Creole Goats Research Articles

Desarrollo folicular y tasa ovulatoria en cabras criollas después de un periodo corto de consumo de trigo protegido de la degradación ruminal

To determine ovarian effects after consumption of wheat protected from ruminal degradation, 40 Creole female goats received for 11 d before a synchronized estrous, 33.2 g/kg.75 of durum wheat treated with 5 % formaldehyde and mixed with 15 % saponified tallow (TW, n=20) or milled durum wheat and separately 15 % saponified tallow (NTW, n=20). Ovarian follicular populations were characterized on d 0, 2, 4 & 6 post-estrus through ultrasound and ovulatory rate estimated on d 9 through CL count after abdominal laparoscopy. Serial blood samples were collected in four animals per experimental group from 0 to 12 h after wheat intake and serum glucose & insulin concentrations were determined. Data were analyzed through Fisher Exact Test or ANOVA for a completely randomized design. Serum glucose and total ovulations did not differ (P>0.20) between experimental groups. Serum insulin was higher (P<0.05) in TW vs NTW during the 0 to 8 h period after wheat intake (6.61 vs 4.82 I¼,UI/ml). TW group showed more follicles < 4 mm on d 0 post-estrus (7.60 vs 7.00 follicles in TW vs NTW, P<0.01), and both, number of total follicles on d 0 and the diameter of the 2nd follicle according to size on d 6 post-estrus tended to be greater in TW (9.70 vs 9.21 follicles and 2.89 vs 2.75 mm in TW vs NTW, P<0.10). Short-term TW intake could influence follicular development in Creole goats without altering ovulation rate or glucose entry to systemic circulation but might increase temporary secretion of insulin

Las vocalizaciones de machos cabríos no estimulan la secreción de la LH ni la ovulación en las cabras anovulatorias

The objective was to determine if the reproduction of goat buck vocalizations stimulate the secretion of LH and ovulation of anoestrus female goats. Forty multiparous Creole goats, isolated from male goats three months before the onset of experiment, were allocated to four groups (n = 10 each). The first group was exposed to one sexually active male. The second group was exposed to vocalizations of males reproduced by compact discs. The third group was exposed to the blank noise produced by a virgin compact disc. The females of the fourth group remained isolated. LH was measured 4 h before and 4 h after the onset of stimulus, while progesterone was determined during the next 28 d. The introduction of the male in the corresponding group increased (P 0.05) in LH pulsatile secretion was observed in vocalization (before 1.0 ± 0.1, after 0.8 ± 0.2), blank noise (before 1.0 ± 0.1, after 0.8 ± 0.1), or isolated (before 0.6 ± 0.2, after 1.1 ± 0.2), groups. All females in the first treatment (exposed to buck) ovulated, whereas none in the other three groups did. These results show that in anovulatory female goats, reproduction of buck vocalizations recorded during sexual courtship, do not stimulate either frequency of LH pulses or ovulation.

Periodo de re-establecimiento de pasturas irrigadas de Dignaria decumbens, época de nacimiento, y la producción de leche y tasa de crecimiento de cabras Creole en Guadalupe

