Kidding Rates Research Articles

An Enhanced Body Condition Improved Sexual Behavior, Ovarian Structure and Function, and Reproductive Fitness in Rangeland-Crossbred Dairy Goats

The possible effect of body condition score (BCS) on ovarian function, sexual behavior, (i.e., females and males; appetitive and consummative), estrus, ovulation, and reproductive performance was investigated in crossbred dairy goats under extensive conditions. Based on their BCS, female goats (n = 48) were divided into two experimental groups, either with a low (LG; 1.0 ± 0.2 units; n = 26) or with a high BCS (HG: 2.5 ± 0.9 units; n = 22). Bucks n = 4; cc = 2.5. Female sexual behavior (i.e., acceptance of anogenital sniffing and approach, flight, and tail wagging) was higher in the HG (p < 0.05). In addition, bucks exposed to HG goats showed more approach and mounting attempts (p < 0.01). There were no significant differences (p > 0.05) between the groups in either the follicular diameter or size. Interestingly, although follicular volume, pregnancy rate, kidding rate, and total number of kids born alive were higher in the HG goats (p < 0.05), there were no significant differences (p < 0.05) in fetal mortality and prolificacy between the HG and LG goats. In addition, the response variables of female ovulation, total number of corpus luteum, ovulation rate, corpus luteum diameter, and luteal tissue volume were more favorable in the HG goats (p < 0.05). Our research results demonstrate that a higher BCS improves not only the reproductive responses, but also sexual behavior (i.e., female and male). Larger ovarian structures, higher ovulation rates, higher pregnancy and kidding rates, and higher prolificacy were observed in the HG goats managed under a marginal semiarid extensive production system.

Effect of supplementation of polyunsaturated fatty acid-rich linseed grain on steroid hormones and reproduction in Goats

The effect of polyunsaturated fatty acid (PUFA)- rich linseed grain supplementation was assessed on steroid hormones and reproduction in goats. Twenty-four acyclic and clinically healthy non-descript goats were divided into 4 equal groups. Gr A(control) was supplemented with concentrate without linseed grain while Gr B, C and D were supplemented with concentrate containing 10, 15 and 20% of linseed grain respectively. Goats were supplemented during prebreeding period for 30 days. Blood samples were collected for estimation of serum estradiol and progesterone during pre-breeding and post-oestrus periods. Serum estradiol concentration (pg/ml) was significantly (P<0.05) higher in Gr B (58.79±3.62), C (70.34±5.95) and D (49.48±5.02) compared to control Gr A (38.51±4.03) on 30 days of pre-breeding period. It was significantly (P<0.05) lower in Gr B (9.61±1.45) compared to A (15.61±2.65), C (12.61±1.35) and D (12.61±2.65) on 7 days of post-oestrus period. Serum progesterone levels were comparable among the groups on 30 days of pre- breeding and on 7 days of post- oestrus period. Blood glucose level was comparable on 21 days of supplementation in pre-breeding and 0 day of postoestrus period. Conception (83.33%) and kidding (83.33%) rates were higher in Gr B compared to control Gr A (50.00 and 33.33%). The study suggested that supplementation of PUFA-rich linseed grain in concentrate @ 15% decreased the serum estradiol and increased the serum progesterone during post-oestrus period and improved the conception and kidding rates in goats.

