Productivity of Native, Alpine and Nubian goat breeds and their crosses in Venezuela

Se revisa la producción, crecimiento y reproducción de la raza caprina criolla (CC) y otras razas selectas Alpina (AA) y Nubiana (NN) y sus cruces en Venezuela. Se comparó el rendi-miento lechero por año de vida (YYL) desde la primera (P1) hasta la tercera (P3) lactación, los pesos al nacimiento (BW), al destete (WW), a los seis meses (W6), al año (YW), fertilidad (YK), prolificidad (LS) y supervivencia al año (YS). Un valor agregado (AV) fue estimado pesando la le-che por año de vida y el 80% del peso al año por año de vida al final de la tercera lactación por la relación de precios leche/peso corporal (1:2). Las razas mejoradas superan a la Criolla en las características productivas y la criolla es mejor en las características reproductivas excepto LS, lo que está asociado con la selección natural. Sólo AA sobrepasa a CC en AV. Se concluye que la superioridad de las razas AA y NN tiende a disminuir con la edad debido principalmente a su escasa eficacia reproductiva

Productivity of Native, Alpine and Nubian goat breeds and their crosses in Venezuela

Se revisa la producción, crecimiento y reproducción de la raza caprina criolla (CC) y otras razas selectas Alpina (AA) y Nubiana (NN) y sus cruces en Venezuela. Se comparó el rendi-miento lechero por año de vida (YYL) desde la primera (P1) hasta la tercera (P3) lactación, los pesos al nacimiento (BW), al destete (WW), a los seis meses (W6), al año (YW), fertilidad (YK), prolificidad (LS) y supervivencia al año (YS). Un valor agregado (AV) fue estimado pesando la le-che por año de vida y el 80% del peso al año por año de vida al final de la tercera lactación por la relación de precios leche/peso corporal (1:2). Las razas mejoradas superan a la Criolla en las características productivas y la criolla es mejor en las características reproductivas excepto LS, lo que está asociado con la selección natural. Sólo AA sobrepasa a CC en AV. Se concluye que la superioridad de las razas AA y NN tiende a disminuir con la edad debido principalmente a su escasa eficacia reproductiva

Riesgos de Extinción del conglomerado nativo de genes bovinos en América Latina: Caso Venezuela

Los riesgos de extinción del conglomerado nativo de genes bovinos son analizados. Los grupos genéticos nativos de América Latina no han sido seleccionados para la producción y el creciente uso de germoplasma exótico amenaza con reemplazar los genes nativos con los introducidos. Esto se ha hecho para complementar el bajo nivel productivo de los grupos nativos, aprovechar la habilidad combinatoria específica de los grupos, y crear nuevos grupos. Pero razones no genéticas también han influido: comparación desleal de grupos genéticos, diluir costos fijos con fines de obtener créditos, falta de protección a los grupos nativos, falta de personal especializado, amplias posibilidades y sistemas de producción, político compatible y oportunidad de negocio. La media anual de importaciones entre 1961 a 1997 es de 7000, 55000, 4200, 68000, y 123000 cabezas para Argentina, Brasil, Colombia, México y Venezuela, respectivamente. La mayor erosión es causada por la inseminación artificial. Asumiendo que en promedio un 5p. 100 de la población es inseminada anualmente, la fracción de genes exóticos actual se estima en 0,23 para Venezuela, 0,17 para México, y 0,15 para el resto. Se concluye que esta práctica..

Riesgos de Extinción del conglomerado nativo de genes bovinos en América Latina: Caso Venezuela

Los riesgos de extinción del conglomerado nativo de genes bovinos son analizados. Los grupos genéticos nativos de América Latina no han sido seleccionados para la producción y el creciente uso de germoplasma exótico amenaza con reemplazar los genes nativos con los introducidos. Esto se ha hecho para complementar el bajo nivel productivo de los grupos nativos, aprovechar la habilidad combinatoria específica de los grupos, y crear nuevos grupos. Pero razones no genéticas también han influido: comparación desleal de grupos genéticos, diluir costos fijos con fines de obtener créditos, falta de protección a los grupos nativos, falta de personal especializado, amplias posibilidades y sistemas de producción, político compatible y oportunidad de negocio. La media anual de importaciones entre 1961 a 1997 es de 7000, 55000, 4200, 68000, y 123000 cabezas para Argentina, Brasil, Colombia, México y Venezuela, respectivamente. La mayor erosión es causada por la inseminación artificial. Asumiendo que en promedio un 5p. 100 de la población es inseminada anualmente, la fracción de genes exóticos actual se estima en 0,23 para Venezuela, 0,17 para México, y 0,15 para el resto. Se concluye que esta práctica..