Se estudió el efecto del periodo de re-establecimiento (PR) de pasturas sobre la producción de leche de cabras Creole y la tasa de crecimiento de sus cabritos mientras pastaban en pasturas irrigadas de Digitaria decumbens en la isla de Guadalupe. Se usaron 84 cabras en un experimento para comparar dos sistemas rotacionales de pastoreo por un periodo de un año. El sistema PR21 permitía siete días de pastoreo y 21 días de re-establecimiento del pasto, mientras el sistema PR 35 permitía siete días de pastoreo y 35 días de re-establecimiento. Se compararon los dos sistemas durante tres estaciones de nacimiento de cabritas; estaciones clasificadas como lluviosa, seca o intermedia. En ambos sistemas se mantuvo una carga animal promedio de 1,800 kg de peso vivo /ha/año. La producción de materia seca (MS) fue mayor (P &lt; 0.01) en el PR 35 que en el PR 21 en las tres estaciones, con 4,935 vs. 2,948 kg/ha, respectivamente. La biomasa total en los pastos al comienzo de cada ciclo de pastoreo variaba entre 11 y 19 kg MS/ animal, según la estación. El periodo de re-establecimiento no tuvo ningún efecto. La producción de leche (938 a 1,033 g leche/día/cabra) varió con la estación pero no con la edad de re-establecimiento. La ganancia diaria promedio en peso de los cabritos del sistema PR 21 fue 23% menor que la de los cabritos en PR 35. Estas diferencias fueron aún mayores cuando la ganancia diaria promedio en peso se ajustó al peso al nacimiento y a la producción de leche de la cabra. Los resultados se pueden haber afectado por la presencia de parásitos gastrointestinales; sin embargo, este experimento demuestra que disminuyendo el periodo de re-establecimiento de Digitaría decumbens manejada intensivamente no se mejora significativamente el desempeño de los animales.

Evaluation of Tree Fodder Silage in the Feeding of Lactating Goats

Solorio-Sánchez, F.J., Sol-Jiménez, J.A., Sandoval-Castro, C.A. and Torres-Acosta, J.F.J. 2007. Evaluation of tree fodder silage in the feeding of lactating goats. J. Appl. Anim. Res., 31: 189–192. Milk yield and quality of goats fed silage made with Taiwan grass (Pennisetum purpureum) and either Albizia lebeck or Piscidia piscipula was evaluated. Six Creole goats received three different diets i) A. lebeck and ii) P. piscipula silage and Hi) control diet oftaiwan grass and commercial concentrate supplement. The voluntary intake of DM, as well as the digestibility of DM and OM were not different (P>0.05). The silage from A. lebeck had the highest ADF and NDF digestibility and N-balance. The milk yield and quality were similar for the three treatments. It was concluded that the silage made with tree fodders mixed with grass is of good quality and can be fed to lactating goats.

Analysis of size and conformation of native Creole goat breeds and crossbreds used in smallholder agrosilvopastoral systems in Puebla, Mexico

Liveweight (LW) of does and bucks of the native Creole goat breed and crosses of Creole does and Nubian bucks, aged 1.5-5 years, were recorded and body traits including: head length (HL), head width (HW), body length (BL), trunk length (TL), chest girth (CG), abdominal perimeter (AP), rump length (RL), and height at withers (HW) were measured to develop equations for predicting LW from the body measurements. Weight, sex, breed and kidding date of 354 kids were recorded at birth, and LW of the kids was measured monthly for one year to determine the effect of kidding season on growth rate. Bucks had higher (p < 0.05) body measurements than the does (HL 15.1 +/- 0.1 vs 16.6 +/- 0.2 cm; BL 97.6 +/- 0.4 vs 104.6 +/- 1.2 cm; CG 78.8 +/- 0.4 vs 79.9 +/- 1.0 cm; AP 82.4 +/- 0.5 vs 87.2 +/- 1.1 cm; HW 62.7 +/- 0.4 vs 70.1 +/- 0.8 cm). With the exception of TL, F2 does had higher (p < 0.05) body measurements and LW (28.8 +/- 1.5 vs 27.7 +/- 0.5 kg) than Creole does. The body traits of the F1 does were similar (p > 0.05) to those of Creole does with the exception of HL, BL and HR. The F2 kids were heavier (p < 0.05) at birth (3.31 +/- 0.1 vs 2.60 +/- 0.1 kg) and grew faster than the Creole kids. Male kids were heavier (p < 0.05) at birth (3.21 +/- 0.10 vs 2.73 +/- 0.13 kg), and grew faster than female kids. Season had a significant effect on birth weight. The results showed that LW of Creole goats and Creole x Nubian does could be estimated in the field using body traits. Birth weight and growth rate of kids could be improved by management practices that affect season of kidding.