371 Influence of Breeding Season Lameness on Reproductive Performance in Meat Goat Does

Abstract Over four years, 564 performance records from 235 does were processed to determine if lameness during the breeding season affected reproductive outcomes in meat goats. Lameness cases were recorded during routine daily herd wellness checks and treated within a short time after diagnosis. Does were bred between September and January. Kids were weaned at 3 mo of age. Fall (September-November) and winter (December-February) records were used to classify does each year as having experienced lameness (LAME) or no recorded lameness case (NOLC) by season. In the fall (F) there were 396 NOLC does and 168 LAME does. Spring kidding rates were greater (P &amp;lt; 0.05) for NOLC-F than for LAME-F (77.1 ± 4.5% vs. 67.9 ± 6.1%). Whole-herd litter size at kidding was greater (P &amp;lt; 0.05) for NOLC-F than for LAME-F (1.18 vs. 1.02 ± 0.1 kids/doe). Summer weaning rates tended to differ (P = 0.08) between the fall lameness groups (NOLC = 68 ± 3.3%; LAME = 59.5 ± 4.6%). Whole-herd litter size at weaning was greater (P &amp;lt; 0.01) for NOLC-F than for LAME-F (0.97 ± 0.05 vs. 0.78 ± 0.06 kids). In the winter (W) there were 473 NOLC does and 87 LAME does. Spring kidding rates were greater (P &amp;lt; 0.01) for NOLC-W than for LAME-W (77.6 ± 4.1% vs. 58.6 ± 7.5%). Whole-herd litter size at kidding was greater (P &amp;lt; 0.01) for NOLC-W than for LAME-W (1.17 vs. 0.9 ± 0.09 kids). Summer weaning rates was higher (P &amp;lt; 0.01) for NOLC-W than for LAME-W (68.5 ± 3.2% vs. 53.0 ± 5.9%). Whole-herd litter size at weaning was higher (P = 0.01) for NOLC-W than for LAME-W (0.95 ± 0.05 vs. 0.73 ± 0.08 kids). Results suggest that lameness in does during the breeding season may negatively impact reproductive outcomes.

Evaluation of Two Estrus Synchronization Protocols on Estrus Response, Conception, and the Kidding Rate during Lower Breeding Season for Abergele Goat in Northern Ethiopia

Reproductive technologies are applied to accelerate genetic progress and enhance the reproductive performance of various livestock species. The experiment was conducted to investigate the effect of pregnant mare serum gonadotropins (PMSGs) and prostaglandin (PGF2α) hormones on the oestrus response, conception rate, and kidding rate during the lower breeding season of the Abergele goat breed. A total of 77 Abergele does (25 for PMSG and 52 for PGF2α protocols) were used for the experiment. Experimental animals were allowed to graze (does) for approximately 8 hours and (bucks) for approximately 4 hours, followed by supplementation with a mixture of 300 to 350 g cowpea hay and wheat bran per day. For PMSG-treated does, a vaginal sponge impregnated with progesterone hormone was inserted and stayed for 12 days. After the removal of the vaginal sponge, 2 ml (400 IU) of PMSG hormone was injected for 25 does and allowed to be mated by selected bucks after 48 hours. While a single injection of PGF2α hormone was administered for 52 does and allowed for mating after 48 hours of hormone administration. The PMSG and PGF2α protocols resulted in estrus responses of 96% and 86.5%, respectively. The conception and kidding rates of does administered with the PGF2α protocol were better, with values of 57.7% and 55.8%, respectively. From the result, it was concluded that Abergele does were better responsive to both prostaglandins and gonadotropin-based protocols in inducing estrus, which can be used as an alternative approach for the improvement of the reproductive performance of goats. However, for the reason of better conception efficiency, kidding rate, and ease of application, the PGF2α protocol was found to be better responsive and effective for synchronizing Abergele does during the lower breeding season.

Assessment of estrous synchronization protocols and pregnancy specific protein B concentration for the prediction of kidding rate in Lezhi black goats

• The onset of estrus is earlier in CIDR + cPGF 2α + eCG. • GnRH treated at CIDR removal showed similar reproductive performance as CIDR + eCG. • PSPB detected with ELISA can identify does carrying four fetuses. The objectives of this study were to assess the efficacy of estrous manipulation protocols and pregnancy specific protein B (PSPB) levels to determine kid number at birth in Lezhi black goats. Eighty-eight does were randomly allocated to three treatments. The PPe group (n = 29) was treated with Controlled Internal Drug Release devices (CIDR) for 7 days and 300 IU eCG and 0.2 mg PGF 2α at the time of CIDR removal. The PPG group (n = 28) was treated with a CIDR for 7 days and 0.2 mg PGF 2α at the time of CIDR removal and 15 μg GnRH at the onset of estrus. The GPG group (n = 31) was treated with 15 μg GnRH (day 0) and 0.2 mg PGF 2α on day 7, and a second GnRH treatment at the onset of estrus. Does at estrus were hand-mated using proven bucks. Estrous response ranged from 80.6%–89.7 %. The onset of estrus for the PPe, PPG and GPG groups was 38.4 ± 1.9, 45.6 ± 1.9 and 53.8 ± 1.4 h (P < 0.05), respectively. Mean kidding rates (205.9 %–227.8 %) and kidding percentages (112.9 %–146.4 %) were not different in the three treatments. At day 85 of gestation, does carrying quadruplets had a greater (P < 0.01) plasma PSPB level than does that delivered one to three kids. In conclusion, PPG may be a useful estrous synchronization protocol in goats. PSPB concentration at day 85 of gestation could be a potential diagnostic tool for predicting quadruplets.