Genetic and Phenotypic Parameters for Carcass Traits of American Shorthorn Beef Cattle

Carcass measurements were taken on 1,292 steers and collected by the American Shorthorn Association. The sires were purebred or appendix-registered Shorthorn. Because all dams were not Shorthorn, genetic fractions of breeds of origin were determined for each dam. Measurements for hot carcass weight; dressing percentage; fat thickness; ribeye area; kidney, pelvic, and heart fat (KPH); marbling; and yield grade were analyzed jointly with a multivariate REML algorithm to estimate heritabilities of and genetic and phenotypic correlations among the traits. The sire model chosen as best fit of the data included fixed effects of herd of origin (377 classes), slaughter group (118 classes), year of birth (1979-1995), and covariates for linear effects of genetic fractions of breeds (13) of dam and slaughter age, with sire (n = 409) as a random effect. Estimates of heritability were .60 ± .19, .49 ± .19, .46 ± .19, .97 ± .21, .45 ± .19, .88 ± .21, and .54 ± .19 for previous order of traits, respectively. Most genetic correlations were not significantly different from zero. Genetic correlations of hot carcass weight were significant and positive with dressing percentage (.65 ± .19) and with ribeye area (.70 ± .14). Dressing percentage was significantly positively genetically correlated with ribeye area (.79 ± .16) and negatively genetically correlated with yield grade ( -.56 ± .29). Yield grade was also significantly negatively genetically correlated with ribeye area ( -.85 ± .10) and positively genetically correlated with fat thickness (.67 ± .15). Most phenotypic correlations were significant and positive. Only the phenotypic correlations of dressing percentage with marbling and with yield grade, and ribeye area with KPH and with marbling were not significantly different from zero. Significant negative correlations were fat thickness with ribeye area ( -.16 ± .04) and ribeye area with yield grade ( -.61 ± .03). Results seem to indicate that genetic antagonisms between quantity and quality traits were small to moderate. Thus, the opportunity seems to exist for breeding plans to improve carcass quality without having any adverse genetic effect on hot carcass weight, dressing percentage, or ribeye area. The high heritability observed for marbling indicates that a low genetic potential for marbling can be remedied by selection within breed

Control parasitario en caprinos usando extracto acuoso de semillas de Nim (Azadirachta indica A Juss) (Goat parasites control using watery extract of Neem seeds(Azadirachta indica A Juss))

The therapeutic effectiveness of the Watery Extract of Nim Seeds (WENS) against goat endo parasites was evaluated in two typical extensive commercial herds of the semi arid environment of Falcon state, Venezuela. The averaged of annual rainfall and temperature for the area is about 600 mm and 26 °C's, respectively. In each herd , two groups of 13 randomly selected adult does were classified as Control (T0) and Treated (TI). The WENS was prepared by adding 750 g of Nim seed flour into 1000 ml of water, letting the solution rest in a refrigerator until the next day. The WENS was administered by via oral in a dose of one ml/kg of body weight, chronologically at the days' 1, 21 and 30 of trial. A coprological test was done in both T0 and TI six days after the administration of the product. Records of the parasitical load transformed to Log10 (PL) and the prevalence (P) of Strongylidos and of Coccidia sp were classified by herd (H); age group (A): x < 3, 3 ≤x, and x < 4; treatments (T); and sampling day (D): 0, 6, 27, 37, 71, and 101. The Proc GLM of SAS was used and the model included Hi for i = 1, 2; Aj for j = 1,. . ., 3; and TDk for k = 1,. . ., 11, the combination T0D101 was missed. Differences statistically significant (P < 0.05) in PL and P between T0 and TI were observed at days 6, 27, and 37. The efficiency of the WENS against Strongylidos was 87 at days 6 and 27, and less than 50 % afterward. There was not statistically significant difference between T0 and TI (P > 0.05) for any of the variables of Coccidia. Results are indicative that the WENS should be considered by commercial goat producers as an alternative to control some endo parasites

Integral farming systems using goats as the base: quail manure as a feeding protein source to post weaning goat kids

