Can advance of first lambing induced by melatonin implants influence the next lambing time in Sarda breed sheep?

2012 ◽  
Vol 92 (1) ◽  
pp. 67-71 ◽  
Author(s):  
Vincenzo Carcangiu ◽  
Maria Consuelo Mura ◽  
Pier Paolo Bini ◽  
Giuseppe Massimo Vacca ◽  
Cinzia Daga ◽  
...  

Carcangiu, V., Mura, M. C., Bini, P. P., Vacca, G. M., Daga, C. and Luridiana, S. 2012. Can advance of first lambing induced by melatonin implants influence the next lambing time in Sarda breed sheep? Can. J. Anim. Sci. 92: 67–71. In adult sheep, exogenously administered melatonin from continuous slow-release implants has been shown to advance the onset of the breeding season by mimicking the stimulatory effect of short days. The aim of this study was to verify if treatment with one or two melatonin implants was effective in advancing the first conception in Sarda ewe lambs, and if this advance would also be seen in the second lambing too. In the first year, 600 ewe lambs were randomly assigned to groups M, M+M and C, each with 200 animals. On Jun. 30, group M received a single implant while group M+M received two implants. Group C was untreated. On Aug. 04, 25 rams were introduced in the groups and removed after 70 d. From these 600 animals the 420 head that lambed prior to Mar. 12 were chosen for the second year. These ewes were subdivided into two groups T1 (ewes who lambed between 2007 Jan. 01 and Feb. 10) and T2 (ewes which lambed between 2007 Feb. 11 and Mar. 12). Both in T1 and T2 the distribution of the animals in M, M+M and C group was maintained. In the first year, the treated animals lambed earlier (P<0.05) and showed higher numbers of lambed ewes at Feb. 10 (P<0.01) and at March 12 (P<0.05) compared with untreated control animals. The animals that showed an advance in the period of their first conception, also showed, in the second breeding year, an advance in the lambing time (P<0.001). This study provides evidence that the advance of first conception, obtained with melatonin treatment also influenced the reproductive activity in the following breeding season.

2008 ◽  
Vol 34 (No. 1) ◽  
pp. 35-41 ◽  
Author(s):  
F. Šrámek ◽  
M. Dubský

Slow-Release Fertilizers (SRF) Silvamix Forte and Silvagen were tested in two-year experiments with container-grown woody plants (<i>Pyracantha coccinea</i>, <i>Thuja occidentalis</i>). Several fertilizing systems were compared: preplant application of SRF into substrate as the sole nutrient source for a two-year period, preplant application of SRF and soluble fertilizer (PG Mix), and preplant application of SRF and soluble fertilizer together with additional fertilizing by solution of nitrogen fertilizer during both growing periods. A system with controlled-release fertilizer (CRF) Osmocote 5&minus;6 was chosen as a control variant; it was incorporated into substrate before planting in the first year and top-dressed in the second year. CRF Plantacote 6M (mixed into substrate before planting and top-dressed in the second year) and Osmocote 16&minus;18 applied only before planting were tested, too. The experiments showed that SRF Silvamix Forte and Silvagen give results comparable with CFR provided that they were incorporated together with soluble ferti-lizer dose and plants were fertilized by solution of nitrogen fertilizer during both growing periods.


1978 ◽  
Vol 90 (2) ◽  
pp. 275-281 ◽  
Author(s):  
Ø. R. Dýrmundsson

SummaryThe paper reports on a study, conducted in four successive seasons, of sexual development and breeding activity in females of the Iceland breed, the only breed of sheep kept in the country. The ewe lambs normally attained puberty in their first year of life, on average at 7 months of age, with marked individual variation in both age and body weight at first oestrus. Ewe lambs always showed oestrus on average slightly later than mature ewes (2–9 years), the mean date of onset of the breeding season of the latter being 8 December, however, with considerable individual variation. Furthermore, ewe lambs had a shorter breeding season (1–4 months) than ewes (4–6 months) and they appeared to experience more silent heats resulting in less regular cyclic activity. There seemed to be a minor increase in the duration of the oestrous cycle with age and ewe lambs clearly exhibited shorter oestrus (heat) than ewes. With seasonal breeding activity ranging from November to May the mid-breeding season occurs some 4–7 weeks after the shortest day.


Author(s):  
A.D. Mackay

A grazing trial evaluated the agronomic effectiveness of 3 different types of phosphate (P) fertilisers. The same fertilisers were also evaluated in a small-plot mowing trial located within the grazing trial. In the grazing trial, which covered 35 ha of summer moist hill country, the partially acidulated phosphate rock (PAPR) and reactive phosphate rock (RPR) were as effective as superphosphate in stimulating legume and pasture production in the first year. In the second year the two slow-release materials continued to perform as well as SSP. In contrast in the mowing trial, superphosphate was more effective than RPR in the first year. This trial technique clearly underestimates the initial effectiveness of PAPR and RPR in grazed hill country. The traditional small-plot mowing trial technique, and the role of PAPR and RPR fertilisers in hill country, both need re-evaluation. Keywords hill country, superphosphate, slow release fertilisers, mowing trials, grazed pasture