Differences among four meat goat breeds for doe fitness indicator traits in the southeastern United States.

Sustainable meat goat production begins with the identification and use of maternal breeds that demonstrate relatively enhanced levels of fitness under less-than-optimal conditions. The Myotonic goat is a heritage breed that is lacking in comparative assessment for female fitness. In this study, Boer ( = 73), Kiko ( = 115), Myotonic ( = 80), and Spanish ( = 114) meat goat does were compared for traits associated with health and reproduction. The herd was semi-intensively managed on humid subtropical pasture for 6 yr. The study included 838 doe-year matings and over 2,000 records for BW, fecal egg count (FEC), and packed cell volume (PCV). Body weights of Boer and Kiko does were heavier ( < 0.05) than for Spanish does, which, in turn, were heavier ( < 0.05) than for Myotonic does. In production does, FEC were lower ( < 0.05) for Myotonic does than for Boer does, whereas Kiko and Spanish does had intermediate FEC that differed ( < 0.05) from Myotonic and Boer does. Kiko, Myotonic, and Spanish does had greater ( < 0.05) PCV than Boer does. Doe age and physiological status also affected ( < 0.05) BW, FEC, and PCV. Annual kidding rates, weaning rates, doe retention rates, and kid crop weaned were greater ( < 0.05) for Kiko and Spanish does than for Boer does, whereas Myotonic does were intermediate and differed ( < 0.05) from the other 3 breeds. The results suggest that Kiko and Spanish does should be preferred over Boer and Myotonic does for sustainable meat goat doe performance under limited-input management conditions. Myotonic does maintained the lowest FEC among all doe breeds and warrant further evaluation as a genetic resource for controlling gastrointestinal parasitism.

Some reproductive, lactation, and kid growth characteristics ofKilis goats under semiintensive conditions

This study was carried out to determine some reproductive and kid growth characteristics as well as some lactation traits of Kilis goats raised under semiintensive conditions in Kilis Province in Turkey. The animal material of the study comprised 502, 698, and 753 heads of Kilis goats in 2013, 2014, and 2015, respectively. At the end of study, multiple birth rates were calculated between 31.5% and 35.7% during the years. Lactation length and lactation milk yield were determined to be between 207.1 ± 0.81 and 232.4 ± 0.65 days and between 315.7 ± 4.16 l and 375.6 ± 3.4 L, respectively during the years. Lactation characteristics of the goats changed due to lactation number. Birth and weaning weights were found as 3.6 ± 0.02 kg and 12.3 ± 0.04 kg, respectively. It was also detected that birth weight was affected by year, sex, birth type, and farm diversity while weaning weight was not affected by birth type. It was concluded that the Kilis goat has satisfactory milk yield and multiple kidding rates in semiintensive conditions in Kilis Province.

Polymorphism and nucleotide sequencing of BMPR1B gene in prolific Assam hill goat

Assam hill goat (Capra hircus) is a prolific local goat in India. bone morphogenetic protein receptor (BMPR1B) gene was studied as a candidate gene for the prolificacy of goats. The objective of the present study was to detect the incidence of mutation in the exonic region of BMPR1B gene of Assam hill goat. Total 90 blood samples were collected randomly from different parts of Assam and genomic DNA were extracted using phenol-chloroform method. The quantity and quality of extracted DNA was examined by spectrophotometry and gel electrophoresis, respectively. PCR amplicon showed a product of 140 bp fragment of BMPR1B gene. The purified product upon digestion with AvaII showed monomorphic banding pattern and revealed wild type alleles with AA genotype. Nucleotide sequencing showed one new mutation 773 (G→C) which is found to be unique in Assam hill goat. Construction of tree at nucleotide level generates from the present experiment lies in common cluster which differs from the other breeds of goat. The analysis of polymorphism for BMPR1B in Assam hill goat indicates that the genetic factor responsible for prolificacy or multiple kidding rates is not related to the reported mutated alleles of BMPR1B gene. Therefore, attempts to be made to detect other SNPs for BMPR1B gene or otherwise effort should be made towards other fecundity gene which might be responsible for the prolificacy of Assam hill goat.

