The influence of age on reproductive performance in the Brown Thornbill

I examined age effects on reproduction in the Brown Thornbill Acanthiza pusilla in Canberra, Australia. I found that the reproductive performance of both males and females improved with age, although only age-related improvement in male performance had a significant effect on annual reproductive success. Reproductive success improved with male age as a result of improved performance during two stages of the breeding cycle: first-year males were less likely to fledge young than those aged two or more, while both first and second-year males were less successful at raising fledglings to independence than males of three or more. Male performance appears to improve over three years as they gain experience at provisioning nestlings and caring for fledglings without attracting predators, rather than as a direct result of improved foraging skills. In contrast, reproductive success only improved slightly with female age, although females of two or more years initiated their first clutch earlier in the season than one-year-old females, and tended to be mure likely to re-nest if a breeding attempt failed. The poor performance of young females appears unlikely to be related to their foraging ability but may be associated with costs imposed by dispersing to a breeding vacancy earlier in the year. Although the reproductive performance of Brown Thornbills improves considerably with age 1 found no evidence that performance improved as a result of repeated breeding attempts with the same partner.

Effect of periparturient diseases accompanied by excessive vulval discharge and weaning to mating interval on sow reproductive performance

Objective To evaluate the effect of periparturient disease accompanied by vulval discharge, and weaning-to-mating intervals, on sow fertility and litter size. Design Reproductive data were collected and analysed from 19 Hungarian swine herds over a 4 year period. Conception rates, farrowing rates and litter sizes of sows with periparturient disease accompanied by vulval discharge were used to evaluate the relationship between duration of vulval discharge and subsequent fertility and litter size. The possibility of interactions between weaning-to-mating intervals and duration of vulval discharges was investigated to determine if there was any effect on subsequent fertility and litter size. Results and conclusions Both parity 1 and parity 2 to 8 sows having had periparturient disease accompanied by vulval discharge in excess of 6 days duration had significantly (P < 0.001) lower subsequent fertility (conception, farrowing and adjusted farrowing rates) compared with sows of similar parity where the duration of vulval discharge was < 4 or 4 to 6 days. There was no difference in fertility rates between sows, in both parity categories, with vulval discharge for < 4 days compared with 4 to 6 days. A duration of vulval discharge in excess of 6 days in parity 1 sows significantly reduced litter size (total born and live-born) in subsequent farrowings, but not in parity 2 to 8 sows. There was no interaction between the duration of vulval discharge and post-weaning to mating intervals. However sows with weaning to mating intervals between 7 and 10 days had smaller (P < 0.001) subsequent litter sizes compared with 3 to 6 or 11 to 14 day intervals. It was concluded that the duration of vulval discharge in excess of 6 days was an indication of a severe persistent endometritis adversely affecting fertility of sows.

Temperament and reproductive performance in farmed sable

Selostus: Tarhatun soopelin luonne ja lisääntymiskyky

Reproductive performance of Santa Inês ewes fed protected fat diet

The objective of this work was to evaluate the reproductive performance of Santa Inês ewes fed a diet supplemented with protected fat. Intervals from lambing to first clinical estrus and to conception, conception rate, prolificacy, live weight and body condition were determined. After lambing, 60 ewes and their offsprings were weighted and randomly assigned to three treatments, based on age, body weight and number of born lambs. Treatments consisted of: control diet, or control diet plus 30 g of protected fat, from lambing to day 25 of post-lambing (Sup25), or to day 60 of post-lambing (Sup60). Out of 60 evaluated ewes, 93.3% returned to estrus, and 74.5% got pregnant, with 73.53% lambing rate and 196.5 days lambing interval. The average periods from lambing to first estrus were 32.4, 27.2 and 35.5 days for ewes fed the control diet, Sup25, and Sup60, respectively. The intervals from lambing to conception were 45.2, 46.5 and 45.2 days, and the supplemented diets did not show differences in comparison to the control diet. Supplementation with protected fat to well-nourished Santa Inês ewes does not improve their reproductive performance.

Milk yield and reproductive performance of dairy heifers and cows supplemented with polyunsaturated fatty acids

The objective of this work was to determine productive and fertility responses of Holstein-Friesian heifers and cows to supplementation with extruded linseed and soybean as sources of polyunsaturated fatty acids (PUFAs). Supplementation had a positive effect on profitability, with significant increases in milk yield in supplemented cows, but not in heifers. Treatments had no effect on milk fat content, but higher milk protein contents were observed with supplementation. A higher conception rate was found for supplemented heifers, but not for cows. Fat sources containing PUFAs are recommended for dairy cattle supplementation, since they improve fertility in heifers and milk yield in cows.

