A note on the effects of pattern of food intake and body condition on the duration of the post-partum anoestrous period and LH profiles in beef cows

1992 ◽  
Vol 54 (1) ◽  
pp. 143-146 ◽  
Author(s):  
I. A. Wright ◽  
S. M. Rhind ◽  
T. K. Whyte
Keyword(s):  
Food Intake ◽  
Luteinizing Hormone ◽  
Body Condition ◽  
Post Partum ◽  
Beef Cows ◽  
Peripheral Circulation ◽  
Pulse Frequency ◽  
Metabolizable Energy ◽  
Unit Increase ◽  
Feeding Regimes

An experiment was conducted to determine the effect of level and pattern of food intake in post-partum beef cows on the length of the post-partum anoestrous period and associated luteinizing hormone profiles. Forty-six multiparous cows were allocated at calving to one of three feeding regimes: 55 MJ metabolizable energy (ME) per day throughout (LL), 145 M] ME per day throughout (HH), or 55 M] ME per day until 6 weeks post partum and then 145 M] ME per day thereafter (LH). The duration of the post-partum anoestrous period was assessed from plasma progesterone profiles. Luteinizing hormone profiles in the peripheral circulation were determined at weeks 3, 6, 8 and 11 post partum from samples collected every 20 min for 10 h.Feeding regime had no effect on either the length of the post-partum anoestrous period, being 99, 89 and 91 (s.e.d. 12·2) days for the LL, LH and HH cows respectively, or on any aspect of luteinizing hormone pulsatility. Body condition at calving was negatively correlated with the duration of the post-partum anoestrous period, each unit increase in body condition at calving being associated with a decrease in the post-partum anoestrous period of 86 (s.e. 21·8) days. Luteinizing hormone pulse frequency at 6 weeks post partum was positively correlated with body condition at calving.This experiment confirms the importance of body condition at calving in influencing the duration of the post-partum anoestrous period and indicates that level and pattern of feeding post partum has little effect when cows calve at a body condition of approximately 2·25.

Effects of body condition, food intake and temporary calf separation on the duration of the post-partum anoestrous period and associated LH, FSH and prolactin concentrations in beef cows

1987 ◽  
Vol 45 (3) ◽  
pp. 395-402 ◽  
Author(s):  
I. A. Wright ◽  
S. M. Rhind ◽  
A. J. F. Russel ◽  
T. K. Whyte ◽  
Alison J. McBean ◽  
...  
Keyword(s):  
Body Condition ◽  
Body Condition Score ◽  
Post Partum ◽  
Beef Cows ◽  
Pulse Frequency ◽  
Metabolizable Energy ◽  
Barley Straw ◽  
Blood Samples ◽  
Feeding Level ◽  
Condition Score

ABSTRACTAn experiment was conducted to examine factors affecting the length of the post-partum anoestrous period and associated effects on LH, FSH and prolactin. Forty-six cows (24 Hereford × Friesian and 22 Blue-Grey) ranging in body condition score at calving from 1·50 to 2·75 were used. They were individually fed chopped barley straw and concentrate at either 50 (low) or 91 (high) MJ metabolizable energy per day from calving. At 34 days post partum half the cows were separated from their calves for 48 h. The duration of the post-partum anoestrous period was estimated from progesterone concentrations in thrice weekly blood samples. Blood samples were collected every 20 min for 10 h periods immediately prior to calf separation, during the last 10 h of calf separation and 1 week later. All samples were analysed for LH, and every third sample was analysed for FSH and prolactin.There were no significant effects of genotype, feeding level or calf separation on the length of the post-partum anoestrous period. There was a negative association between body condition score at calving and the length of the anoestrous period, with each unit increase in body condition score reducing the anoestrous period by 43 (s.e. 20) days. There was some evidence that feeding level affected the number of thin cows (body condition score ≤2·25 at calving) which were still acyclic at the end of the experiment, but not the number of fat cows (body condition score ≥2·5 at calving).FSH levels were not affected by any of the factors examined. Prolactin concentrations were higher in fatter cows, in cows on the higher level of feeding and in Blue-Grey cows. Prolactin concentrations decreased during the period of calf separation. Genotype and feeding level had no effect on LH concentration or LH pulse frequency. LH pulse frequency was increased (P < 0·05) during the period of calf separation, but there was no effect 1 week later. There was a significant positive relationship between LH puise frequency and body condition score at calving in two of the three sampling periods.It is suggested that the effect of body condition on the duration of the post-partum anoestrous period i s mediated through effects on LH pulse frequency.

