102,131 research outputs found
Reproductive rhythm and litter weaning age as they affect rabbit doe performance and body energy balance
No full textOne hundred and twenty multiparous does were synchronized to give birth the same day (initial kindling). The trial lasted until the successive (final) kindling. Immediately following initial kindling, 22 does were selected for comparative slaughter. The remaining does were assigned to three reproductive rhythms and mated 2 ( R2), 11 ( R11) or 26 ( R26) days post partum. Within each rhythm, the does were further divided into two groups with litters weaned at 21 ( W21) or 25 ( W25) days of age. A total of 54 does were pregnant and were slaughtered soon after final kindling. By increasing the kindling-to-mating interval from 2 to 26 days, total milk production was increased (5590 to 6065 g for R2 and R26, respectively; P < 0·05); voluntary food intake during lactation was not affected (356 g/day on average), but during the dry period was reduced (182 to 169 g/day; P < 0·05) in this way accounting for a decrease during the experimental period on the whole (299 to 249 g/day; P < 0·01). At the final kindling, the number of kits born per litter was lower in does submitted to the R11 than to the R26 rhythm ( P < 0·01). By increasing the kindling-to-mating interval, doe body water concentration decreased, while fat and energy increased ( P < 0·01) and higher empty body gain was recorded (from -123 to -4, and to + 97 g, in R2, R11 and R26 does, respectively; P < 0·001). As a result, body protein, fat and energy balances changed from negative values to approach equilibrium as reproductive rhythm became extensive (energy balance : -0·14, -0·02 and + 0·01 of the initial body content in R2, R11 and R26 does, respectively; P < 0·001). At 28 days after kindling, blood leptin concentration was higher ( P < 0·01) and IGF-1 lower ( P < 0·05) in R26 does. Daily food intake throughout the experiment was lower ( P < 0·05) in W21 does due to the longer dry period. Increasing weaning age from 21 to 25 days increased both number of kits born alive per litter (from 7·4 to 9·6; P < 0·05) and doe body water concentration, while body energy tended to decrease ( P < 0·1). At 28 days after kindling lower blood leptin concentration was recorded in W21 than W25 does (1·87 v. 2·76 μg/l, P < 0·05)
THE EFFECTS OF ALFAPROSTOL (PGF2a analogue) AND eCG ON REPRODUCTIVE PERFORMANCES IN POSTPARTUM RABBITS
No full text[EN] The aim of this study was to verify the effectiveness of post partum pharmacological oestrus synchronisation with alfaprostol or eCG in improving rabbit doe reproductive performances and to evaluate the incidence of pseudopregnancy in this species. One hundred and eighty commercial hybrid rabbit does, multiparous and lactating, were randomly divided into three groups (n=60) and treated on day 8 post partum (pp) as follows: Group A, 1 mL s.c. vitaminic solution with 200 mg alfaprostol, a synthetic analogue of PGF2a; Group B, 1 mL sc vitaminic solution with 20 I.U eCG; Group C (Control) 1 mL sc vitaminic solution. On day 11 pp (3 days after treatment), all the rabbits were artificially inseminated (AI), and injected with 0.8 mg of buserelin i.m. to induce ovulation. Concurrently, blood samples were taken for progesterone (P4) analysis by RIA with the following schedule: day 8 pp (before treatment), day 11 pp (before AI and the induction of ovulation) and day 16 pp (5 days after AI). Fertility was not influenced by hormonal treatments (71.7% and 71.2% respectively) compared to control (66.1%). Conversely, both PGF2a and eCG hormonal synchronisation treatments increased (P1 ng/mL). On day 5 after insemination 95.5% had P4 values, which attest to the presence of functional corpora lutea (CL) (P4>2 ng/mL). The results of this study show that as long as rabbitry is properly managed zootechnically and sanitarily, drugs such as alfaprostol and eCG, while not ameliorating fertility rate when used for post partum oestrus sychronisation, can increase litter size.Mollo, A.; Veronesi, M.; Battocchio, M.; Cairoli, F.; Brecchia, G.; Boiti, C. (2003). THE EFFECTS OF ALFAPROSTOL (PGF2a analogue) AND eCG ON REPRODUCTIVE PERFORMANCES IN POSTPARTUM RABBITS. World Rabbit Science. 11(2):63-74. https://doi.org/10.4995/wrs.2003.498SWORD637411