NCSynch: A novel, progestagen-free protocol for ovulation synchronization and timed artificial insemination in goats

The objective of this study was to compare overall pregnancy success achieved using a combined ovulation synchronization-timed artificial insemination (NCSynch-TAI) protocol with that obtained using estrus synchronization and artificial insemination (AI). Multiparous Boer and Boer-cross does (n=132) were randomly assigned within age (year 1) or parity (years 2 and 3) to one of two treatments. Control does received 15mg prostaglandin F (PGF; Lutalyse®) on days 1 and 10 of treatment. Estrus onset was checked twice daily with separately penned, intact bucks (year 1) or a vasectomized buck penned with the does (years 2 and 3). Control does were bred by AI 12h after estrus onset using frozen semen. NCSynch-TAI does received 15mg PGF on day 1 of treatment. Does received 50μg GnRH (Cystorelin®) on day 8, and 15mg PGF was given on day 15. On day 18, NCSynch-TAI does were appointment bred using frozen semen and received 50μg GnRH at breeding. Pregnancy status was determined using transabdominal ultrasonagraphy with kidding rates also recorded. In year 1, 13 of 15 control does (87%) were detected in estrus with 8 pregnant to AI for an overall pregnancy rate of 53%. For NCSynch-TAI, 15 does were bred and 11 (73%) became pregnant. In year 2, 24 of 26 controls (92%) were detected in estrus with 19 pregnant to AI (73% overall pregnancy rate). For NCSynch-TAI, 26 does were bred and 20 (77%) became pregnant. In year 3, 21 of 25 controls (84%) were detected in estrus with 8 pregnant to AI (32% overall pregnancy rate). For NCSynch-TAI, 25 does were bred and 14 (56%) became pregnant. Across all years, the overall pregnancy rate for NCSynch-TAI does (45/66, 68%) did not differ (P=0.075) compared to controls (35/66; 53%). Kidding rates for the two treatments (68% vs. 51%, respectively) also did not differ (P=0.075). In summary, pregnancy success following the use of NCSynch-TAI was comparable to that obtained when does were bred based on detection of estrus.

Efficiency of donor cell preparation and recipient oocyte source for production of transgenic cloned dairy goats harboring human lactoferrin

The objective was to investigate the effects of the transgenic donor cell synchronization method, oocyte sources, and other factors, on production of hLF-gene nucleus transfer dairy goats. Three transfected cell lines from ear biopsies from three 3-mo-old Saanen dairy goats (designated Number 1, Number 2, and Number 3, respectively) were selected as karyoplast donors for somatic cell nuclear transfer (SCNT) after detailed identification (including PCR and sequencing of PCR products). In donor cell cycle synchronization studies, the apoptosis rate of hLF transgenic fibroblasts was not different (P > 0.05) after 3 days of serum starvation or 2 days of contact inhibition. Additionally, there was no effect (P > 0.05) on developmental capacity of reconstructed embryos; however, the kidding rate of recipients in the serum starvation group was higher than that in the contact inhibition group (18 vs. 0%, respectively). The production efficiency of the transgenic cloned goats using donor cells from the Number 1 dairy goat cell line was higher than those using the Number 2 and the Number 3 cell lines (kidding rates were 18, 2, and 0%, respectively, P < 0.05). The oocyte source did not significantly affect the pregnancy rate of hLF-transgenic cloned dairy goats, but more fetuses were aborted when using in vitro matured oocytes compared to in vivo matured oocytes. In summary, utilizing transfected 3-mo-old dairy goat fibroblasts as donor cells, seven live offspring were produced, and the hLF gene was successfully integrated. This study provided additional insights into preparation of donor cells and recipient oocytes for producing transgenic cloned goats through SCNT.

Studies on farmer awareness on caprine abortion and the presence of Brucella abortus and Brucella melitensis in selected flocks in an arid zone of Nigeria