Effects of body condition at calving and feeding level after calving on LH profiles and the duration of the post-partum anoestrous period in beef cows

1992 ◽  
Vol 55 (1) ◽  
pp. 41-46 ◽  
Author(s):  
I. A. Wright ◽  
S. M. Rhind ◽  
T. K. Whyte ◽  
A. J. Smith
Keyword(s):  
Body Condition ◽  
Post Partum ◽  
Live Weight ◽  
Pulse Amplitude ◽  
Beef Cows ◽  
Pulse Frequency ◽  
Metabolizable Energy ◽  
Feeding Level ◽  
Effect Of Feeding ◽  
Body Condition Scores

AbstractAn experiment was conducted to examine the effects of body condition at calving and feeding level post partum on the duration of the post-partum anoestrous period in beef cows. Forty-seven cows were used in each of 2 years. Cows were fed differentially before calving to achieve two levels of body condition at calving in November and December and were then fed at one of two levels of feeding post partum in a 2 × 2 factorial experiment. At calving, mean body condition scores were 2·85 (F) and 2·23 (T) (P < 0·001) while live weights were 521 kg and 457 kg (P < 0·001) for F and T cows respectively. After calving metabolizable energy intakes were 111 and 118 MJ/day (H) or 56 and 64 MJ/day (L) in years 1 and 2 respectively. The H cows maintained live weight during the first 61 days of lactation while the L cows lost live weight (0·0 v. -1·1 kg/day, P < 0·001). The number of cows still acyclic on 1 May each year was higher (P < 0·01) on the TL treatment (10/24) compared with the other treatment combinations (FH: 2/22; FL: 5/22; TH: 2/24). The effect of level of feeding on the duration of the anoestrous period was significant in the T cows (89 v. 116 days for TH and TL cows respectively; P < 0·01) but not in the F cows (80 v.89 days for the FH and FL cows respectively; P > 0·05). At 3 weeks post partum LH pulse frequency was higher in F than in T cows and tended to be higher in H than in L cows. At 6 and 9 weeks post partum LH pulse frequency was higher in H than L cows. LH pulse amplitude was higher in F than T cows at 3 weeks post partum and tended to be higher at 6 weeks post partum. It is concluded that both body condition at calving and feeding level after calving influence the duration of the post-partum anoestrous period with the effect of feeding level being particularly pronounced in thin cows.

FSH and LH receptor concentrations in large ovarian follicles of beef cows in high and low levels of body condition at nine weeks post partum

1992 ◽  
Vol 4 (5) ◽  
pp. 515 ◽  
Author(s):  
SM Rhind ◽  
TA Bramley ◽  
IA Wright ◽  
SR McMillen
Keyword(s):  
Luteinizing Hormone ◽  
Body Condition ◽  
Post Partum ◽  
Follicle Stimulating Hormone ◽  
Beef Cows ◽  
Ovarian Follicles ◽  
Lh Receptor ◽  
The Mean ◽  
Low Levels ◽  
Body Condition Scores

