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At least 1,171 records · Page 65Linked to original sources
PubMed1975

The effects of nutrition on the reproductive performance of Finn x Dorset ewes. I. Plasma progesterone and LH concentrations during late pregnancy.

Progesterone and LH concentrations were measured in the plasma of blood samples taken from forty-eight pregnant ewes on Days 100, 120 and 134 of gestation. The ewes, in two groups of twenty-four were maintained from Day 100 until parturition on two planes of nutrition which supplied daily energy and protein intakes of about 4-1 or 2-3 Mcal metabolizable energy and either 192 or 111 g digestible crude protein per ewe. Within the groups, the ewes carried one, two or three fetuses and the feed intake was adjusted according to litter size to produce a uniform nutritional state within the group. On Day 100, litter size affected the concentration of plasma progesterone (P less than 0-001), but had no effect on Days 120 or 134 when the ewes were fed according to litter size. The low feed intake however caused a significant increase in plasma progesterone concentrations. The LH concentrations showed no major changes during late pregnancy and no effect of nutrition or little size on the plasma hormone concentration was observed. It was concluded that the effect of litter size on plasma progesterone concentration recorded on Day 100 or gestation was partly mediated by level of nutrition.

Animal Nutritional Physiological Phenomena↗
PubMed1984

Effects of oestradiol benzoate treatment on the reproductive performance and endocrine status of sows after lactations of 10 or 35 days.

Forty-two Landrace X Large White sows were used in 3 studies of oestradiol benzoate treatment 24 h (E1) or 48 h (E2) after piglet removal, following lactations of 10 (S) or 35 (L) days, or were untreated controls (C). For Exp. 1, oestradiol benzoate doses were 4, 16 and 64 micrograms/kg body weight; since highest mean LH peaks followed use of the 16 micrograms/kg dose, this treatment was used in later studies. Treatments for Exp. 2 were S-E1 and L-E1 (N = 3). Pregnancy rates were 1/3 and 2/3, respectively, while 10-day weaned sows tended to have longer weaning-remating intervals, shorter oestrous periods and lower post-injection oestradiol peaks. Post-treatment LH peaks were recorded from all L-E1 sows, but only one S-E1 animal. Treatments S-E2, L-E2, S-C and L-C (N = 6) were used in Exp. 3; pregnancy rates were 1/6, 6/6, 5/6 and 6/6, respectively, while peak oestradiol levels were 49.5 +/- 8.3, 74.8 +/- 15.1, 21.7 +/- 2.0 and 51.8 +/- 26.5 pg/ml, respectively. Weaning-remating intervals were extended in S-C sows (P less than 0.05), while oestradiol treatment prolonged behavioural oestrus. LH peak values were reduced after short lactations, but not affected by oestradiol treatment. Plasma prolactin concentrations at weaning were higher in sows in treatment S than in treatment L, while at the subsequent oestrus in oestradiol-treated sows they were elevated more and for longer periods than in controls. These results demonstrate that reduced gonadotrophin secretion and fertility after short lactations are not overcome by treatment with oestradiol benzoate.

Animals↗
PubMed2006

Endocrine characteristics of late pregnant hyperketonaemic ewes and their reproductive performance following the induction of ovarian cyclicity out of the breeding season.

Ketosis was diagnosed in a flock of Merino ewes that conceived from synchronised oestrus in the early autumn period. On day 140 of pregnancy the ewes were sampled for determination of betaOH-butyrate (BHB), AST, glucose, non-esterified fatty acids (NEFA), total cholesterol (TCH), insulin, T4, T3, cortisol, IGF-1 and leptin. The results were evaluated according to the number of fetuses born some days later and the presence of hyperketonaemia (BHB: > or = 1.60 mmol/l). In May, about 3 months after lambing, cyclic ovarian function was induced (Cronolone + eCG), and the ewes were inseminated artificially (AI) 48 h after the removal of gestagen-containing sponge. At the time of AI and 10 days later blood samples were collected again to check the plasma levels of the same constituents as previously (in samples taken at AI), and to monitor the ovarian response by assaying progesterone (in both samples). On day 140 of gestation significantly lower BHB levels were detected in dams with single (n = 41) than in those with twin (n = 57) pregnancies. Hyperketonaemia was found only in ewes bearing twins (n = 27). These animals had higher NEFA and cortisol, and lower TCH, insulin, IGF-1, leptin and T3 levels than their normoketonaemic twin-bearing flock-mates, and those with single pregnancy. The blood glucose concentrations varied within a wide range, and the means of groups did not exhibit any significant differences. The formerly hyperketonaemic individuals were characterised by lower leptin level 3 months after lambing, and they showed a poorer response to the cycle-induction procedure than the others. The non-responders had lower IGF-1 and leptin levels than those ovulated after this treatment. It was concluded that the subclinical form of ovine ketosis is characterised by complex endocrine alterations, reflecting an obvious form of negative energy balance. If attempts to induce cyclic ovarian function outside the breeding season are made soon after lambing, the ovarian response and fertility of these ewes may also be depressed.