A survey was conducted to evaluate farmer’s awareness on caprine abortion and the occurrence of Brucella abortus and Brucella melitensis in flocks in the arid zone of Nigeria. The survey revealed that 80% of the flocks studied had a mean kidding rate of 3 per 2 years, while 19% had a rate of 1 per year. The result also showed that 47% of the farmers use deep burial, 11% discards aborted materials freely, only 3% of farmers burn the foetuses and 15% do not bother at all. The survey further revealed that 42% of farmers seek veterinary assistance, 30% employ the use of local remedies, while 10% were not aware of the availability of veterinary care. Of the 250 blood samples screened, the result showed that 3.2 and 5.6% of the samples were positive for antibodies against B. melitensis antigen using Rose Bengal plate test (RBPT) and complement fixation test (CFT), respectively. Whereas, 1.6 and 3.2% tested positive for antibodies against B. abortus antigen with RBPT and CFT respectively at a titre level >10. The results also demonstrate the superiority of the CFT over the RBPT. Sex predisposition was particularly not significant (P< 0.05) in this study. There was a moderate level of awareness among farmers in this area and considerable low reproductive efficiency in goats as a consequence of poor kidding rates. The study identified farmer education as a possible risk factor for caprine abortion and lowered fertility. It was concluded that caprine brucellosis is still endemic in Nigeria and that B. abortus antibodies exist in goats, thus underscoring the need to separate goats from cattle during grazing or housing. Key words: Abortion, Brucella abortus, Brucella melitensis, goats, Nigeria.

Fixed-time deep uterine insemination in PGF2α-synchronized goats

The aim of this investigation was to optimize fixed-time insemination in goats by clustering ovulations in prostaglandin F2α-synchronized goats either with gonadotropin releasing hormone (GnRH) or human chorionic gonadotropin (hCG). The underlying intention was to reduce the incidence of short cycles by providing a more sustained stimulation of the corpus luteum by substituting the commonly used GnRH with longer-acting hCG. It was conjectured that this might render the corpus luteum less prone to premature regression. Sixty pluriparous does were administered 5 mg of the prostaglandin F2α preparation dinoprost (Dinolytic; Pharmacia and Upjohn, Erlangen, Germany) during the luteal phase of the estrous cycle. Twenty of these does were administered 0.004 mg of the GnRH analog buserelin (Receptal; Intervet, Unterschleissheim, Germany) 48 hours later; another 20 does received 500 IU hCG (Chorulon; Intervet, Unterschleissheim, Germany) instead. Sixteen hours later the does were inseminated with frozen-thawed semen. The remaining 20 does served as controls and were inseminated 16–18 h after the onset of detected estrus. All 60 treated goats displayed estrous symptoms, the time of onset being similar for all groups (42.6, 37.6, and 40.5 hours after treatment for GnRH-treated, hCG-treated, and control does, respectively). The duration of estrus in the GnRH-treated group was 10 h less than in the other groups (45.1 vs. 56.4 and 54.4 h, P < 0.05). The number of ovulations (assessed by ultrasound monitoring) did not differ among groups (2.4, 2.1, and 2.5, P > 0.05). Monitoring of serum progesterone revealed that the incidence of corpus luteum insufficiency was significantly higher in GnRH- and hCG-treated does than in the control group (40% and 35% vs. 5%, P < 0.05). The pregnancy rate was 50% in the GnRH and 35% in the hCG group as compared with 60% in the controls. Corresponding kidding rates were 40%, 35%, and 60% (P > 0.05). When disregarding does with corpus luteum insufficiency, pregnancy rates would have been 83%, 54%, and 63%, and kidding rates 67%, 54%, and 63%, respectively. The average number of kids born was 1.88, 1.71, and 1.83, respectively (P > 0.05). It may be concluded that fixed time insemination of cycling does treated with prostaglandin F2α during the luteal phase, followed by ovulation induction with GnRH or hCG, would be an effective management tool if it were possible to control the high incidence of corpus luteum insufficiency. The attempt to achieve this by substituting GnRH with hCG, was not met with success. Until a solution for the problem has been found, it is advisable to inseminate prostaglandin-synchronized does 16–18 hours after the onset of detected estrus.

Vaginal deposition of frozen-thawed semen in Norwegian Dairy goats: Comparison of single and double insemination with equal total number of spermatozoa

In a field trial, a total of 472 Norwegian Dairy goats showing natural estrus were artificially inseminated with frozen-thawed semen. The farmers themselves performed vaginal deposition of 400 × 10 6 spermatozoa; one half of the does received two straws (200 × 10 6 spermatozoa/straw) at the same time (single AI), while the other half received two straws (200 × 10 6 spermatozoa/straw) 12 h apart (double AI). The commercially available extender Andromed ® was used for dilution. The does were housed at 15 different farms, and on average 31 does were inseminated per farm. Non return rates (NRR) and kidding rates after single insemination were 64.3% and 58.3%, respectively. Double inseminations resulted in a NRR of 62% and a kidding rate of 57%. No significant difference between single and double AI was seen in the study. This study indicates that single or double vaginal insemination with an equal total number of frozen-thawed spermatozoa (400 × 10 6) can give acceptable fertility results in Norwegian Dairy goats. However, studies on reducing sperm numbers are called for to allow AI donor bucks to be used to their fullest potential.

