Parturition, weaning and shearing data of K´aras and Ch´accus lamas, collected from 1995 to 2001 at the IVITA Research Center, Maranganí of San Marcos University, was used in the present study to estimate the heritability (h2), repeatability and genetic correlations between body weight at birth, weaning and first and second shearing, by adjusting the fata for the effect of year, age of mother and sex of baby lama. The h2 value was analyzed by the nested effect using a model for brothers, brothers in law and by regression baby-mother. Heritability for body weight for both K´aras and Ch´accus lamas was high, while for birth weight and weight at first and second shearing varied from medium to high. The repeatability estimated by intraclass correlation for body weight of Ch´accus and K´aras was lower (0.3-0.4) than those estimated by regression (0.6-0.7, respectively). Genetic correla...

En la Estación de Camélidos - Marangani, Cusco, del Instituto Veterinario de Investigaciones Tropicales y de Altura (IVITA) - (lat. sur 14, 30'; long oeste 71 ; altitud 4100-4200 m precipitación pluvial, 900 mm y temperatura promedio 6.5"C) se realizó un estudio de alimentación post destete en alpacas y llamas y su efecto sobre la obtención de peso necesario (alpacas = 30 kg; llamas = 50 kg) para que puedan ser empadradas al año de edad. Se usó el mismo diseño en alpacas y llamas como sigue: T1) Pasto cultivado, área 2 ha, n = 30 y T2) Pradera natural, área 15 ha, n = 30. En T1 el pastoreo fue rotativo en sus parcelas con 7 d de pastoreo y 40 d de descanso; en T2 el pastoreo fue continuo. Mensualmente desde setiembre 1997 (destete) hasta marzo 1998 se registró el peso corporal y los animales que alcanzaban el peso apropiado eran separados para el empadre. Al final del estudio...

The present study was carried out at IVITA-Maranganí Experimental Station to evaluate the animal response to fattening in llamas of two ages submitted to different nutritional regimes in two seasons. An irrestricted randomize design with 2 x 2 x 3 factorial arrangement (two ages: 1 and 2; two seasons: rainy and dry; and three nutritional regimes: natural pasture, mixture of phalaris + clover, and mixture ofryegrass + clover) was used. A total of 60 male llamas (30 of one year and 30 of two years old) were used during a 90-day period of fattening. The stocking rate was 5, 10 and 10 animals/ha for natural pasture, phalaris + clover, and ryegrass + clover, respectively. The body weight gain was evaluated at different periods: 0-30, 31-60, 61-90, 0-60 and 0-90 days (d). Differences in body weight gain was observed in llamas of two years old (183 g/d) as compared with those of one year of ag...

The aim of this study was to evaluate the effect of fresh (YHF) and powder (YHP) egg yolk on the motility, viability, functional integrity of the plasma membrane (HOST) and pregnancy rate after insemination using fresh and chilled semen. Thirty ejaculates of five alpacas were collected by the post-copulation method during the months of January to March. Ejaculates were diluted in Tris-glucose plus glycerol to a final concentration of 5%, and the two types of egg yolk were added at a final concentration of 20%. Diluted semen was separated into aliquots and maintained at 15 °C for 8 h and 5 °C for 24 h, where 180 alpacas were inseminated. Motility, viability and sperm HOST value stored at 15 and 5 °C were not affected by the type of egg yolk. Similarly, pregnancy rates were rather similar when inseminated with fresh semen (50.0 and 46.7%), or kept at 15 °C (43.3 and 40%) or 5 °C (33.3...

The aim of this study was to evaluate the pregnancy and natality rate of artificial insemination (AI) in alpacas, using fresh semen, with one and two services, in Cusco, Peru. Semen from 10 alpacas was collected by the post-copula method between January and March, using ejaculates that had volume ≥1 ml, motility ≥60% and light red or creamy white color. The ejaculates were diluted in Tris-glucose and egg yolk at a concentration of 20%. For AI, alpacas with history of previous births, ≥20-day post-partum and body condition ≥3, receptive to the male and with a preovulatory follicle ≥7 mm were selected. The induction of ovulation was done with the administration of 80 μg buserelin/animal. The females were inseminated 26-30 h after the induction of ovulation, with diluted fresh semen (1 ml with 25x106 spermatozoa), deposited inside the body of the uterus. The diagnosis of pregnanc...