Evaluation of targeted drenching using Famacha© method in Creole goat: Reduction of anthelmintic use, and effects on kid production and pasture contamination

Haemonchus infection was monitored for 2 years (six kidding periods) in a Creole goat flock grazing under oceanic–tropical climate. Two hundred and thirty individual does were involved from late pregnancy to weaning. Anaemia diagnoses using Famacha© method and packed cell volume (PCV) were compared. The best agreement (Kappa = 0.33) was found if anaemia was declared when PCV values fell to 16 or below and Famacha© score was 4 or 5. Drenching policy according to Famacha© method was compared to systematic drenching policy. Using the Famacha© method allowed a dramatic decrease in anthelmintic use during the periparturient period (0.57 individual dose instead of three doses for the control). The proportion of the nematode population on the pasture not derived from previously-treated goats (in refugia) was estimated to about 79% (65–90%) of the pasture contamination derived from the Famacha© group. On the average, goats which needed to be drenched produced less than the control or undrenched goats (kid average daily gain was decreased by about 15%). The repeatability of the need for drenching individual does was estimated to 0.41. The older goats or the goats in poorer body condition at kidding needed more drenching than the younger animals and the animals in good body condition. Consequently the Famacha© method may be used as an additional tool for the culling management.

Genetic variability in resistance to gastro-intestinal strongyles during early lactation in Creole goats

AbstractThe study was undertaken in a Creole goat flock at INRA-Gardel in Guadeloupe, to evaluate the opportunity to use artificial selection as a means of controlling gastro-intestinal infection during early lactation. The flock grazed all year on Digitaria decumbens pastures. Faecal and blood samples were taken from kids at 11 months of age and from does at kidding before drenching (week 0) and at weeks 4 and 6 after kidding. Faecal egg counts (FEC) were estimated using a modified McMaster method. Blood samples were used to determine packed cell volume (PCV) and eosinophil concentrations (EOS) values. Haemonchus contortus, Trichostrongylus colubriformis and Oesophagostomum columbianum were the main strongyle species identified in faecal cultures. The data came from 1092 litters obtained from 688 does sired by 142 bucks and 413 dams. Variance and covariance components for genetic and residual effects were estimated with multivariate animal models using the restricted maximum likelihood VCE package. Repeatability and overall heritability for FEC during the post-partum period were 0·17 and 0·10±0·02. The genetic correlations between FEC and PCV were −0·56±0·11 at 4 weeks after kidding and −0·79±0·13 at 6 weeks after kidding. The genetic correlations between FEC and EOS were 0·37±0·15 at 4 weeks after kidding and 0·68±0·17 at 6 weeks after kidding. Hence, does that contributed least to pasture contamination during the postpartum period also had low EOS and high PCV breeding values. The genetic correlations between FEC measured at 11 months of age and FEC during periparturient period ranged from 0·57±0·12 to 0·76±0·16. Therefore, breeding goats for increased resistance during the post-weaning period will lead to a less marked and less persistent rise in doe FEC during early lactation. The epidemiological implications of this selection have to be quantified in terms of lower pasture contamination, lower kid parasitism, and higher milk production of does.

Morphometry, Carcass Yield and Traits of Mexican Creole Goat Kids Slaughtered and Packed in a Federal Inspection Plant

Morphometry, Carcass Yield and Traits of Mexican Creole Goat Kids Slaughtered and Packed in a Federal Inspection Plant

Control de residuos después del pastoreo, la estación y las características de forrajes tropicales pastoreados por cabras y ovejas en Guadalupe (FWI).

