Análisis económico del uso de clorhidrato de zilpaterol en la alimentación de corderas

Con el objetivo de realizar un análisis económico sobre el uso de clorhidrato de zilpaterol en ovinos se realizó una investigación con datos provenientes de la engorda de 24 corderas Dorper - Pelibuey en finalización mediante la técnica de costos, ingresos y rentabilidad. Los animales se dividieron en dos grupos de 12 corderas cada uno: Testigo (T1), alimentados con una dieta basal + 100 g de trigo molido, y (T2), que recibieron la dieta basal + 100 g de trigo molido con 10 mg de clorhidrato de zilpaterol (CZ) cada animal durante 24 horas, por 34 días. El contenido de la dieta tuvo 15.8% de proteína cruda (PC) y 2.8 Mcal/kg de energía metabolizable (EM), con un costo de producción de $3.96 por kg. Las variables de interés fueron peso inicial, peso final, ganancia de peso, conversión alimenticia y peso en canal. Para T1 el costo de producción, ingreso y ganancia/animal, por venta en canal, fueron de$823.1, $918.4 y$95.3, mientras que para T2 fueron de $863.8,$1,111.0 y $247.1, respectivamente. Asimismo,la relación beneficio-costo (RB/C) en canal para T1 fue de 1.11 y para T2 de 1.29. Se concluye que la rentabilidad fue mayor en animales suplementados en la dieta con clorhidrato de zilpaterol en relación con los animales testigo

Zilpaterol hydrochloride improves growth performance and carcass traits without affecting wholesale cut yields of hair sheep finished in feedlot

Growth of the sheep meat industry throughout the world has been slow compared with meat industries of other domestic animals. Therefore, increasing productivity and efficiency of sheep meat production are key factors to enhance the competi- tiveness of this industry (Montossi et al. 2013). The use of β2- adrenergic agonists (β2-AA) as growth promoters has demon- strated to increase sheep meat production by improving protein deposition in muscle (Domínguez-Vara et al. 2013). The use of such technology in the lamb fattening systems could be a nutritional strategy to improve their competitiveness.Fourteen Dorper × Pelibuey ram lambs (initial body weight [BW] = 37.4 ± 1.0 kg and age = 4.5 mo) were housed in individual pens during a 30-d feeding period, and then slaughtered to determine the effects of zilpaterol hydrochloride (ZH) supplementation on productive performance, carcass characteristics and wholesale cut yields. Lambs were assigned under a randomized complete block design (initial BW as blocking factor) to one of two dietary treatments: basal diet without (control) or with 10 mg daily of ZH/lamb. Lambs fed ZH had greater (P ≤ .04) final BW, average daily gain and dry matter intake, but similar (P = .24) feed efficiency compared with control lambs. Hot and cold carcass weight, dressing percentage, longissimus muscle area and leg perimeter were greater (P ≤ .05) for ZH-fed lambs than for control lambs. With exception of blood percentage which decreased (P < .01) with ZH, wholesale cut yields and non-carcass components were unaffected (P ≥ .12) by ZH supplementation. In conclusion, ZH can be used to improve growth rate and dressing percentage, but not to increase wholesale cut yields in feedlot finishing ram lambs.This study was supported by PROMEP-SEP under the thematic network ‘Uso de Promotores de Crecimiento en Ovinos de Pelo (2014–2017

Efectos del genotipo, tamaño de la camada y el sexo sobre las características de la canal y el perfil de ácidos grasos en corderos de pelo

The effect of the genotype (Pelibuey vs Katahdin), type of lambing (single vs. double) and sex (males vs. females) on the characteristics of the carcass and its cuts, in addition to the fatty acid profile of the loin were evaluated in 66 lambs slaughtered at weaning. The yield of the carcass and ribs were higher (P<0.05) in the Pelibuey breed. Slaughter weight, carcass weight and rib yield were higher (P<0.01) in single-born lambs, while the yield of shoulder and leg were lower (P<0.01) than in double-born lambs. The proportion of soft tissue of the different cuts was higher (P<0.05), but that of bone was lower (P< 0.05) in single-born lambs than in double-born lambs. Females had a higher (P<0.05) proportion of soft tissue and a lower proportion of bone (P<0.01) than males. The concentrations of C18:1n7 and C20:4n-6 were higher (P<0.05) in the Pelibuey breed than in the Katahdin breed, while the C22:5n-3 and C22:6n-3 were lower. The percentage of monounsaturated fatty acids was higher (P<0.05) in the meat of single-born lambs, while that of total polyunsaturated fatty acids and n-3 was higher (P<0.05) in double-born lambs. The characteristics of the carcass, the tissue composition of the commercial cuts and the fatty acid profile in hair sheep slaughtered at weaning varied more due to the type of lambing than due to the genotype or sex.El efecto del genotipo (Pelibuey vs Katahdin), tipo de parto (simple vs dobles) y sexo (machos vs. hembras) sobre las características de la canal y de sus cortes, además del perfil de ácidos grasos del lomo fueron evaluados en 66 corderos sacrificados al destete. El rendimiento de la canal y del costillar fue mayor (P<0.05) en la raza Pelibuey. El peso al sacrificio, peso de canal y rendimiento del costillar fue mayor (P<0.01) en crías de parto simple, mientras que el rendimiento de paleta y pierna fue menor (P< 0.01) que en crías de parto doble. La proporción del tejido blando de los diferentes cortes fue mayor (P<0.05), pero el de hueso fue menor (P< 0.05) en crías de parto simple que las de parto doble. Las hembras tuvieron mayor (P<0.05) proporción de tejido blando y menor proporción de hueso (P<0.01) que los machos. Las concentraciones de C18:1n7 y C20:4n-6 fueron mayores (P< 0.05) en la raza Pelibuey que, en la Katahdin, mientras que los C22:5n-3 y C22:6n-3 fueron menores. El porcentaje de ácidos grasos monoinsaturados fue mayor (P<0.05) en la carne de crías de partos simples, en tanto que el de los ácidos grasos poliinsaturados totales y n-3 fue mayor (P<0.05) en crías de partos dobles. Las características de la canal, la composición tisular de los cortes comerciales y el perfil de ácidos grasos en ovinos de pelo sacrificados al destete mostraron más cambios por el tipo de parto que por el genotipo o el sexo

