Producción de leche en vacas de doble propósito tratadas conoxitocina bajo condiciones de trópico húmedo mexicano

Research employing crossbred cows (½, ¾ and 7/8 B. Taurus x B. indicus) during the first 60 d of lactation was carried out at three commercial dairies, where feeding is based fundamentally on rotational grazing of tropical grasses. Supplemental feeding of the cows and their calves varied among the herds, but consisted mainly of mineral salts, poultry litter and other local resources. Two treatments related to the milking procedures were compared at each site. At Rancho Los Rejones (RLR) 11 cows per group were subjected to either: no stimulation to milk letdown other than that involved in routine 2x/d mechanical milking (control) or injection of 8 IU of oxytocin (OT) a.m. and p.m., three quarters being milked and the other left to be suckled by the calf. At Rancho Las Palmas (RLP) and Rancho La Isla (RLI) the 60-d period was divided into four successive 15-d phases. At RLP two groups of nine cow alternated by phase between the treatments: 8 IU/d of OT at the sole daily mechanical milking of three quarters or dummy insertion of a hypodermic needle without hormone (HN). At RLI one group of six cows received teat simulation by the calf (CS) prior to hand milking and six others received 10 IU/d of OT during two 15-d phases, alternating with CS in the other two phases. Milk production (kg/d) responded more to OT use than to routine stimulation at RLR (8.46 vs. 4.28, P<0.01), to HN at RLP (4.07 vs. 2.73, P<0.001) or to CS at RLI (8.58 vs. 5.48, P<0.05). At RLR body condition score of the cows did not differ between treatments, but at RLI use of OT resulted in greater weight loss than CS (51.08 vs. 17.24 kg). Weight gain of the calves (g/d) of cows treated with OT was slightly higher at RLR (381 vs. 328), but lower at RLP (252 vs. 333) and especially at RLI (561 vs. 719, P<0.01) relative to non-use of the exogenous hormone. In conclusion, the use of OT in early lactation improved milk yield, but it can also result in weight loss by the dam and reduced weight gain by the calf, to the detriment of double purpose operations.Se realizó experimentación usando vacas cruzas (½, ¾ and 7/8 B. taurus x B. indicus) durante los primeros 60-d de lactancia en tres ranchos comerciales donde la alimentación se basa fundamentalmente en pastoreo rotativo de gramíneas tropicales. La alimentación suplementaria de las vacas y sus crías varió entre los tres hatos, pero constó mayormente de sales minerales, pollinaza y otros recursos locales. Se compararon dos tratamientos relacionados con el ordeño en cada lugar. En Rancho Los Rejones (RLR) se sometieron 11 vacas por grupo a los tratamientos: ningún estímulo para la eyección de la leche en adición al rutinario del ordeño mecánico 2 x/d (control) o inyección de 8 UI de oxitocina (OT) a.m. y p.m., ordeñándose tres pezones y dejando el otro para la cría. En Rancho Las Palmas (RLP) y Rancho La Isla (RLI) se dividió al período de 60 d en cuatro sucesivos lapsos de 15. En RLP se alternaron por lapso dos grupos de nueve vacas entre los tratamientos: 8 UI/d de OT al ordeño mecánico único del día de tres pezones o la inserción de una aguja hipodérmica sin inyectar hormona (AH). En RLI un grupo de seis vacas recibió el estímulo de la cría sobre los pezones (EC) antes del ordeño manual y otras seis recibieron 10 UI/d de OT durante dos lapsos de 15 d, alternando con EC en los otros dos. La cosecha de leche (kg/D) respondió mejor al uso de OT que al estímulo rutinario en RLR (8.46 vs. 4.28, P<0.01), a AH en RLP (4.07 vs. 2.73, P<0.001) o a EC en RLI (8.58 vs. 5.48, P<0.05). En RLR la puntuación de condición corporal de las vacas no difirió entre tratamientos, pero en RLI el uso de OT resultó en mayor pérdida de peso materno que el EC (51.08 vs. 17.24 kg). La ganancia de peso de las crías (g/d) de vacas tratadas con OT fue levemente mayor en RLR (381 vs. 328), pero menor en RLP (252 vs. 333) y RLI 561 vs. 719, P<0.01) relativo al no uso de la hormona exógena. En conclusión, el uso de OT en lactación temprana promovió mayor producción de leche vendible, pero puede a la vez resultar en pérdida de peso corporal de la vaca y ganancias de peso menores en las crías, efecto adverso en un sistema doble propósito