2012 ◽  
Vol 65 (4) ◽  
pp. 123-132 ◽  
Author(s):  
Zenia Michałojć ◽  
Michał Koter

A study on azalea (<em>Rhododendron </em>L.), 'Kilian' and 'Persil', was conducted in 2009–2010. Plants were grown in pots in the open air, in a peat substrate with a pH of 4.8. The effect of the following fertilization methods was studied: I – traditional fertilization (single fertilizers were applied in 2 rates); II – a slow-release fertilizer (Hortiform pH); III – combined fertilization (¼ of the rate of nutrients was applied in the form of single fertilizers and ¾ in the form of Hortiform pH). The slow-release fertilizer Hortiform pH and combined fertilization were applied once in each study year when filling the pots with growing medium. Fertilizers were applied at the basic rate (D1) and at a twice higher rate (D2). In the first year of cultivation, the study showed no significant effect of fertilization method on shoot length in both azalea cultivars, whereas in the second year the longest shoots were found after application of the slow-release fertilizer Hortiform pH. In both years of the study, significantly longer shoots were found in the cultivar 'Persil' after application of the lower fertilizer rate (D1) than after application of the higher fertilizer rate (D2). On the other hand, the study showed that the fertilizer rate had no effect on shoot length in 'Kilian'. After application of the higher fertilizer rate, a higher content of nitrogen and potassium as well as a lower content of phosphorus, calcium, and magnesium were determined in the leaves of both cultivars. The study found the following percentages to be the optimal nutrient content in azalea leaves: 1.88 – 2.20% N; 1.0 – 1.7% K; and 0.60% – 1.20% Ca, while the phosphorus content of 0.09 – 0.25% and the magnesium content of 0.14 – 0.25% were shown to be the lower limit for optimal plant nutrition. After the end of the growing season, a low content of all nutrients in the medium was found in both study years, irrespective of the applied fertilizer rate and fertilization method.


Author(s):  
P. R. Garwood

The population of Streptosyllis websteri at Newton, Northumberland shows epigamous reproduction and has an extended spawning season from April to July, during which there are two main peaks of spawning activity. Most individuals spawn twice in the breeding season at the beginning of their third year of life, although some individuals may contribute to the second spawning peak of the breeding season at the beginning of their second year. Growth rates are remarkably uniform, and year classes are usually clearly distinguishable using setiger number frequency distributions. Observations on growth and mortality suggest that there is competition for resources amongst the new recruitment class over the first few months of life, but that overall survival through the first year is density independent and likely to be determined by external factors. Larval development is largely benthic, and it is unlikely that there is any prolonged truly pelagic larval phase.


2009 ◽  
Vol 57 (4) ◽  
pp. 531-540 ◽  
Author(s):  
Vera Faigl ◽  
Mónika Keresztes ◽  
Margit Kulcsár ◽  
Sándor Nagy ◽  
Zsuzsanna Keresztes ◽  
...  

The objective of this study was to evaluate the effect of long-term melatonin treatment applied during the non-breeding season on semen characteristics, endocrine function of testicles and baseline level of insulin-like growth factor-I (IGF-I) in Awassi rams kept in the temperate continental zone of Europe and used as semen donors in an artificial insemination (AI) programme. On 23 February (day 0), slow-release melatonin implants were inserted subcutaneously into rams (n = 8). Control animals (n = 8) received no treatment. In both groups, basic semen parameters (concentration, total motility, fast and slow forward motility, morphology), GnRH-induced testosterone response and basal IGF-I concentration were evaluated on days 0, 47 and 71. No differences were found in concentration of spermatozoa, total motility, and numbers of spermatozoa with fast and slow progressive motility and normal/abnormal morphology between the melatonin-treated and the control group. However, in melatonin-treated animals, basal and GnRH-induced testosterone levels were slightly elevated on day 47 and became significantly higher on day 71 (P < 0.05) as compared to controls. There was no difference in plasma IGF-I levels between the groups. In conclusion, slow-release melatonin applied during the non-breeding season improves testicular testosterone production but does not influence the semen characteristics and the IGF-I level of semen donor Awassi rams used in an AI programme and kept in the temperate continental zone of Europe.


Animals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1898
Author(s):  
Luisa Pulinas ◽  
Giovanni Cosso ◽  
Maria Consuelo Mura ◽  
Melissa Carvajal-Serna ◽  
Hatem Ouled Ahmed ◽  
...  

Stakeholders place great emphasis upon rationalizing the management and rearing techniques which are utilized within sheep farms. The present study aimed to investigate factors which may improve the reproductive performance of melatonin-treated Sardinian sheep via a series of three trials. The first trial (n = 100) investigated the effect of melatonin treatment alongside body condition score (BCS), the second trial (n = 150) investigated the effect of treatment alongside the date of treatment (treatment period) and the third trial (n = 150) investigated the effect of treatment alongside the previous lambing of the ewes. The findings indicated that melatonin is an effective tool for anticipating and improving the reproductive activity of in Sarda breed sheep during the springtime. Furthermore, to obtain optional results, melatonin implantation should be conducted in April, in ewes that have a BCS of >2.5 and that have passed their third month of lactation.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Stvarnik Mateja ◽  
Lindtner-Knific Renata ◽  
Štokar Žan ◽  
Gregurić Gračner Gordana ◽  
Mićunović Jasna ◽  
...  