An experiment was conducted to determine whether or not the effect of body condition at parturition, and thereafter, on the duration of the post-partum anoestrous period was mediated through differences in gonadotrophin receptor concentrations in the ovarian follicles. Two groups of cows were fed to achieve body condition scores of > or = 2.75 (H; n = 14) or < or = 2.00 (L; n = 15) at parturition (this had led to differences in the duration of post-partum anoestrus in previous experiments) and then fed to maintain liveweight and condition until ovariectomy at nine weeks post partum. There was no effect of body condition on the mean (+/- s.e.) number of large (> or = 8 mm diameter) follicles per cow (3.0 +/- 0.27) but a greater proportion of the follicles of H cows, compared with L cows, was oestrogenic (secreting > 250 pg oestradiol h-1 in culture) (0.75 v. 0.5; chi 2 = 3.40; P = 0.06). Mean concentrations (pg hormone bound per mg protein) of follicle stimulating hormone (FSH) receptors in both granulosa (H, 157.3; L, 136.6; standard error of difference (s.e.d.) = 27.2) and thecal tissue (H, 4.14; L, 4.35; s.e.d. = 1.66) were similar for H and L cows. There was no difference associated with treatment in luteinizing hormone (LH) receptor concentrations in either granulosa (H, 40.3; L, 37.2; s.e.d. = 6.67) or thecal tissue (H, 48.9; L, 48.0; s.e.d. = 6.03). The concentration of FSH receptors in granulosa tissue was lower in non-oestrogenic follicles than in oestrogenic follicles (80.0 v. 188.1; s.e.d. = 40.4; P < 0.01).

Circulating concentrations of LH and FSH and pituitary responsiveness to GnRH in intact and ovariectomized suckled beef cows in two levels of body condition

1990 ◽  
Vol 51 (1) ◽  
pp. 93-101 ◽  
Author(s):  
I. A. Wright ◽  
S. M. Rhind ◽  
T. K. Whyte ◽  
A. J. Smith ◽  
S. R. McMillen ◽  
...  
Keyword(s):  
Body Condition ◽  
Body Condition Score ◽  
Post Partum ◽  
Live Weight ◽  
High Sensitivity ◽  
Fold Increase ◽  
Beef Cows ◽  
Pulse Frequency ◽  
Condition Score ◽  
Physiological Dose

ABSTRACTThe effect of body condition on hypothalamic and pituitary function in post-partum suckled beef cows was studied. Thirty-eight Blue-Grey cows were calved at a body condition score of either 2·35 (L) or 2·80 (H), fed to maintain live weight and body condition thereafter and ovariectomized at either 5 or 9 weeks post partum. The H cows had higher LH pulse frequencies before ovariectomy (0·36 v. 0·28 pulses per h; P < 0·05) and 15 days after ovariectomy (0·86 v. 0·72 pulses per h; P < 0·01), indicating a direct effect of body condition on GnRH release from the hypothalamus. Body condition had no effect on the ability of the pituitary to release LH in response to a physiological dose (2·5 u.g) of GnRH in entire or ovariectomized cows at 5 or 9 weeks post partum. The magnitude of the increase in circulating levels of LH following GnRH injection was greater at 9 weeks compared with 5 weeks post partum (2·23 v. 1·73 u.g/1; P < 0·001) in entire cows, but there was no difference between 5 and 9 weeks in ovariectomized cows. Following ovariectomy there was a 2·5-fold increase in LH pulse frequency within 15 days and LH pulse frequency approached 1 pulse per h in all treatments groups. It is concluded that both the hypothalamus and the pituitary are capable of functioning normally by 5 weeks post partum in suckled beef cows, that the pulsatile release of GnRH from the hypothalamus is inhibited, possibly due to a very high sensitivity to oestradiol, and that the sensitivity of the pituitary to the negative feedback effect of oestradiol may decrease with time post partum.