Se mantuvieron cabras "Creole" (G) y ovejas "Martinik" (S) en praderas tropicales en un sistema rotacional para probar el efecto del control del forraje residual después del pastoreo sobre la producción y la composición morfológica y química del forraje. Un sistema mecánico de corte de forraje residual y su remoción (RM) se comparó con un sistema testigo (RR) durante tres estaciones (seca, intermedia y lluviosa) en un año completo. El peso de biomasa al inicio de los periodos de pastoreo difirió entre tratamientos: 3,123 vs. 5,010 kg MS/ha en parcelas de GRM y GRR, y 2,538 vs. 3,753 kg MS/ha en las de SRM y SRR, respectivamente. La estructura vegetal fue mejorada en los sistemas RM. Se determinó una mayor proporción de hojas (42% vs. 36%), similar proporción de tallos (cerca de 43%), y menor proporción de material muerto (15% vs. 19%) en GRM vs. GRR. En las parcelas SRM y SRR, los valores correspondientes de hojas fueron 46% vs. 36%; tallos, 36%; y material muerto, 17% vs. 20%, respectivamente. Es probable que la diferencia de 29% mayor en acumulación de forraje en las praderas de cabras sobre las de ovejas se relacione a su más alto índice nutritivo de nitrógeno (82 vs. 60%). Los efectos estacionales fueron discutidos. La composición química del forraje no difirió entre tratamientos y estaciones. El contenido de proteína cruda obtenida fue de 115 y 85 g/kg MS y de 90 y 65 g/ kg MS antes y después del pastoreo en las parcelas de cabras y ovejas, respectivamente. Las características del forraje no limitaron el crecimiento de los cabritos y corderos, y la ganancia diaria de peso no difirió entre tratamientos. Se recomienda explotar el forraje residual con herbívoros asociados con miras a lograr un manejo práctico al del residuo removido.

Impact on productivity of peri-parturient rise in fecal egg counts in Creole goats in the humid tropics

The control of gastrointestinal nematodes requires an understanding of their epidemiology so that particular parasite stages can be targeted. Dam infection during early lactation is one example of this in ruminant nematode infections. The existence of the peri-parturient relaxation in immunity and its impact on productivity were examined in a Creole goat flock from Guadeloupe, exposed to mixed natural infection (predominantly Haemonchus contortus and Trichostrongylus colubriformis). A total of 1511 l were obtained from 909 does resulting from 463 dams and 150 sires. Fecal and blood samples were collected at kidding before anthelmintic drenching, 4 and 6 weeks after kidding. The traits analyzed were logarithm transformed fecal egg counts (FEC), packed cell volume (PCV), and logarithm transformed blood eosinophilia counts (EOS) for does at each sampling point and changes in these during the postpartum period. With the exception of the PCV values measured at kidding, lactating does had significantly higher FEC and lower PCV than control dry does at every sampling point. Geometric means of FEC in lactating does were 819 ± 174, 677 ± 146 and, 699 ± 160 eggs per gram (EPG) at kidding, 4 and 6 weeks after kidding respectively. Geometric means of FEC in dry does were 187 ± 57, 89 ± 28, 133 ± 43 at these time points, respectively. EOS differences were not consistent between groups and probably not specific enough for variations in Creole goats’ peri-parturient rise to be discussed. As does aged, their egg output decreased and primiparous does always had greater egg output than multiparous ones. Overall, does’ FEC at 4 weeks after kidding decreased by 1.3% each year. The higher the litter size, the higher the FEC at kidding and inverse applied for PCV measurements. Does that stopped lactating had significantly lower FEC and higher PCV values than lactating does with low milk yields. Higher infection rates during early lactation in Creole goats were recorded in does with lower maternal ability assessed by the average daily weight gain of kids between 10 and 30 days of age. Kids from dams with higher FEC (i.e. >600 EPG higher than corresponding does) had 17% lower average daily weight gain between 30 and 70 days postpartum and were approximately 1 kg lighter at weaning than kids from dams with lower FEC. Thus, it is clear that a peri-parturient rise in FEC exists in Creole goats. By controlling the intensity of this peri-parturient rise in FEC, herd health and productivity could be substantially improved.