Se utilizó información de parición, destete y esquila de llamas Cha´ccus y K´aras, de los registros de la Estación Experimental del Centro de Investigaciones IVITA-Maranganí del periodo 1995-2001. Se estimó la heredabilidad (h2), repetibilidad y correlaciones genéticas de peso corporal al nacimiento, destete, y primera y segunda esquila ajustando los datos por efecto del año de producción, edad de la madre y sexo de la cría. Los valores de h2 se estimaron a través de un diseño de hermanos enteros, de medios hermanos paternos y regresión cría madre. La h2 para el peso al destete, tanto en llamas K´ara como en Cha´ccus fue alta, mientras que para el peso al nacimiento y peso vivo a la primera y segunda esquila tuvo valores de medio a alto. Los índices de repetibilidad para el peso vivo en llamas Cha´ccus y K´aras, estimados a través del método de la correlación intr...

En la Estación de Camélidos - Marangani, Cusco, del Instituto Veterinario de Investigaciones Tropicales y de Altura (IVITA) - (lat. sur 14, 30'; long oeste 71 ; altitud 4100-4200 m precipitación pluvial, 900 mm y temperatura promedio 6.5"C) se realizó un estudio de alimentación post destete en alpacas y llamas y su efecto sobre la obtención de peso necesario (alpacas = 30 kg; llamas = 50 kg) para que puedan ser empadradas al año de edad. Se usó el mismo diseño en alpacas y llamas como sigue: T1) Pasto cultivado, área 2 ha, n = 30 y T2) Pradera natural, área 15 ha, n = 30. En T1 el pastoreo fue rotativo en sus parcelas con 7 d de pastoreo y 40 d de descanso; en T2 el pastoreo fue continuo. Mensualmente desde setiembre 1997 (destete) hasta marzo 1998 se registró el peso corporal y los animales que alcanzaban el peso apropiado eran separados para el empadre. Al final del estudio...

The present study was carried out at IVITA-Maranganí Experimental Station to evaluate the animal response to fattening in llamas of two ages submitted to different nutritional regimes in two seasons. An irrestricted randomize design with 2 x 2 x 3 factorial arrangement (two ages: 1 and 2; two seasons: rainy and dry; and three nutritional regimes: natural pasture, mixture of phalaris + clover, and mixture ofryegrass + clover) was used. A total of 60 male llamas (30 of one year and 30 of two years old) were used during a 90-day period of fattening. The stocking rate was 5, 10 and 10 animals/ha for natural pasture, phalaris + clover, and ryegrass + clover, respectively. The body weight gain was evaluated at different periods: 0-30, 31-60, 61-90, 0-60 and 0-90 days (d). Differences in body weight gain was observed in llamas of two years old (183 g/d) as compared with those of one year of ag...

El objetivo del estudio fue evaluar el efecto de la yema de huevo fresca (YHF) y en polvo (YHP) sobre la motilidad, viabilidad, integridad funcional de la membrana plasmática (HOST) y tasa de preñez con semen fresco y refrigerado. Se colectaron 30 eyaculados de cinco alpacas mediante el método poscópula en los meses de enero a marzo. Los eyaculados fueron diluidos en Tris-glucosa y glicerol a una concentración final de 5%, y usando los dos tipos de yema de huevo a una concentración final de 20%. El semen diluido se separó en alícuotas y se mantuvo a 15 ºC por 8 h y a 5 ºC por 24 h, y se inseminaron 180 alpacas. El tipo de yema no afectó la motilidad,  viabilidad y el valor HOST en los espermatozoides conservados a 15 y 5 ºC. De igual manera, los porcentajes de preñez no variaron cuando se inseminaron con semen fresco (50.0 y 46.7%), mantenido a 15 ºC (43.3 y 40%) o refrige...

The aim of this study was to evaluate the pregnancy and natality rate of artificial insemination (AI) in alpacas, using fresh semen, with one and two services, in Cusco, Peru. Semen from 10 alpacas was collected by the post-copula method between January and March, using ejaculates that had volume ≥1 ml, motility ≥60% and light red or creamy white color. The ejaculates were diluted in Tris-glucose and egg yolk at a concentration of 20%. For AI, alpacas with history of previous births, ≥20-day post-partum and body condition ≥3, receptive to the male and with a preovulatory follicle ≥7 mm were selected. The induction of ovulation was done with the administration of 80 μg buserelin/animal. The females were inseminated 26-30 h after the induction of ovulation, with diluted fresh semen (1 ml with 25x106 spermatozoa), deposited inside the body of the uterus. The diagnosis of pregnanc...

