EFFECT OF LACTATION FEED INTAKE AND GONADOTROPHIN-RELEASING HORMONE ON THE REPRODUCTIVE PERFORMANCE OF SOWS

1987 ◽  
Vol 67 (3) ◽  
pp. 715-719 ◽  
Author(s):  
R. N. KIRKWOOD ◽  
E. S. LYTHGOE ◽  
F. X. AHERNE
Keyword(s):  
Reproductive Performance ◽  
Feed Intake ◽  
Intramuscular Injection ◽  
Crude Protein ◽  
Releasing Hormone ◽  
Feeding Level ◽  
Low Level ◽  
Estrus Detection ◽  
Gonadotrophin Releasing Hormone ◽  
In Pregnancy

Twenty-four first parity and 48 multiparity crossbred sows (Yorkshire × Landrace) were used in a 2 × 2 factorial design involving high (H) or low (L) lactation feed intakes and the intramuscular injection, or not, of 50 μg of gonadotrophin-releasing hormone (GnRH) at the onset of the first postweaning estrus. All sows were weighed at farrowing and weaning. The H feed intake entailed feeding sows at levels of 10, 13, and 14% of each sow's immediate postfarrowing metabolic weight during weeks 1, 2, and 3–4 of lactation, respectively. Low-fed sows received 50% of the H feed level. The diet contained 12.5 MJ DE kg−1 and 16% crude protein. Between weaning and mating, and following mating, all sows were fed 2.25 kg daily of the lactation diet. After weaning, sows were exposed to a boar twice daily to facilitate estrus detection. GnRH was administered at the onset of standing heat. All sows were slaughtered 25 d after mating at which time the reproductive tracts were removed and examined to determine the number of ovulations and the number of viable embryos. Low-level feeding resulted in an extension of the remating interval (5.9 ± 0.3 vs. 4.5 ± 0.2 d; P < 0.05), an increased incidence of anestrus (16.7 vs. 3.6%; P > 0.1) and a reduction in pregnancy rates (69.7 vs. 81.6%; P > 0.1). Interactions were noted between lactation feeding level and GnRH injection (P < 0.05) and between parity and GnRH injection (P < 0.05) for number of viable embryos. The data obtained suggest that both low level of feeding during lactation and a young age are associated with decreased embryo numbers, but this situation is alleviated by the administration of GnRH. Key words: Sows, feed intake, estrus, GnRH

THE INFLUENCE OF FEEDING LEVEL DURING LACTATION ON THE OCCURRENCE AND ENDOCRINOLOGY OF THE POSTWEANING ESTRUS IN SOWS

1987 ◽  
Vol 67 (2) ◽  
pp. 405-415 ◽  
Author(s):  
R. N. KIRKWOOD ◽  
S. K. BAIDOO ◽  
F. X. AHERNE ◽  
A. P. SATHER
Keyword(s):  
Reproductive Performance ◽  
Feed Intake ◽  
Crude Protein ◽  
Gonadotropin Releasing Hormone ◽  
Embryo Survival ◽  
Treatment Groups ◽  
Feeding Level ◽  
Low Level ◽  
Sow Lactation ◽  
Estradiol 17Β

