scholarly journals A new parameter describing fertility in rabbits at the farm level: the kit index

2018 ◽  
Vol 61 (4) ◽  
pp. 463-467 ◽  
Author(s):  
Steffen Hoy

Abstract. The kit index (KI) combines the kindling rate (KR) and the average litter size (LS) per group of does, per breeding round, per year, or per farm and represents the number of total or live-born kits per 100 inseminated does. The KR is the percentage of kindlings per number of inseminated does. Mathematically, the KI is the product of the KR multiplied by the average LS. The KI was calculated on the basis of 12 730 inseminated does and 89 864 live-born kits from one rabbit farm during a 25-month period from 2015 to 2017. The average KR was 70.1±9.1 % with a minimum (per breeding round) of 35.4 % and a maximum of 90.8 %. The average LS of total kits born was 9.16±0.91, whilst the average litter size of live-born kits was 8.87±0.90. The KI of total kits born was calculated to be 649± 121 kits per 100 inseminated does (min of 332, max of 971), while the KI of live-born kits ranged between 326 and 944 kits per 100 inseminated does (mean of 626±122). The KI is a normally distributed parameter with respect to both the total kits born and the live-born kits per 100 inseminated does. All three parameters (KR, LS, and KI) were characterized by large variations from week to week with a tendency toward a reduction in the summer months. No difference was found between the two housing units, but large differences were found between the two genetic strains used on the given farm. Therefore, it can be concluded that the KI is able to characterize the complex fertility situation on the given rabbit farm. The KI can be used to demonstrate and to solve problems regarding artificial insemination, in addition to general issues with insemination management.

2021 ◽  
Vol 52 (5) ◽  
Author(s):  
Jani Mavromati ◽  
Luigj Turmalaj

This study was conducted on a central Albanian pig farm with a capacity of 80 sows. A uniform distribution of piglets born and the number of reared piglets sold every week and month was the target. To achieve this goal, a hormone-based synchronization scheme was used, combined with the use of one, two, or three artificial insemination sessions during the same oestrus. The main reproduction indices of sows were monitored, and the results indicated that the farrowing rate after the first insemination was 78.57%, 83.64% and 83.33% for the three groups in which one, two and three artificial insemination sessions were used during the same oestrus, obtained by inoculation with the hormone Sergon PG 400/200 IU. Average litter size (the number of live born piglets) per farrowing sow was 10.22 ± 0.33, 10.8 ± 0.2 and 10.6 ± 0.3 in the three groups, respectively. The fecundity index (FI) was 803, 905.8 and 883.3 in the three experimental groups of sows, respectively. A total of 1436 piglets from 136 farrowing sows were sold during 2018, achieving uniform sales of over 100 pigs per month with a weight over 90 kg. Therefore, it can be concluded that oestrus synchronization of sows with the Sergon PG 400/200 hormone can achieve a uniform distribution of piglets born and consequently a uniform distribution of piglets sales per week or month, regardless of the fact that this should be achieved at a larger scale. The best result as seen in the reproductive indicators was achieved by the use of artificial insemination with two sperm inoculations at a 12-hour interval during the same oestrus, synchronized by the Sergon PG 400/200 hormone.


2019 ◽  
Vol 3 (2) ◽  
pp. 885-892
Author(s):  
Marie Louise M Pedersen ◽  
Ingela H Velander ◽  
Mai Britt F Nielsen ◽  
Nils Lundeheim ◽  
Bjarne Nielsen

Abstract In pig production, Pietrain and Duroc lines are often used as terminal sire lines to produce crossbred slaughter pigs. The objective of this study was to identify the differences in paternal fertility and mortality during the suckling period of crossbred progeny from Pietrain and Duroc terminal sire lines. In total, 87 purebred Duroc boars and 68 purebred Pietrain boars were used as terminal sires to produce 1,823 crossbred Duroc litters (D-litters) and 1,705 crossbred Pietrain litters (P-litters) in two production herds. The sows were crosses between DanBred Landrace and Yorkshire (F1). All boars were kept at the same artificial insemination (AI) station, and all semen doses were produced in the same laboratory. The experiment was balanced according to herd, boars, and time, with approximately 13 sows from each herd mated to each boar within each breed. The results showed higher fertility expressed as litter size at birth in P-litters compared with D-litters led to 0.5 higher total number born (TNB) for P-litters (P = 0.0076). However, piglet mortality including number of stillborn piglets was lower in D-litters compared with P-litters (P < 0.0001), and 5 d after farrowing, the average litter size in P-litters ranged 0.4 below the litter size in D-litters (P < 0.027). At 21 d after birth, mean litter size in P- and D-litters were 14.5 and 14.9 piglets per litter, respectively (P < 0.015). This indicated that Pietrain progenies were weaker than Duroc progenies, and it was concluded that use of Duroc boars as the terminal sire line led to lower piglet mortality. In the two herds, the mean piglet mortality rate including still born piglets ranged from 19.5% to 23.6% and from 17.6% to 19.1% in P- and D-litters, respectively.


