36 research outputs found
Resposta à vermifugação seletiva em ovinos de diferentes raças sob pastejo contínuo nos trópicos úmidos
El objetivo fue evaluar la respuesta bajo un programa de desparasitación selectiva de ovejas Pelibuey (PB, n=12), Katahdin (KT, n=12), Pelibuey x Katahdin (PB:KT, n=15) y Pelibuey x Dorper (PB:DP, n=15) bajo pastoreo continuo sobre la excreción de huevos por gramo de heces (HPG), peso vivo (PV), condición corporal (CC), nivel de anemia (FAMACHA), hematocrito (Hto), hemoglobina (Hb) y la frecuencias de desparasitación. Las variables fueron evaluadas mediante un análisis de varianza considerando como tratamiento los grupos raciales (PB, KT, PB:KT y PB:DP) a través de los cuatro periodos de evaluación con medidas repetidas (días 20, 48, 76 y 104) en el tiempo y sus interacciones. Las frecuencias de desparasitación de las ovejas en cada categoría se analizaron mediante tablas de contingencia y pruebas de Chi cuadrada. Los valores de HPG fueron más altos (p<0.05) para las ovejas de los grupos raciales PB y PB:DP comparado a las ovejas KT y PB:KT. Contrariamente, las ovejas PB y PB:KT mostraron niveles mayores (p<0.05) de Hto comparadas con las ovejas KT y PB:DP. Sin embargo, los niveles de Hb encontrados fueron similares entre los grupos raciales evaluados. La proporción total acumulada revela que las ovejas PB:DP fueron las que mas requirieron (p<0.05) ser desparasitadas al menos una vez (32.8%). No se encontraron diferencias significativas entre los grupos raciales PB, KT y PB:KT. De acuerdo a los indicadores de PV, CC, Famacha, HPG, Hto, Hb y proporción de animales desparasitados durante el periodo evaluado, las ovejas del grupo racial PB:KT observaron el mejor comportamiento. Por tanto, la elección adecuada del mejor genotipo para condiciones de pastoreo combinado a un programa de desparasitación selectiva, puede contribuir significativamente en el control de nematodos gastrointestinales.The aim was to evaluate the response under a selective deworming program of Pelibuey (PB, n=12), Katahdin (KT, n=12), Pelibuey x Katahdin (PB:KT, n=15) and Pelibuey x Dorper (PB :DP, n=15) ewes under continuous grazing on the excretion of eggs per gram of feces (HPG), live weight (LW), body condition score (BCS), level of anemia (FAMACHA), hematocrit (Hto), hemoglobin (Hb ) and deworming frequencies. The variables were evaluated by means of an analysis of variance considering as treatment the racial groups (PB, KT, PB:KT and PB:DP) through the four evaluation periods with repeated measures (days 20, 48, 76 and 104) in time and their interactions. The deworming frequencies of the sheep in each category were analyzed using contingency tables and Chi-square tests. HPG values were higher (p<0.05) for ewes from the PB and PB:DP breed groups compared to KT and PB:KT ewes. In contrast, PB and PB:KT ewes showed higher levels (p<0.05) of Hto compared to KT and PB:DP ewes. However, the Hb levels found were similar between the racial groups evaluated. The accumulated total proportion reveals that PB:DP ewes were the ones that most required (p<0.05) to be dewormed at least once (32.8%). No significant differences were found between the PB, KT and PB:KT racial groups. According to the indicators of LW, BCS, Famacha, HPG, Hto, Hb and proportion of dewormed animals during the evaluated period, the sheep of the PB:KT breed group observed the best behavior. Therefore, the adequate choice of the best genotype for grazing conditions combined with a selective deworming program can contribute significantly to the control of gastrointestinal nematodes
The reinsertion of controlled internal drug release devices in goats does not increase the pregnancy rate after short oestrus synchronization protocol at the beginning of the breeding season