3-Hydroxybutyric Acid↗
PubMed2003

[Effect of acetylsalicylic acid on the reproductive performance and on offspring from wistar rats].

UNLABELLED: The aim of this paper was to perform a randomized, controlled and blinded study to investigate if a therapeutic dose of acetylsalicylic acid (ASA), taken by pregnant women, may also cause embryotoxic or congenital abnormalities on experimental animal. METHODS: Females were confirmed to have mated by observations of sperm in a vaginal smear. The day on which spermatozoa were found in the vaginal smear was considered as day 1 of gestation (GD1). After randomization, mated females were assigned to experimental groups and individually caged, were given 50 mg/kg/day of acetylsalicylic acid, by needle gavage once daily, during two different periods of pregnancy. One group of dams (n=11) received aspirin from day 1 to 4 of pregnancy (before embryonic implantation) for evaluation of the blastocysts, and another group received aspirin from day 6 to 15 of pregnancy (organogenic period) for fetal evaluation. Control groups (n=12) received distilled water in same volume and during same periods as their respective experimental groups. RESULTS AND CONCLUSION: The treatment of the dams with ASA, according to minimal therapeutic dose used for humans, did not cause embryotoxic or major malformations on experimental animal but was responsible for rate increased of fetuses presenting ureteric dilatation. After analysis of the data, it appears that, although direct conclusive evidence of adverse effects in humans is lacking, a potential hazard dose exists and thus the indiscriminate use of acetylsalicylic acid (aspirin) is contraindicated.

Animals↗
PubMed1990

Long-term effects of corn gluten feed on the reproductive performance and weight of gestating sows.

Corn gluten feed (CGF) was evaluated as the primary energy and protein source for gestating sows. Eighty gravid multiparous Yorkshire x Landrace sows were assigned randomly to three treatment groups for the entire three-parity trial. The gestation treatment diets were 1) corn-soybean meal fed at 1.8 kg/d (control), 2) CGF plus soybean meal fed at 2.3 kg/d (CGF-low) and 3) CGF plus soybean meal fed at 2.6 kg/d (CGF-high). The CGF diets contained 92.2% and 93.7% CGF, respectively. Feeding levels of Diets 2 and 3 were based on the assumption that CGF had 80% and 70% of the net energy value of corn, respectively. All sows had ad libitum access to a conventional corn-soybean meal diet during lactation and were fed 3.2 kg/d during breeding. Intakes of gestation treatment diets were increased 25% during winter months. Based on litter size and weight, the performance of sows fed CGF did not differ from that of the sows fed the control diet. Mean number of pigs at birth and 21 d (weaning) for the three parities were: (control) 10.16, 7.65; (CGF-low) 11.30, 8.44; (CGF-high) 10.73, 8.13, respectively. Pigs from CGF-fed sows were smaller at birth (P less than .05), but subsequent pig weights did not differ. Mean pig birth and 21-d weights for the three parities were: (control) 1.44, 5.18; (CGF-low) 1.30, 4.84; (CGF-high) 1.31, 5.01 kg, respectively. CGF-low sows weighed less (P less than .01) at d 109 of gestation than did the control and CGF-high sows, which did not differ in weight.(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Feed↗
PubMed1996

Influence of gilt age and body composition at first breeding on sow reproductive performance and longevity.

