Effects of treatment with a gonadotrophin-releasing hormone analogue on follicle development in dairy cows fed one of two different diets

2001 ◽  
Vol 26 (2) ◽  
pp. 451-455
Author(s):  
E.C.L. Bleach ◽  
C.L. Moore ◽  
H.J. Zeale ◽  
P.G. Knight
Keyword(s):  
Dairy Cows ◽  
Luteal Phase ◽  
Cycle Length ◽  
Crude Protein ◽  
Oestrous Cycle ◽  
Follicle Development ◽  
Releasing Hormone ◽  
Ovulatory Follicle ◽  
Metabolisable Energy ◽  
Phase Length

AbstractFollicle development occurs in two or three waves during the bovine oestrous cycle. Artificially extending the duration of ovulatory follicle dominance influences pregnancy rates in cattle, as does the interval from emergence to oestrus in dairy cows undergoing spontaneous oestrous cycles. The objectives of the presented study were to determine whether the interval from ovulatory follicle emergence to oestrus might be altered by diet and/or gonadotropin-releasing hormone (GnRH) treatment. Lactating primiparous Holstein/Friesian cows (n=21) were randomly allocated to one of two diets at calving (Diet 1, n=ll, DM 480 g/kg, metabolisable energy 12.0 MJ/kg DM crude protein 178 g/kg DM, oil B 48 g/kg DM, neutral detergent fibre 318 g/kg DM and diet 2, n=10, DM 440 g/kg, metabolisable energy 12.1 MJ/kg DM, crude protein 172 g/kg DM, oil B 40 g/kg DM, neutral detergent fibre 300 g/kg DM). From 10 days after observed oestrus (oestrus 1), ovarian follicular and luteal development was monitored by daily transrectal ultrasonography until the subsequent oestrus and ovulation. A GnRH analogue was injected (i.m.; 10 μg) 12 days after oestrus 1 in 6 cows fed diet 1 and 5 cows fed diet 2. Oestrous cycle length was longer (p<0.05) in control cows fed diet 1 than those fed diet 2. Treatment with GnRH increased (p<0.005) cycle length in cows fed diet 2 but not those fed diet 1. Increases in cycle length observed were associated with longer luteal phase length. Follicular phase length was reduced (p<0.05) by GnRH treatment in cows fed diet 1. Ovulatory follicles emerged later (p<0.05) in control cows fed diet 1 than those fed diet 2. GnRH treatment delayed (p<0.01) the emergence of the ovulatory follicle in cows fed diet 2, this delay was associated with an increase (p<0.05) in the incidence of 3 follicle waves in oestrous cycles following GnRH treatment. The interval from emergence of the ovulatory follicle to the subsequent oestrus was similar among the treatment groups. We conclude that treatment with GnRH during the mid-luteal phase may delay the emergence of the ovulatory follicle. However, the response is dependent on diet fed. Where ovulatory follicle emergence is delayed, the interval from emergence to the subsequent oestrus was unaffected since oestrous cycle length is extended.

Supplementation of grazing dairy cows with a brewers grains/treated straw mixture

1990 ◽  
Vol 1990 ◽  
pp. 46-46 ◽  
Author(s):  
J.D. Leaver ◽  
R.C. Campling
Keyword(s):  
Dairy Cows ◽  
Crude Protein ◽  
Dry Matter ◽  
Barley Straw ◽  
Severe Drought ◽  
Grass Silage ◽  
Metabolisable Energy ◽  
Grazing Dairy Cows ◽  
Similar Cost ◽  
Friesian Cows

Supplementary feeding of grazing dairy cows is often uneconomic, and whilst supplementation with silage (buffer feeding) can be worthwhile, this often leads to a depletion of winter forage stores. In this study, a mixture of brewers grains and treated straw was used as a supplement. Offered as a 1:1 mixture in the dry matter (DM), it is a purchased substitute for grass silage, having a similar cost, and similar metabolisable energy (ME) and crude protein (CP) contents. The high seasonality adjustments to milk price in mid-late season make supplementation potentially worthwhile.Experiments were carried out from April to September in 1988 and 1989, which had moderate and very low rainfall respectively. Each year 20 British Friesian cows which calved December to March (1988 experiment) and February-April (1989) were allocated at random to either treatment B or C. In B, the cows were offered a 1:1 mixture (DM basis) of brewers grains and NaOH treated chopped barley straw for 60 minutes after morning milking. In C, the cows received no supplement. Both groups were fed 1.0 kg/day of concentrates in the milking parlour. Due to the severe drought in 1989, concentrate feeding was increased to 5.0 kg/day for all cows during the last 4 weeks of the experiment. Also, urea-treated whole crop wheat was fed at a level of 2.5 kg DM/day during the last 7 days.

