scholarly journals Photoperiod-Treatment in Mediterranean Bucks Can Improve the Reproductive Performance of the Male Effect Depending on the Extent of Their Seasonality

Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 400
Author(s):  
Luis A. Zarazaga ◽  
María Carolina Gatica ◽  
Manuel Delgado-Pertíñez ◽  
Horacio Hernández ◽  
José Luis Guzmán ◽  
...  

This study examines the effectiveness of the photoperiod treatment (extra light for 88 days) to render the bucks sexually active during the seasonal anoestrous in order to induce a male effect, depending on the reproductive seasonality of the breed of the bucks used. In April, 57 anoestrous Blanca Andaluza does were distributed into four groups with three males each: 13 were exposed to control Murciano–Granadina bucks (lower seasonality); 15 were exposed to photostimulated Murciano–Granadina bucks; 14 were exposed to control Blanca Andaluza bucks (higher seasonality), and 15 were exposed to photostimulated Blanca Andaluza bucks. After male introduction, the sexual behaviour of the bucks was assessed, and harness marks recorded doe oestrous behaviour. Ovulation was confirmed from plasma progesterone, and the ovulation rate was assessed by transrectal ultrasonography. Fecundity, fertility, prolificacy and productivity were also determined. All of the does in all of the groups showed ovulation. Interaction between both sources of variation was observed: the percentage of females showing oestrous (p < 0.01) and productivity (p < 0.05) was the lowest in the Blanca Andaluza control group (50% and 0.36 ± 0.17 goat kids born/female, respectively). In conclusion, photoperiod-treated bucks efficiently induce a male effect, but photostimulation could be more necessary for breeds with deep seasonality.

1986 ◽  
Vol 43 (2) ◽  
pp. 285-292 ◽  
Author(s):  
S. M. Rhind ◽  
B. A. Morris ◽  
Jill Clayton ◽  
J. M. Doney ◽  
R. G. Gunn ◽  
...  

ABSTRACTBorder Leicester × Scottish Blackface (Greyface) ewes of three groups, each comprising 118 animals in a wide range of body condition scores, were mated at a synchronized oestrus in mid October. The ewes were passively immunized against testosterone (group P), actively immunized against androstenedione (group F), or not treated (group C). All ewes were slaughtered at return to service or at 35 to 45 days of pregnancy and ovulation rates and numbers of embryos present were determined. Mean ovulation rates of ewes in group P were higher than in those in group C (P < 0·05) and this difference was evident at most levels of body condition. The absolute increase in ovulation rate, compared with the control group, was similar at all condition scores. Mean ovulation rates of ewes in group F were higher than those in group C (P < 0·001) and the magnitude of the increase was greater in ewes in higher condition scores. The incidence of ova wastage was variable but differences between treatments in mean ovulation rate were generally reflected in mean litter size. The conception rates of immunized ewes were depressed compared with those of control animals, particularly in ewes with a body condition score less than 3·0 at mating. Consequently, there was no improvement in the potential lambing rate of immunized ewes following only one cycle of mating. Circulating antibody titres were not related to conception rate or body condition at mating and were related to ovulation rate only in group F ewes. It is concluded that immunization against steroids, using either passive or active techniques, can improve the reproductive performance of individual ewes but improvement in the performance of the flock as a whole may only be achieved under optimal conditions of nutrition and season.


2008 ◽  
Vol 20 (9) ◽  
pp. 42
Author(s):  
M. Shikh Maidin ◽  
A. Chadwick ◽  
P. C. Khaiseb ◽  
P. A. Hawken ◽  
G. B. Martin

The productivity of Cashmere goats depends on their reproductive performance, which, in turn, depends on their level of nutrition. Ovulation rate and pregnancy in sheep are both affected by nutrition, but little is known about the response of female goats (does) to supplementary feeding. The lupin group (n = 40) received 250 g lupin per head per day in addition to pasture whereas the control group (n = 40) received no nutritional supplement. Both groups were synchronised for 17 days with intravaginal progestagen pessaries. The supplement was fed for 21 days, commencing 7 days before the bucks were introduced and intravaginal pessaries were removed (Day –2). Does were expected to ovulate 2 days later on Day 0 and the bucks were removed on Day 3. Blood was sampled for progesterone every 3 days from buck removal (Day 3) until Day 18. Ovulation rate was assessed by trans-rectal ultrasonography on Day 13 and pregnancy was diagnosed by trans-abdominal ultrasonography on Day 61 of the experiment. Does supplemented with lupins had a numerically higher ovulation rate than does fed only on pasture, but this difference was not significant (1.76 ± 3.21 v. 1.52 ± 3.79; P > 0.05). Similarly, there was no difference in the numbers of does conceiving to the first service between the lupin and control group (89% v. 94%; P > 0.05). Progesterone concentrations on Day 12 were higher in does supplemented with lupins than does fed only pasture (6.29 ± 0.27 ng/mL v. 5.41 ± 0.27 ng/mL; lupin and control group; P < 0.05). In conclusion, lupin supplementation induced a numerical increase in ovulation rate but this difference failed to reach significance. Does supplemented with lupins had higher concentrations of progesterone during early pregnancy, which is the opposite effect to that previously reported in sheep.


