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Neither the age (average 74.3 ± 2.9 days) nor the arrival weight of males and females (average 15.38 ± 0.25 kg) at the fattening farm, after the lactation period, were statistically significant. At the end of the fattening period, statistically significant differences were found for the weights and growth of the two sexes (25.91 ± 0.59 kg vs. 22.52 ± 0.52 kg (p-value: 0.000), and 242.15 ± 10.15 g/day vs. 178.51 ± 9.86 g/day (p-value: 0.006) in males and females respectively). Regarding carcass conformation measurements, the differences between sexes were statistically significant for: K, G and Th, but not F. In the carcass performance, there were significant differences between males (7.5 ± 0.3) vs. females (6.7 ± 0.2) (p-value: 0.023), which means that the males had a rating of R- and the females O+. Regarding tissue composition, only the percentage of muscle was significantly higher in males (58.50 ± 0.88) than in females (52.94 ± 0.76), (p-value: 0.011). After the logical differences between males and females, the study showed that both sexes had a higher growth potential than the final weights at which the study was carried out, since they did not show a high fattening (22.76 ± 0.86 percentage). Our results were in accordance with other authors. This research has been financed by a collaboration agreement between the Agricultural Technological Institute of Castilla and León (ITA- CYL), the University of Valladolid (UVa) and the Scientific Park Foundation of the UVa and the project AGL2016-75159-C2-1-R funded by the Spanish State Research Agency (AEI) and the European Regional Development Fund Light lamb Growth Carcass Merino breed Unpublished

Acknowledgements and funding to the Analytical Services of UZ. Age Sex Nutritional value Quality Published

Background: We hypothesized that a diet with old man saltbush hay used as an alternative source of nutrients could partially replace the concentrate in the feeding of feedlot lambs. Objective: This study evaluated the behavior and performance of lambs fed diets containing increasing levels of old man saltbush hay plus concentrate. Methods: Twenty-four castrated Santa Inês lambs at approximately eight months of age (22 ± 1.97 kg) were confined in a randomized complete design and fed diets containing 30, 40, 50, and 60% (dry matter: DM) of old man saltbush hay. Results: The intake of DM and neutral detergent fiber was not affected (p>0.05) by the level of old man saltbush hay. Intake of mineral salt decreased (p0,05) por los diferentes niveles de inclusión de hierba-sal. La ingestión de sal mineral se redujo (p0,05) pelos diferentes níveis de erva-sal. A ingestão de sal mineral reduziu (p

Objetivo. Evaluar el efecto de tres promotores de crecimiento sobre el consumo de alimento (CA) y ganancia diaria de peso (GDP) en corderos de pelo. Materiales y métodos. Fueron asignados aleatoriamente 12 corderos en cuatro tratamientos con tres repeticiones cada uno: Tratamiento 1 control (T1-C; dieta basal), tratamiento 2 (T2; complementación con 0.125 g de clorhidrato de zilpaterol (Zilmax®), tratamiento 3 (T3; complementación con 3 g de Clorhidrato de Ractopamina (LAPI-RACTO®) y tratamiento 4 (T4; 12 mg de zeranol en implantes) (Zearalenona-Ralgro®). Se utilizó un diseño estadístico de bloques completos al azar. Resultados. Se encontró una diferencia significativa en el CA (p0.05). El T4 presentó mayor ganancia diaria de peso (GDP) versus con el T2 (p, Objective. Evaluate the effect of three growth promoters on feed intake (FI) and daily weight gain (DWG) in hair lambs. Materials and methods. Twelve lambs were randomly assigned to four treatments with three repetitions each one: Control 1 treatment (C-T1; basal diet), treatment 2 (T2; supplementation with 0.125 g of Zilpaterol Hydrochloride (Zilmax®), treatment 3 (T3; supplementation with 3 g of Ractopamine Hydrochloride (LAPI-RACTO®) and treatment 4 (T4; 12 mg of Zeranol in implants) (Zearalenone-Ralgro®). A randomized complete block statistical design was used. Results. The study found a significant difference in food consumption (p0.05). T4 presented greater DWG versus to T2 (p