Intake and milk production of suckling Creole goats reared at pasture in humid tropics according to the post-grazing residue management

Creole suckling goats, reared on rotationally grazed tropical pasture were used to study the effect of post-grazing residue control on forage intake and milk production. The pastures were irrigated and fertilized with 500 kg ha −1 year −1 of commercial fertilizer (30% N, 12% P 2O 5, 18% K 2O). A system in which residuals were mown (RM) was compared to the control (Residuals Remained, RR) at three parturition seasons (dry, intermediate and wet). For both pasture management systems, each plot of 4100 m 2 was equally divided into five paddocks. Animals grazed the forage within each paddock for 7 days. Thereafter, pastures were grazed after every 28-day regrowth period for a full year. Each group at each season was composed of 20 goats weighing 36.0 ± 2.5 kg LW (half of them were pregnant and half were lactating). Milk production (oxytocin method), live weight (LW), body condition score (BCS) and intake (fecal index method) were determined using six multiparous twin-bearing goats from each group for each season (35.2 ± 5.0 kg LW) during 1 year. Herbage biomass (3.12 t DM/ha versus 4.98 t DM/ha, P < 0.001) was lower in RM than RR treatments while it was the opposite for the crude protein content of vegetation (123 g/kg DM versus 110 g/kg DM, P < 0.05). The organic matter digestibility, DM intake and organic matter intake averaged 0.695, 88 and 69 g/W −0.75, respectively. The daily milk production over the 12 weeks of lactation averaged 1.06 kg/day in both groups. The fat and protein contents reached on average 56 and 37 g/kg, respectively. Goats lost about 3.5 kg LW during lactation but did not lose BCS. No significant differences in intake, milk and body traits were observed among the two management systems (i.e. RM and RR). Seasonal effects ( P < 0.01) were found and are discussed. Highest values were obtained during the intermediate season, 20% more forage ( P < 0.05) and 17% more milk ( P < 0.01). The forage biomass and feeding value were not limiting factors and generated adequate levels of intake and production whatever the pasture management system. Removing post-grazing residues in intensive grazing systems with suckling goats reared in tropical conditions, would not change the intake level or milk production of the does compared to the control system. It is recommended to develop new grazing systems, which would allow the use of post-grazing residues.

Preweaning Productivity of Suckling Goats and Sheep in Guadeloupe (FWI) under Intensive Reproductive Rate and Grazing Management

In Guadeloupe, small ruminants are reared for meat production under pasture conditions. Intensive rotative grazing systems (irrigated, fertilized and high-stocked tropical pastures) allow satisfactory levels of production but generate high post-grazing residues. Experiments were designed to control these. A system in which residuals were mown (RM) was tested in comparison to the control system (residuals remained, RR). The same design was carried out over two years with Creole goats and Martinik sheep. An accelerated reproductive rate (3 parturitions over 2 years) was carried out. Systems were compared at three parturition seasons per year (dry, intermediate and rainy seasons). Each group was composed of 20 goats (36.0+/-2.5 kg) or 20 ewes (46.8+/-2.4 kg). The systems exhibited high levels of productivity in both species compared to other results in the tropics: more than 50 and 30 offspring born alive per hectare and per reproductive season for the goat and ewe flocks, respectively. The annual production at birth was 110 kg kids/ha per year and 133 kg lambs/ha per year (i.e. 21% more). Corresponding values at weaning were 630 kg kids/ha per year and 785 kg lambs/ha per year (i.e. 25% more). The RM system produced 10% more than the RR system in Creole goats, while it produced 35% more in Martinik sheep. Seasonal effects and other factors of variation are discussed.