2015 ◽  
Vol 5 (1) ◽  
pp. 557-564
Author(s):  
Mr Aderson Martins Viana Neto

This study aimed to evaluate the reproductive performance of crossbred sheep (New Address) nulliparous, primiparous and pluriparous, subjected or not to the male effect. There were used 79 ewes and two rams (one vasectomised ram – teaser ram) and a breeder). In the first year, the females were subjected to the male effect (ME: male effect), in the following year, there has been no application of this method (AME: absence of male effect). Ewes subjected to ME showed a higher synchronization (P <0.05) compared to AME females. Nulliparous and primiparous ewes subjected to ME exhibited a higher synchronization, in relation to ewes in the absence of male effect. When specified by birth order, there were superior results (P <0.05) within the same method (AME) for prolificacy index and twinning rate for pluriparous females relative to nulliparous and primiparous. There were also significant differences (P <0.05) for the use of the male effect, but with superiority of pluriparous and primiparous females when compared to nulliparous. Between the methods, ME primiparous females (72.22%) were superior (P <0.05) to AME ewes (33.33%) for twinning rate. Thus, it can be concluded that the male effect is feasible for estrus synchronization in ewes up to the first lambing birth, besides possibly causing better ovulation rate, due to better results of twinning rate and prolificacy index.


1993 ◽  
Vol 57 (2) ◽  
pp. 281-286 ◽  
Author(s):  
M. C. G. Davies ◽  
N. F. G. Beck

AbstractAn investigation was conducted to compare, the LH, prolactin and progesterone profiles of ewe lambs with ewes during oestrus and early pregnancy. Peak LH concentration was significantly lower (P < 0·05) and duration of release tended to be shorter during oestrus in ewe lambs. Furthermore, this smaller LH peak tended to be associated with a lower ovulation rate. LH pulse rate, amplitude and concentration were similar in both groups during day 13 of pregnancy. However, LH concentration was higher in ewe lambs compared with ewes on day 28 of pregnancy. Peak prolactin concentration was lower during oestrus in ewe lambs (P < 0·05) but there was no difference between the two groups during early pregnancy. Plasma progesterone concentrations were similar in both groups until day 13 of pregnancy. Thereafter, mean progesterone concentration was lower, from day 14 to 30, in the ewe lambs (P < 0·05). These results indicate that in ewe lambs and ewes maintained under identical conditions plasma hormone profiles differ during oestrus and early pregnancy. Moreover, these differences probably contribute towards the lower reproductive performance of ewe lambs.


1971 ◽  
Vol 13 (4) ◽  
pp. 669-675 ◽  
Author(s):  
P. H. Brooks ◽  
D. J. A. Cole

SUMMARYTwo groups of 24 Landrace × Large White gilts were allocated at puberty to two feeding regimes during oestrus. The control group received 1·8 kg food/day throughout the oestrus period, while the flushed group had an additional 1·8 kg immediately after mating on the first day of oestrus. The treatments were imposed at the first post-puberal heat (second heat) and at the post-weaning oestrus in the second and third parities. The sows remained on the same treatment throughout the experiment. Litter performance was measured in the first two parities. The sows were slaughtered on day 25 of their third gestation to provide data on ovulation rate and embryo mortality. Increasing feed intake to 3·6 kg on the day of mating did not significantly affect the number of piglets born, number born live, or mean piglet weight, in either the first or second parity. In the third parity, ovulation rate, embryo number at 25 days of gestation and embryo mortality were unaffected by treatment.


2017 ◽  
Vol 57 (10) ◽  
pp. 2066 ◽  
Author(s):  
J. Araya ◽  
M. Bedos ◽  
G. Duarte ◽  
H. Hernández ◽  
M. Keller ◽  
...  