Human appropriation of net primary productivity (HANPP) integrates ecological and socioeconomic perspectives on land use by quantifying the amount of net primary production (NPP) appropriated by society through biomass harvest from the ecosystem. The main objective of this study was to determine the spatial patterns of HANPP related to lamb and wool production from sheep farms across the province of Santa Cruz. The HANPP was obtained by dividing the sum of the biomass used in livestock products (lamb and wool) by the NPP. In addition, we examined the spatial relationship between HANPP and potential plant biodiversity and net carbon balance at the farm level under livestock land use across our study region. At the regional level, livestock production accounted for an average of 11.35% of appropriated NPP, and HANPP ranged from 0.75 to 50%. The map of HANPP across Santa Cruz showed low values in the vegetation transition (ecotone) between Nothofagus antarctica forests and grasslands in the west, in the south, and in wetlands where the most productive rangelands dominate. High values were observed in the northwest and central areas of the province. There were differences in HANPP across vegetation types with mean values that varied from 3.93% in grasslands on the Humid Magellanic Steppe to 12.33% in the Central Plateau. Simple linear regression analysis for HANPP evaluated in Southern Patagonia showed a negative linear relationship (p < 0.05) with vascular plant biodiversity and net carbon balance at the farm level. The method used to map HANPP related to livestock provisioning ecosystem services (ES) in the present study (lamb and wool), may be integrated into decision support systems. In this context, low HANPP values (

Background: The use of pequi by-product as animal feed is an appealing alternative to reduce overall production costs. However, little is known regarding its effects on animal performance as well as the ideal inclusion level in the diet. Objective: To evaluate performance, intake, and digestibility of confined lambs receiving diets containing different levels of pequi by- product as a partial substitute for corn silage. Methods: The experiment was conducted in Curvelo, Brazil, using twenty-five crossbred Santa Inês male lambs (17.83 ± 1.73 kg) aged six months for 92 days. Increasing levels of pequi by-product (0, 6, 12, 18, and 24%) replacing corn silage were evaluated in a completely randomized design. Analysis of variance and regression were performed, with 5% significance level. Results: Inclusion of pequi by-product did not influence (p>0.05) average daily gain, total weight gain, or feed conversion ratio. No effect (p>0.05) was also observed on intake of dry matter, organic matter, ether extract, crude protein, neutral detergent fiber, total carbohydrates, and total digestible nutrients. However, a linear decrease was observed (p0,05) en la ganancia de peso diaria, ganancia de peso total, ni conversión alimenticia. No se observó efecto (p>0,05) en la ingesta de materia seca, materia orgánica, extracto etéreo, proteína bruta, fibra detergente neutra, carbohidratos totales y nutrientes digestibles totales. Sin embargo, se observó una reducción lineal (p0,05) o ganho de peso médio diário, o ganho de peso total e a conversão alimentar. Também não foi observado efeito (p>0,05) no consumo de matéria seca, matéria orgânica, extrato etéreo, proteína bruta, fibra em detergente neutro, carboidratos totais e nutrientes digestíveis totais. Entretanto, foi observada redução linear (p

En el sur de Santa Cruz se desarrolló un trabajo con el objetivo de evaluar el aprovechamiento de una pastura pura (PP) de pasto ovillo (Dactylis glomerata L.) y una pastura mezcla (PM) de pasto ovillo y agropro intermedio (Agropyron intermedium (Host) Beavois en estado reproductivo y el desempeño productivo de corderas desde el 29 de diciembre al 08 de abril de la temporada 2020-2021. En un lote de animales señalados elegidos al azar de tres campos se determinó el peso vivo (PV) inicial y final (I y F), ganancias y rangos de PVI y PVF y la condición corporal (CC) I y F. Las pasturas se muestrearon en las fechas establecidas de uso para determinar la cobertura vegetal (CV), biomasa aérea (BA), altura de plantas (AP), material vivo y muerto (MV y MM), proteína bruta (PB), fibra en detergente neutro y ácida (FDN y FDA) y digestibilidad de la materia seca (DMS). Se calcularon la BA digestible y desaparecida mediante fórmula. El trabajo incluyó registros de lluvias y temperaturas. El análisis estadístico relacionó la CV y AP con la BAI y BAF y la PB, FDN, FDA y DMS de las PP y PM con el MM recolectado. En los animales, se establecieron asociaciones entre el PV y la CC por fecha, y el MV, PB y DMS con el PV. En la PM, la BA se redujo a la mitad al final del pastoreo con una caída apreciable del MV que aumentó el MM. La PB, FDN y FDA de ambas pasturas correlacionaron con el MM. Hubo una mejora en el PVF por rango del lote de corderas evaluadas. Se concluye la necesidad de ajustar, entre otras prácticas, la carga animal, ingreso y tiempos de pastoreo que permitan un mayor aprovechamiento de este tipo de pasturas en los momentos de mejor calidad nutricional. EEA Santa Cruz Fil: Utrilla, Víctor Ricardo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Santa Cruz. Grupo Producción Agropecuaria; Argentina. Fil: Utrilla, Víctor Ricardo. Universidad Nacional de la Patagonia Austral. Unidad Académica Río Gallegos; Argentina. Fil: Andrade, Miguel Alberto. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Santa Cruz; Argentina Fil: Andrade, Miguel Alberto. Universidad Nacional de la Patagonia Austral. Unidad Académica Río Gallegos; Argentina. Fil: Gallardo, Rodrigo Martin. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Santa Cruz; Argentina.