The Center for the Development of Sheep and Goat Production (CEFOPROCA) seeks, through guided actions, to transform the mono producer traditional systems into small integral farming systems, with the purpose of improving the productivity of the systems and also the nutritional level of rural communities. The Center is at 30 m.o.s.l., with an average of annual rain fall between 900 and 1100 mm, temperature of 27 °C's, 89% of humidity, and it has a red of five production units. To low production cost the quail manure fed as protein source to post weaning goat kids was evaluated. Twelve kids randomly selected were fed with 150 g of yucca flour (Manihot esculenta   , Crants) + 150 g of quail manure (TI), and another group of equal number with 300 g of commercial concentrated (TII), both groups pastured in pens of Brachiaria decumbens   . The yucca and the quail manure were blended and milled together previous to the supply. The animals were weighed at the beginning of the experiment and after two weeks of adaptation to fixed intervals of 15 days. The amount consumed for feeding groups was determined by the difference among offered minus refused. The Proc GLM of SAS was used for the analysis and the model included treatment: TI and TII; sex: males and females; trial period (DEE): 0, 15,..., 90; treatment x DEE; and initial body weight as (co)variable. The least square means of average daily gain were of 0.053 ± 0.003 vs. 0.087 ± 0.003 kg for TI and TII respectively, and they varied significantly among treatments during the test period. The greatest difference of 0.050 ± 0.01 kg (P &lt; 0.05) was observed at the day 30, decreasing to 0.030 ± 0.01 kg (P &lt; 0.05) by the end of trial. Part of the difference among treatments is associated to differences in consumption. More research is needed, given the economic importance of fodder resources for the local production units

Influence of dominance relationships on the estimation of dominance variance with sire-dam subclass effects

Two data sets from the USDA Livestock and Range Research Laboratory mere analyzed to study dominance variance and the influence of dominance relationships. The first consisted of 4,155 birth weight (3,884 weaning weight) records of inbred USDA Line 1 Herefords. The second consisted of 8,065 birth weight (7,380 weaning weight) records from a line-cross experiment with five lines. Two models were used. Both included fixed effects of year-sex of calf and age of dam, and covariates for calving date, inbreeding of animal, and inbreeding of dam. For the second set, additional covariates were line composition and heterozygosity coefficients. Random effects were direct and maternal additive genetic, maternal permanent environment, sire-dam subclass, and residual. Model 1 considered sire-dam subclasses unrelated. Model 2 related sire-dam subclasses with a parental dominance relationship matrix. Variance components were estimated using REML. Differences between estimates with Model 1 and 2 were unimportant except for dominance variance. For the first data set, estimates with Model 2 of relative genetic direct and maternal variances, direct-maternal correlation, permanent environment, and dominance variances for birth weight were .35, .13, -.02, .03, and .25, respectively, and they were .39, .11, .04, .06 and .14 for the second data set. For weaning weight, the first data set estimates were .20, .15, -.37, .19, and .11, respectively, and they were .16, .20, -.07, .18, and .18 for the second data set. Changes, decreases and increases, in estimates of dominance variances may be due to increased information from relationships and family types other than full-sibs. The assumption of unrelated sire-dam subclasses might not be appropriate for estimation of dominance variance in populations with many dominance relationships among siredam classes

Kidding frequency by month and geographical area of goat in range systems

Un total de 349 partos fue usado para evaluar la frecuencia por mes y área geográfica. Las regiones geográficas fueron Paraguaná, Pedregal, y Aregue, localizadas en ambientes áridos a altitudes de 20, 250, y 600 m.s.n.m. respectivamente. El manejo es extensivo y la fracción directa de genes Criollo fue estimada en 95%. El “Proc Freq” de SAS fue usado para estimar la frecuencia por mes y área geográfica. Los resultados muestran dos picos de pariciones, claramente demarcados, pero con variaciones significativas entre regiones. La frecuencia acumulada en los dos primeros y cuatro últimos meses del año alcanzó valores de 36,8; 31,6 y 16,7; y de 48,5; 45,2 y 64,0% en las regiones de Pedregal, Paraguaná, y Aregue respectivamente. Los picos de pariciones son indicativos de dos temporadas de monta que se inician con las lluvias en los meses de abril y agosto, y se extienden por dos a tres meses. Lo que hace que en septiembre y octubre coincidan las temporadas de monta y parto. La duración y variación por región de la temporada de monta evidencian que ésta puede ser manejada en favor de una mejor producción.416 - [email protected] total of 349 records of kidding was used to evaluate frequency by month and geographical area. Regions studied were Paraguaná, Pedregal, and Aregue, located in arid environments to altitudes of 20, 250, and 600 m.a.s.l respectively. Flocks are range managed and the direct fraction of genes Creole averaged 95%. Proc Freq of SAS was used to estimate frequencies by month and geographical area. Results show two picks for kidding, clearly demarcated, but with significant variation among regions. The accumulated frequency in the first two and last four months of the year reached values of 36.8, 31.6, and 16.7 and of 48.5, 45.2, and 64.0% in the regions of Pedregal, Paraguaná, and Aregue respectively. Kidding picks are indicative of two mounting seasons that begin with the rains of months of April and August. Long and by region variation are indicative that mounting season can be managed in benefit of a better production