La hipocalcemia en la vaca lechera. Revisión

Calcium (Ca) levels decrease in blood and cytosol at the time of calving, altering nerve impulse transmission, muscle contraction, and immune cell activity. In the nervous system, Ca participates in the conduction of stimuli. In the muscular system, it decreases contractions, causing alterations in smooth muscle, uterus and mammary gland. In the uterus, there is retention and storage of uterine fluids and waste, with bacterial complications. In the immune system, the function of neutrophils is important, and it manifests itself with a decrease in cells engaged in phagocytosis, predisposing to mastitis and metritis. In bovine hypocalcemia, two manifestations are distinguished: clinical and subclinical. In the clinical one (Ca values less than 5.5 mg/dl), homeostasis alters, with loss of appetite, decubitus and lethargy. Subclinical hypocalcemia is more common (Ca between 8.0 and 5.5 mg/dl), and homeostasis does not alter, but muscle contraction and immune function decrease. The treatment is based on the application of calcium orally in standing cows, and intravenously in prostrate cows. Prevention depends on the inclusion of rations that contain anionic salts, which favors the stimulus to maintain blood Ca levels to control the level of cations and anions. In addition, Ca can be administered orally. Calcium homeostasis in lactation is regulated by the serotonin hormone, which stimulates the parathyroid hormone and bone resorption in osteoclasts.Los niveles de calcio (Ca) disminuyen en sangre y citosol al momento del parto, alterando la transmisión del impulso nervioso, la contracción muscular y la actividad de las células inmunes. En el sistema nervioso el Ca participa en la conducción de estímulos. En el sistema muscular disminuye la contracción causando alteraciones en músculo liso, útero y glándula mamaria. En el útero hay retención y almacenamiento de fluidos y desechos uterinos, con complicaciones bacterianas. En el sistema inmune, es importante la función de los neutrófilos y se manifiesta con una disminución de células dedicadas a la fagocitosis predisponiendo a mastitis y metritis. En la hipocalcemia bovina se distinguen dos presentaciones: clínica y subclínica. En la clínica (valores de Ca inferiores a 5.5 mg/dl) se altera la homeostasis con pérdida de apetito, decúbito y letargo. La hipocalcemia subclínica es más común (Ca entre 8.0 y 5.5 mg/dl), y no se altera la homeostasis, pero si se reduce la contracción muscular y la función inmune. El tratamiento se basa en la aplicación de calcio vía oral en vacas de pie, y vía endovenosa en las vacas postradas. La prevención depende de la inclusión de raciones que contengan sales aniónicas con lo cual se favorece el estímulo de mantener los niveles de Ca sanguíneos para controlar el nivel de cationes y aniones. Además, se puede administrar Ca vía oral. La homeostasis de calcio en la lactancia es regulada por la hormona serotonina, que estimula a la hormona paratiroidea y la reabsorción ósea en los osteoclastos

Effect of maternal intrinsic factors on productivity and efficiency at weaning in commercial flock of Pelibuey ewes in the tropic of Tabasco, Mexico: Effect of maternal intrinsic factors on productivity and efficiency at weaning in commercial flock of Pelibuey ewes in the tropic of Tabasco, Mexico