Correlations between milk production and kinetic variables in milk of cephalothin administered to lactating goats

The aim of the present study was to correlate the milk production and the kinetic variables in milk of cephalothin administered to goats. Twenty healthy creole goats in milk production were used. Cephalothin was administered by intravenous route (20 mg/kg b.w.). Milk samples were collected at 0.25, 0.5, 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 8.0 and 12.0 hours postadministration of the antibiotic. Cephalothin concentrations were measured in milk samples by high performance liquid chromatography. The values (mean &amp;plusmn; standard error) of milk production collected during 24 hours previous to the administration of the antibiotic were 761.5 &amp;plusmn; 111.1 ml. The results of the kinetic variables (mean &amp;plusmn; standard error) of cephalothin in milk were: AUC = 5.4 &amp;plusmn; 1.6 &amp;micro;g/ml/h; C&lt;sub&gt;max&lt;/sub&gt;= 1.1 &amp;plusmn; 0.3 &amp;micro;g/ml and t&lt;sub&gt;max &lt;/sub&gt;= 1.7 &amp;plusmn; 0.1 h. The correlation coefficients AUC-milk production, C&lt;sub&gt;max&lt;/sub&gt;-milk production and t&lt;sub&gt;max&lt;/sub&gt;-milk production were: 0.602 (P &amp;lt; 0.01), 0.596 (P &amp;lt; 0.01) and 0.398 (P &amp;lt; 0.1), respectively. In conclusion, the areas under the curve and the maximum concentrations and the time to reach them in milk are in fact related to the volume of milk produced by the goats

Relevance of the variability of kidding day in Creole goats in Guadeloupe

The results of 5732 records of kids born between 1985 and 1996 at Gardel Agricultural Experiment Station (INRA) in Guadeloupe, were used in order to estimate the effect of kidding day (KD) on individual preweaning growth performances, total productivity of Creole goats and litter size. The flock was subjected to a restricted mating season for a long time, by using male effect. The results of the fixed linear model showed a highly significant ( P<0.001) effect of KD on growth rate and total productivity of does. Live weights of kids born around the 21st day of the kidding period (KP) was 4% to 7% higher than those of kids born the first day of the KP. For total productivity of does, this ratio did not reached more than 4%. The optimum at 70 days of age occurred around 14th day of the KD with 3% of improvement of total productivity. No effect was observed upon litter size. The genetic (co)variance components were estimated by six different Individual Animal Models. The heritability ( h 2) estimated from the best model, was h D 2=0.25±0.05 for genetic direct effect; h M 2=0.09±0.04 for genetic maternal effect and the genetic correlation between direct and maternal effects was −0.86±0.12. The use of KD could be highly recommended in a breeding program in this population of Creole meat goats, since it is quite easy to record under commercial conditions as a character related to reproductive performance.

Preliminary assays for the development of a probiotic for goats

In order to determine probiotic properties, 137 strains of lactic acid bacteria from the feces of Creole goats were screened, only six were resistant to pH 2.0 and bile salts (0.3%). Three strains identified as Lactobacillus and two as Enterococcus showed agglutination with the treated yeast. Between them, Lactobacillus DDL17, DDL19, DDL48 and Enterococcus DDE39 demonstrated high specificity in this test because the correspondent agglutination was inhibited by one sugar, suggesting the presence of a lectin-like structure in their cell walls, which could be due to adhesion ability. Another Enterococcus strain (DDE55) showed low affinity because five sugars inhibited the agglutination of the treated yeasts. The results of hydrophobic properties showed that the strains who were able to agglutinate yeasts presented similar hydrophobic characteristics as hexadecane, xylene and toluene, but high specificity was not related to a high hydrophobicity. Only two strains (Lactobacillus DDL19 and DDL48) showed aggregation with the lowest concentration of ammonium sulfate, complementing the hydrophobicity assay. Only one strain, Lactobacillus DDL48, showed an inhibition against an enteric indicator strain (Salmonella Typhimurium and Escherichia coli O111). This inhibitory action was not affected by the addition of catalase and no inhibition was detected after neutralizing the supernatant culture fluid. These strains could be pre-selected in order to complete studies focused on designing a probiotic for use in goat feed.