Ovarian follicular populations, steroidogenic capacity and physiological status in post-partum suckling beef cows in high and low body condition

1989 ◽  
Vol 1989 ◽  
pp. 149-149
Author(s):  
R. Prado ◽  
S.M. Rhind ◽  
I.A. Wright ◽  
A.J.F. Russel ◽  
S.M. McMillen ◽  
...  
Keyword(s):  
Body Condition ◽  
Body Condition Score ◽  
Post Partum ◽  
Weight Maintenance ◽  
Live Weight ◽  
Beef Cows ◽  
Pulse Frequency ◽  
Physiological Status ◽  
Condition Score ◽  
Maintenance Ration

Recent evidence indicates that body condition at calving has an important effect on the length of the post-partum anoestrous period in beef cows being longer in cows calving in low body condition (Richards et al, 1986, Wright et al, 1987). It is known that body condition affects baseline concentrations of LH (Rutter and Randel, 1984) and LH pulse frequency (Wright et al, 1987). However, the effect of body condition on ovarian follicles has not been studied.An experiment was designed to examine the effect of body condition score (BCS) at calving on follicle populations, follicular steroidogenic capacity, follicular histology and patterns of gonadotropin release at two different stages of the post-partum period (5 and 9 weeks after calving) in suckling beef cows.Thirty-eight suckling Blue-Grey cows with a mean live-weight of 567 ± 9.4 kg and mean BCS of 3.0 ± 0.05 at 110 days before calving to a synchronized insemination were differentially fed so that they achieved BCS of 2.83 ± 0.05 and 2.30 ± 0.05 for cows on a high (H) and low (L) plane of nutrition, respectively. After calving cows were fed a live-weight maintenance ration according to individual requirements. Cows of each BCS were ovariectomized at either 5 (w5) or 9 (w9) weeks after calving and follicles > 3mm in diameter were dissected from the ovaries and incubated for 2 h in culture medium (Medium 199) at 37°C. Follicles were then kept in Bouin's solution until histological examination. Follicle incubates were assayed for progesterone, testosterone and oestradiol. Blood samples were taken 2 days before ovariectomy for 10 h every 15 minutes and were later assayed for LH (all the samples) and FSH (every third sample).

Ovulation of the first dominant follicle arising after day 21post partumin suckling beef cows

2002 ◽  
Vol 75 (1) ◽  
pp. 115-126 ◽  
Author(s):  
K. D. Sinclair ◽  
G. Molle ◽  
R. Revilla ◽  
J. F. Roche ◽  
G. Quintans ◽  
...  
Keyword(s):  
Plasma Insulin ◽  
Body Condition Score ◽  
Post Partum ◽  
Beef Cows ◽  
Pulse Frequency ◽  
Metabolizable Energy ◽  
Insulin Concentration ◽  
Dominant Follicle ◽  
Plasma Insulin Concentration ◽  
Once Daily

AbstractThe effects of body condition score (BCS) of 2·0 or 3·0 units at calving (low v. moderate), post-partum energy intake at 0·6 or 1·0 MJ metabolizable energy (ME) per day per kg M0·75 (low v. high) and unrestricted or restricted (once daily) suckling on the ability of cows to ovulate were studied in a 2 ✕ 2 ✕ 2 factorial design with each treatment replicated eight times. Calf isolation and restricted suckling were imposed shortly after selection of the first dominant follicle (DF) to emerge after day 21 post partum. The episodic release of LH (sampled at 15-min intervals for 10 h) was determined 48 h before and 48 h after the day calf isolation and restricted suckling commenced. Additional blood samples were collected weekly for plasma insulin determination. The mean interval from calving to first ovulation was shorter for cows in moderate than low BCS at calving (47·8 v. 57·1 days, s.e.d. = 4·50, P < 0·05), and for cows suckling once daily than for those with unrestricted suckling (42·9 v. 62·0 days, s.e.d. = 4·50, P < 0·001). Post-partum nutrition did not affect this interval. Mean LH pulse frequency prior to the start of restricted suckling was higher for cows of moderate than low BCS at calving (3·2 v. 1·6 pulses per 10 h, s.e.d. = 0·60, P < 0·05). Subsequently, LH pulse frequency was higher for cows suckling once daily than for those with unrestricted suckling (4·0 v. 2·2 pulses per 10 h, s.e.d. = 0·82, P < 0·05). More cows in moderate than low BCS ovulated the first DF to emerge after day 21 post partum (within 4 to 6 days) in response to restricted suckling (69 v. 25%, P < 0·05). LH pulse frequency prior to restricted suckling increased (P < 0·05) with plasma insulin concentration (categorized as low, < 5; moderate, 5 to 8; and high, >8 mIU per l). There were indications of interactions between suckling treatment and BCS (P < 0·08), and suckling treatment and plasma insulin concentration (P < 0·06), on LH pulse frequency, which suggested that calf restriction could alleviate the suppressive effects of under nutrition on episodic LH release. Amongst cows suckling once daily, the non-ovulating animals had fewer LH pulses prior to restricted suckling and smaller, slower growing DF, indicating an inability of the DF to respond to increased LH pulse frequency following calf restriction. Cows of moderate BCS, particularly those with moderate to high levels of plasma insulin (³ 5 mIU per l), responded favourably to restricted suckling. In contrast, excessively thin cows with low plasma insulin concentrations (<5 mIU per l), that had most to gain from restricted suckling, responded poorly.