Oestrus synchronization with short-term and long-term progestagen treatments in goats: the use of GnRH prior to short-term progestagen treatment

The aim of the present study was to determine the efficacy of the synchronization of oestrus using short- and long-term progestagen treatments in Hair goats at the onset of the breeding season, and to evaluate the effect of the exogenous GnRH administration immediately prior to short-term progestagen treatment on the reproductive performance. A total of 75 Hair goats, aged 2.5–5 years-old were used in this experiment. Goats were divided equally into three groups (n=25 per group). Animals in LT-FGA (long-term progestagen treatment), ST-FGA (short-term progestagen treatment) and Gn-ST-FGA (GnRH-short-term progestagen treatment) groups received an intravaginal sponge (day 0) containing 30 mg fluorogestone acetate (FGA) for 14, 8 and 8 days, respectively, plus 75 µg cloprostenol i.m. 24 h before sponge removal and 400 I.U. equine chorionic gonadotrophin (eCG) i.m. at the time of sponge removal. In addition, the goats in the Gn-ST-FGA group received 10.5 µg busereline acetate i.m. at the time of sponge insertion (day 0). Oestrus response for all treatment groups was 100%. The mean interval from sponge removal and the onset of oestrus for the LT-FGA, ST-FGA and Gn-ST-FGA groups was 28.0±1.0 h, 28.8±1.1 h and 33.1±2.0 h, respectively. No significant difference in onset of oestrus among groups was recorded. The pregnancy rate, kidding rate, multiple kidding rates and litter size were 72.0, 61.1, 45.5% and 1.6 in the LT-FGA, 70.8, 76.5, 69.2% and 1.8 in the ST-FGA and 58.3, 78.6, 63.6% and 1.6 in the Gn-ST-FGA groups, respectively. The pregnancy rates were similar in the LT-FGA (72.0%) and ST-FGA (70.8%). However, the kidding rate, multiple kidding rates and litter size were numerically higher in the ST-FGA (76.5%, 69.2% and 1.8, respectively) group than in the LT-FGA (61.1%, 45.5% and 1.6, respectively) group. Although not statistically different, pregnancy rate and litter size was lower in the Gn-ST-FGA group (58.3% and 1.6, respectively) compared with the ST-FGA (70.8% and 1.8, respectively).In conclusion, it can be said that oestrus synhcronization with long-term progestagen treatment (14 d-FGA- PGF2α- eCG) could be replaced with short-term progestagen treatment (8 d-FGA-PGF2α- eCG) without a reduction in oestrus rate and fertility parameters in lactating goats at the beginning of breeding season. However, the use of GnRH prior to short-term progestagen treatment (8 d-FGA-PGF2α- eCG) do not have a positive effect on fertility parameters in goats.

Successful artificial insemination using semen frozen and stored by an ultrafreezer in the Majorera goat breed

The semen of five Majorera breed bucks was collected and processed to reach a final concentration of 200 × 10 6 spermatozoa/straw in the extender containing 4% of glycerol and 12% of egg yolk. Two freezing techniques were assessed: (LN) straws were frozen and stored in liquid nitrogen, and (ULF) straws were frozen and stored in the ultra-low freezer at −152 °C. Semen quality (sperm motility, acrosome integrity and abnormal sperm cells percentages) was determined for different storage times (1, 30, 90 and 365 days of cryopreservation). Thereafter, 150 Majorera goats were assigned to four experimental groups: for groups LN-1 ( n = 40) and LN-6 ( n = 35), the goats were transcervically inseminated with frozen-thawed semen stored for 1 and 6 months in liquid nitrogen, respectively, while for groups ULF-1 ( n = 40) and ULF-6 ( n = 35), the goats were transcervically inseminated with frozen-thawed semen stored for 1 and 6 months in an ultra-low freezer at −152 °C, respectively. The pregnancy rate was determined by transabdominal ultrasound scanning; in addition, the kidding rate and prolificacy were recorded at parturition. In vitro results showed that the freezing protocol did not affect sperm quality with similar values for up to 1 year of cryopreservation. The kidding rates were not significantly different between experimental groups (43.6%, 38.5%, 42.8% and 40.0% for groups LN-1, ULF-1, LN-6 and ULF-6, respectively). In all experimental groups, the kidding rate and prolificacy were significantly higher ( p < 0.01) in multiparous than in nulliparous goats. Therefore, the in vitro results and fertility trials confirmed the efficiency of the ULF technique for freezing and storage of goat semen.