Seasonal ovulatory activity exists in tropical Creole female goats and Black Belly ewes subjected to a temperate photoperiod

BackgroundSeasonality of ovulatory activity is observed in European sheep and goat breeds, whereas tropical breeds show almost continuous ovulatory activity. It is not known if these tropical breeds are sensitive or not to temperate photoperiod. This study was therefore designed to determine whether tropical Creole goats and Black-Belly ewes are sensitive to temperate photoperiod. Two groups of adult females in each species, either progeny or directly born from imported embryos, were used and maintained in light-proof rooms under simulated temperate (8 to 16 h of light per day) or tropical (11 – 13 h) photoperiods. Ovulatory activity was determined by blood progesterone assays for more than two years. The experiment lasted 33 months in goats and 25 months in ewes.ResultsMarked seasonality of ovulatory activity appeared in the temperate group of Creole female goats. The percentage of female goats experiencing at least one ovulation per month dramatically decreased from May to September for the three years (0%, 27% and 0%, respectively). Tropical female goats demonstrated much less seasonality, as the percentage of goats experiencing at least one ovulation per month never went below 56%. These differences were significant.Both groups of temperate and tropical Black-Belly ewes experienced a marked seasonality in their ovulatory activity, with only a slightly significant difference between groups. The percentage of ewes experiencing at least one ovulation per month dropped dramatically in April and rose again in August (tropical ewes) or September (temperate ewes). The percentage of ewes experiencing at least one ovulation per month never went below 8% and 17% (for tropical and temperate ewes respectively) during the spring and summer months.ConclusionsAn important seasonality in ovulatory activity of tropical Creole goats was observed when females were exposed to a simulated temperate photoperiod. An unexpected finding was that Black-Belly ewes and, to a lesser extent, Creole goats exposed to a simulated tropical photoperiod also showed seasonality in their ovulatory activity. Such results indicate that both species are capable of showing seasonality under the photoperiodic changes of the temperate zone even though they do not originate from these regions.

Management of photoperiod to control caprine reproduction in the subtropics

Reproductive seasonality is observed in some breeds originating from or adapted to subtropical latitudes. In ‘photoperiodic flexible breeds’, such as Australian cashmere goats, the annual breeding season can be manipulated through nutrition, whereas in ‘photoperiodic rigid breeds’, such as Creole goats from subtropical Mexico, sexual activity can be controlled by altering the photoperiod. In males from the latter breed, artificial long days, whether or not accompanied by the administration of melatonin, stimulate sexual activity during the non-breeding season. These treated males are able to induce the sexual activity of anoestrous females through the male effect under intensive or extensive conditions. Photoperiodic treatments and the male effect can be easily integrated into different breeding management systems in subtropical latitudes.

Direct genetic and maternal effects affecting litter size, birth weight and pre-weaning losses in Creole goats of Guadeloupe

AbstractThe litter size (LS), or its equivalent the number of kids born in the litter (NB), of Creole goats in Guadeloupe was studied by two procedures. The first approach considered LS as a single trait and as a characteristic of the mother of the litter, and was studied by an univariate animal model (UAM). The second procedure treated NB, the individual birth weight (BW) and loss of kids (LK) as traits belonging to the animals born in the litter and their dam, in a multitrait animal model (MAM). The heritability for genetic direct effect (h2a) for LS estimated by UAM (0·14) was 40% lower than the corresponding value for NB estimated by MAM. The most appropriate of the 6 MAMs tested estimated heritabilities (h2a) of 0·24, 0·22 and 0·17 for NB, BW and LK, respectively, while maternal effects (h2m) were 0·20, 0·24 and 0·09 for the same characters. The genetic correlations between direct and maternal effects (ram) were negative –0·611 and –0·725 for NB and LK, respectively, and not significantly different from zero for BW. This study explored the possibility of using the information on NB, BW and LK recorded in each animal born in the litter in order to analyse the genetic variability of these traits.

