Synchronisation of oestrus in indigenous goats: the use of different progestagen treatments

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Date
2000-11
Authors
Motlomelo, Khoboso Christina
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University of the Free State
Abstract
English: A study aimed at comparing the efficiency of different progestagen treatments used for oestrous synchronization in indigenous South African goats was carried out between February (autumn) and September (spring), 2000. The study was carried out at Paradys experimental farm, of the University of the Orange Free State situated approximately 20km south of Bloemfontein, in the Free State province. Forty-eight indigenous feral does and 42 Boer does were used in this experiment, during the normal breeding season. The two breeds were randomly allocated and distributed between the three progestagen synchronizing treatment groups of 30 does per group. The treatment groups were medroxyprogesterone acetate (MAP), fluorogestone acetate (FGA) and controlled internal drug release dispenser (CIDR) groups. These three main progestagen treatment groups were further subdivided into six flush feeding groups of 15 does each, namely A1 (MAP X flush feeding); A2 (MAP X control); B1 (FGA X flush feeding); B2 (FGA X control); C1 (CIDR X flush feeding) and C2 (CIDR X control). Three groups (A1, B1 and C1) were flush fed with crushed maize for 3 weeks prior to breeding. Progestagen treatment was administered for 16 days. All does were injected with 300lU PMSG im at the time of progestagen withdrawal. Oestrus was detected with the aid of vasectomized bucks at 8 hour intervals for a period of 96 hours following progestagen treatment. Blood samples were collected at 4 day intervals during synchronization and at 8 hour intervals after progestagen treatment removal, as well as at days 14 and 21 following AI. Six weeks prior to kidding, pregnant does were divided into two groups, one supplemented with whole maize grain, while another one acted as a control group, irrespective of flush feeding and progestagen treatment prior to pregnancy. The parameters measured, included body weight, oestrous response, onset of oestrus, duration of oestrus, conception rate, gestation length, total litter weight, litter size, kid birth weight, sex of kids and mortality rates of kids. Body weight of the does was not affected by progestagen treatment, flush feeding or pregnancy supplementation. Higher body weights at breeding were associated with a higher conception rate. Weight gain or loss prior to breeding had no effect on conception rate and litter size. Prior to synchronization, only 17.8% of the experimental does were observed to be cyclic. Following oestrous synchronization, the overall oestrous response recorded was 96.6%. Oestrous response for three progestagen treatments was 93.1%, 96.7% and 100.0% for MAP, FGA and ClDR, respectively. Progestagen treatment had a significant (P<0.01) effect on the time to onset of oestrus following cessation of progestagen treatment, with ClDR treated does exhibiting oestrus earlier (27.2±4.5h), compared to the FGA (30.9±4.6h) and MAP (32.2±7.1h) treated does. There was no significant difference on the duration of induced oestrous period between the three progestagen treatment groups (FGA: 32.0±13.7h; MAP: 32.6±13.8h and ClDR: 35.2±13.7h). The mean serum progesterone concentration in CIDR treated does was significantly (P<0.05) higher from day of device insertion until cessation of treatment, when compared to the MAP and FGA treated does. No significant difference in serum progesterone concentrations was observed between MAP and FGA treated does throughout the observation period. At the onset of oestrus, the mean serum progesterone concentrations were 0.3±0.2ng/ml, 0.2±0.5ng/ml and 0.4±0.1ng/ml for MAP, FGA and CIDR, respectively. The difference was non-significant. At 21 days following AI, pregnant does had significantly (P<0.01) higher serum progesterone concentrations (17.3±0.9ng/ml), than the non-pregnant does (3.6±5.4ng/ml). The overall conception rate for all groups was 52.2%. The conception rates for the CIDR, MAP and FGA groups were 46.7%,51.7% and 60.0%, respectively. The differences were non-significant. The mean gestation length for all groups was 149.1±4.1 days. Gestation length was not affected by progestagen treatment, flush feeding or late pregnancy supplementation. Does bearing quadruplets had a significantly (P<0.05) shorter gestation length (142.7±2.8 days), when compared to does bearing singles, twins and triplets (150.0±2.8 days, 148.8±4.3 days and 150.0±4.1 days, respectively). The total litter weight for single births was significantly (P<O.01) lower, than that of multiple births (3.6±0.4; 6.0±0.9; 6.7±1.5; 6.4±0.5 for singles, twins, triplets and quadruplets, respectively). The mean litter size was 2.0±0.9 and this was not affected by progestagen treatment. Flush fed does had a significantly (P<0.05) lower litter size, when compared to the control does (1.8±O.9 vs 2.3±1.0). Does lighter than 41kg produced a significantly (P<0.01) lower litter size, when compared to heavier does. The average birth weight of the kids was 2.7±0.5kg and was not affected by late' pregnancy supplementation. Crossbred (Indigenous X Boer) and male kids (2.7±0.8kg and 2.7±O.8kg, respectively) were significantly (P<0.05) heavier when compared to pure Boer and female kids (2.6±0.9kg and 2.6±O.8kg) at birth. The mean birth weights for quadruplets, triplets, twins and singles were 1.6±0.3kg, 2.3±O.6kg, 3.1±0.5kg and 3.6±0.4kg, respectively, and these differed significantly (P<O.01)from each other. The overall perinatal mortality rate of kids up to 48 hours postpartum was 22.3%. Kids from supplemented pregnant does had significantly (P<0.05) higher perinatal mortality rate when compared to kids from the control does (31.9% vs 14.0%), respectively. Perinatal mortality rates of kids increased with an increase in litter size and decreased with an increase in birth weight. It is concluded that synchronization of oestrus with the use of progestagen (irrespective of the type used), is efficient in synchronizing oestrus. The type, duration and time of nutritional supplementation as well as the body condition of the animal should be born in mind whenever flush feeding and supplementation programmes are considered. There are many factors (nutritional and managerial) that could influence the conception rate following fixed-time AI in goats.