Trabajo de investigación cuya temática es la sincronización del estro en ovejas de pelo.This study aimed to evaluate the effect of reinserting controlled internal drug release (CIDR) devices after fixed-time artificial insemination (FTAI) on pregnancy rates in goats. Oestrus was synchronized with a short (5 days) CIDR protocol, and FTAI was conducted 54 hours after CIDR removal. According to the reinsertion of CIDR after FTAI, goats were assigned to three treatments: G0 control group (n = 29), no CIDR reinsertion; G7 group (n = 27), CIDR reinserted 7 days; G14 group (n = 29), CIDR reinserted 14 days. Blood samples were collected to determine progesterone levels. Oestrus appearance (92.9%), interval of CIDR removal to oestrus (IRE = 34.1 ± 1.1 hours), interval of oestrus onset to artificial insemination (IEAI = 20.2 ± 1.0 hours), mean duration of oestrus (38.4 ± 1.4 hours), and pregnancy rates (61.0%) were similar (P > .05) among groups. Progesterone concentrations were higher (P .05) for all groups. In conclusion, reinsertion of CIDR for 7 or 14 days after a short oestrus synchronization protocol and FTAI did not increase the overall pregnancy rate of goats
Desempeño productivo y análisis económico de una engorda intensiva de corderos tratados con zeranol y andrógenos inyectable bajo condiciones tropicales
The aim of this study was to compare the productive performance and profitability of the fattening of Kathadin male and female lambs (n=97) in confinement treated with Zeranol (ZNL), androgens (AND) and ZNL+AND under a 2x4 factorial design. The lambs treated with ZNL received 0.2 mg/kg of body weight (BW) every 28 d, those treated with AND received Nandrolone Decanoate + Trenbolone + Boldenone Undecinelate, via IM in doses of 0.3 mg/kg + 0.4 mg/kg + 0.3 mg/kg of BW, respectively, every 28 d, those treated with ZL+AND received the same doses of the mentioned drugs, while those in the control group received 0.5 mL of saline solution. Final body weight (FBW), daily weight gain (DWG), feed conversion (FC) on dry basis (DM) and wet basis (WM), and voluntary intake (VC) in DM and WM were evaluated. The FBW was different (p<0.05) between treatments in males and females. The DWG was higher (p<0.05) for females treated with AND compared to those treated with ZNL and AND+ZNL, the latter being similar to those of the control group. Females treated with AND registered a lower (p<0.05) VC compared to those treated with ZNL and AND+ZNL. Net utility, benefit: cost ratio and profitability were better in animals treated with AND. The administration of AND represents a viable alternative to make more efficient the confinement fattening systems of lambs.El objetivo del estudio fue comparar el desempeño productivo y la rentabilidad de una engorda de corderos machos y hembras Kathadin (n=97) en confinamiento tratados con Zeranol (ZNL), andrógenos (AND) y ZNL+AND bajo un diseño factorial 2x4. Los corderos tratados con ZNL recibieron 0.2 mg/kg de peso vivo (PV) cada 28 d, los tratados con AND recibieron Decanoato de nandrolona + Trembolona + Undecinelato de boldenona, vía IM en dosis de 0.3 mg/kg + 0.4 mg/kg + 0.3 mg/kg de PV, respectivamente, cada 28 d, los tratados con ZL+AND recibieron las mismas dosis de los fármacos mencionados, en tanto que los del grupo control recibieron 0.5 ml de solución salina. Se evaluó el peso vivo final (PVF), ganancia diaria de peso (GDP), conversión alimenticia (CA) en base seca (BS) y base húmeda (BH), y el consumo voluntario (CV) en BS y BH. El PVF fue diferente (p<0.05) entre tratamientos en hembras y machos. La GDP resultó mayor (p<0.05) para hembras tratadas con AND en comparación con las tratadas con ZNL y AND+ZNL, siendo las últimas similares a las del grupo control. Las hembras tratadas con AND registraron un menor (p<0.05) CV en comparación con las tratadas con ZNL y AND+ZNL. La utilidad neta, relación beneficio: costo y rentabilidad fueron mejores en los animales tratados con AND. La administración de AND representa una alternativa viable para hacer más eficiente los sistemas de engorda de corderas y corderos en confinamiento
Changes in air quality in Mexico City, London and Delhi in response to various stages and levels of lockdowns and easing of restrictions during COVID-19 pandemic