A two-diet system andad libitumlactation feeding of the sow 1. Sow performance

1996 ◽  
Vol 62 (2) ◽  
pp. 337-347 ◽  
Author(s):  
M. Neil ◽  
B. Ogle ◽  
K. Annèr
Keyword(s):  
Food Consumption ◽  
Post Partum ◽  
Live Weight ◽  
Metabolizable Energy ◽  
Backfat Thickness ◽  
Conventional Diet ◽  
Feeding Regimes ◽  
Ad Libitum ◽  
The Difference ◽  
Depth Condition

AbstractEffects of a two-diet system combined withad libitumlactation feeding of sows on food consumption, sow live weight (LW), backfat depth, condition scoring, rebreeding interval, symptoms of agalactia and culling were studied on 60 sows followed for four parities. Feeding regimes were: CR, conventional i.e. restricted during gestation and lactation; SA, a simplified diet offered at a restricted level during gestation and a conventional dietad libitumduring lactation; CA, conventional during gestation and the same dietad libitumduring lactation. During lactation CR sows consumed 5·9 kg food daily (71 MJ metabolizable energy (ME)), whereas SA and CA sows consumed on average 7·0 kg (85 MJ ME), the difference being larger in multiparous than in primiparous sows and larger in the first than in later weeks of lactation. From the second farrowing onward sows on CR treatment were lighter and had thinner backfat and lower condition scores than sows on CA treatment, with sows on SA treatment in between, i.e. approaching the CR sows in the gestation periods and the CA sows in the lactation periods. At first service LW was 130 kg and backfat thickness 14 mm. During the fourth lactation LW averaged 190 kg in CR sows and around 220 kg for SA and CA sows, and backfat thickness was 11 mm in CR sows and around 16 mm in SA and CA sows. SA sows tended to rebreed earlier after weaning than did CR or CA sows. CA sows and in particular SA sows had higher incidences of agalactia symptoms and higher rectal temperatures post partum than CR sows. The culling rates did not differ between feeding regimes, although the predominant causes for culling did, being shoulder lesions and abscesses in thin CR sows and leg disorders in SA and CA sows. At the end of the experiment, however, more SA sows than others were retained in the experimental herd. It was concluded that the SA feeding regime was superior in terms of sow performance, despite an increased incidence of agalactia symptoms.