The relative importance of energy and protein in the concentrate on intake and yield of milk constituents by freisland ewes offered hay ad-libitum

1994 ◽  
Vol 1994 ◽  
pp. 207-207
Author(s):  
R.G. Wilkinson ◽  
C.M. Minter ◽  
G. Duffy ◽  
J. Celerier
Keyword(s):  
Dairy Cows ◽  
Crude Protein ◽  
Relative Importance ◽  
Dairy Sheep ◽  
Total Response ◽  
Metabolisable Energy ◽  
Forage Intake ◽  
Fat Yield ◽  
Protein Supply ◽  
To Receive

Increasing the level of concentrate fed to lactating ruminants reduces forage intake, but increases the yield of milk and milk constituents (Aston et al. 1991). However, the proportion of the total response due to additional metabolisable energy (ME) or crude protein supply (CP) is unclear. Recent work with dairy cows (Aston et al. 1992) suggests that additional ME or CP fed as concentrate reduced and slightly increased silage intake respectively. Additional CP had twice the effect on milk and three times the effect on protein yield than additional ME. However, ME and CP were equally important in determining fat yield. The objective of the trial was to investigate whether dairy sheep respond to additional ME or CP supply as concentrate in a similar way to dairy cows.Three concentrate diets were formulated to contain 13.0 MJ/kg DM ME and either 100 (A), 200 (B) or 400 (C) g/kg DM CP. After weaning (6 weeks), 24 mature Freisland ewes were housed individually, and allocated by liveweight and initial milk yield to receive concentrate DM at daily rates of 0.8 kg, providing 10.4 MJ/day ME and 160 (B) or 320 (C) g/day CP (LLP, LHP), or 1.6 kg, providing 20.8 MJ/day ME and 160 (A) or 320 (B) g/day CP (HLP, HHP). The trial lasted 8 weeks and was analysed as a 2 X 2 factorial design.

330 Effect of inducing high or low progesterone concentrations during ovulatory follicle development on double ovulation and fertility of lactating dairy cows

2016 ◽  
Vol 94 (suppl_2) ◽  
pp. 155-155
Author(s):  
J. P. N. Martins ◽  
D. Wang ◽  
N. Mu ◽  
A. P. Martini ◽  
G. F. Rossi ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Follicle Development ◽  
Lactating Dairy Cows ◽  
Ovulatory Follicle

Miniature ponies: 2. Endocrinology of the oestrous cycle

2008 ◽  
Vol 20 (3) ◽  
pp. 386 ◽  
Author(s):  
O. J. Ginther ◽  
M. A. Beg ◽  
A. P. Neves ◽  
R. C. Mattos ◽  
B. P. L. Petrucci ◽  
...  
Keyword(s):  
Maximum Concentration ◽  
Luteal Phase ◽  
Plasma Concentrations ◽  
Oestrous Cycle ◽  
Slow Increase ◽  
Lh Surge ◽  
Ovulatory Follicle ◽  
The Future ◽  
Three Phases

Plasma concentrations of FSH, LH, oestradiol and progesterone were studied daily during 12 interovulatory intervals and 21 periovulatory periods in nine Miniature ponies. The peak of the FSH surge that was temporally associated with emergence of the future ovulatory follicle occurred when the follicle was ~9 mm, compared with a reported diameter of 13 mm in larger breeds. The ovulatory LH surge involved a slow increase between Days 13 and 18 (ovulation = Day 0; 0.6 ± 0.1 ng day–1), a minimal increase or a plateau on Days 18 to 21 (0.04 ± 0.1 ng day–1), and a rapid increase after Day 21 (2.2 ± 0.4 ng day–1; P < 0.0001). The end of the plateau and the beginning of the rapid increase occurred on the day of maximum concentration in the oestradiol preovulatory surge. An unexpected mean increase and decrease in LH occurred (P < 0.04) on Days 5 to 9. Concentrations of oestradiol and progesterone seemed similar to reported results in larger breeds. Results indicated that in Miniature ponies the peak of the FSH surge associated with emergence of the future ovulatory follicle occurred at a smaller diameter of the future ovulatory follicle than in larger breeds, the ovulatory LH surge increased in three phases, and the ovulatory LH surge was followed by an LH increase and decrease during the early luteal phase.