Afrikaans: 'n Studie gemik op die vergelyking van verskillende progestageen behandelings op die doeltreffendheid van estrus sinkronisasie by inheemse Suid-Afrikaanse bokke is uitgevoer tussen Februarie (Herfs) en September (Lente), 2000. Die studie is uitgevoer op Paradys proefplaas van die Universiteit van die Oranje-Vrystaat, geleë ongeveer 20 km suid van Bloemfontein in die Vrystaat provinsie. Ag-en-veertig inheemse bokooie en 42 Boerbokooie is in die studie gebruik, tydens die normale teelseisoen. Die twee rasse is ewekansig geallokeer tussen die drie progestageen sinkronisasie behandelingsgroepe (30 ooie per groep). Die behandelingsgroepe was medroksiprogesteroon (MAP), fluorogestoon asetaat (FGA) en 'n beheerde interne hormonale verspreider (ClDR). Hierdie drie hoof progestageen behandelings is verder onderverdeel in ses prikkelvoedingsgroepe (15 ooie per groep), naamlik A1 (MAP x prikkelvoeding); A2 (MAP x kontrole); B1 (FGA x prikkelvoeding); B2 (FGA x kontrole); C1 (CIDR x prikkelvoeding); C2 (CIDR x kontrole). Die drie groepe (A1, B1, C1) het prikkelvoeding van gebreekte mielies ontvang vanaf 3 weke· voor KI. Progestageen behandeling is toegedien vir 16 dae. Alle ooie het 300 IU PMSG binnespiers ontvang met progestageen onttrekking. Estrus waarnemings is elke 8 ure vir 'n periode van 96 uur na progestageen behandeling m.b.v. gevasektomiseerde ramme gedoen. Bloed monsters is gekollekteer met 4 dae intervalle tydens sinkronisasie en na onttrekking met 8 uur intervalle, asook by dag 14 en 21 na KI. Ses weke voor lam is die dragtige ooie verdeel in twee groepe, die een groep het byvoeding van heel mielies ontvang, terwyl die ander groep gedien het as kontrole. Parameters gemeet het ingesluit, liggaamsgewig, estrus respons, begin van estrus, duur van estrusperiode, konsepsiesyfer, duur van dragtigheid, werpselgrootte, totale werpselgewig, geboortegewig van lammers, geslag van lammers en mortaliteite by lammers. Liggaamsgewig van die ooie is nie betekenisvol beïnvloed deur progestageen behandeling, prikkelvoeding of byvoeding tydens dragtigheid. Hoër liggaamsgewigte by paring was geassosieerd met 'n hoë konsepsiesyfer. Liggaamsgewig toename of afname voor teling het geen effek op konsepsie en werpselgrootte gehad nie. Voor sinkronisasie was slegs 17.8% van die ooie siklies. Met sinkronisasie is 'n algehele estrus respons van 96.6% gemeet. Estrus respons vir die drie progestageen behandelings was 93.1%, 96.7% en 100% vir die MAP, FGA en CIDR groepe respektiewelik. Tipe (progestageen behandeling het 'n betekenisvolle (P<0.01) effek gehad op die tyd tot estrus na progestageen behandeling, met die CIDR groep wat estrus vroeër (27.2 ± 4.5h) getoon het, vergeleke met FGA (30.9 ± 4.6h) en MAP (32.2 ± 7.1h) behandelde ooie. Geen betekenisvolle verskil in die duur van die geïnduseerde estrusperiode is gevind tussen die groepe (FGA: 32.0 ± 13.7h; MAP: 32.6 ± 13.8h; CIDR: 35.2 ± 13.7h). Die gemiddelde serum progesteroonkonsentrasie in die CIDR behandelde ooie was betekenisvol (P<0.05) hoër vanaf die dag van behandeling tot die beëindiging van behandeling, wanneer vergelyk word met die MAP en FGAgroepe. Geen betekenisvolle verskil in serum progesteroonkonsentrasie