Two experiments were performed with 78 second parity Lacombe sows to determine the influence of nutrition on reproductive performance. During a lactation of 35 d sows were fed daily either 3 (L) or 6 kg (H) of a diet having 16% crude protein and 12.5 MJ DE kg−1. For exp. 1, six L- and six H-fed sows were given an intravenous injection of gonadotropin releasing hormone (GnRH) at 21 d of lactation and blood was sampled at −30, −10, 0, 10, 20, 30, 45, 90 and 120 min from the time of injection. Prestimulation luteinizing hormone (LH) levels were lower for L-fed than for the H-fed sows (1.34 ± 0.1 vs. 1.93 ± 0.2 ng mL−1' P < 0.02). Peak LH levels achieved after UnKH injection, however, did not differ significantly (5.0 ± 0.6 and 5.8 ± 0.5 ng mL−1 for L and H sows, respectively). In exp. 2, 38 sows were fed the H and 40 fed the L level of feed throughout a 5-wk lactation. As expected, low-level feeding in lactation resulted in a greater body weight and backfat loss (17.4 ± 1.6 vs 41.2 ± 2.3 kg and 3.2 ± 0.4 vs. 6.3 ± 0.1 mm; P < 0.001 for both). Low-level feeding also resulted in an increased incidence of anestrus (15.0 vs. 0.0%) and an extended remating interval (140.7 ± 11.7 vs. 103.4 ± 2.1 h; P < 0.05). At the postweaning estrus, sows were inseminated with either fresh (F) or thawed (T) semen. Treatment groups were thus HF, LF and LT. Pregnancy rate was influenced by both feed level and semen type (90, 72, 69 and 39% for groups HF, HT, LF and LT, respectively). Ovulation rate was unaffected by feed intake (18.7 ± 0.9 vs. 18.2 ± 0.5 for L and H sows, respectively) but embryo survival was influenced by both feed intake and semen type (82.7 ± 2.5, 46.4 ± 9.7, 68.3 ± 9.6 and 53.7 ± 9.8% for groups HF, HT, LF and LT respectively). Eight H and twelve L-fed sows were blood-sampled via indwelling vena caval cannulae at 6-h intervals from weaning until the end of estrus. No treatment effect was noted for plasma levels of LH, growth hormone, estradiol-17β or testosterone during this period. It was concluded that low-plane feeding in lactation and the consequent increased weight and backfat loss reduce reproductive performance of sows. However, the mechanism(s) controlling this effect remain to be fully elucidated. Key words: Sow, lactation, nutrition, estrus

The effect on the reproductive performance of sows of dietary protein concentration and pattern of feeding in pregnancy

1969 ◽  
Vol 73 (2) ◽  
pp. 301-309 ◽  
Author(s):  
I. H. Pike ◽  
T. G. Boaz
Keyword(s):  
Reproductive Performance ◽  
Crude Protein ◽  
Protein Concentration ◽  
Fish Meal ◽  
Live Weight ◽  
Lactation Performance ◽  
Large White ◽  
Low Protein ◽  
Lower Capacity ◽  
In Pregnancy

SUMMARYIn a factorial experiment the effect of two protein intakes and three patterns of feeding in the second pregnancy of 48 Large White x Wessex Saddleback sows was examined. The high protein (HP) diet (19·5% crude protein) contained 15% white fish meal. The low protein (LP) diet (10·5% crude protein) contained cereal protein only. Nutrient components of the diets differed in protein only. The pattern treatments involved allowances of 1·8 kg (L), 2·7 kg (C) and 3·6 kg (H) per day, the three pregnancy patterns being HL, C and LH with the changeovers made from the 49th to the 63rd day post coitum (p.c). Sows on the three pattern treatments received the same total amount of feed from 0–112 days p.c. and were treated alike at farrowing and during lactation.Fertility and parturition results were similar for all treatments, but the number of piglets alive after birth (when weighed) was least for LP sows on the HL pattern. At 3 weeks of age the size and weight of litters on HP sows were significantly greater than those on LP sows (P < 0·05 and < 0·001 respectively). More piglets were weaned by HP sows than LP sows (P < 0·05). HP sows gained more weight in pregnancy (P < 0·001) which was slightly longer, and lost more weight in lactation (P < 0·05) than LP sows.The HL pattern of feeding was associated with smaller live weight gains in pregnancy than the LH pattern (P < 0·001) and the total birth weight of HL litters was lighter than LH (P < 0·05), mean piglet weights being similar. Lactation performance was unaffected by pattern treatment.The main conclusion is that a low intake, particularly during the latter half of pregnancy, of protein which is of vegetable origin, is associated with decreased viability of the piglets at birth and in early suckling life, and with lower capacity of the sows for milk production.

scholarly journals The reproductive performance of dairy cows with anovulatory anoestrus that were injected with either gonadotrophin-releasing hormone or oestradiol benzoate as part of a re-treatment process after insemination