Inducing ovulation with oestradiol cypionate allows flexibility in the timing of insemination and removes the need for gonadotrophin-releasing hormone in timed AI protocols for dairy cows

2017 ◽  
Vol 29 (3) ◽  
pp. 468 ◽  
Author(s):  
R. M. Ferreira ◽  
H. Ayres ◽  
L. U. Gimenes ◽  
F. P. Torres ◽  
F. A. Lima ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Pregnancy Rates ◽  
Holstein Cows ◽  
Device Removal ◽  
Releasing Hormone ◽  
Ovulatory Follicle ◽  
Oestradiol Benzoate ◽  
Gonadotrophin Releasing Hormone

The effects of addition of gonadotrophin-releasing hormone (GnRH) to a progesterone plus oestradiol-based protocol and timing of insemination in Holstein cows treated for timed AI (TAI) were evaluated. Cows (n = 481) received a progesterone device and 2 mg oestradiol benzoate. After 8 days, the device was removed and 25 mg dinoprost was administered. Cows were allocated to one of three (Study 1; n = 57) or four (Study 2; n = 424) groups, accordingly to ovulation inducer alone (Study 1; oestradiol cypionate (EC), GnRH or both) or ovulation inducer (EC alone or combined with GnRH) and timing of insemination (48 or 54 h after device removal; Study 2). In Study 1, the diameter of the ovulatory follicle was greater for GnRH than EC. Oestrus and ovulation rates were similar regardless of ovulatory stimuli. However, time to ovulation was delayed when GnRH only was used. In Study 2, cows treated with GnRH or not had similar pregnancy per AI (P/AI) 30 days (41.5% vs 37.3%; P = 0.28) and 60 days (35.9% vs 33.0%; P = 0.61) after TAI. TAI 48 and 54 h after device removal resulted similar P/AI at 30 days (40.3% vs 38.5%; P = 0.63) and 60 days (33.8% vs 35.1%; P = 0.72). Thus, adding GnRH at TAI does not improve pregnancy rates in dairy cows receiving EC. The flexibility of time to insemination enables TAI of a large number of cows using the same protocol and splitting the time of AI.

scholarly journals Level of circulating concentrations of progesterone during ovulatory follicle development affects timing of pregnancy loss in lactating dairy cows

2018 ◽  
Vol 101 (11) ◽  
pp. 10505-10525 ◽  
Author(s):  
J.P.N. Martins ◽  
D. Wang ◽  
N. Mu ◽  
G.F. Rossi ◽  
A.P. Martini ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Pregnancy Loss ◽  
Follicle Development ◽  
Lactating Dairy Cows ◽  
Ovulatory Follicle

The effects of raising post-oestrus progesterone concentrations on luteal activity in post-partum dairy cows

1999 ◽  
Vol 68 (3) ◽  
pp. 527-532 ◽  
Author(s):  
A. O. Darwash ◽  
G. L. Ward ◽  
G. E. Lamming ◽  
J. A. Woolliams
Keyword(s):  
Dairy Cows ◽  
Untreated Control ◽  
Luteal Phase ◽  
Post Partum ◽  
Milk Samples ◽  
Holstein Friesian ◽  
The Mean ◽  
And Control ◽  
Phase Length ◽  
Friesian Cows

AbstractIn order to investigate the rationale of manipulating post-ovulation progesterone (P4) concentrations, luteal activity was measured in 10 Holstein-Friesian cows treated with a progesterone-releasing device (CIDR, 1·9 g P4) inserted on the morning of day 2 post-oestrus for a period of 7 days and compared with 10 untreated control animals. Milk samples were collected daily during afternoon milking from 7 days pre- to 24 days post-oestrus and P4 concentrations were measured using enzyme-linked immuno-sorbent assay (ELISA). The milk P4 profiles were used to assess the effects of early post-oestrus P4 elevation on five intervals of the luteal phase. In the treated (T) and control (C) animals, the mean interval from oestrus to P4 rise (≥3 μg/l), was 2·38 (s.e. 0·18) and 4·90 (s.e. 0·28) days, respectively, (P < 0·01). The mean interval from oestrus to the attainment of peak P4 concentrations was not significantly different (P > 0·05) between the T (14·75 (s.e. 1-62) days) and С (14·30 (s.e. 0·70) days) animals, with cows in the T group showing a more variable (F7 9 = 4-30, P < 0·05) interval to the occurrence of the peak. The interval from peak P4 to corpus luteum (CL) regression (when P4 fell below ≥3 μg/l) was not significantly different between the T (4·13 (s.e. 1·30 days) and С (5·60 (s.e. 0·88) days) groups. Furthermore, CIDR insertion did not alter luteal phase length, number of days with P4 concentrations ≥3 μg/l (T = 16·50 (s.e. 0·80) v.C = 15·00 (s.e. 0·47) days) or the interval from oestrus to CL regression (T = 18·88 (s.e. 0·79) v.C = 19·90 (s.e. 0·41) days). We conclude that treatment with CIDR 2 days after oestrus successfully increased the availability of P4 to cows without significantly affecting luteal phase characteristics.