The effect of the dietary electrolyte balance on the plasma energy, protein, mineral variables and endocrine profile of pluripare rabbit does
No full textIn this research, the effect of the electrolyte balance (dEB, dEB=Na+K-Cl) on the plasma energy, protein, enzyme, mineral profile and on the endocrine response of rabbit does was studied. The animals, belonging to the Grimaud genotype, were at the third reproductive cycle. The rabbits were allocated to reproductive cages and divided into two groups to be fed two diets with different electrolyte balances (dEB1=27 meq/100g and dEB2=35 meq/100g). The diets were similar in ingredients, protein (CP=19.81% d.m.) and energy content (DE=2945 kcal/kg d. m.), whereas they had different sodium content (dEB1=0.21% d.m. and dEB2=0.38% d. m.). The animals were fed the two diets from first mating (20 weeks of age) until the litter weaning of the third reproductive cycle. From the mating of the third cycle the environmental temperature averaged 15°C and the relative humidity was about 79%. At about 39 weeks of age, five days after parturition, a blood sampling was performed on the does. Results pointed out that the two dEB levels did not significantly affect the body weight and feed intake of rabbit does. No significant dEB effect was observed on the main variables of plasma metabolic (glucose, triglycerides, cholesterol, total proteins, albumin and globulines), enzyme (aspartate-aminotransferase, alanine-aminotransferase, ?-glutamyl-transpeptidase), and mineral (Ca, P, K, Na, Cl) profile. The plasma concentration of 17ß-oestradiol was similar between the two groups. Cortisol plasma level slightly increased in dEB2 rabbits. Also the triiodothyronine (T3) and thyroxine (T4) were unaffected by the dietary dEB level as well as the free fractions (FT3 and FT4). The results point out that a prolonged administration of a diet with an electrolyte balance of 35 meq/100 g does not affect the metabolic and mineral profile nor the oestradiol plasma level but tendentially increases the thyroid hormones of pluripare lactating rabbit does when they are in neutral thermal conditions
A study on the reproductive performance and physiological response of rabbit bucks fed diets with two different mineral contents
No full textThe reproductive performance and the plasma biochemical profile of rabbit bucks relating to two dietary electrolyte balances (dEB, dEB=Na+K-Cl) were investigated. Two pelleted diets were fed the male rabbits from the first mating (50 weeks of age) until the weaning of the litters of the third reproductive cycle. The diets were similar in composition and were isoproteic (crude protein=19.81% d. m.) and isoenergetic (digestible energy=2945 kcal/kg d. m.); the sodium content was 0.21 an 0.38% d. m. and the electrolyte balance was 27 meq/100g and 35 meq/100 g in the dEB1 and dEB2 diets, respectively. The higher sodium level in the diet was obtained by increasing the mineral content in the supplement of the feed. Matings occurred with natural insemination. The trial started in the summer period under a hot climate but the third cycle presented neutral thermal hygrometric conditions (temperature=15°C and relative humidity=79%). The photoperiod was 16L:8D. At the third cycle, at 70 weeks of age, the bucks were submitted to a blood sampling early in the morning. At the third reproductive cycle, the dEB2 diet did not significantly affect the body weight and the feed intake of the rabbits. The two experimental groups presented a similar number of kids born and born alive and number of kids/mating. Plasma glucose, triglycerides, cholesterol, total proteins, albumin and globulines resulted unaffected by the diets. The plasma enzyme activities (aspartate-aminotransferase, alanine-aminotransferase, γ-glutamyltranspeptidase) and the mineral contents of calcium, phosphorus, potassium, sodium and chloride were similar between the groups. No significant difference was observed for plasma cortisol, even if the higher dEB level induced a tendential decrease in dEB1 group. T3 (thriiodothyronine), T4 (thyroxine) and FT3 (free T3) were similar between the groups. FT4 (freeT4) slightly increased in the dEB2 rabbits. Results indicate that using daily rations with an electrolyte balance ranging from 27 to 35 meq/100 g continuously for three reproductive cycles did not exert any effect on the reproductive performance of the bucks nor on the biochemical profile