Regression analysis was used to evaluate the effects of gilt age and body composition at first breeding on sow performance over three parities. Eighty-seven Yorkshire x Landrace F1 gilts were used. Variation in age and body composition at first breeding was obtained by breeding gilts at puberty, second, or third estrus and by providing those gilts bred after puberty one of four nutritional regimens from puberty until breeding: 1) 2.7 kg/d of a 14.3% CP, 3.5 Mcal ME/kg diet (H), 2) maintenance ME and CP/d (M), 3) half-maintenance ME and CP/d (1/2M), and 4) M or 1/2M until anestrus, then 2.27 kg/d of a 14.0% CP corn-soybean meal diet until first breeding. Body composition at first breeding was determined using live weight, backfat thickness, and deuterium oxide space as variables in prediction equations. All females were treated similarly after first breeding. Age and body composition at first breeding were not related (P > .10) to litter size at birth or weaning in parities 1, 2, 3, or overall. Increasing age at first breeding was related to small increases in pig birth weights (P < .001) in parity 1 and average pig weaning weight (P < .001) in parities 1, 2, and overall. Body composition of gilts at first breeding was not related (P > .10) to pig birth weights and was inconsistently related to pig weaning weights in parities 2 and 3 (P < .001). Females heavier at first breeding remained heavier (P < .01) throughout the experiment. Age and body composition at first breeding were not different (P > .10) for gilts completing three parities (n = 53) compared with gilts failing to complete three parities (n = 34). Results show no large effects of gilt age or body composition at first breeding on sow productivity and longevity over three parities.

Aging↗
PubMed2001

Effect of human chorionic gonadotropin on luteal function and reproductive performance of high-producing lactating Holstein dairy cows.

The objectives were to evaluate effects of human chorionic gonadotropin (hCG) (3,300 IU i.m.) administered on d 5 after AI on CL number, plasma progesterone concentration, conception rate, and pregnancy loss in high-producing dairy cows. Following the synchronization of estrus and AI, 406 cows were injected with either hCG or saline on d 5 after AI in a randomized complete block design. Blood sampling and ovarian ultrasonography were conducted once between d 11 and 16 after AI. Pregnancy diagnoses were performed on d 28 by ultrasonography and on d 45 and 90 after AI by rectal palpation. Treatment with hCG on d 5 resulted in 86.2% of the cows with more than one CL compared with 23.2% in controls. Plasma progesterone concentrations were increased by 5.0 ng/mL in hCG-treated cows. The presence of more than one CL increased progesterone concentration in hCG-treated cows but not in controls. Conception rates were higher for hCG-treated cows on d 28 (45.8 > 38.7%), 45 (40.4 > 36.3%), and 90 (38.4 > 31.9%) after AI. Treatment with hCG improved conception rate in cows losing body condition between AI and d 28 after Al. Pregnancy losses were similar between treatment groups. Treatment with hCG on d 5 after AI induces accessory CL, enhances plasma progesterone concentration, and improves conception rate of high-producing dairy cows.

Animals↗
PubMed1980

Effects of winter and summer energy levels on heifer growth and reproductive performance.

Three heifer development trials were conducted with 337 crossbred heifers (125, 105 and 107 heifers in trials 1, 2 and 3, respectively) over a 3-year period. Heifers were fed low quality fescue hay ad libitum plus 0, 1.22 or 2.45 kg of ground ear corn (GEC) daily during the winter feeding phase of all three trials. Winter gains and final winter and summer condition scores increased (P less than .05) in each trial as winter level of GEC increased. In each trial, summer gains followed the reverse order of winter gains (P less than .05). Conception rate, mean number of days pregnant (as determined by rectal palpation) and adjusted weaning weight of progeny increased linearly with winter level of GEC when pooled over trials. Differences between animals fed 0 and 2.45 kg of GEC were significant. Conception rate and adjusted weaning weight of progeny of the heifers retained in the breeding herd increased (P less than .05) as level of GEC increased when data were pooled over trials. Calving date and percentage live progeny were not significantly affected by winter treatment. Summer daily gains and condition scores were increased by additional summer energy (2.45 kg GEC/day) in trial 3. Conception rate and mean number of days pregnant (conception date) favored heifers given the summer supplementary feeding (2.45 kg GEC) treatment. Among heifers retained in the breeding herd, there were no significant differences between the 0- and 2.45-kg GEC summer treatment groups in conception rate, calving date, percentage live progeny or adjusted weaning weight of progeny.

Animals↗