Effect of undegradable protein given for six weeks before calving on the performance of dairy cows in the subsequent lactation

1996 ◽  
Vol 1996 ◽  
pp. 85-85 ◽  
Author(s):  
R.J. Dewhurst ◽  
D.W.R. Davies ◽  
W.J. Fisher ◽  
K. Aston
Keyword(s):  
Dairy Cows ◽  
Dietary Protein ◽  
Crude Protein ◽  
Dry Period ◽  
Grass Silage ◽  
Holstein Friesian ◽  
Unrestricted Access ◽  
Metabolisable Energy ◽  
Ad Libitum ◽  
Friesian Cows

Previous studies (Moorby et al, 1994) have shown increased yields of protein and lactose in the subsequent lactation as a consequence of feeding additional undegradable dietary protein (UDP) and restricting energy intake during the dry period. This experiment was undertaken to investigate the effect of supplementary UDP in the dry period diet of Holstein-Friesian cows given unrestricted access to grass silage and 1.5 kg of barley per day.Sixty-one cows received diets based on ad libitum access to grass silage with either (a) 1.5 kg barley / day or (b) 1.0 kg barley and 0.5 kg Maize Gluten Meal / day. After calving, cows had ad libitum access to grass silage (Metabolisable Energy (ME)=11.3 MJ/kg DM; crude protein (CP)=181 g/kg DM) and received 5 kg/day of concentrates (ME=13.0 MJ/kg DM; CP=250g/kg DM).

The use of GNRH to control follicular development in cows

1996 ◽  
Vol 1996 ◽  
pp. 95-95
Author(s):  
A.R. Peters ◽  
S.J. Ward ◽  
P.J. Gordon ◽  
G.E. Mann
Keyword(s):  
Dairy Cows ◽  
Present Experiment ◽  
Luteal Phase ◽  
Ovarian Function ◽  
Steroid Hormone ◽  
Follicular Development ◽  
Follicle Development ◽  
Preovulatory Follicle ◽  
Hormone Production ◽  
Gonadotrophin Releasing Hormone

Fertility after prostaglandin (PG) may be compromised by the variability in timing of oestrus and ovulation, which are in turn influenced by the ovarian follicular status at the time of injection. Gonadotrophin-releasing hormone (GnRH) treatment in the luteal phase a few days before PG can reprogramme and thus synchronise preovulatory follicle development (Wolfenson et al., 1994). A second GnRH treatment can then be given after PG, to further improve the synchrony of ovulation (Pursley et al., 1995). The present experiment was carried out to test the effect of this combined GnRH - PG - GnRH regime on ovarian function and steroid hormone production in dairy cows.

The response of dairy cows given high levels of molasses to dietary levels of fermentable metabolisable energy

1994 ◽  
Vol 1994 ◽  
pp. 39-39
Author(s):  
T. Yan ◽  
D.J. Roberts
Keyword(s):  
Fatty Acids ◽  
Free Fatty Acids ◽  
Dairy Cows ◽  
Crude Protein ◽  
Energy Requirement ◽  
Current Experiment ◽  
Negative Effects ◽  
Feed Ingredient ◽  
Metabolisable Energy ◽  
Crude Protein Level

Unprotected tallow is used as a feed ingredient to meet the energy requirement of high milking dairy cows, but its hydrolysed free fatty acids in the rumen can inhibit microbial activity and dietary fibre digestion. However, the negative effects of the tallow could be minimized when high levels of molasses are also fed since feeding molasses could shorten the retention time of the hydrolysed free fatty acids in the rumen. In addition, molasses contains a large proportion of non-structural carbohydrates (sugars) which have fast fermentation rates in the rumen. When a diet is formulated to have a low fermentable metabolisable energy (FME) concentration, supplementing with a high molasses level may partially make up the deficiency of the energy requirement of the microorganisms in the rumen of dairy cows. Previous experiments have showed that molasses could be fed to dairy cows up to 312 g/kg DM without adverse effect (Yan and Roberts, 1992) and a crude protein level at 160 g/kg DM in the diet containing 310 g/kg DM of molasses was satisfactory for feed intake and milk production of dairy cows (Yan and Roberts, 1993). The current experiment was subsequently undertaken to investigate the response of dairy cows given high levels of molasses to dietary levels of FME produced by altering unprotected tallow concentrations in diets.

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