2013 ◽  
Vol 82 (1) ◽  
pp. 38-43 ◽  
Author(s):  
E. Wydooghe ◽  
E. Berghmans ◽  
T. Rijsselaere ◽  
A. Van Soom

Dystocia may occur in all dog breeds, but the English bulldog is predisposed because of its conformation and specific problems such as anasarca pups. In this study, the frequency of abnormal pups and breeding problems in English bulldogs was investigated by a questionnaire containing information on 39 bitches in total. In 74.4% of these bitches, artificial insemination was performed. At the end of gestation, 25.8% of the bitches suffered from respiratory problems and partial anorexia. The average duration of gestation was 58.7 days counted from the first day of mating. Caesarean section was performed in 94.8% of the cases, with natural delivery in only 5.2% of the bitches. In this study, the average litter size was six pups. Thirteen percent of the pups were stillborn, 8.2% of the pups alive were deformed, with palatoschisis (38.8%) and anasarca (27.7%) being the most commonly observed abnormalities. Ten percent of the pups died before the age of weaning.


Reproduction ◽  
2000 ◽  
pp. 361-366 ◽  
Author(s):  
E Ubilla ◽  
PG Rebollar ◽  
D Pazo ◽  
AI Esquifino ◽  
JM Alvarino

The effects of a transient doe-litter separation on plasma prolactin, FSH and oestradiol concentrations, as well as the effect on LH response to exogenous GnRH administered at the time of artificial insemination, were determined in nursing rabbits. The effects on fertility, and litter size after parturition, as well as litter survival after doe-litter separation, were also studied. Control does (n = 12) had free access to nursing, whereas biostimulated does (n = 12) were separated from their litters for 48 h before artificial insemination. Plasma prolactin concentrations were decreased 24 h after the doe-litter separation (P < 0.05). The response of prolactin to suckling reached 10 times the basal values measured on day 10 after parturition (P < 0.0001). Increased oestradiol concentrations were found during the 48 h after the doe-litter separation: at 0 h, before artificial insemination (P< 0. 0001), 1.0-2.0 h after artificial insemination (P < 0.001), at 2.5 h (P < 0.05), 3.0 h (P < 0.01), and at 3.5 h (P < 0.05) after artificial insemination. Exogenous GnRH administered at the time of artificial insemination caused a greater LH response in does previously separated from their litters during 48 h (P < 0.01). The transient doe-litter separation did not affect plasma FSH concentrations, fertility, litter size or litter survival. These results suggest that a transient separation of nursing does from their litters before artificial insemination results in a decrease in plasma prolactin concentrations that could promote growth of follicular waves, and high steroidogenesis activity, leading to increased oestradiol concentrations and inducing higher sensitivity of the pituitary gland to exogenous GnRH. These findings associated to the absence of suckling episodes would lead to higher LH response and, therefore, exert a major effect on fertility.


Author(s):  
Tshepo Teele

Background: This study aimed to investigate the influences of sexual preparation on the effects of boars’ semen viability on the fertilization capacity of artificially inseminated sows. After all, boar sires more pigs than farrowed by a sow which the boar has been mated to improve reproductive parameters in response to AI. Methods: The semen viability of boars were studied during various sexual stimulations and analyzed during the study period. Sperm rich fractions were collected and separated at every level of sexual stimulation during the morning (08:30) and the afternoon (14:30) hours, respectively. Artificial insemination was performed following three levels of sexual preparations of boars (0 minutes of sexual restraint (MSR), 5 MSR and 10 MSR) before semen collection. Receptive sows were inseminated and evaluated for fertility traits using non-return rate, farrowing rate and litter size. Result: The non-return rate was recorded as a percentage of sows conceived after insemination over the total number of sows inseminated. The farrowing rate was recorded as a percentage of sows that farrows over the number of sows conceived and litter size as several live piglets per sow. Sexual desire was influenced by sexual preparations and significantly influenced the fertility of the artificially inseminated sows. This study is of practical significance to the animal breeder mainly because boars have greater influence than sows on the average litter size and live piglets. The study concludes that the use of at least 5 to 10 minutes of sexual restraint during the afternoon periods prior to semen collection and artificial insemination is found to be a practical method for optimizing sperm viability and fertility of sows in the intensive system.