Efecto del aceite de palma sobre el crecimiento y capacidad reproductiva de carneros de pelo púberes

The average daily gain (GDP), semen quality, libido, and serviceability in 8 hair rams (Black Belly × Kathadin and Pelibuey × Kathadin) supplemented with rations containing a 3 % of palm oil (AP) or animal fat (GA) were studied during 120 days. During the first 60 days, lambs were fed with 300 g/animal/d of a diet with 3 % of animal fat and, the following 60 days, each lamb received 500 g of feed. In the experimental group GA was replaced by AP. The average daily weight gain (GDP), body condition score (CC), scrotal circumference (CE), thoracic perimeter (PT), height at withers (AC) and length from the withers to the rump (LCG) were evaluated. The seminal quality was evaluated from 6 months of age and average weight of 26.0 kg. During seven weeks, the volume, concentra- tion, mass motility, individual primary abnormalities and living sperm percentage were assessed. To evaluate the libido and capacity of mating, the males were placed for 15 minutes with estrogenized females; number of mounts (NM), number of servi- ces (NS), number of mounts by service (NMS), reaction time (TR) to matings (1M, 2M, 3M) and services (1S, 2S, 3S), were recorded. The varia- bles were analyzed by ANOVA. There were no differences among AP and GA for the evaluated variables for PV, GDP, PT, CC, AC, and LCG. Semen quality, libido and serving capacity were similar. The number of services and reaction times for mount and service were also similar for both treatments, however diferents were observed in the number of mounts and so in number of mounts by service. The AP is an energetic alternative that can be considered in the feeding of rams in the tropics without affecting growth, the seminal quality and libido.Se evaluó la ganancia diaria de peso (GDP), calidad seminal, libido y capacidad de servicio en carneros de pelo, bajo pastoreo y suplementados con raciones conteniendo un 3 % de aceite de palma (AP) o grasa animal (GA). Se utilizaron ocho corderos Black Belly × Kathadin y Pelibuey × Kathadin. A los animales se les suministró durante los primeros 60 días, 300 g por cabeza de una ración con 3 % de GA, cantidad que se elevó a 500 g desde los 60 a los 120 días. En el grupo expe- rimental GA se sustituyó por la misma proporción de aceite de palma. Cada 14 días se evaluó el peso vivo (PV), GDP, condición corporal (CC), circun- ferencia escrotal (CE), perímetro torácico (PT), altura a la cruz (AC) y largo de la cruz a la grupa (LCG). La calidad seminal se evaluó a partir de los 6 meses de edad con un peso promedio de 26,0 kg. Durante siete semanas, se evaluó el volumen, concentración, motilidad masal e individual, % de anormalidades primarias y % de espermatozoides vivos. La libido y capacidad de monta se valoró con hembras estrogenizadas registrando el nú- mero de montas (NM), el número de servicios (NS), el número de montas por servicio (NMS), tiempo de reacción (TR) a las sucesivas montas (1M, 2M, 3M) y servicios (1S, 2S y 3S). Las variables se analizaron mediante un ANOVA. No se registraron diferencias entre AP y GA para las variables PV, GDP, PT, CC, AC y LCG. La calidad seminal, libido y capacidad de servicio fueron similares en ambos tratamientos. El número de servicios y el tiempo de reacción a la monta o al servicio fueron similares en ambos tratamientos sin embargo se observa- ron diferencias en el número de montas lo que se reflejó en el número de montas por servicio. El aceite de palma es una alternativa energética para la alimentación de carneros en el trópico que no afecta al crecimiento, calidad seminal y libido

Ovulatory response and embryo quality in Katahdin ewes supplemented with palm oil