The different effects of linseed and fish oil supplemented diets on insulin sensitivity of rabbit does during pregnancy
No full textThis study investigates the effects of linseed (rich in ɑ-linolenic acid (ALA)) and fish oil (rich in eicosapentaenoic (EPA) and docosahexaenoic acid (DHA)) supplementation on the insulin resistance of pregnant rabbits. Two months before insemination, the rabbits (15 animals/group) were fed different diets: commercial standard (group C), supplemented with 10% extruded linseed (group L), and 3% fish oil (group FO). The L group does showed both the highest feed intake before AI (P < 0.01) and the highest body weight (BW) throughout pregnancy (P < 0.001). The L does yielded less milk than the C does (P < 0.001); however, no differences were observed in either weight or size of litter at weaning. Regardless of diet, insulin concentrations and HOMA-IR values were higher during the first half of pregnancy (P < 0.001). Nevertheless, the L does showed higher mean insulin concentrations than FO rabbits (P < 0.01) and the lowest glucose clearance (P < 0.01) during pregnancy. On the other hand, pregnant FO rabbits showed the lowest glucose concentrations (P < 0.05) and the lowest Homeostasis model assessment values for insulin resistance (HOMA-IR, P < 0.05) as well as a faster restoration of baseline glucose levels following glucose load (P < 0.001). Before and during pregnancy, the BW of the rabbits was positively related to fasting sample- and tolerance test-derived indices of insulin resistance (P < 0.05) suggesting that a high pre-pregnancy BW predisposes to gestational insulin resistance. Linseed supplementation increased BW and predisposed to insulin resistance during pregnancy; whereas, fish oil improved insulin sensitivity without significant changes in BW
Effect of LNA integration on endocrine and metabolic parameters in dairy cattle
No full textIn a field trial the effect of long term supplementation of different levels of estruded linssed and energy levels on milk yeld and plasma concentrations of insulin, T3,cortisol, leptin, glucose and non esterified fatty acids (NEFA) in dairy cow in early lactation, were evaluated. Fifth seven italian holstein fresian cows reared in Parmigiano Reggiano cheese area, homogeneous for lactation number, days in miilkings (DIM) (41±12d), BCS (3.17±0.14) in productive level in the previous lactations, were allotted into three experimental groups, in different farms, with similar management system (Control group - C 1.45 Mcal NEI/Kg DM, 280 g/d Omega-Lin® - Mignini &Petrini 0280; 1.51 Mcal NEI/Kg DM, 450 g/d Omega-Lin® - Mignini &Petrini 0450; 1.56 Mcal NEI/Kg DM) and feed isonitrogenous TMR diets. Omega-Lin® contained 70% of exstruded linseed. Blood samples were taken by coccigeal vein and blood parameters evaluated. Fixed effect of diet, parity and hear within diet were tested. Parity showed a significant effect only for milk yeld and T3, while diet influenced significantly milk yield, T3, leptin and NEFA. Milk yield was higher in 0450 group compared to the control one (43.61 vs 35.51: P<0.01). T3 showed the highest level in 0450 group if compared with C group (1.32 nmol/l vs 1.07 nmol/l: P<0.01) while 0280 group showed an intermediated level. NEFA as indicators of body lipids mobilization showed the highest in C group (0.50 mmol/l) and lower in 0280 group (0.29 mmol/l) (P<0.01) while 0450 showed an intermediated level. Opposite results were found for leptinwhich showed the highest level in 0280 group and the lowest in C group (4.08 ng/mL vs3.08 ng/mL: P<0.05) while 0450 group showed an intermediate level. No significant differences were found in the other parameters although cortisol and insulin are key players in the control of intermediary metabolism and glucose as indicator of energy balance. In conclusion leptin, T3, NEFA levels in 0450 group put in eveidence a better energy utilization for milk yield although the trend of these parameters showed in 0280 group should be explained by a probably different genetic valueof the cows among farms. Further analyses will be desiderable
Metabolic adaptations in neonatal mother-deprived rabbits
