INDUCTION OF CYCLIC ACTIVITY IN THE EARLY POSTPARTUM DAIRY COW

1976 ◽  
Vol 56 (3) ◽  
pp. 467-473 ◽  
Author(s):  
J. G. MANNS ◽  
G. RICHARDSON
Keyword(s):  
Dairy Cows ◽  
Dairy Cow ◽  
Saline Control ◽  
Cyclic Activity ◽  
Blood Samples ◽  
Important Constraint ◽  
Lactating Dairy Cows ◽  
Early Postpartum ◽  
Prostaglandin F ◽  
Estradiol 17Β

Twenty-five lactating dairy cows were treated with either saline (control), 500 μg gonadotropin-releasing hormone (GnRH), GnRH + 10 mg estradiol 17β (E2), E2, or GnRH + E2 + 25 mg prostaglandin F2α (PGF2α) at approximately 11 days postpartum. Blood samples were taken at the time of injection and then twice each week for about 30 days. Treatment with GnRH alone gave the largest LH peak; LH production appeared to be inhibited when E2 was given with GnRH. Plasma estrogen concentrations were above 1 ng/ml for 12 h in all animals receiving estrogen alone or in combination. None of the treatments hastened initiation of cyclic activity which began at an average of 19 days postpartum. It seems unlikely that postpartum anestrus is an important constraint to early rebreeding in dairy cows.

The effect of asynchronous diets on the function of the rumen in the lactating dairy cow

1998 ◽  
Vol 1998 ◽  
pp. 19-19
Author(s):  
A.R. Henderson ◽  
P.C. Garnsworthy ◽  
J.R. Newbold ◽  
P.J. Buttery
Keyword(s):  
Protein Synthesis ◽  
Dairy Cows ◽  
Dairy Cow ◽  
Production Performance ◽  
Early Lactation ◽  
Microbial Protein ◽  
Nutrient Flows ◽  
Lactating Dairy Cows ◽  
Overall Efficiency ◽  
Fermentation Parameters

Sinclair et al. (1993) found that a diet formulated to be synchronous with regard to hourly release of nitrogen and energy increased microbial protein synthesis by 14% in sheep. Dairy cows in early lactation experience a shortfall of energy and protein, with available protein determining the overall efficiency of metabolism (MacRae and Lobley, 1986) and subsequent milk production. It is therefore necessary to maximise microbial protein yield during this period. In this study diets were designed for lactating dairy cows to contain the same feed ingredients, but to release nitrogen and energy in the rumen at different times. Rumen fermentation parameters, nutrient flows to the small intestine and production performance were investigated.

scholarly journals Reduced progesterone concentration during growth of the first follicular wave affects embryo quality but has no effect on embryo survival post transfer in lactating dairy cows

Reproduction ◽  
2011 ◽  
Vol 141 (3) ◽  
pp. 333-342 ◽  
Author(s):  
Fernando A Rivera ◽  
Luís G D Mendonça ◽  
Gláucio Lopes ◽  
José E P Santos ◽  
Rolando V Perez ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Estrous Cycle ◽  
Embryo Quality ◽  
Post Partum ◽  
Embryo Survival ◽  
Follicular Wave ◽  
Lactating Dairy Cows ◽  
Prostaglandin F ◽  
Donor Cows

Fertility of lactating dairy cows is associated with reduced progesterone (P4) concentration compared with nonlactating animals. The objective of the current study was to determine whether P4 during growth of the first follicular wave (FFW) affects embryo quality. Lactating Holstein cows at 33±3 days post partum were allocated to one of three treatments. Cows in the FFW and FFW with P4 (FFWP) treatments started the superstimulation protocol on day 1 of the estrous cycle and second follicular wave (SFW) cows started the superstimulation protocol on estrous cycle day 7. Cows were superstimulated with 400 mg of NIH-FSH-P1 (FSH) given twice daily for 5 days, two prostaglandin F2α (PGF2α) injections given with the ninth and tenth injections of FSH, GNRH given 48 h after the first PGF2α injection, and timed insemination 12 and 24 h after the GNRH injection. Cows in the FFWP treatment received two intravaginal P4 inserts during the superstimulation. Embryos were recovered 6.5 days after artificial insemination and excellent/good and fair embryos were frozen and transferred. Blood was sampled daily from estrous cycle day 0 until insemination from donor cows. During the superstimulation protocol, P4 was (P<0.01) greatest for SFW cows followed by FFWP and FFW cows respectively. The percentage of embryos–oocytes from SFW and FFWP cows classified as excellent/good and fair embryos was (P=0.02) greater than those of FFW cows. Pregnancy per embryo transfer was not (P≥0.73) affected by embryo donor treatment. Reduced embryo quality of cows induced to ovulate the follicles from the first follicular wave is a consequence of reduced P4 during follicle growth.