The aims of this study were to evaluate the superovulatory response (SR), embryo quality and embryonic development in Katahdin ewes that received a dietary supplement of palm oil (PO). Ten ewes were assigned to receive 35 g palm oil (n = 10, PO3) and 10 to receive 70 g palm oil (n = 10, PO6) for 25 days. On day 0, the ewes were synchronized with 0.3 mg progesterone-releasing devices (CIDR-G®). From days 6 to 9, the donors were superovulated with 200 mg follicle-stimulating hormone (FSH) (Folltropin-V®) at decreasing doses every 12 hours (40 - 40, 30 - 30, 20 - 20 and 10 - 10 mg/ewe). On day 8, the devices were removed and donors were mated twice with fertile rams at 12-h intervals. Seven days after mating, the embryos were recovered and evaluated for their stage of development and quality grade (1 = excellent, 2 = good, 3 = bad and 4 = degenerated). In addition, on days 0, 7 and 15, blood samples were taken to determine cholesterol, triglycerides, insulin and insulin-Iike growth factor-1 (IGF-1) concentrations in serum blood. Using chi-square and t-tests, the superovulatory response (SR), ovulation rate (OR), total embryonic structures (TES), transferable embryos (TE), degenerated embryos (DEs) and developmental stage and quality were evaluated. No significant differences were observed between treatments for SR, OR, TES and TE variables or for cholesterol, triglycerides, insulin and IGF-1 concentrations. There were differences in the numbers of DE, as well as a trend for more homogeneous developmental stage in the embryos of ewes supplemented with PO6, as well as a higher number of quality 1 embryos and lower numbers of quality 3 and 4 embryos. Palm oil supplementation could be a recommendable practice to improve the quality of embryos and homogenous developmental stage (morula and blastocyst).Keywords: Fatty acids, ovarian activity, shee

Evaluación de una vacuna de ADN y su péptido recombinante contra inhibina alfa (165-300) sobre la respuesta inmune y fertilidad en ratones

Abstract: The aim was to evaluate a DNA vaccine (INHA-DNA) and its recombinant peptide INHA-rec) against inhibin alpha (INHA) on the immune response and fertility in mice. Sixteen Balb/c mice were divided into two groups of 8 each and under a heterologous prime boost immunogenic scheme one group were inoculated with 100 μg of INHA-DNA and 14 d later with 100 μg of INHA-rec. The control group received saline solution. After the first birth, a booster was given with both antigens (INHA-DNA + INHA-rec). Immunization with 100 μg of INHA-DNA and INHA-rec induced high levels of anti-INHA antibody, as well as greater weight and size litter (P <0.05) compared to control. The mean fertility was similar between INHA (67%) and control (60%). In conclusion, the DNA vaccine and its recombinant antigen against INHA are capable of inducing immunity against INHA by increasing litter size without an apparent negative effect on fertility in mice.Resumen: Se evaluó la vacuna de ADN (INHA-DNA) y su péptido recombinante (INHA-rec) contra inhibina alfa (INHA) sobre la respuesta inmune y la fertilidad en ratones. Dieciséis ratones Balb/c fueron divididos en dos grupos, 8 cada uno. Bajo un esquema de inmunización prime boost heterólogo, un grupo fue inoculado vía intramuscular (IM) con 100 µg de INHA-DNA y 14 d, después con 100 µg de INHA-rec. El grupo control recibió solución salina. Se aparearon las hembras en dos ocasiones. Posterior al primer parto se dio un refuerzo vía IM con ambos inmunógenos (100 µg INHA-DNA + 100 µg INHA-rec). La inmunización con 100 µg de INHA-DNA y INHA-rec indujo altos niveles de anticuerpo anti INHA, mayor tamaño y peso de camada (P<0.05) comparados con el control. La fertilidad promedio fue similar entre los tratados (67%) y control (60%). En conclusión, la vacuna de ADN y su antígeno recombinante es capaz de inducir títulos de anticuerpos contra INHA incrementando el tamaño de camada, sin un efecto negativo sobre la fertilidad en ratones

