~ months or less had higher yields per day for the interval between calves than did cows that required more than ~ months before reproducing in studies by Gaines and Palfrey (i931) and Chapman and Casida (I935). This observ...

The dairy farming systems of Western Europe are based on a simple feeding system composed of grazed and preserved grass, maize silage and concentrates in variable proportions. There is, nevertheless, a great diversity of feeding strategies between dairy farms. Over 5 years, we studied the direct and delayed effects of four feeding strategies on the lactation and reproduction performances of Hol...

The objective of this study was to determine the effects of two different time of GnRH injection after artificial insemination (A.I) (d 6 and d 12) on reproductive performances of Holstein cows during the warm season.  Cows randomly assigned to treatments 1) No GnRH injection (control, n = 300),2) GnRH injection at day 6 after A.I (G6, n=300) and 3) GnRH injection at day 12 after A.I (G12, n=30...

Dairy cows that are being cared for in family businesses were used to compare the pregnancy rates by applying different time periods, using progesterone devices, and fixed-time artificial inseminations. The randomly divided into 3 groups. Group 1(n = 56); On day 0, GnRH (IM) (10mg Buserelin acetate, Ovarelin, CEVA DIF) + Progesterone implants (PRID®) (1,55 g CEVA), Day 8 PGF2α (Dinoprost tromet...

Genetic trend for milk yield in the artificially sired Holstein population in the northeastern United States was estimated from solutions for simultaneous genetic evaluations of bulls and cows for an animal model using mixed model equations and including all known relationships among the population by years of birth of 1960 to 1980 (1978 for bulls). First lactation milk records of 1,074,971 art...

The establishment and maintenance of pregnancy in lactating dairy cows is a complex biological event that is influenced by a multitude of factors, from the reproductive biology of the cow to managerial aspects of the dairy farm. It is often mentioned in the scientific literature that fertility in dairy cows has declined concurrent with major advances in milk production. Some of this decline is ...

the objective of this study was to determine the effects of two different time of gnrh injection after artificial insemination (a.i) (d 6 and d 12) on reproductive performances of holstein cows during the warm season.  cows randomly assigned to treatments 1) no gnrh injection (control, n = 300),2) gnrh injection at day 6 after a.i (g6, n=300) and 3) gnrh injection at day 12 after a.i (g12, n=30...

Water is used in dairy farming for producing feed, watering the animals, and cleaning and disinfecting barns and equipment. The objective of this study was to investigate the drinking and cleaning water use in a dairy cow barn. The water use was measured on a well-managed commercial dairy farm in North-East Germany. Thirty-eight water meters were installed in a barn with 176 cows and two milkin...