Es de suma importancia generar condiciones que permitan reducir las pérdidas de corderos al momento de la parición: en el artículo te ofrecemos alternativas para lograrlo. EEA Balcarce Fil: Cesa, Ariela. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Cuenca del Salado; Argentina. Fil: Asencio, Edmundo. Actividad privada; Argentina.

The aim was to determine the quality parameters and oxidative stability of colour, lipids and proteins (formation of carbonyls) of vacuum packed lamb at a constant temperature of 2 °C ±1 °C up to 15 days post mortem. The suitability of lamb loin (longissimus lumborum) for ageing and optimal ageing period to obtain optimum sensory properties, especially tenderness and aroma was determined. A sample of 100 g lamb meat contains 23.48 g protein, 69.66 g water and 5.48 g fat. Lamb samples were the most tender after 11 days (both, sensory assessed and instrumentally measured – share force decreased by 61%) and had the best aroma after 15 days post mortem. In the meantime, the lamb became significantly brighter and more saturated (higher L*, a* and b* values), the content of secondary lipid oxidation products increased (1.7 times higher amount of malondialdehyde), and the content of protein carbonyls decreased to the initial value, despite an initial increase observed 11 days post mortem. We found that lamb loin is suitable piece for ageing; the optimal duration of ageing of loins is 15 days post mortem., Cilj rada bio je odrediti značajke kvalitete i oksidacijsku stabilnost boje, lipida te bjelančevina (stvaranje karbonila) janjetine pakirane u vakuumu, starosti do 15 dana nakon klanja, pri stalnoj temperaturi od 2 °C ± 1 °C. Utvrđivana je primjerenost janjećeg filea (longissimus lumborum) za zrenje te optimalno vrijeme zrenja, a kojima se postižu najbolja senzorička svojstva, posebice mekoća i aroma. Uzorak od 100 g janjetine sadrži 23,48 g bjelančevina, 69,66 g vode i 5,48 g masti. Uzorci janjetine su bili najmekši 11 dana nakon klanja (senzorička procjena i mekoća utvrđena instrumentima – udio sile smanjen je za 61 %), pri čemu je najbolja aroma utvrđena 15 dana nakon klanja. Janjetina je starenjem postala značajno svjetlija i zasićenija (veće vrijednosti L*, a* i b*), povećao se sadržaj sekundarnih produkata oksidacije lipida (1,7 puta veća količina malondialdehida), dok se sadržaj proteinskih karbonila, po početnom povećanju zabilježenom 11 dana nakon klanja, smanjio na početnu vrijednost. U svrhu objektivnije procjene brzine oksidacije bjelančevina u janjetini, valja napomenuti da je sedmodnevno smrzavanje mesa prije analize značajno smanjilo sadržaj proteinskih karbonila (32 %). Utvrđeno je da je janjeći file primjeren za produženo zrenje, pri čemu optimalno trajanje zrenja filea iznosi 15 dana nakon klanja., Das Ziel der Arbeit war es, die Qualitätsparameter und die oxidative Stabilität von Farbe, Lipiden und Proteinen (Bildung von Carbonylen) von vakuumverpacktem Lammfleisch bei einer konstanten Temperatur von 2 °C ±1 °C bis zu 15 Tage nach der Schlachtung zu bestimmen. Es wurde die Eignung der Lammlende (longissimus lumborum) für die Reifung und die optimale Reifezeit zur Erzielung optimaler sensorischer Eigenschaften, insbesondere der Zartheit und des Aromas bestimmt. Eine Probe von 100 g Lammfleisch enthält 23,48 g Eiweiß, 69,66 g Wasser und 5,48 g Fett. Die Lammfleischproben waren nach 11 Tagen am zartesten (sowohl sensorisch beurteilt als auch instrumentell gemessen - der Anteil nahm um 61% ab) und hatten nach 15 Tagen nach dem Schlachten das beste Aroma. Mit der Reifung wurde das Lammfleisch deutlich heller und gesättigter (höhere L*-, a*- und b*-Werte), der Gehalt an sekundären Lipidoxidationsprodukten stieg an (1,7-mal höhere Menge an Malondialdehyd), und der Gehalt an Proteincarbonylen sank auf den