Productivity of Angora goats in the communal rangelands of Molimo-Nthuse area in Lesotho

Production parameters were determined for kidding, offtake and mortality rates, and milk production and composition of Angora goats in two communal agro-ecological zones, Mountains and Lowlands, of Molimo-nthuse area in Lesotho. True incidence rates and risk rates as used in dynamic populations were used to calculate the different production parameters. A completely randomized design was used to compare the differences between the two agro-ecological zones. Angora goats in the two agro-ecological zones produced milk similarly (p > 0.05) in amounts and composition. There were no significant (p > 0.05) differences in annual kidding, mortality and offtake rates between Angora goats kept in the Lowlands and those in the Mountains. However, high mortality rates and mortality risk rates were observed in both zones. Thus, the risk rates that suckling Angora goats would die within their first 6 months after birth were 28% and 34% for the Mountains and Lowlands, respectively. It is suggested that future emphasis should be on reducing kid mortality through better herding of the goats and improvement of pre- and post-partum nutrition of the doe in this communal livestock farming system.

The effects of progesterone priming on reproductive performance of GnRH-PGF2α-treated anestrous goats

The objective of this experiment was to determine the effect of a 5-day progesterone priming prior to a GnRH-PGF2alpha treatment on reproductive performance of anestrous goats. Thirty-six Mountain Black goats were randomly assigned in a 2 x 2 factorial arrangement and were administered intravaginally on day -12, either with 300 mg progesterone inserts (CGPE and CGP) or with 0 mg progesterone (GPE and GP) for 5 days. On day -6, the goats were injected with 100 microg GnRH, followed 6 days later by 15 mg PGF2alpha (day 0), the time at which the goats in the CGPE and GPE groups were administered 300 IU eCG injections and those in CGP and GP groups were administered the control solution. The goats were exposed to four fertile bucks at 0 h and were checked for breeding marks at 6-h intervals for 72 h. Blood samples were collected from all goats for progesterone analysis. Progesterone concentrations increased only in CGPE and CGP during the period of device insertion but remained low in GPE and GP groups (P < 0.001). Progesterone levels at the time of GnRH injection on day -6 were basal (0.2 +/- 0.04 ng.mL-1) among the groups and began to increase starting on day -2. Day 0 progesterone concentrations differed (P < 0.05) among groups and were significantly influenced by CIDR-G (P < 0.001). A similar proportion of goats expressed estrus and intervals to detected estrus were shorter (P < 0.05) in the CGPE and GPE groups than in GP with no difference between the CGPE, CGP and GPE or between CGP and GP groups. The number of goats ovulating based upon elevated progesterone levels on day 0 was significantly greater (P = 0.002) in CGPE (9/9) and CGP (9/9) than GPE (6/9) and GP (5/9) groups and was significantly influenced by CIDR-G (P = 0.03). All pregnant goats had elevated progesterone concentration on day 0 and none of the goats with basal progesterone levels became pregnant. Pregnancy and kidding rates, twinning percentage and the number of kids born per goat exposed were greater (P < 0.05) among goats treated with progesterone and eCG. In conclusion, progesterone priming and eCG are essential for producing higher rates of pregnancy and kidding in GnRH-PGF2alpha-treated anestrous goats.