EFFECTS OF HARVESTING ON LEAF PRODUCTION AND REPRODUCTIVE PERFORMANCE OF Copernicia prunifera (Mill.) H.E. Moore1

ABSTRACT This work aimed to evaluate the consequences of the monthly extraction of immature leaves in survival, leaf production and reproductive performance ofCopernicia prunifera H. E. Moore palm, popularly known as carnaúba. One hundred sixty reproductive adult palms were monitored for 17 months in four extractive communities located at the coast of the state of Piauí. As a result, it was observed that leaves, flowers, fruits and seeds production were reduced in the palm submitted to 50% or 75% monthly extraction. Higher levels of extraction were followed by smaller levels in seed germination. No deaths were observed even in the group subjected to 75% monthly leaves exploration. In order not to produce damage to palm trees development it is suggested that leaf extraction rate should not exceed 25% monthly as well as pausing of extractive activity preferentially during fruit maturation.

Study of the effects of ß-myrcene on rat fertility and general reproductive performance

ß-Myrcene (MYR) is a monoterpene found in the oils of a variety of aromatic plants including lemongrass, verbena, hop, bay, and others. MYR and essential oils containing this terpenoid compound are used in cosmetics, household products, and as flavoring food additives. This study was undertaken to investigate the effects of MYR on fertility and general reproductive performance in the rat. MYR (0, 100, 300 and 500 mg/kg) in peanut oil was given by gavage to male Wistar rats (15 per dose group) for 91 days prior to mating and during the mating period, as well as to females (45 per dose group) continuously for 21 days before mating, during mating and pregnancy, and throughout the period of lactation up to postnatal day 21. On day 21 of pregnancy one-third of the females of each group were submitted to cesarean section. Resorption, implantation, as well as dead and live fetuses were counted. All fetuses were examined for external malformations, weighed, and cleared and stained with Alizarin Red S for skeleton evaluation. The remaining dams were allowed to give birth to their offspring. The progeny was examined at birth and subsequently up to postnatal day 21. Mortality, weight gain and physical signs of postnatal development were evaluated. Except for an increase in liver and kidney weights, no other sign of toxicity was noted in male and female rats exposed to MYR. MYR did not affect the mating index (proportion of females impregnated by males) or the pregnancy index (ratio of pregnant to sperm-positive females). No sign of maternal toxicity and no increase in externally visible malformations were observed at any dose level. Only at the highest dose tested (500 mg/kg) did MYR induce an increase in the resorption rate and a higher frequency of fetal skeleton anomalies. No adverse effect of MYR on postnatal weight gain was noted but days of appearance of primary coat, incisor eruption and eye opening were slightly delayed in the exposed offspring. On the basis of the data presented in this paper the no-observed-adverse-effect level (NOAEL) for toxic effects on fertility and general reproductive performance can be set at 300 mg of ß-myrcene/kg body weight by the oral route.

A study of selected factors influencing the reproductive performance of the common tern (Sterna hirundo) at Port Colborne, Ontario in 1973 and 1974

Several study areas were investigated at two Port Colborne terneries during the summers of 1973 and 1974 in an attempt to determine the influence of clutch size, time of clutch initiation, position in the colony, proximity to Ring-billed Gulls, vegetation and nesting substrate on the reproductive performance of the Common Tern. Hatching success and reproductive success (the number of chicks fledged per egg laid) were generally higher for 3-egg than 2-egg clutches but fledging (the number of chicks fledged per egg hatched) success was usually independant of clutch size. Hatching, fledging and reproductive success declined as a function of time of clutch initiation. Mean clutch sizes also generally declined as a function of time. Nests located in the center of the colony exhibited higher fledging success than those on the periphery. Rock-based clutches had a lower hatching success than clutches initiated on sand or dried vegetation. Reproductive performance did not appear to be related to proximity to Ring-billed Gulls or vegetation within the study area.