Ausgangswert, trotz eines 11 Tage nach der Schlachtung beobachteten anfänglichen Anstiegs. Für eine realistische Bewertung der Proteinoxidationsrate bei Lammfleisch ist zu beachten, dass ein 7-tägiges Einfrieren des Fleisches vor der Analyse den Proteincarbonylgehalt signifikant reduzierte (32%). Es wurde herausgefunden, dass die Lammlende ein für die Reifung geeignetes Stück ist; die optimale Dauer der Reifung der Lenden beträgt 15 Tage nach dem Schlachten., El fin de este estudio fue determinar los parámetros de calidad y estabilidad oxidativa del color, de los lípidos y proteínas (formación de carbonilo) de cordero envasado al vacío hasta 15 días después del sacrificio, a una temperatura constante de 2 ° C ± 1 ° C. Se determinó la idoneidad del filete de cordero (longissimus lumborum) para la crianza y el período óptimo de crianza para obtener las mejores propiedades sensoriales, especialmente ternura y aroma. Una muestra de 100 g de carne de cordero contiene 23,48 g de proteína, 69,66 g de agua y 5,48 g de grasa. Las muestras de cordero tuvieron la mayor ternura 11 días después del sacrificio (tanto evaluadas sensorialmente como medidas instrumentalmente; la proporción de fuerza se redujo en un 61%), con el mejor aroma determinado 15 días después del sacrificio. El cordero se volvió significativamente más brillante y saturado con la edad (valores más altos de L *, a * yb *), el contenido de productos secundarios de oxidación de lípidos aumentó (1,7 veces mayor cantidad de malondialdehído), mientras que el contenido de proteína carbonilo, luego del aumento inicial registrado 11 días después del sacrificio, se ha reducido al valor inicial. Para evaluar de manera más objetiva la tasa de oxidación de proteínas en el cordero, debe tenerse en cuenta que con la congelación de la carne durante siete días antes del análisis se redujo significativamente el contenido de proteína de los carbonilos de proteína (32%). Fue determinado que el filete de cordero era apto para el envejecimiento, siendo la duración óptima del envejecimiento del filete 15 días después del sacrificio., Il presente studio aveva lo scopo di determinare le caratteristiche concernenti la qualità e la stabilità ossidativa del colore, dei grassi e delle proteine (formazione di carbonile) della carne d’agnello confezionata sottovuoto a 15 giorni dalla sua macellazione a una temperatura costante di 2 °C ± 1 °C. È stata accertata l’idoneità del filetto d’agnello (longissimus lumborum) all’invecchiamento e la sua durata ottimale cui si attribuiscono i migliori risultati in termini di proprietà sensoriali, tenerezza e aroma. Il campione di 100 g di carne d’agnello contiene 23,48 g di proteine, 69,66 g d’acqua e 5,48 g di grassi. I campioni di carne d’agnello col maggior grado di tenerezza si sono dimostrati quelli dopo 11 giorni dalla macellazione (valutato sensorialmente e misurato con gli strumenti – sforzo di taglio ridotto del 61%), mentre il miglior aroma è risultato quello della carne a 15 giorni dalla macellazione. La carne d’agnello, col passare del tempo, è diventata più chiara e opaca (valori L*, a* e b* più alti), è aumentato il contenuto dei prodotti secondari dell’ossidazione dei lipidi (la quantità di malondialdeide è risultata 1,7 volte superiore), mentre il contenuto di carbonile proteico, dopo un iniziale incremento a 11 giorni dalla macellazione, s’è ridotto al valore iniziale. Ai fini di una valutazione maggiormente aggettiva della velocità di ossidazione delle proteine nella carne d’agnello, va detto che, dopo sette giorni di congelatore prima dell’analisi, il contenuto di carbonili proteici nella carne s’è sensibilmente ridotto (32%). È stato accertato che il filetto d’agnello è idoneo all’invecchiamento, laddove la sua durata ottimale è di 15 giorni dopo la macellazione.