AbstractThe aim of this study was to determine the percentage of hatched and fertilized eggs in female Hermann’s tortoises before and after the removal of males after breeding.A breeding group of Testudo hermanni boettgeri with 50 females and 12 males was included in the study. In the first year, all adults were together in the same habitat until reproductive activity was observed. After the end of May, the males and females were separated for the next two active seasons. The number of eggs and number of second clutches decreased gradually. In the first year, 76.0% of females laid eggs; in the second year, 24.0%; and in the third year, only 8.0%. Second clutches were observed in ten females (26.3%) in the first year, while in the next two years, one female had a second clutch. There was a small but significant correlation between the weight of a single tortoise and the number of eggs laid but no significant correlation between the weight of the tortoise and its average egg weight. The weight (15.1-16.8 g), length (33.9-36.1 mm) and width of each egg (27.5-28.0 mm) was measured.During the laying season, the eggs were put into incubators. The incubation length varied from 52 to 70 days. After the end of incubation, eggshell mortality and its causes (19.3-52.5%) were examined. In the first year, the viability rate of the incubated eggs was 80.7%; in the second year, 80.5%; and in the third year, 47.8%. Among the unhatched eggs in the first year, 62.5% were unfertilized, 53.1% were infected, 28.1% were dehydrated and 21.9% were found in various stages of embryonic development.


1992 ◽  
Vol 32 (4) ◽  
pp. 421 ◽  
Author(s):  
NM Fogarty ◽  
DG Hall ◽  
ST Dawe ◽  
W Atkinson ◽  
C Allan

The spring reproductive activity of ewes following a late winter lambing, and varying duration of suckling or lamb weaning age of 6-13 weeks, was investigated in 321 Booroola Merino x Dorset (BD) and 543 Trangie Fertility Merino x Dorset (TD) ewe records over 2 years and 238 Border Leicester x Merino (BLM) ewes in the second year. The ewes were joined about 12 weeks post-partum in November for 6 weeks, following lambing in July-August to conform to an %-monthly lambing regime. In the first year, ewes were run with vasectomised rams and oestrus, ovulation rate, and interval to first observed oestrus were determined under a simulated joining regime. In the second year entire rams were joined in spring following July-August lambing and oestrus, pregnancy, fetal number, lambs born per ewe joined and lambing interval were analysed. Amongst ewes rearing lambs, longer suckling significantly increased the interval to first oestrus and the lambing interval (P<0.01), but had no effect on the percentage of ewes expressing oestrus, percentage of pregnant ewes or lambs born. Significantly fewer ewes that lambed but failed to rear any lambs (LL), than ewes rearing lambs expressed oestrus, ovulated and became pregnant. This resulted in considerably lower lambing rates for LL ewes (95.8 v 137.2% lambs born, P<0.01). Reproductive activity was not greatly affected by ewe liveweight or liveweight gain during joining. BD and TD ewes had hgher pregnancy and lambing rates and a shorter lambing interval than BLM ewes. Ovulation rate and fetal number increased with the number of lambs being reared (0.20 � 0.08 and 0.11 � 0.04 per lamb, P<0.05). The results show that high pregnancy and lambing rates can be achieved from natural joining in the spring following late winter lambings within an 8-monthly lambing regime, when lambs are weaned prior to joining.


2007 ◽  
Vol 64 (5) ◽  
pp. 468-475 ◽  
Author(s):  
Paula de Almeida Rodrigues ◽  
Lia de Alencar Coelho ◽  
Keico Okino Nonaka ◽  
Aya Sasa ◽  
Wilter Ricardo Russiano Vicente ◽  
...  

The increased emphasis placed on lamb production in Brazil points to the need for a better knowledge of the annual pattern of reproductive activity in ewe lambs. This study evaluates the annual estrous activity pattern of hair and wool ewe lambs raised in southeast Brazil. Estrous characteristics were recorded for 12 months in ten Santa Inês and 21 Romney Marsh and Suffolk ewe lambs. Santa Inês ewe lambs exhibited a greater length of the normal estrous cycle (14 to 19 days) than Romney Marsh and Suffolk ewe lambs (17.0 ± 0.1 days vs. 16.5 ± 0.2 and 15.9 ± 0.2 days). All the ewe lambs presented a greater number of periods of estrus per animal per month for single estrous cycles (up to 26 days) during autumn and winter. During spring and summer there was a reduction of this number but this decline varied according to the breed. For Santa Inês ewe lambs the reduction was only significant in the summer. For wool ewe lambs the reduction was significant in both seasons but was more accentuated for Romney Marsh. The Romney Marsh ewe lambs had a more restricted breeding season than Suffolk and both presented optimal estrus activity in autumn and winter. Santa Inês ewe lambs had a continuous distribution of estrous cycles along the year, although presenting a reduction in the number of estrous periods in the summer. The ewe lambs of three breeds presented characteristics of sexual immaturity, like irregular estrous cycles and silent ovulations.


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