The effect of plane of nutrition in early lactation on the performance of beef cows

1979 ◽  
Vol 29 (3) ◽  
pp. 293-303 ◽  
Author(s):  
B. G. Lowman ◽  
R. A. Edwards ◽  
S. H. Somerville ◽  
G. M. Jolly
Keyword(s):  
Weight Loss ◽  
Milk Yield ◽  
Crude Protein ◽  
Post Partum ◽  
Live Weight ◽  
Beef Cows ◽  
Metabolizable Energy ◽  
Yield Response ◽  
Mating Period ◽  
Digestible Crude Protein

ABSTRACTTwenty-one mature autumn-calving Blue Grey cows were divided into three groups for a 3-year change-over experiment, and each group was allocated to one of three planes of nutrition for the first 150 days of lactation during each year. Milk yields were recorded by machine milking twice daily. The three planes of nutrition corresponded to 1·63, 1·21 and 0·89 of the cow's maintenance allowance 12 h post partum. Increasing the plane of nutrition significantly (P<0·05) increased 150-day cumulative milk yield, but had no significant effect on milk composition. The extent of live-weight loss decreased significantly (P<0·001) as plane of nutrition increased and was reflected in cows maintaining better condition, measured as condition score, through the experimental period.The small 150-day cumulative milk yield response (32·8 kg per additional 10 MJ metabolizable energy and 62 g digestible crude protein/day) demonstrated the limitation of feeding beef cows for increased milk production in comparison with feeding the calf directly. However, the possible relationship between plane of nutrition, live-weight loss and fertility suggests an important limitation of under-feeding cows during the mating period. Within the constraints imposed, the medium treatment (64 MJ metabolizable energy and 516 g digestible crude protein/day) resulted in levels of cow performance similar to those currently recorded in commercial units. One of the major constraints in the present investigation was the high level of body reserves available in the cows at the start of lactation.

Effect of body condition and energy utilization on the length of post-partum anoestrus in PRID-treated and untreated post-partum Bos indicus (Zebu) cattle

1997 ◽  
Vol 65 (1) ◽  
pp. 17-24 ◽  
Author(s):  
E. Mukasa-Mugerwa ◽  
D. Anindo ◽  
A. Lahlou-Kassi ◽  
N. N. Umunna ◽  
A. Tegegne
Keyword(s):  
Body Condition ◽  
Post Partum ◽  
Average Daily Gain ◽  
Good Condition ◽  
Bos Indicus ◽  
Metabolizable Energy ◽  
Energy Utilization ◽  
Ovarian Activity ◽  
Zebu Cattle ◽  
Body Reserves

AbstractForty-five Bos indicus (zebu) cows were blocked by body condition (BC) score at calving and allocated by body weight (BW) to three treatments: untreated controls (CON), and progesterone-releasing intra-vaginal device (PRID)-treated at either 45 (T45) or 60 days (T60) post partum. Cows were given food individually and blood-sampled three times a week for progesterone. Calves sucked twice a day and were weighed weekly. PRIDs resulted in only 21% of cows responding at 60 days and they did not reduce anoestrus (PPI) or calving interval (CI) (P > 0·05). Dry matter (DM) and metabolizable energy (ME) intake were 7·1 (s.e. 0·6) kg and 54·3 (s.e. 4·6) MJ/day, respectively. BC score and BW at calving, and ME intake influenced cow and calf average daily gain ranging from −580 to 625 and 331 to 868 g/day, respectively. Milk yield during the first 4 months was 507 (s.e. 97) l. Cows gained 25 kg per unit increase in condition but lost 50 kg for a unit decline. CI (mean 14·2, range 10 to 24 months) was inversely related to BC score at calving (r = −0·31) and was delayed by a long PPI (r = 0·51), ranging from 38 to 297 days. Most (95%) cows experienced one or more ‘silent ovulations’ before first oestrus, the number extending PPI length (r = 0·49, P < 0·001). Efficiency of ME utilization was higher for smaller cows of 240 (s.e. 28) kg at calving. It is concluded that: (1) PRID treatment before 60 days post partum is unlikely to reduce anoestrus in Boran zebu cattle; (2) given adequate energy intake zebu cattle in thin condition at calving initially replenish body reserves at the cost of lactation and experience more ‘silent’ ovarian activity before returning to oestrus; (3) cows in good condition at calving express maximum lactation potential, mobilizing their own body reserves to support milk production, yet resume oestrous activity earlier despite weight losses to support higher milk yields.

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