Sainfoin (Onobrychis viciifolia) is a forage legume with a medium content of proanthocyani-dins (PAC), which may affect animal performance and product quality. The objective of the present study was to assess the effect of PAC from sainfoin fed to dams, using polyethylene glycol (PEG) as a blocking agent, on the performance and carcass and meat quality of their suckling male lambs. After lambing, twenty lactating dams were fed fresh sainfoin ad libitum plus 200 g per day of barley; ten were orally dosed with water (Sainfoin), and ten were dosed orally with a water dilution of 100 g PEG (Sainfoin + PEG). Their lambs (4.1 ± 0.64 kg at birth) suckled ad libitum until they reached the target slaughter weight of 10–12 kg. The presence of PAC in the dams’ diet did not affect the growth, blood metabolites and carcass weight and fatness of the suckling lambs but decreased the lightness of caudal fat (p < 0.05) and increased the weight of the digestive compartments (p < 0.05). Regarding the meat characteristics, PAC only decreased polyphenols content (p < 0.05). In conclusion, the presence of PAC in the dams’ diet had not significant effects on the performance and product quality of their suckling lambs. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.

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Ternasco de Aragón

Ternasco de Aragón

Ewes fed sainfoin (a source of condensed tannins "CT") may influence the homeostasis of the gastrointestinal tract of suckling lambs. This study investigated the effects of CT from sainfoin in the maternal diet on plasma fructosamine, faecal coccidian excretion, and gene expression of immune and antioxidant markers in jejunum and ileum of suckling lambs. Twelve Rasa Aragonesa lambs with their dams were selected. The maternal diet was based on fresh sainfoin (SAINFOIN, n = 6) and sainfoin + polyethylene-glycol (SAINFOIN + PEG, as a CT-binder, n = 6) plus a daily supplement of 200 g barley in both groups. A lower percentage of lambs that shed more than 10 oocysts/g faeces was observed in SAINFOIN compared to the SAINFOIN + PEG group (p = 0.07). Jejunal gene expression of transforming growth factor-β1, tumour necrosis factor-α, and glutathione peroxidase (GPX) 1 and 4 were lower in the SAINFOIN group (p < 0.05). In contrast, ileal catalase and GPX2 expression were increased in the SAINFOIN group (p < 0.05). Overall, the results suggest that the presence of CT in the dams' diets has a positive effect on reducing excreted coccidian oocysts and favours antioxidant-immune crosstalk at gut level in suckling lambs. This research was funded by the Ministry of Science, Innovation and Universities of Spain and the European Regional Development Funds, grant number INIA RTA2017-00008-C02-01 and 02.

This study aimed at evaluating the effects of dietary carob (Ceratonia siliqua L.) pulp, a by-product of the fruit processing industry, on light lamb performances, time budget behaviour, coefficients of total tract apparent digestibility (CTTAD) and blood metabolites. A total of 144 crossbred lambs with 41 ± 5.5 days of age were monitored in two consecutive batches. They were housed in groups of 6 lambs (3 females and 3 males) balanced according to weaning body-weight and assigned to one of three isoenergetic and isoproteic concentrate-based diets: C0 (without carob pulp), C15 (150 g/kg of carob pulp) and C30 (300 g/kg of carob pulp). At 50, 65 and 80 days of age, feed, faeces and blood samples were collected, and behaviour was recorded. The type of concentrate did not have effect on lamb growth and concentrate intake (P > 0.05). However, the concentrate feed conversion ratio (FCR) was higher for C15 and C30 compared to C0 (P < 0.05). The time budget behaviours were not affected by diets (P > 0.05). The time spent lying resting and standing static increased throughout the fattening period (P < 0.05), but self-grooming, feeding, exploration, movement and positive social interactions decreased with age (P < 0.05). Regarding the CTTAD of dry matter (DM), organic matter (OM) and crude protein (CP), it was noted that C30 had the lowest digestibility of these nutrients with respect to C0 and C15 (P < 0.05). Furthermore, the total condensed tannins (CT) content in faeces was higher in C30 compared to C0 and C15 (P < 0.05). The age of lambs affected the CTTAD of DM, OM, CP and phosphorus, which were lower at 50 days than in the rest of control days (P < 0.05). Blood metabolites were not affected by experimental diets (P > 0.05). However, urea concentrations increased significantly from 50 to 65 days of age, while glucose decreased concomitantly (P < 0.05). In conclusion, dietary carob pulp inclusion up to 300 g/kg does not negatively affect animal daily gains, daily activity budgets and metabolic nutritional status, but reduces diet digestibility and increases the concentrate FCR. Although a carob pulp inclusion of up to 150 g/kg in the energy-rich concentrate-based diet for weaned light lambs increases the concentrate FCR while keeping the daily gain, this dietary strategy would be a good trade-off between animal performances and circular economy principles. This research was funded by the Ministry of Science, Innovation of Spain and the European Regional Development Funds, grant number INIA RTA2017-00008-C02. Jonathan Pelegrin-Valls is in receipt of an early-stage research staff grant by the Generalitat de Catalunya-European Social Funds. We greatly appreciate the technical assistance of Joan Carles Melo and Bonàrea staff during on-farm animal handling and measurements.