The impacts of COVID-19 lockdown restrictions have provided a valuable global experiment into the extent of improvements in air quality possible with reductions in vehicle movements. Mexico City, London and Delhi all share the problem of air quality failing WHO guideline limits, each with unique situations and influencing factors. We determine, discuss and compare the air quality changes across these cities during the COVID-19, to understand how the findings may support future improvements in their air quality and associated health of citizens. We analysed ground-level PM10, PM2.5, NO2, O3 and CO changes in each city for the period 1st January to August 31, 2020 under different phases of lockdown, with respect to daily average concentrations over the same period for 2017 to 2019. We found major reductions in PM10, PM2.5, NO2 and CO across the three cities for the lockdown phases and increases in O3 in London and Mexico City but not Delhi. The differences were due to the O3 production criteria across the cities, for Delhi production depends on the VOC-limited photochemical regime. Levels of reductions were commensurate with the degree of lockdown. In Mexico City, the greatest reduction in measured concentration was in CO in the initial lockdown phase (40%), in London the greatest decrease was for NO2 in the later part of the lockdown (49%), and in Delhi the greatest decrease was in PM10, and PM2.5 in the initial lockdown phase (61% and 50%, respectively). Reduction in pollutant concentrations agreed with reductions in vehicle movements. In the initial lockdown phase vehicle movements reduced by up to 59% in Mexico City and 63% in London. The cities demonstrated a range of air quality changes in their differing geographical areas and land use types. Local meteorology and pollution events, such as forest fires, also impacted the results
Genes con efecto mayor sobre la fertilidad de ovejas. Revisión
The genetic study on sheep breeds with naturally high ovulation rate (OR) and prolificacy, has allowed to detect theparticipation of several genes. Among them there are the ones related to the transforming growth factor-betasuperfamily (BMPRIB, GDF9 and BMP-15), as well as to other genes with major effect, such as the distal-lesshomeobox 3’ (FecL), estrogen receptor (ESR), prolactin receptor (PRLR) and inhibin receptor (INHA and INHB).However, sheep homozygous for the majority of the allelic variants in BMP-15 or GDF9 are sterile, for which it isimportant the understanding of the genetic and molecular basis of these polymorphisms, for their use in rationalprograms of genetic improvement on prolificacy. Polymorphism in the melatonin gene (MTNR1) has been associatedwith non-reproductive seasonality in sheep. Selecting several sheep breeds for these characteristics has significantlyreduced the seasonal anoestrus, showing reproductive activity during spring and summer. It seems that these genesin some breeds may be interacting additively and an allelic variant in a breed may not be present in other, or twobe present at the same time; therefore, the understanding of the genetic mechanisms that affect ovulation rate andprolificacy are important for the selection of reproductive traits.El estudio genético en razas de ovejas que naturalmente presentan altas tasas de ovulación (TO) y de prolificidad, ha permitido detectar la participación de varios genes. Entre ellos están los relacionados a lasuperfamilia del factor de crecimiento transformante B (BMPRIB, GDF9 y BMP-15), así como de otros genes con efecto mayor, tales como el “distal-less homeobox 3” (FecL), el receptor de estrógenos (ESR), el receptor de prolactina (PRLR) y el de las inhibinas (INHA y INHB). Sin embargo, las ovejas homocigotas para la mayoría de las variantes alélicas en BMP-15 o GDF9 son estériles, por lo que es importante el entendimiento de las bases genéticas y moleculares de estos polimorfismos, para su uso en programas racionales de mejoramiento genético con énfasis en la prolificidad. El polimorfismo en el gen de la melatonina (MTNR1) se ha asociado con la no estacionalidad reproductiva en ovejas. La selección en varias razas de ovejas para estas características ha reducido significativamente el anestro estacional, mostrando actividad reproductiva durante la primavera y el verano. Sin embargo, parece ser que estos genes en algunas razas pueden estar interactuando aditivamente, y una variante alélica en una raza puede no aparecer en otra, o bien dos al mismo tiempo, por lo que son variados los mecanismos genéticos que afectan la tasa ovulatoria y prolificidad
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
Saneamiento de suelos contaminados con metales pesados derivados de la explotación mineral
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
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