2007 ◽  
Vol 78 (1) ◽  
Author(s):  
B.V.E. Segwagwe ◽  
J. Malmo ◽  
K.L. Macmillan ◽  
P.D. Mansell
Keyword(s):  
Dairy Cows ◽  
Pregnancy Rate ◽  
Reproductive Performance ◽  
Conception Rate ◽  
Control Group ◽  
Releasing Hormone ◽  
Start Date ◽  
Oestradiol Benzoate ◽  
Conception Rates ◽  
Gonadotrophin Releasing Hormone

This experiment compared the reproductive performance of synchronised anoestrous dairy cows that were treated initially with a combination of progesterone and oestradiol benzoate and then with either gonadotrophin-releasing hormone (GnRH) or oestradiol benzoate to resynchronise returns to service. It was hypothesised that injecting anoestrous dairy cows with GnRH 12-15 days after insemination and coinciding with the time of insertion of a controlled intravaginal progesterone-releasing (CIDR) device would increase conception rates to the preceding 1st insemination compared with oestradiol benzoate treated cows; both GnRH and oestradiol benzoate would resynchronising the returns to service of those cows that did not conceive to the preceding insemination. Groups of cows in 11 herds were presented for a veterinary examination after they had not been seen in oestrus postpartum. Those cows diagnosed with anovulatory anoestrus (n = 1112) by manual rectal palpation and / or ultrasonography were enrolled in the trial. Each enrolled cow was injected with 2mg oestradiol benzoate i.m. on Day -10, (where Day 0 was the 1st day of the planned insemination) concurrently with vaginal insertion of a CIDR device. The device inserted was withdrawn on Day -2 and then each cow injected i.m. with 1 mg of oestradiol benzoate on Day -1 unless it was in oestrus. Observation for oestrus preceded each insemination. Every cow that had been inseminated on Days -1,0,1 or 2 was presented for treatment for resynchrony on Day 14 (n=891). They were divided into 2 groups; those with an even number were each injected i.m. with 250 µg of a GnRH agonist (Treatment group n = 477); each of the cows with an odd number injected i.m. with 1mg of oestradiol benzoate (control group, n = 414). Each GnRH or oestradiol benzoate injection preceded reinsertion of a CIDR device previously inserted from Days -10 to -2. It was withdrawn on Day 22, 24 hours before injecting 1mg oestradiol benzoate. Cows observed in oestrus were submitted for a 2nd insemination. Every enrolled cow still present in the herd was pregnancy tested by palpation of uterine contents per rectum about 6 weeks later and again at the end of a herd's seasonal breeding programme. The alternative use of GnRH instead of oestradiol benzoate did not affect the percentage of cows conceiving within 3 days of the mating start date (MSD) (35.6 %vs 35.3 %, P=0.90), resubmission rates for a 2nd insemination among cows not pregnant to the 1st insemination (81.6 % vs 83.5 %, P=0.41), 6-week pregnancy rate (59.3 % vs 60.6 %, P=0.65), 21-week pregnancy rate (86.6 vs 85.0, P=0.36), mean interval from MSD to conception (32.5 + 1.8 days vs 29.9 + 1.8 days, P = 0.26) or conception rate of cows reinseminated by Day 28 (43.3 % vs 38.8 %, P=0.39). When GnRH conception rate of cows reinseminated by Day 28 (43.3% vs was compared with oestradiol benzoate, it did not increase conception rates to the 1st service; it was as effective as oestradiol benzoate in synchronising returns to service in previously treated anoestrous cows that did not conceive to the 1st service. Its use affected neither conception rates to the preceding 1st inseminations nor to the following 2nd inseminations.

