The effect of treatment with a GnRH analogue on postpartum reproductive performance in Friesian cows

Use of the gonadotrophin releasing hormone (GnRH) analogue, buserelin has been shown to be effective reducing embryo mortality, by a luteoprotective mechanism, in reproductively normal dairy cows. Drew and Peters, (1991) increased mean pregnancy rates to AI from 53.4 to 65.4% in dairy herds by a buserelin treatment, given 10-12 post service. The objective of this experiment was to determine whether buserelin can also have a beneficial effect on pregnancy rate, in normal and known problem suckler cows.Seventy-eight Hereford x Friesian cows (from 0-4 parities) were used. Forty were considered reproductively normal ('normal' cows) having calved each year from their first season and currently with a 10 week old calf at-foot; while 38 had a history of reproductive disorders ('suspect' cows) and had not calved in the previous 15 months (May 1994 to July 1995).

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The effect of treatment with a gonadotrophin releasing hormone on the fertility of beef cows

Proceedings of the British Society of Animal Science ◽

10.1017/s0308229600030385 ◽

1996 ◽

Vol 1996 ◽

pp. 67-67

Author(s):

Duncan Pullar ◽

Anthony Wrathall

Keyword(s):

Beef Cows ◽

Dairy Herds ◽

Gnrh Analogue ◽

Reproductive Disorders ◽

Releasing Hormone ◽

History Of ◽

Buserelin Treatment ◽

Effect Of Treatment ◽

Gonadotrophin Releasing Hormone ◽

Friesian Cows

Use of the gonadotrophin releasing hormone (GnRH) analogue, buserelin has been shown to be effective reducing embryo mortality, by a luteoprotective mechanism, in reproductively normal dairy cows. Drew and Peters, (1991) increased mean pregnancy rates to AI from 53.4 to 65.4% in dairy herds by a buserelin treatment, given 10-12 post service. The objective of this experiment was to determine whether buserelin can also have a beneficial effect on pregnancy rate, in normal and known problem suckler cows.Seventy-eight Hereford x Friesian cows (from 0-4 parities) were used. Forty were considered reproductively normal ('normal' cows) having calved each year from their first season and currently with a 10 week old calf at-foot; while 38 had a history of reproductive disorders ('suspect' cows) and had not calved in the previous 15 months (May 1994 to July 1995).

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Administration of GnRH at Onset of Estrus, Determined by Automatic Activity Monitoring, to Improve Dairy Cow Fertility during the Summer and Autumn

Animals ◽

10.3390/ani11082194 ◽

2021 ◽

Vol 11 (8) ◽

pp. 2194

Author(s):

Zvi Roth ◽

Yaron Z. Kressel ◽

Yaniv Lavon ◽

Dorit Kalo ◽

David Wolfenson

Keyword(s):

Metabolic Diseases ◽

Experimental Period ◽

Visual Observation ◽

Activity Monitoring ◽

Least Square ◽

Gnrh Analogue ◽

Automatic Activity ◽

Effect Of Treatment ◽

Uterine Diseases ◽

And Control

We examined gonadotropin-releasing hormone (GnRH) administration at onset of estrus (OE), determined by automatic activity monitoring (AAM), to improve fertility of dairy cows during the summer and autumn. The study was performed on two dairy farms in Israel. The OE was determined by AAM recorded every 2 h, and a single im dose of GnRH analogue was administered shortly after OE. Pregnancy was determined by transrectal palpation, 40 to 45 d after artificial insemination (AI). Conception risk was analyzed by the GLIMMIX procedure of SAS. Brief visual observation of behavioral estrus indicated that about three-quarters of the events (n = 40) of visually detected OE occurred within 6 h of AAM-detected OE. Accordingly, the GnRH analogue was administered within 5 h of AAM-detected OE, to overlap with the expected endogenous preovulatory LH surge. Overall, pregnancy per AI (P/AI) was monitored over the entire experimental period (summer and autumn) in 233 first, second or third AI (116 and 117 AI for treated and control groups, respectively). Least square means of P/AI for treated (45.8%) and control (39.4%) groups did not differ, but group-by-season interaction tended to differ (p = 0.07), indicating no effect of treatment in the summer and a marked effect of GnRH treatment (n = 58 AI) compared to controls (n = 59 AI) on P/AI in the autumn (56.6% vs. 28.5%, p < 0.03). During the autumn, GnRH-treated mature cows (second or more lactations), and postpartum cows exhibiting metabolic and uterine diseases, tended to have much larger P/AI than their control counterparts (p = 0.07–0.08). No effect of treatment was recorded in the autumn in first parity cows or in uninfected, healthy cows. In conclusion, administration of GnRH within 5 h of AAM-determined OE improved conception risk in cows during the autumn, particularly in those exhibiting uterine or metabolic diseases postpartum and in mature cows. Incorporation of the proposed GnRH treatment shortly after AAM-detected OE into a synchronization program is suggested, to improve fertility of positively responding subpopulations of cows.