No full text[EN] In order to study the metabolic adaptation in response to 48 h transient doe-litter separation (DLS) in young rabbits (5 rabbits/d group) between postnatal 9 and 11 d, plasma concentrations of thyroid hormones T3 and T4, insulin, leptin, glucose, triglycerides (TG), and free fatty acids (FFA) were examined before (6-8 d), during (9-11 d), and after separation (12-16 d). T3 concentrations in newborn control rabbits gradually increased from 0.6 ng/mL at postnatal 6 d to 1.0 ng/mL at postnatal 16 d, whereas those of T4 remained fairly constant (25 ng/mL) up to postnatal 14 d, when T4 gradually declined to 8 ng/mL. T3 values of DLS newborn rabbits did not differ from those of controls at postnatal 10 and 11 d, but were lower (P<0.05) at postnatal 12 d, while T4 concentrations in DLS animals increased, although not significantly, between postnatal 10 and 12 d compared to controls. Insulin concentrations in young control rabbits ranged between 0.6 and 1.0 mg/L in the early postnatal days, whereas those for leptin averaged 2-3 ng/mL. Insulin and leptin values in DLS newborn rabbits were lower (P<0.05) at postnatal 10 and 11 d, but thereafter rebounded to levels close to those of controls. Glycaemia showed a comparable trend in both groups, ranging between 170 and 190 mg/dL up to postnatal 14 d, but thereafter decreased (P<0.05) to values of 120-130 mg/dL independently of treatment. Concentrations of TG varied greatly from day to day around a mean value of 300 mg/dL, whereas those of FFA remained at approximately the same steady-state levels from postnatal 6 to 16 d, averaging 0.8 mM without any significant differences between groups. In conclusion, these findings confirm that newborn rabbits can cope with the metabolic stress of starvation associated with DLS by lowering insulin and leptin concentrations while maintaining those of thyroid hormones, an overall endocrine response which, together with temporary increase of glucorticoids, successfully maintains an adequate energy balance.This work was partially supported by a grant from the Italian “Ministero Istruzione Università e Ricerca” (Progetto Ricerca Interesse Nazionale – Prot. 2001072484 and 2003074002) and by generous donations from the BC Red-water Trust (Perugia, Italy). Procedures conformed to animal care guidelines and were approved by the Bioethical Committee of the University of Perugia in accordance with the current laws of Italy. The authors gratefully acknowledge the revision of the English text by Sheila Beatty.Brecchia, G.; Zerani, M.; Bonano, A.; Boiti, C. (2010). Metabolic adaptations in neonatal mother-deprived rabbits. World Rabbit Science. 18(4):229-236. https://doi.org/10.4995/wrs.2010.78022923618
Milk production of pseudopregnant multiparous does
No full textThe aim of the experiment was to evaluate the milk production of pseudopregnant does. In this experiment, data of multiparous, inseminated, pregnant (IP, n=15) does and two groups of presumably pseudopregnant multiparous does: inseminated, non-pregnant (INP, n=17) and induced to ovulation by GnRH (1.5 microgram per animal) at the day of insemination (11 d after parturition) (non-inseminated, ovulating: NIO, n=15) were analysed. The progesterone level was measured at the 12th d after treatment to determine if females were pseudopregnant. All IP and NIO does were pregnant and pseudopregnant, respectively. Within the INP group, 10 and 7 does were diagnosed as positive (INPO) or negative (INPNO) for pseudopregnancy. Two of the INPNO does perished during lactation. The average milk production of groups IP, INP and NIO was 212, 92 and 72 g/d, respectively (P160 g in the various groups were: IP=0, 0, 0, 0 and 100%, NIO=20, 13, 27, 40 and 0%, INP=15, 15, 15, 55 and 0%, respectively. The daily milk yield of the 5 INPNO does was 2, 6, 27, 84 and 139 g, respectively. These results demonstrated that multiparous empty does, pseudopregnant or non-pseudopregnant, can produce milk, but in lower quantities than multiparous does after kindling.Szendrö, Z.; Matics, Z.; Brecchia, G.; Theau-Clément, M.; Nagy, Z.; Princz, Z.; Biró-Németh, E.... (2010). Milk production of pseudopregnant multiparous does. World Rabbit Science. 18(2). https://doi.org/10.4995/wrs.2010.18.1018
A study on the reproductive performance and physiological response of rabbit bucks fed on diets with two different mineral contents
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