Effect of cortisol on the response to gonadotrophin releasing hormone in the boar

1983 ◽  
Vol 97 (1) ◽  
pp. 75-81 ◽  
Author(s):  
R. M. Liptrap ◽  
J. I. Raeside
Keyword(s):  
Pituitary Gland ◽  
Anterior Pituitary ◽  
Plasma Cortisol ◽  
Intramuscular Injection ◽  
Anterior Pituitary Gland ◽  
Nacl Solution ◽  
Hormonal Response ◽  
Releasing Hormone ◽  
Gonadotrophin Releasing Hormone ◽  
Different Doses

The effect of intracarotid perfusion of 40 mg cortisol for 1 h on the hormonal response to three different doses of an intramuscular injection of synthetic gonadotrophin releasing hormone (GnRH) was compared to that of GnRH injected during intracarotid perfusion with 0·9% (w/v) NaCl solution in five boars. The increase in production of LH, above basal values, in response to injection of 0·25 μg GnRH midway through perfusion was only slightly greater (P > 0·05) in boars receiving cortisol compared to that when the same boars received saline. When 0·5 μg GnRH was injected midway through perfusion, a significantly greater (P<0·05) increase in production of LH above basal levels occurred during cortisol administration than occurred when saline was given. Injection of 1·0 μg GnRH in boars during cortisol perfusion resulted in significantly greater (P<0·01) production of LH, above basal levels, compared to the increase above basal levels that resulted when this dose of GnRH was given during intracarotid saline treatment. Increases in plasma values of testosterone reflected the increases in levels of LH. The results suggest that acute elevations in plasma cortisol may, under some circumstances, enhance the increased production of LH in the boar by increasing the responsiveness of the anterior pituitary gland to GnRH.

Effect of pretreatment with insulin on the response of buffaloes with inactive ovaries to gonadotrophin-releasing hormone agonist treatment in summer

2007 ◽  
Vol 19 (2) ◽  
pp. 351 ◽  
Author(s):  
Adel A. Ramoun ◽  
Khalid T. Osman ◽  
Samy A. Darwish ◽  
Aly M. Karen ◽  
Magdy H. Gamal
Keyword(s):  
Intramuscular Injection ◽  
Control Group ◽  
Dominant Follicle ◽  
Once Daily ◽  
Releasing Hormone ◽  
Sterile Saline ◽  
Induction Rate ◽  
Gonadotrophin Releasing Hormone ◽  
Egyptian Buffalo ◽  
Buffalo Cow

The aim of the present study was to evaluate the effect of a pretreatment with insulin on the response of buffalo cows with inactive ovaries to gonadotrophin-releasing hormone agonist (GnRHa) treatment during hot summer months (July and August). Thirty-six Egyptian buffalo cows with inactive ovaries were randomly allocated into three groups: (1) group treated with GnRHa (G1, n = 16) in which each buffalo received an intramuscular injection of 250 mg of GnRHa (Day 0; gonadorelin, Fertagyl); (2) group treated with insulin before the GnRHa injection (G2, n = 8) in which each buffalo received a subcutaneous injection of biphasic insulin at a dose of 0.25 IU kg–1 bodyweight once daily starting at Day –3 for 3 consecutive days, followed by an intramuscular injection of 250 mg of GnRHa on Day 0; and (3) the control group (G3, n = 12) in which each buffalo cow received an intramuscular injection of 2.5 mL of sterile saline on Day 0. The ovaries of all animals were examined by trans-rectal ultrasonography (5 MHz) on Days –7, –3 and 0 and continued thereafter at 4-day intervals until oestrus or the end of the experiment. On the same days that ultrasound examinations were performed blood samples were collected to measure the progesterone concentrations. Administration of insulin for 3 days before GnRHa injection (G2) significantly (P < 0.05) increased the diameter of the largest follicle from 6.85 ± 0.64 to 12.4 ± 0.88 mm. There was a significant (P < 0.01) increase in the oestrous induction rate in G2 compared with both G1 and G3 during the first 12 days after the treatment interval. It is concluded that pretreatment with insulin for 3 days before GnRHa injection increases the diameter of the dominant follicle and therefore the oestrous induction rate of acyclic buffaloes.