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Effect of treatment with ivermectin on reproductive performance of yearling beef heifers

Theriogenology ◽

10.1016/0093-691x(95)00168-8 ◽

1995 ◽

Vol 44 (2) ◽

pp. 189-197 ◽

Cited By ~ 10

Author(s):

R.L. Larson ◽

L.R. Corah ◽

M.F. Spire ◽

R.C. Cochran

Keyword(s):

Reproductive Performance ◽

Beef Heifers ◽

Effect Of Treatment

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The influence of winter nutrition, grazing system and stocking rate on the performance of spring-calving Hereford × Friesian cows and their calves 1. Winter nutrition

Animal Science ◽

10.1017/s0003356100000696 ◽

1982 ◽

Vol 34 (2) ◽

pp. 213-224 ◽

Cited By ~ 6

Author(s):

R. D. Baker ◽

Y. L. P. Le Du ◽

J. M. Barker

Keyword(s):

Milk Production ◽

Reproductive Performance ◽

Metabolizable Energy ◽

Average Weight ◽

Stocking Rate ◽

Calf Growth ◽

Grazing System ◽

Significant Depression ◽

Made In ◽

Friesian Cows

ABSTRACTIn three experiments the effects of giving Hereford × Friesian cows 61 to 64 MJ/day of metabolizable energy in the last 8 weeks of pregnancy, followed by either 49 to 56 (L) or 85 to 100 (H) MJ/day for the first 8 weeks of lactation, were determined. A further comparison was made in experiment 3, in which energy intakes were restricted to 46 and 64 MJ/day (M) in the two periods respectively. The L and M groups had a similar average weight loss of approximately 55 kg over winter whereas the H groups maintained their weight. The L and M treatments had a negligible effect on milk production at 3 weeks post calving but they caused a significant depression at 6 weeks in experiments 2 and 3. Milk energy and protein concentrations were reduced in all three experiments. Calf growth was similar on both treatments in experiment 1 but was 9 to 13% lower in experiments 2 and 3 for the L and M groups compared with the H group. Reproductive performance was not significantly affected. There was a substantial increase in milk production for all groups on turnout to grazing. This was greater for the L and M groups so that their summer milk production was almost equal to that of the H group. Cows from L and M groups gained more weight at pasture. By the end of the trials cows and calves from all treatments had similar weights except in experiment 3, when cows from the L and M treatments were still lighter than those from the H treatment.

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A protocol for initiating oestrus and ovulation earlypost partumin dairy cows

Animal Science ◽

10.1017/s1357729800052073 ◽

2001 ◽

Vol 72 (3) ◽

pp. 539-546 ◽

Cited By ~ 8

Author(s):

A. O. Darwash ◽

G. E. Lamming ◽

M. D. Royal

Keyword(s):

Reproductive Performance ◽

Post Partum ◽

Treatment Protocol ◽

Ovarian Activity ◽

Milk Samples ◽

Management Regime ◽

Holstein Friesian ◽

Prostaglandin F ◽

The Mean ◽

Friesian Cows

AbstractThe objective of the present study was to evaluate the efficacy of a prostaglandin F2α(PGF2α) and progesterone (P4) treatment in initiating oestrus and ovulation post partum (PP) in Holstein-Friesian cows. Using four herds, the treatment protocol consisted of a single intra-muscular injection of PGF2α(Estrumate) between days 12 to 14 PP followed 48 h later by progesterone treatment via intra-vaginal CIDR insertion for a period of 7 days. Milk samples for progesterone determination were collected three times weekly from 7 to 65 days PP. The ovarian activity and reproductive performance of treated (T, no. = 153) animals and untreated control cows (C, no. = 315) were compared. Treatment was effective (P< 0·001) in reducing the mean interval to PP commencement of luteal activity from 29·62 (s.e. 0·82) days to 22·09 (s.e. 0·70) days. The mean interval to first PP oestrus in the T animals was significantly reduced (P< 0·001) from 55·62 (s.e. 1·58) days to 44·91 (s.e. 1·44) days and the incidence of silent ovulation in cycles between days 21 to 65 PP was reduced (P< 0·001) from 56·28% to 42·27%. In two herds under one management regime and with a similar block-calving pattern (no. = 280 animals), the treatment protocol was beneficial to the overall reproductive performance as there was a significant shortening in the mean interval to first PP service (75·82 (s.e. 1·93) v. 80·86 (s.e. 1·32) days) and in the interval to PP conception (83·07 (s.e. 2·49) v. 88·90 (s.e. 1·95) days), bothP< 0·05.

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