Semen from alpacas was collected by two methods: by aspiration from the female’s vagina following mating and with an artificial vagina. Semen was collected, evaluated and extended with Tris buffer, and then used in artificial insemination. Altogether 160 female alpacas with proven reproductive history and five males were used. Semen was collected by vaginal aspiration from 10 females using five males as semen donors; likewise, semen from the same males was collected with an artificial vagina twice a week 50 times. Volume, motility, spermatic concentration, live spermatozoa, viscosity and color was evaluated. Seminal characteristics of semen collected by aspiration and with an artificial vagina were: volume (3.6 and 1.5 mL), motility (73.4 and 69.0%), sperm concentration (75.2 and 80.3 million/mL), live spermatozoa (75.3 and 70.8%) respectively, with statistical difference between metho...

The effect of oestradiol (E2 ) during the maternal recognition of pregnancy (9-11 days after ovulation) was studied in 44 alpacas that were >20 days after delivery. The alpacas were mated with an intact male (>15 minutes) and received 500 IU of hCG to induce ovulation. The females were divided in 3 groups: Group G1 (n=14) received 0.2 ml. i.m. of an A, D and E vitaminic complex on days 8 and 9 post-ovulation. Group G2 (n=15) received 200 mg of E2 and 0.2 ml i.m. of the vitamin complex (similar to G1 ) on days 8 and 9 post-ovulation. Group G3 (n=15) received 20 mg of progesterone and 0.2 ml i.m. of the same vitamin complex on day 9 post-ovulation. The females were confronted with a male to evaluate their sexual behavior (accept or denial) and then, transrectal ecography of the ovaries and uterus was conducted on days 2, 8, 13, 19, 27, 30 and 60 post-ovulation. Embryonic survival was...

The effect of the exogenous progesterone (P4) on the development of follicular waves in llamas was studied in twenty-five females. According to dose and regimen for P 4 administration, animals were allocated to 5 groups (n=5): 00 (control group ), G 1 (30 mg P /day for 2 days); G2 (30 mg P/day for 4 days); G3 (50 mg P /day for 2 days) and G4 (50 mg P /da y for 4 days ). Development of dominant ():. 7 mm) and subordinated follicles (>3 mm and < 7 mm) were monitored daily by transrectal ultrasonography. The minimun size reachedbythedorninantfollicleingroupsGl (4.6±0.9mm), G3(5.1±1.5 mm) andG4(5.3 ± 1.6 mm) were smaller (P< 0.05) than group 00 (8.5 ± 1.0 mm). The whole follicular regression of the dominant follicle in groups G 1 (5.5 ± 2.0 mm), G2 (5.9 ± 1.4 mm) and G3 (5.3 ± 3. 3 mm) were larger (P< 0.05) than group 00 (0.9 ± 1.4 mm). The number of subordinated follicle...

In order to study the effect of testosterone on penis-prepucial adherences,twenty alpacas were selected from a flock of male tuis. Fourteen and six of the selected animals were one and two years old respectively, from which 90% showed almost complete penis-prepucial adherence (0 and 1 grade) and the remaining showed a grade 2 adherence. Animals were randomly assigned to two treatment groups (Toand T2) according to age and adherence grade in order to achieve experimental equilibrium. Each T2 animal received 327 mg of testosterone i.m. distributed in three doses,on a two-week interval. Both body weight and adherence releasing grade were evaluated fortnightly; testicular size and sexual behaviour were recorded weekly. A larger releasing adherence was observed in one-year-old alpacas in T2, specially between weeks sixth and ninth, after treatment (P<0.08). There was a treatment-age intera...

Semen de alpaca fue colectado por dos métodos: por aspiración de la vagina de la hembra después de la monta natural y con vagina artificial. El semen colectado fue evaluado y diluido con Tris tamponado, y luego usado en inseminacion artificial. Se trabajó con 160 alpacas hembras adultas de capacidad reproductiva comprobada y 5 alpacas machos. Se colectó semen post cópula de los cinco machos en 10 hembras, y se hicieron 50 colecciones de semen con vagina artificial de estos machos, dos veces por semana. Se determinó volumen, motilidad, concentración espermática, porcentaje de espermatozoides vivos, viscosidad y color. Los resultados para semen colectado por aspiración de la vagina y con vaginal artificial fueron: volumen (3.6 y 1.5 mL), motilidad (73.4 y 69.0%), concentración espermática (75.2 y 80.3 millones/mL), espermatozoides vivos (75.3 y 70.8%), respectivamente, con dife...