The response of sows to increased nutrient intake during mid to late gestation

2006 ◽  
Vol 57 (1) ◽  
pp. 33 ◽  
Author(s):  
R. H. King ◽  
P. J. Eason ◽  
R. J. Smits ◽  
W. C. Morley ◽  
D. J. Henman
Keyword(s):  
Birth Weight ◽  
Protein Content ◽  
Energy Intake ◽  
Litter Size ◽  
Feed Intake ◽  
Crude Protein ◽  
Late Gestation ◽  
Feeding Level ◽  
Subsequent Fertility ◽  
Dietary Treatments

Five hundred and ten multiparous sows were allocated at 66 days after mating to one of 6 dietary treatments that were imposed for the subsequent 35 days. The dietary treatments were 5 feeding levels of 2.2, 2.6, 3.0, 3.4, and 3.8 kg/day of a gestation diet containing 12.9 MJ DE/kg, 127 g crude protein/kg, and 5.6 g lysine/kg, plus a protein intake treatment where sows received 2.8 kg/day of a lactation diet containing 13.8 MJ DE/kg, 168 g crude protein/kg, and 8.3 g lysine/kg. After the treatment period, all sows were offered the lactation diet at the common feeding level of 3.0 kg/day and after farrowing, all sows were offered this diet ad libitum throughout lactation. Increasing feeding levels between Day 66 and Day 101 of pregnancy increased (P < 0.001) liveweight gain prior to farrowing but increased (P < 0.001) liveweight loss during lactation. The majority of the extra maternal energy intake during mid to late gestation was deposited as maternal gain. These linear weight responses during lactation were explained by the significant inverse relationship between voluntary daily feed intake in lactation (FI) and average daily digestible energy intake in the previous gestation (DE): Neither increasing the feeding level during mid to late gestation nor increasing the protein content of the diet had any significant effect on litter birth weight, average piglet birth weight, or the standard deviation of individual piglet birth weight within the litter. In addition, there were no significant effects of gestation feeding treatments on litter size weaned or weaning weight. Furthermore, neither increasing the feeding level during mid to late gestation nor increasing the protein content of the gestation diet had any significant effect on subsequent fertility or litter size. In conclusion, when average individual piglet birth weight is already well in excess of 1.5 kg, there is no significant response to feed intake levels between 2.2 and 3.8 kg/day when offered between Day 66 and Day 101 of gestation.

EFFECTS OF INJECTION OF GONADOTROPIN-RELEASING HORMONE ON SOW FERTILITY

1989 ◽  
Vol 69 (1) ◽  
pp. 123-129 ◽  
Author(s):  
A. D. GOONERATNE ◽  
R. N. KIRKWOOD ◽  
P. A. THACKER
Keyword(s):  
Reproductive Performance ◽  
Artificial Insemination ◽  
Anterior Pituitary ◽  
Intramuscular Injection ◽  
Follicle Stimulating Hormone ◽  
Gonadotropin Releasing Hormone ◽  
Serum Concentrations ◽  
Releasing Hormone ◽  
Conception Rates ◽  
And Control

A total of 159 Landrace × Yorkshire sows were used to study the effects of an intramuscular injection of gonadotropin-releasing hormone (GnRH) at estrus on reproductive performance. Artificial insemination at 24 h or 24 and 40–44 h following treatment, resulted in similar conception rates for GnRH-treated (77.5 and 69.2%) and control sows (70.0 and 67.5%). Conception rates were not affected by insemination regime. GnRH treatment resulted in slightly improved litter sizes in comparison with control sows (10.45 vs 9.92; P > 0.20) whether inseminated once or twice, but had no effect on piglet weight at birth. Litter size and piglet weight at weaning were also not influenced by treatment. GnRH treatment (100 μg) induced increases in serum concentrations of luteinizing hormone (LH) and follicle stimulating hormone (FSH) from the anterior pituitary within 30 min and maximal serum concentrations were observed 90–120 min postinjection. The induced release of both LH and FSH was of short duration (< 4 h), compared to the natural surge of LH which followed later, coincident with estrus. It was concluded that the overall reproductive performance of sows was not significantly influenced by GnRH treatment immediately prior to estrus. Key words: Sow, GnRH, pituitary response, reproductive performance

Sign in / Sign up

Export Citation Format

Share Document