PERFORMANCE OF HAIR EWES LAMBS WITH DIFFERENTS LEVELS OF PALM KERNEL MEAL IN GRAINS SUBSTITUTION

The nutritional status is an important factor on the productive and reproductive performance in ewes. Four levels of palm kernel meal (HP) in substitution of corn grain were evaluated on posweaning performance of hair ewe lambs. Forty-three hair ewe lambs (11.72 ± 0.33 kg de body weight) were assigned to isoenergetic and isoproteic diets with 0, 15, 30 and 45% of HP (HP0, HP15, HP30 y HP45, respectively; n=9 per treatment) and grazing (PASTO), for 112 days. It was evaluated the final live weight (PVF), daily weight gain (GDP), body condition (CC), feed conversion (CA), and feed efficiency (EUA). In base to economic registers was determined the optimal economic and profit maximization of the levels evaluated. The CC was similar (P > 0.05) between HP0, HP15, HP30 and HP45. The PVF, GDP, CA and EUA, between HP0, HP15 and HP30 were similar (P < 0.05), with tendencies to be different (P < 0.08) with the lambs of HP45 and different (P < 0.05) with PASTO. The lambs of HP45 and PASTO recorded the lowest GDP (99.03 ± 0.89 and 42.84 ± 0.51 g d-1), CA (6.24 ± 0.57 and 13.82 ± 4.0 kg feed kg-1 of live weight) and EUA (18.64 ± 1.4 and 8.09 ± 0.99%). The economic optimal was obtained between 15 and 30% of inclusion of HP and the maximum profit obtained was $286.80 pesos with HP30. So it is possible to replace grains with HP up to 30% with similar performance and better profit

Use of equine chorionic gonadotropin (eCG) in Mashona heifers, under a J-Synch synchronization protocol, and its effect in pregnancy rate: Use of equine chorionic gonadotropin in a J-Synch protocol in heifers

Objective: The objective of the present study was to evaluate the J-Synch protocol with two doses of eCG in beef heifers during the summer in Northeast Mexico. Design/methodology/approach: In this experiment, 218 heifers of the Mashona breed (109/treatment) with a live weight of 350 ±12.1 kg were used. On Day 0, all heifers received an intravaginal device (1.2 g P4) plus 2 mg, i.m., EB; On day 5, it was withdrawn and 0.15 mg of D-Cloprostenol was applied; where treatment 1 (T1) consisted of the application of 250 IU of eCG; in treatment 2 (T2), 300 IU of eCG was applied. Subsequently, the total number of heifers from both treatments were inseminated at a fixed time (FTAI) at 72 hours after the removal of the device with frozen bull semen; likewise, at the time of the FTAI, 10.5 µg of GnRH was applied to each heifer. Results: There were no significant differences (p &gt; 0.05) in the percentage of estrus at the first service (T1 = 91%; T2 = 96%; as well as in the percentage of repeaters (T1 = 25.2% vs T2 = 19 .2%). For the inseminating technician and the color of the heifers' coat, there was an effect on the percentage of heifers repeating estrus. For the percentage of pregnancy at first service, it was 64.8% for T1 and 70.1 % for T2 (p &gt; 0.05) There was only an effect of the inseminator technician in terms of pregnancy percentage, varying from 63.4% for the best-qualified technician vs. 48.6% for the one with the lowest percentage. Limitations on study/implications: At least in this study, the pregnancy rate in beef heifers will depend mainly on the experience and skill of the inseminator technician. Findings/conclusions: According to the present investigation, the indistinct application of 250 or 300 IU of eCG can be used with the same results of the presence of estrus and gestation during the summer season in beef heifers, however, the inseminator technician has an important role on pregnancy outcomes.O Objective: To evaluate the J-Synch protocol with two eCG doses in beef heifers during the summer in northeastern Mexico. Design/Methodology/Approach: 218 heifers (109/treatment) with a body weight of 350 ± 12.1 kg were used. A J-Synch protocol was applied in order to evaluate two eCG doses: T1 (250 IU) and T2 (300 IU). Subsequently, the total number of heifers from both treatments were inseminated at a fixed time (FTAI): 72 h after removing the device. Results: No significant differences (p&gt;0.05) were recorded in the estrous percentage at first service (T1 = 91%; T2 = 96%) and in the repeating heifers (T1 = 25.2%; T2 = 19.2%). The insemination technician and coat color variables impacted the estrous percentage in repeating heifers. The pregnancy percentage at first service was 64.8% and 70.1% for T1 and T2 (p&gt;0.05), respectively. The insemination technician had a variable effect on the pregnancy percentage, from 63.4% (the best-qualified technician) to 48.6% (the technician who obtained the lowest percentage). Study Limitations/Implications: The pregnancy rate in beef heifers will depend mainly on the experience and skill of the insemination technician. Findings/Conclusions: The same results were obtained regarding the presence of estrous and pregnancy in beef heifers during the summer season, either with 250 or 300 IU of eCG