1956 ◽  
Vol 34 (4) ◽  
pp. 273-281 ◽  
Author(s):  
Wm. Rowan ◽  
L. B. Keith

In conjunction with studies of the "10-year cycle" of snowshoe hares, almost 900 hares were collected in the Anzac district of Alberta during the period May, 1949, to April, 1956. Embryo numbers and sex ratios were among the data gathered from post-mortem examinations of these hares. It was found that the average litter size was 3.82; the modal litter size was four and the range was from one to seven. The average number of litters each season was calculated at 2.75. The annual reproductive potential is thus 10.51 (3.82 × 2.75) young per female hare. This is more than 50% greater than that indicated by comparable data from Minnesota. It is suggested that herein lies the cause of higher peak populations in northern regions. Sex ratios shifted from a marked excess of females in the year 1949–1950 to about even numbers of both sexes during the two subsequent years. Since the change in sex ratio occurred at the peak of the cycle, the two factors are believed to be in some manner correlated.


Author(s):  
Mark P. Mooney ◽  
H. Losken Wolfgang ◽  
Michael I. Siegel ◽  
Janice F. Lalikos ◽  
Albert Losken ◽  
...  

The lack of an animal model of congenital coronal suture (CS) synostosis has prompted the widespread use of an experimental rabbit model using adhesive Immobilization of the CS. Such postnatal models have helped make significant scientific contributions but may still not fully represent all aspects of the human congenital condition. In the March 1993 issue of The Cleft Palate-Craniofacial Journal we reported a female rabbit born in our laboratory with complete bilateral CS synostosis. This follow-up study presents our attempts to breed this animal and establish a strain of cranlosynostotic rabbits. To date, we have accomplished 10 back- and intercrosses with these animals and have produced a total of 71 live offspring; 10 animals exhibited complete nonsyndromic unilateral (plagiocephalic) or bilateral (brachycephalic) CS synostotic deformities at birth, and 19 animals exhibited partial CS synostosis that showed more than 75% growth retardation across the CS (well below the 95% confidence interval for normals). Results revealed that gestational time and litter size averages were consistent with those reported for the strain, although the average litter size decreased with increased inbreeding. By 1.5 weeks of age the completely synostosed animals already exhibited brachycephalic cranial vaults and midfacial hypoplasia compared to unaffected siblings. Initial pedigree analysis suggested an autosomal dominant inheritance pattern with incomplete penetrance and variable expressivity. The development of such a congenital rabbit model may prove useful In helping to understand the etiopathogenesis of this condition In human populations.


1991 ◽  
Vol 71 (2) ◽  
pp. 589-591 ◽  
Author(s):  
R. N. Kirkwood ◽  
P. A. Thacker

One hundred gilts and one hundred mixed-parity sows of Yorkshire and Landrace breeding were inseminated with semen with or without an additional 10 μg estradiol-17β. Pregnancy rates of gilts receiving estradiol-supplemented and control semen were 90 and 79%, respectively (P < 0.09). The estradiol supplementation of semen did not improve the pregnancy rates or litter size in sows. Key words: Swine, artificial insemination, estradiol


1991 ◽  
Vol 71 (1) ◽  
pp. 237-239 ◽  
Author(s):  
P. A. Thacker ◽  
A. D. Gooneratne ◽  
R. N. Kirkwood

Pregnancy rates and litter sizes following insemination of sows with fresh-extended and frozen-thawed semen averaged 71 vs. 53% and 10.6 vs. 4.4, respectively, and was not affected by the addition of 12.5 μg relaxin to semen. These results indicate no relaxin mediated effect on either pregnancy rate or litter size when sows are artificially inseminated with relaxin-supplemented semen. Key words: Artificial insemination, relaxin, sows


1981 ◽  
Vol 32 (2) ◽  
pp. 227-229 ◽  
Author(s):  
A. Lahlou-Kassi ◽  
M. Marie

ABSTRACTThe elements of prolificacy have been analysed for the D'man sheep, a prolific Moroccan breed, by laparotomy on 38 animals. The average ovulation rate was 2·50 (s.e.0·45); a slight difference was observed between nulliparous and multiparous ewes due to high simultaneous activity by both ovaries in the latter group. Embryonic survival (42% overall) was 94% (87 to 100%) for multiparous and 44% (36 to 52%) for the nulliparous ewes at one ovulation, decreasing with increasing numbers of corpora lutea. The average litter size showed an optimum at four ovulations.


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