Replacement of soyabean meal by barley or wheat distillers grains for lactating dairy cows

2002 ◽  
Vol 2002 ◽  
pp. 108-108
Author(s):  
J.D. Sutton ◽  
D.J. Humphries ◽  
R H Phipps ◽  
M. Witt
Keyword(s):  
Dairy Cows ◽  
Milk Production ◽  
Dairy Cow ◽  
Present Experiment ◽  
Distillers Grains ◽  
Complete Replacement ◽  
Lactating Dairy Cows ◽  
Soyabean Meal

The complete replacement of soyabean meal by maize distillers grains (MDG) in dairy cow diets had no significant effects on milk production, rumen digestion or the supply of non-ammonia N to the duodenum (Sutton et al., 2000; Phipps et al., 2001). The present experiment was designed to extend this work by examining the response when barley (BDG) or wheat (WDG) distillers grains replaced soyabean meal.

Improving reproductive performance in lactating dairy cows by synchronising ovulation or inducing oestrus

2002 ◽  
Vol 50 (2) ◽  
pp. 231-234 ◽  
Author(s):  
Gy. Gábor ◽  
J. P. Kastelic ◽  
S. Pintér ◽  
Keyword(s):  
Dairy Cows ◽  
Reproductive Performance ◽  
Fixed Time ◽  
Pregnancy Rates ◽  
Preliminary Trial ◽  
Lactating Cows ◽  
Lactating Dairy Cows ◽  
Considerable Promise ◽  
Holstein Friesian ◽  
Prostaglandin F

Lactating crossbred Holstein-Friesian dairy cows (n = 331) were started on an Ovsynch regimen 68 ± 8.2 days after calving; 200 µg GnRH intramuscularly (i.m.) on Days 0 and 9, and 35 mg prostaglandin F2a i.m. on Day 7. Thirty-eight and 31 cows (11.5 and 9.4%, respectively) were in oestrus on Days 0 to 6 and 7 to 8, respectively, and inseminated, and the remainder were fixed-time inseminated (on Day 10). For these three groups, pregnancy rates (60-65 days after breeding) were 31.6, 38.7 and 34.0%, respectively (P = 0.82) and calving rates were 100, 100 and 89.9% (P = 0.23). In a preliminary trial, twelve lactating cows (45 to 60 days postpartum) with inactive ovaries were given 1500 IU eCG i.m.; 10 were in oestrus within 10 days after treatment (and inseminated) and eight of these were pregnant (30 days after breeding). The Ovsynch program resulted in acceptable reproductive performance in cyclic cows and eCG treatment has considerable promise for inducing oestrus in anoestrous cows.

scholarly journals Effects of GnRH, PGF2α and oxytocin treatments on conception rate at the time of artificial insemination in lactating dairy cows

2011 ◽  
Vol 56 (No. 6) ◽  
pp. 279-283 ◽  
Author(s):  
A. Gümen ◽  
A. Keskin ◽  
G. Yilmazbas-Mecitoglu ◽  
E. Karakaya ◽  
S. Cevik ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Artificial Insemination ◽  
Reproductive Tract ◽  
Female Reproductive Tract ◽  
Conception Rate ◽  
Beneficial Effects ◽  
Lactating Dairy Cows ◽  
Conception Rates ◽  
Prostaglandin F ◽  
And Control

In several studies, hormones such as gonadotropin-releasing hormone (GnRH), prostaglandins and oxytocin were used to increase pregnancy rate by inducing ovulation and improving the sperm transport in the female reproductive tract in lactating dairy cattle. The objective of this study was to compare the effects of GnRH, prostaglandin F<sub>2&alpha;</sub> (PGF<sub>2&alpha;</sub>) and oxytocin treatments at the time of artificial insemination (AI) after spontaneous oestrus on the conception rate (CR) of lactating dairy cows. Oestrus was detected by visual observations by experienced personnel. All cows (n = 430, 308 Holstein-Frisian and 122 Swedish-Red dairy cows) were inseminated based on the am/pm rule by veterinarians of the farm. After AI, cows were alternately assigned to one of the four treatment groups: (1) GnRH (n = 113); (2) PGF<sub>2&alpha;</sub> (n = 106);<br />(3) oxytocin (n = 106) and (4) non-treated control (n = 105). Pregnancy diagnosis was performed 28&ndash;34 and 58&ndash;64 days post-insemination by transrectal ultrasonography. Conception rates on days 28&ndash;34 and 58&ndash;64 were not different among GnRH (46.0%; 52/113 and 44.3%; 50/113), PGF<sub>2&alpha;</sub> (37.7%; 40/106 and 35.9%; 38/106) and control (49.5%; 52/105 and 47.6%; 50/105) groups. However, conception rates were lower (P = 0.02) in oxytocin (31.1%; 33/106 and 30.2%; 32/106) than in GnRH and control groups on days 28&ndash;34 and 58&ndash;64. Other covariant factors, such as milk production, days in milk (DIM), breed, parity, service number did not affect the conception rate. Thus, there were no beneficial effects of treatments with GnRH and PGF2&alpha; at the time of AI, and oxytocin had an adverse effect on CR in lactating dairy cows in this study.

The effect of aspirin on prostaglandin F 2α secretion in lactating dairy cows

2016 ◽  
Vol 32 (5) ◽  
pp. 681-686 ◽  
Author(s):  
J.A. Spencer ◽  
K. Steinkamp ◽  
B. Shafii ◽  
A. Ahmadzadeh
Keyword(s):  
Dairy Cows ◽  
Lactating Dairy Cows ◽  
Prostaglandin F
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