The ovulation can be induced by the introduction of a male among a group of anovulatory goats, a phenomenon called the ‘male effect’. The objective of this study was to determine whether maintaining bucks over 35 days after the initial introduction of males, improves pregnancy rate in goats. We used sexually active bucks, which were joined (n = 2 each) with three groups of goats (n = 30 each): (i) males remained with females for 15 days (Control group); (ii) males remained with females for 35 days (same buck group); (iii) males were removed at Day 23 and replaced by other males, which were not familiar to the females and which remained with females until Day 35 (new buck group). Percentage of goats ovulating did not differ among groups at Day 19 (≥87%; P = 0.12). Pregnancy rates at Day 35 did not differ between groups (≥70%; P = 0.90). At Day 55, pregnancy rates were similar in the same and new buck groups (96%; P = 1.0), but were higher than that of the Control group (73%; P < 0.05). Therefore, maintaining bucks over 35 days after the onset of the male effect improved pregnancy rate more than 20 points compared with females that remained with the same bucks for 15 days only.


Animals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 197
Author(s):  
Hiroaki Okawa ◽  
Missaka M.P. Wijayagunawardane ◽  
Peter L.A.M. Vos ◽  
Osamu Yamato ◽  
Masayasu Taniguchi ◽  
...  

This study investigated the efficacy of intrauterine infusion of a chitosan solution (CHT) on uterine recovery in early postpartum dairy cows with or without endometritis, and their subsequent reproductive performance. In Experiment 1, cows with endometritis at 3 weeks postpartum were administered CHT (n = 5) and prostaglandin F2α (PGF2α) (n = 4). Untreated cows (n = 7) served as the control group. In Experiment 2, 18 cows with a normally recovered uterus at the fresh cow check (mean, 35 days postpartum) were assigned to the CHT (n = 10) and control (n = 8) groups, and intrauterine infusion was conducted in the CHT group. Overall, in Experiment 1, the percentage of polymorphonuclear leukocytes significantly declined in the CHT group (32.3 ± 10.2 to 5.5 ± 2.4, p < 0.05) from week 3 to week 5, but no decline occurred in the PGF2α and control groups. In Experiment 2, the CHT and control groups showed no significant differences in reproductive parameters, suggesting the absence of adverse effects of CHT on fertility. These results suggest that intrauterine infusion of CHT in the early postpartum period effectively accelerates uterine recovery from endometritis and might be a suitable replacement for PGF2α administration.


1991 ◽  
Vol 53 (3) ◽  
pp. 407-409 ◽  
Author(s):  
F. Forcada ◽  
J. A. Abecia ◽  
L. Zarazaga

The attainment of puberty in September-born early-maturing ewe lambs was studied at Zaragoza (latitude 41° 40' N). Thirty twin Salz females were allocated to two groups receiving two nutrition levels after 3 months of age: high (500 g/day lucerne hay and 500 g/day concentrate) (H) and low (500 g/ day lucerne hay) (L). Oestrus was detected daily by aproned rams. Corpora lutea were counted after oestrus and plasma progesterone levels monitored each week.In the first breeding season (January to February) the percentage of females showing sexual activity (silent emulation or oestrus and ovulation) was higher in the H compared with the L group (67 and 20%; P < 0/05). Nonpubertal oestrus before the main breeding season was detected in 67% of animals. In the main breeding season and for H and L groups respectively, percentage of females showing silent ovulation before puberty was 67 and 33% and mean age at puberty extended to 319 (s.e. 4-8) and 314 (s.e. 3·7) days. Ovulation rate at puberty was 1·73 (s.e. 0·13) and 1·33 (s.e. 0·15) respectively (P < 0·05).


1979 ◽  
Vol 59 (3) ◽  
pp. 481-490 ◽  
Author(s):  
P. MATTON ◽  
V. ADELAKOUN ◽  
J. J. DUFOUR

Plasma steroids (cortisol, progesterone, estrone and estradiol) were studied during the peripartum period in cows with three different types of parturition: unifoetal normal (VUN), unifoetal with retained placenta (VRP), multifoetal with or without retained placenta (VG). In the control group, cortisol rose gradually from 8 ng/ml on day −7 to 11 ng/ml on the day of parturition and thereafter came back to the level of day −7. In the VRP group, cortisol was slightly lower than in the control on day −7 and it did not vary significantly before or after parturition. In the group of cows with multiple births, where retained placenta was encountered in 3/4 cases, cortisol was much higher than in control animals. Plasma progesterone decreased gradually from 5.5 ng/ml to less than 1 ng/ml on the day of parturition in the control group. In the group VRP and VG, it was significantly higher than in the control on the 2 days before and on the day of parturition. The patterns of estrone and estradiol were similar in the groups VUN and VRP until the first day following parturition, but much higher in the cows giving birth to twins. During the postpartum period, the drop in estrogens was much slower in the VRP and VG groups than in the VUN control group. These results suggest that retention of the placenta is not linked with the plasma concentration of cortisol but rather associated with an increased level of progesterone on the day of parturition and that the slower decrease in estrogen levels after parturition would be the result of the persisting attachment of the foetal membranes.


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