Intergenerational effects of birth weight on glucose tolerance and reproductive performance

Women who were themselves small-for-gestational age (SGA) are at a greater risk of adulthood diseases such as non-insulin-dependent diabetes mellitus (NIDDM), and twice at risk of having an SGA baby themselves. The aim of this study was to examine the intergenerational pig. Low (L) and normal (N) birth weight female piglets were followed throughout their first pregnancy (generation 1 (0)). After they had given birth, the growth and development of the lightest (I) and heaviest (n) female piglet from each litter were monitored until approximately 5 months of age (generation 2 (G2)). A glucose tolerance test (GTT) was conducted on G1 pig at similar to 6 months of age and again during late pregnancy; a GTT was also conducted on G2 pigs at similar to 4 months of age. G1 L offspring exhibited impaired glucose metabolism in later life compared to their G1 N sibling but in the next generation a similar scenario was only observed between I and n offspring born to G1 L mothers. Despite G1 L mothers showing greater glucose intolerance in late pregnancy and a decreased litter size, average piglet birth weight was reduced and there was also a large variation in litter weight; this suggests that they were, to some extent, prioritising their nutrient intake towards themselves rather than promoting their reproductive performance. There were numerous relationships between body shape at birth and glucose curve characteristics in later life, which can, to some extent, be used to predict neonatal outcome. In conclusion, intergenerational effects are partly seen in the pig. It is likely that some of the intergenerational influences may be masked due to the pig being a litter-bearing species.

A cross-sectional study of reproductive performance of smallholder dairy cows in coastal Tanzania

A retrospective cross-sectional study was conducted on 200 randomly selected smallholder farms from a mixed dairy farming system in Tanga, Tanzania, between January and April 1999. We estimated the frequency and determinants of long calving interval (LCI), retention of fetal membrane (RFM), dystocia, and abortion in smallholder crossbred cattle and explored birth trends. The mean calving interval was 500 days and birth rate was 65 per 100 cow-years. Dystocia was reported to affect 58% of calvings, and 17.2% of animals suffered RFM. Using mixed effect models, the variables associated with LCI, RFM and dystocia were breed, level of exotic blood and condition score. Zebu breeding was associated with LCI (odds ratio (OR) = 2.3, p = 0.041) and Friesian breeding with lower odds for RF (OR = 0.26, p = 0.020). Animals with higher levels of exotic blood had lower odds for evidence of dystocia (OR = 0.45, p = 0.021). Evidence of dystocia was significantly associated with poor condition score (beta = -1.10, p = 0.001). Our observations suggest that LCIs are common in smallholder dairy farms in this region and a likely source of economic loss. Dystocia, RFM, poor condition score and mineral deficiency were common problems and were possibly linked to LCI.

Reproductive performance of the generalist predator Hypoaspis aculeifer (Acari : Gamasida) when foraging on different invertebrate prey

In this study, we assessed the influence of prey quality and prey biomass during a standardized 3-week test on adult survival and reproductive output of the predatory mite Hypoaspis aculeifer when fed one of six different diets: springtails (Folsomia candida and Folsomia fimetaria), a storage mite (Caloglyphus cf. michaeli), an oligochaete (Enchytraeus crypticus), a nematode (Turbatrix silusiae), and a 1:1:1 mix of F. candida:F.fimetaria:E. crypticus. Our results revealed that a single prey species may be nutritionally sufficient for a 3-week period, as H. aculeifer performed equally well, or better, on a diet based on a 1:1:1 mix of F. candida:F. fimetaria:E. crypticus. However, when fed C. cf. michaeli, H. aculeifer had a poor reproductive output (< 200 juveniles) and a reduced survival (60-70%). Thus, investigators should validate their choice of prey prior to testing H. aculeifer performance during toxicant exposure. (c) 2007 Elsevier B.V. All rights reserved.

Reproductive performance of prepubertal Bos indicus heifers after progesterone-based treatments