El efecto del estradiol (E2 ) durante el periodo de reconocimiento maternal de la preñez (días 9-11 post-ovulación) fue estudiado en 44 alpacas con descanso postparto > 20 días. Los animales fueron sometidos a una monta controlada con macho entero (>15 minutos) y se les aplicó 500 UI de gonadotropina coriónica humana (hCG) vía i.m. Los animales fueron divididos en 3 grupos: El grupo G1 (n=14) recibió 0.2 ml de una solución de vitaminas A, D y E vía i.m. los días 8 y 9 post-ovulación. El grupo G2 (n=15) recibió 200 mg de E2 vía i.m. + 0.2 ml de la solución de vitaminas aplicada en G1 los días 8 y 9 postovulación. El grupo G3 (n=15) recibió 20 mg de progesterona + 0.2 ml de la solución vitamínica el día 9 post-ovulación. Las hembras fueron enfrentadas al macho para evaluar el comportamiento sexual de las hembras y paralelamente, se les realizó una ecografía tr...

The effect of the exogenous progesterone (P4) on the development of follicular waves in llamas was studied in twenty-five females. According to dose and regimen for P 4 administration, animals were allocated to 5 groups (n=5): 00 (control group ), G 1 (30 mg P /day for 2 days); G2 (30 mg P/day for 4 days); G3 (50 mg P /day for 2 days) and G4 (50 mg P /da y for 4 days ). Development of dominant ():. 7 mm) and subordinated follicles (>3 mm and < 7 mm) were monitored daily by transrectal ultrasonography. The minimun size reachedbythedorninantfollicleingroupsGl (4.6±0.9mm), G3(5.1±1.5 mm) andG4(5.3 ± 1.6 mm) were smaller (P< 0.05) than group 00 (8.5 ± 1.0 mm). The whole follicular regression of the dominant follicle in groups G 1 (5.5 ± 2.0 mm), G2 (5.9 ± 1.4 mm) and G3 (5.3 ± 3. 3 mm) were larger (P< 0.05) than group 00 (0.9 ± 1.4 mm). The number of subordinated follicle...

Se seleccionaron 20 animales de un hato de tuis machos, de los cuales 14 y 6 fueron de 1 y 2 años de edad, respectivamente, y donde el 90% tuvo adherencia pene-prepucial casi completa (grado 0 y 1) y el resto adherencia del grado 2; a fin de estudiar el efecto de la testosterona en la liberación de las adherencias. Se formaron al azar dos grupos de tratamiento (T0 Y T2), conservando el equilibrio experimental en función de la edad y grados de adherencia. Cada animal del grupo T2 recibió vía i.m. un total de 327 mg de testosterona, distribuidos en tres aplicaciones, con intervalos de 2 semanas. El peso corporal y el grado de liberación de las adherencias fueron evaluados cada dos semanas, y el tamaño testicular y el comportamiento sexual fue registrado semanalmente. Mayor porcentaje de liberación de adherencia se observó en alpacas de un año de edad de T2, especialmente entre la...

A flock of 82 llamas with their calves was used to evaluate the hip area and thigh volume of the young and the size of the mammary gland of the dam as possible indicators for early selection of llamas for meat production. In the young, the development of hips and thighs at 2, 8, and 15 months of age and the correlation of these measurements with body weight and chest circumference were evaluated, whereas in the dams, the relation between size of the mammary gland and body weight at weaning of the calf was evaluated. Size of hip was calculated as a geometric figure using the Autocad software, and the size of the thigh was expressed as the volume of a truncated cone. The increase of body weight (65.3%), hip area (51.5%), thigh volume (53.2%) were significantly higher (p<0.05) than the increase in chest circumference (32.9%). Animals were distributed into two groups according to hip area...

Sixty-five 3-4 years old Corriedale ewes were used from April to August 2002 to evaluate the effect of PGF2µ treatment at days 4 (GP4) and 10 (GP10) of the estrous cycle on (i) the percentage of estrus, (ii) variability within animals in the onset of estrus, (iii) the length of the treatment-estrus interval and, (iv) the rate of pregnancy. The estrous cycle was synchronized inserting intravaginal sponges impregnated with 30 mg of fluorogestone acetate (FGA) during 12 days. After the occurence of estrus (estrus = day 0), 20 ewes at day 4 (GP4) and 22 at day 10 (GP10) were treated with 0.175 mg of an analogue of PGF2µ. The 23 remaining ewes were not treated and kept as control group (GC). Estrus was detected by introducing vasectomized rams to the flock at 6, 12 and 17 h on daily basis. All FGA-synchronizated ewes showed estrus, as well as after the treatment with PGF2µ; however, the on...