is waargeneem in die MAP en FGA behandelde ooie tydens die observasieperiode. Aan die begin van estrus was die serum progesteroonkonsentrasies 0.3 ± 0.2ng/ml, 0.2 ± 0.5ng/ml en 0.4 ± 0.1ng/ml vir die MAP, FGA en CIDR groepe respektiewelik (geen betekenisvolle verskil). By 21 dae na KI het dragtige ooie 'n betekenisvolle (P<0.01) hoër serum progesteroonkonsentrasie (17.3 ± 0.9ng/ml) gehad, vergeleke met die nie-dragtige ooie (3.6 ± 5.4ng/ml). Die gemiddelde konsepsiesyfer vir alle groepe was 52.2% en was nie beïnvloed deur prikkelvoeding of progestageen behandelings nie. Die konsepsiesyfers behaal vir die CIDR, MAP en FGA groepe was 46.7%,51.7% en 60.9% respektiewelik. Die gemiddelde dragtigheidsduur vir alle bokooie was 149.1 ± 4.1 dae, met hierdie parameter wat nie beïnvloed word deur progestageen behandeling, prikkelvoeding of laat-dragtigheid byvoeding nie. Ooie met vierlinge het 'n betekenisvolle (P<0.05) korter dragtigheidsperiode (142.7 ± 2.8 dae), vergeleke met ooie wat enkelinge, tweelinge en drielinge (150.0 ± 2.8 dae, 148.8 ± 4.3 dae en 150.0 ± 4.1 dae, respektiewelik) gehad. Die totale werpselgewig vir enkelinge was betekenisvol (P<0.01) laer as veelvoudige geboort.es (3.6 ± 0.4; 6.0 ± 0.9; 6.7 ± 1.5; 6.4 ± 0.5 vir enkelinge, tweelinge, drielinge en vierlinge, respektiewelik). Die gemiddelde werpselgrootte vir alle diere was 3.2 ± 0.9 en dit was nie betekenisvol geaffekteer deur progestageen behandeling. Prikkelvoeding het gelei tot 'n betekenisvol (P<0.05) laer werpselgrootte, vergeleke met kontrole diere (1.8 ± 0.9 vs 2.3 ± 1.0). Bokooie ligter as 41 kg het betekenisvol (P<0.01) laer werpselgroottes produseer, vergeleke met swaarder diere. Die gemiddelde geboortegewig van die lammers was 2.7 ± 0.5kg en was nie beïnvloed deur laat-dragtigheid byvoeding. Kruis (Inheems x Boer) en manlike lammers (2.7 ± 0.8kg en 2.7 ± 0.8kg respektiewelik) was betekenisvol (P<0.05) swaarder as Boer en vroulike lammers (2.6 ± 0.9kg en 2.6 ± 0.8kg) met die geboortegewig vir vierlinge, drielinge, tweelinge en enkelinge was 1.6 ± 0.3kg, 2.3 ± 0.6kg, 3.1 ± 0.5kg en 3.6 ± O.4kg respektiewelik, en het betekenisvol (P<0.01) verskil van mekaar. Die algehele mortaliteit van die lammers tot 48 uur na-geboorte was 22.3%. Lammers van gesupplementeerde dragtige ooie het 'n betekenisvol (P<0.05) hoër mortaliteitssyfer gehad, vergeleke met lammers van kontrole ooie (31.9% vs 14.0%). Peri-natale mortaliteite van lammers het verhoog met 'n verhoging in werpselgrootte en het afgeneem met 'n toename in geboortegewig. Samevattend kan gesê word dat sinkronisasie van estrus deur die gebruik van progestageen (ongeag die tipe gebruik) in S.A. Boer en Inheemse bokooie, doeltreffend is. Die tipe, duur en tyd van byvoeding, asook die liggaamskondisie van die dier moet in gedagte gehou word wanneer prikkelvoeding en byvoedingsprogramme oorweeg word. Daar is verskeie faktore (voeding en bestuur) wat konsepsie kan beïnvloed na vasgestelde tyd KI by bokke.
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Goats -- Breeding, Goats -- Reproduction, Dissertation (M.Sc.(Agric. (Animal Science))--University of the Free State, 2000
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