The objective was to evaluate the effects of exogenous progesterone (P4) on reproductive performance of prepubertal Bos indicus heifers. Prepubertal Nelore heifers (n = 589; 24.0 +/- 1.13 mo; 298.0 +/- 1.89 kg; body condition score of 3.2 +/- 0.26; mean +/- SEM) were randomly assigned to receive, between experimental Days -12 and 0: no treatments (CIDR0; n = 113); a new intravaginal insert (CIDR) containing 1.9 g of P4 (CIDR1; n = 237); or a similar insert previously used three times, with each use occurring for 9 d (CIDR4; n = 239). An additional treatment group was pubertal heifers given 12.5 mg dinoprost tromethamine im on Day 0 (PGF; n = 346), and used as controls for evaluation of conception rates. on Day 0, transrectal palpation was done for uterine score evaluation (UtS; 1-3 scale), blood samples were taken for serum P4 concentrations, and follicle diameter (FD) was measured. The breeding season started on Day 1 and consisted of AI after detection of estrus between Days I and 45, and exposure to bulls between Days 46 and 90. There were effects of treatment (P < 0.05) on serum concentrations of P4 on Day 0 (0.37 +/- 0.16, 2.31 +/- 0.11, and 1.20 +/- 0.11 ng/mL for CIDR0, CIDR1, and CIDR4, respectively; mean SEM), FD on Day 0(9.45 +/- 0.24, 9.72 +/- 0.17, and 11.42 +/- 0.16 mm), UtS on Day 0 (1.49 +/- 0.06, 1.88 +/- 0.04, and 2.24 +/- 0.04), estrus detection rates at 7 d (19.5, 42.6, and 38.3%) and 45 d (52.2, 72.1, and 75.3%) of the breeding season, and on pregnancy rates at 7 d (5.3, 14.3, and 18.4%), 45 d (27.4, 39.2, and 47.7%) and 90 d (72.6, 83.5, and 83.7%) of the breeding season. Conception rate 7 d after the start of the breeding season was greater (P < 0.05) in heifers from the CIDR4 (46.8%) and PGF (43.8%) groups than in the CIDR0 (27.3%) and CIDR1 (33.7%) groups. In conclusion, exogenous P4 hastened puberty and improved pregnancy rates at the beginning of the breeding season in prepubertal Bos indicus heifers. Furthermore, previously used CIDR inserts were better than new inserts. (C) 2010 Elsevier B.V. All rights reserved.

Strategic supplementation of calcium salts of polyunsaturated fatty acids to enhance reproductive performance of Bos indicus beef cows

Five experiments evaluated the effects of supplemental Ca salts of PUFA on reproductive function of Bos indicus beef cows. In Exp. 1, nonlactating and multiparous grazing cows (n = 51) were assigned to receive (as-fed basis) 0.1 kg of a protein-mineral mix + 0.1 kg of ground corn per cow/d, in addition to 0.1 kg per cow/d of 1) Ca salts of PUFA (PF), 2) Ca salts of SFA (SF), or 3) kaolin (control). Treatments were offered from d 0 to 20 of the estrous cycle. No treatment effects were detected on serum progesterone concentrations (P = 0.83), day of luteolysis (P = 0.86), or incidence of short cycles (P = 0.84). In Exp. 2, nonlactating and multiparous grazing cows (n = 43) were assigned to receive PF, SF, or control from d 0 to 8 of the estrous cycle. on d 6, all cows received (intramuscularly) 25 mg of PGF(2 alpha). No treatment effects were detected on serum progesterone concentrations on d 6 (P = 0.37), and incidence (P = 0.67) or estimated time of luteolysis (P = 0.44). In Exp. 3, twenty-seven lactating and multiparous grazing cows, approximately 30 to 40 d postpartum, were assigned to receive PF or control for 10 d beginning at the first postpartum ovulation. No treatment effects were detected (P = 0.85) on incidence of short cycles. In Exp. 4, lactating and multiparous grazing cows (n = 1,454), approximately 40 to 60 d postpartum, were assigned to receive 1 of the 7 treatments for 28 d after timed AI (TAI; d 0): 1) control from d 0 to 28, 2) SF from d 0 to 14 and then control, 3) PF from d 0 to 14 and then control, 4) SF from d 0 to 21 and then control, 5) PF from d 0 to 21 and then control, 6) SF from d 0 to 28, and 7) PF from d 0 to 28. Cows receiving PF for more than 21 d after TAI had greater (P < 0.01) pregnancy to TAI compared with all other treatments combined (50.4 vs. 42.4%, respectively). In Exp. 5, lactating and multiparous grazing cows (n = 501), approximately 40 to 60 d postpartum, were assigned to receive 1 of the 4 treatments for 21 d after TAI (d 0): 1) PF from d 0 to 14 and then control, 2) control from d 0 to 6 and then PF, 3) control from d 0 to 13 and then PF, and 4) PF from d 0 to 21. Cows receiving PF after d 14 of the experiment had greater (P = 0.02) pregnancy to TAI compared with cows not receiving PF during the same period (46.8 vs. 33.1%, respectively). In summary, supplemental Ca salts of PUFA during the expected time of luteolysis increased pregnancy to TAI in beef cows.