Evaluation of ewe efficiency or productivity is a complex trait because of several factors that are related to produce heavy litters (lamb growth traits) per ewe. The objective of present study was to evaluate maternal intrinsic effects (body weight, body condition score, udder type, litter size, lamb sex) on litter growth traits (litter weight at lambing [LBW] and at weaning adjusted for 70 days [LWW70]) as a criteria of productivity and some indexes of efficiency in Pelibuey ewes. Data of body weight (BW), body condition scores (BCS), and udder types (UT) were taken at lambing, likewise at weaning BW (WBW), on 48 multiparous Pelibuey ewes. Additionally, litter size, sex, birth and weaning weight, were recorded for each offspring; this information was used to calculate LBW, LWW70, average daily gain (ADG), and the following indexes: Ewe efficiency (EEF) expressed as kg of lamb weaned per kg ewe BW at lambing, EEF0.75&nbsp;&nbsp; expressed as kg of lamb weaned per kg ewe metabolic BW (BW0.75) at lambing, and EEF2 expressed as kg of lamb weaned ± ewe BW gained or lost at waning per kg ewe BW at lambing. For statistical analysis, ewes were classified according to BW (low, medium and high), BCS (low and high) and udder type (I, II, III and IV) at lambing. High BW ewes had greater (P? 0.01) LLW and LWW70 than low BW ewes. Ewe BW at lambing did not affect (P&gt; 0.05) any productivity index. Also, BCS from lambed ewes did not alter (P&gt; 0.05) the productivity parameters. The udder type affected only LWW70 and productivity indexes, being similar among ewes with type-I, II and III udders, but lower in ewes with type-IV udders. Likewise, double litters were heavier at birth and weaning than single litters, affecting EEF and EEF0.75, but not EEF. The Pelibuey ewe’s productivity in humid tropic depends on the maternal BW, udder type at lambing and prolificacy, being a better productivity when ewes have a high BW, double lambing and non-misshapen udders.Objective: To evaluate maternal intrinsic effects (body weight, body condition score, udder type, litter size, lamb sex) on litter growth traits (litter weight at lambing [LBW] and at weaning adjusted for 70 days [LWW70] and at weaning adjusted for 70 days [LWW70) as a criteria of productivity and some indexes of efficiency in Pelibuey ewes. Design/Methodology/Approach: Data of body weight (BW), body condition scores (BCS), and udder types (UT) were taken at lambing, likewise at weaning BW (WBW), on 48 multiparous Pelibuey ewes. Additionally, litter size, sex, birth and weaning weight, were recorded for each offspring; this information was used to calculate LBW, LWW70, average daily gain (ADG), and the following indexes: Ewe efficiency (EEF) expressed as kg of lamb weaned per kg ewe BW at lambing, EEF0.75   expressed as kg of lamb weaned per kg ewe metabolic BW (BW0.75) at lambing, and EEF2 expressed as kg of lamb weaned ± ewe BW gained or lost at waning per kg ewe BW at lambing. For statistical analysis, ewes were classified according to BW (low, medium and high), BCS (low and high) and udder type (I, II, III and IV) at lambing. High BW ewes had greater (P≤ 0.01) LLW and LWW70 than low BW ewes. Results: Ewe BW at lambing did not affect (P&gt; 0.05) any productivity index. Also, BCS from lambed ewes did not alter (P&gt; 0.05) the productivity parameters. The udder type affected only LWW70 and productivity indexes, being similar among ewes with type-I, II and III udders, but lower in ewes with type-IV udders. Likewise, double litters were heavier at birth and weaning than single litters, affecting EEF and EEF0.75, but not EEF. Conclusions: The Pelibuey ewe’s productivity in humid tropic depends on the maternal BW, udder type at lambing and prolificacy, being a better productivity when ewes have a high BW, double lambing and non-misshapen udders

Glutamate Supply Reactivates Ovarian Function while Increases Serum Insulin and Triiodothyronine Concentrations in Criollo x Saanen-Alpine Yearlings’ Goats during the Anestrous Season

The possible effect of glutamate supplementation upon ovarian reactivation and serum concentrations of insulin (INS) and triiodothyronine (T3) in anestrous yearling goats was evaluated. Goats (n = 32, 12 mo., 26&deg; North, 1117 m) with a similar live weight (LW) and body condition score (BCS) were blood sampled twice per week for two weeks (2 &times; 1 week &times; 2 weeks) to confirm the anestrus status (&lt;1 ng P4/mL; RIA). Thereafter, goats were randomly assigned to either 1) Glutamate (GLUT; n = 16, LW = 27.1 &plusmn; 1.09 kg, 3.5 &plusmn; 0.18 units, IV-supplemented with 7 mg of glutamate kg&minus;1 LW), or 2) Control (CONT; n = 16; LW = 29.2 &plusmn; 1.09 kg; BCS = 3.5 &plusmn; 0.18, IV saline). During the treatment period, 16 goats (eight/group) were blood sampled twice per week for six weeks. Such serum samples (2 &times; 1 week &times; 6 weeks) were quantified by their P4 content to evaluate the ovarian-luteal activity, whereas a sample subset (1 &times; 1 week &times; 6 weeks) was used to quantify their INS &amp; T3 content to evaluate their metabolic status. Neither LW (28.19 kg; p &gt; 0.05) nor BCS (3.51 units; p &gt; 0.05) differed between treatments. Goats depicting ovarian reactivation favored the GLUT group (50 vs. 12.5%; p &lt; 0.05). Neither INS (1.72 &plusmn; 0.15 ng mL&minus;1) nor T3 (2.32 &plusmn; 0.11 ng mL&minus;1) differed between treatments, yet a treatment x time interaction regarding INS &amp; T3 concentration across time favored (p &lt; 0.05) the GLUT group. The results unveil exogenous glutamate as an interesting modulator not only of ovarian reactivation, but of metabolic hormone synthesis