Consequences of Post-grazing Residues Control and Birth Season on the Body Traits, Reproductive Performance and Offspring’s Growth of Suckling Goats and Ewes Reared at Pasture in Guadeloupe (FWI)

In Guadeloupe small ruminants (SR) are reared for meat production under pasture conditions. Intensive rotational grazing systems (irrigated, fertilised and high stocked) allow reasonable levels of production but generate high post-grazing residues. Experiments were designed to control them. A system in which residuals were mown (RM) was tested in comparison to the control system (Residuals Remained, RR). The same design was carried out for two years with Creole goat (G) and Martinik sheep (S). An accelerated reproductive rate (3 parturitions over 2 years) was carried out. Systems were compared at three parturition seasons per year (dry, intermediate and rainy seasons). Each group was composed of 20 goats (36.0±2.5 kg) or 20 ewes (46.8±2.4 kg). The female body traits did not vary according to pasture management and seasons. The stocking rate averaged 1,400 kg LW/ha. The mean fertility rate for does varied significantly (p<0.05) within the kidding season, from 80.4±0.5% to 93.7±2.9% while the mean litter size was 2.30±0.07 total kids born. No effect of pasture system was observed. Corresponding values for ewes were 83.2±12.8% vs. 75.6±12.5% (p<0.05) and 2.43±0.24 vs. 2.03±0.29 (p<0.01) total lambs born for SRM and SRR ewes, respectively. A seasonal effect was observed upon ewe performances. The preweaning mortality of kids and lambs averaged 16.3% and 14.4%, respectively. It was 7 and 9 percentage points more (p<0.01) for RR than for RM kids and lambs, respectively. For both species, weaning took place at an average age of 81.4±3.6 days. In Creole kids, live weight at birth and at weaning were 1.9±0.2 kg and 8.9±0.8 kg, respectively. In the Martinik sheep, the traits averaged 2.9±0.2 kg and 18.9±0.9 kg. For both traits in both species, significant (p<0.05) group×season interactions were recorded. The consequences of elimination of post-grazing residues varied according to the SR species, the environmental conditions and the animal physiological status. The forage characteristics were not limiting factors since forage availability in the RM systems (2,300 and 2,600 kg DM/ha, respectively) and chemical composition were at satisfactory levels (CP content averaged 12 and 10%). It is recommended to develop new grazing system which would allow the use of post-grazing residues instead of mowing the refusals. (Asian-Aust. J. Anim. Sci. 2003. Vol 16, No. 8 : 1108-1117)

Seasonality of estrus and ovulation in Creole goats of Argentina

Adult non-pregnant and non-lactating native Creole does ( n=9) were used to characterize the seasonal variations in estrous and ovarian activity during a period of 18 month beginning in January. The goats were maintained in an open barn under constant nutritional levels, natural photoperiod and daily exposure to males. Vasectomized bucks were used twice daily to detect estrus, and ovarian activity was monitored by assessing serum progesterone concentrations from blood samples collected twice weekly. Live weight was recorded at monthly intervals. During the first year, the proportion of ovulating animals increased gradually from February to April (6/9–9/9), remained elevated (July, 9/9) and then declined gradually between August and September (7/9–4/9). No ovulations were recorded between October and February (following year). During the second year, the proportion of ovulating does increased gradually from March to April and all the females remained cycling throughout the end of the experimental period. A similar distribution was observed for estrus although with a slightly shorter period of anestrus between November and January. Maximal and minimal periods of sexual activity were associated with winter and summer solstices, respectively. During the periods of sexual activity (breeding season), there was a higher proportion of estrous cycles (associated estrus and ovulation) around the winter solstice whereas dissociated cycles (estrous behavior only or silent ovulation) were more frequent at the beginning and at the end of the breeding season. Similarly, the proportion of cycles of abnormal duration (either short or long) was higher at the beginning and at the end of the breeding season. The native Creole does in Argentina, fed constantly throughout the year, exhibit a seasonal pattern of reproduction.