Pellet-freezing of Damascus goat semen in a chemically defined extender

During the breeding season of goats (12 bucks and 64 does) in Egypt, five experiments were conducted using a chemically defined cryoextender (CDE) to investigate: (1) the influence of rates of semen dilution (1:2, 1:4 and 1:19) and methods of thawing of frozen semen pellets (dry thawing versus wet thawing) on sperm progressive motility (SPM), sperm acrosome abnormalities (SAA) and rate of lipid peroxidation in semen as measured by malonaldehyde (MAL) production, and (2) the effect of insemination of does in natural ( n = 38) and cloprostenol-synchronized ( n = 26) estrus with frozen semen on their kidding rates and prolificacy. Semen (two successive ejaculates/buck) was collected twice a week via an AV and only ejaculates of >2500 × 10 6 sperm/ml and 70% SPM were diluted in one step at 30 °C with the CDE, cooled to 5 °C over a 4 h-period, frozen in the form of 0.30 ml pellets and stored in liquid nitrogen for 72 h. The results revealed that post-thaw SPM of semen diluted at a rate of 1:4 was significantly ( P < 0.01) higher than that of semen diluted at the other rates. Dilution of semen at a rate of 1:19 (≤151 × 10 6 sperm/ml) not only minimized ( P < 0.01) pre-freeze and post-thaw SPM, but also augmented ( P < 0.01) pre-freeze and post-thaw rates of lipid peroxidation as evidenced by the high level of MAL production and the ability of antioxidants (1 mg/ml EDTA, 200 U/ml bovine liver catalase, 0.61 mg/ml reduced glutathione and 0.11 mg/ml sodium pyruvate) to restore ( P < 0.01) pre-freeze and post-thaw SPM. Frozen semen pellets exposed to dry thawing had a greater percentage of SPM ( P < 0.01) as well as lower values of SAA and MAL ( P < 0.01) than those exposed to wet thawing. Although the kidding rates did not vary significantly among does in natural (55.26%) and synchronized (53.85%) estrus, a higher ( P < 0.05) prolificacy was obtained after their insemination in natural (1.81 ± 0.16) rather than in synchronized (1.22 ± 0.11) estrus.

Effect of cervical and vaginal insemination with liquid semen stored at room temperature on fertility of goats

The effect of vaginal and cervical deposition of liquid semen stored at room temperature on the fertility of goats was tested in a field trial in which 217 Norwegian Dairy goats aged between 6 months and 7.5 years from 14 farms were inseminated after natural oestrous. Cervical insemination with 200 × 10 6 spermatozoa resulted in 25-day non-return and kidding rates of 87.0 and 78.0%, and vaginal insemination gave 85.5 and 74.3%, respectively. There was no significant difference between the cervical and vaginal inseminations ( P = 0.59 for the 25-day non-return and P = 0.40 for the kidding rates). Farm had a significant effect on the 25-day non-return rate ( P = 0.03) but not on the kidding rate ( P = 0.07). There were no significant differences between the fertility rates for different bucks ( P = 0.36 for the 25-day non-return and P = 0.15 for the kidding rates). Fertility results after vaginal insemination were encouragingly high. Vaginal insemination is a simple, less costly and time consuming technique compared to others, also bringing into focus the animal welfare aspects of the artificial insemination procedure. As the final goal is to establish a technique that could be applied similarly on a large scale by all farmers, vaginal insemination must be considered as a method that would simplify the use of liquid buck semen in Norway.

Risk factors involved in conception, abortion, and kidding rates of goats under extensive conditions

Multiple logistic regressions were used to investigate the effect of body weight, certain body measurements, lactation, parity, polledness, and certain blood minerals and metabolites at mating on the reproductive performance of does. Data were obtained from 374 brucellosis-free mixed-breed does of different ages and parities and kept under natural range conditions. Body condition score (BCS) was not a risk factor regarding pregnancy, but compared to all other does, the thinnest goats (BCS<1.5; 5-point scale) were nine times more likely to abort. Trends were noted for the youngest does to have a higher risk of aborting (four times higher). Polled goats had a 1.5 times higher chance of aborting. Goats with serum Ca concentrations >10 mg per 100 ml and urea >10 mg per 100 ml were twice as likely to abort than goats with lower levels of these blood components. Goats with serum glucose concentrations >60 mg per 100 ml had twice higher odds of kidding, compared to goats with lower serum glucose concentrations. Primiparous does were three times less likely to kid than multiparous does. Other variables significantly ( P<0.05) associated with kidding rate were BCS, serum urea, creatinine levels and polledness. Pregnancy was more likely to occur in goats with serum Mg levels >4 mg per 100 ml, serum urea between 6 and 10 mg per 100 ml, serum glucose >60 mg per 100 ml, and serum Ca >10 mg per 100 ml. Results of this study emphasize the importance of removing risk factors such as low body energy reserves, low serum glucose levels, young does, polled animals and low Mg and Ca intake at mating as a possible means for improving the reproductive performance of goats under natural range conditions.