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Congenital malformations are abnormalities of structure, formation or function observable at birth that causes great economic losses in livestock industry. In this study, we describe the incidence of the main congenital anomalies encountered in the last year (June 2020-June 2021) in ruminants from Elazig region according to species, breed, age and sex, number of pregnancies, rectal examination, and method of conception employed. A total of 79 congenital anomalies encountered in 73 animals during this study were evaluated. Of 73 animals most of congenital anomalies were calves (84.93%) and males (68.49%). It was determined that the most common type of congenital anomaly in calves was hernia umbilicalis (21.51%) while in lambs and goat kids was atresia ani. Most of these anomalies were formed in the abdominal wall and organs of gastrointestinal system (46.84%). Congenital anomalies in calves and lambs were more frequently when they came from the first pregnancy of their dams, while in goat kids when their dam had the second pregnancy. Most of small ruminant that had congenital anomalies came from dams with multiple gestation. Rectal examinations performed in cattle during the early stages of gestation was probably one of a predisposing factor for the formation of congenital malformations in this specie. More studies that include the participation of diagnostic laboratories are needed to improve the characterization of congenital anomalies that contribute to the implementation of preventive and control measures in the herds of these species in our region.

El objetivo de este ensayo fue estudiar el efecto de la deficiencia subclínica de zinc (Zn) en corderos sobre variables de interés productivo, el balance de nitrógeno (N) y parámetros hematológicos. Diez corderos de raza Corriedale, con un peso promedio de 10,09 kg, fueron asignados aleatoriamente a dos grupos: Basal (B, 10 ppm de Zn) y Suplementado con 30 ppm de Zn (Z). El ensayo se extendió por el término de 20 semanas y los animales fueron pesados cada 4 semanas. También con esta periodicidad, se obtuvieron muestras de sangre por punción de vena yugular. En las semanas 6 y 20 se evaluó la digestibilidad aparente de la materia seca (DAMS) y el balance de N. Al final del ensayo se midió la producción y la calidad de la lana de los corderos. La ganancia de peso y la calidad de la lana fueron similares en ambos grupos, mientras que la producción de lana fue un 37,4 % superior en el grupo Z. De acuerdo al primer periodo de balance, la DAMS fue similar en ambos grupos, pero la retención de N fue significativamente mayor en el grupo Z que en el grupo B (5,53 vs 4,03 g/día). En el segundo periodo de balance hubo una tendencia similar. No hubo diferencias entre los grupos en hematocrito, concentración de hemoglobina, conteo de glóbulos rojos, leucocitos totales, linfocitos y neutrófilos. Estos resultados sugieren que la deficiencia subclínica de Zn reduce la producción de lana, lo que puede estar relacionado con una menor síntesis proteica. The objective of this trial was to study the effect of subclinical zinc (Zn) deficiency in lambs on productive variables, nitrogen (N) balance and hematological parameters. Ten Corriedale lambs, with an average weight of 10.09 kg, were randomly assigned to two groups: Basal (B, 10 ppm Zn) and Supplemented with 30 ppm Zn (Z). The trial lasted 20 weeks. The animals were weighed every 4 weeks. Also with this perio-dicity, they were bled by jugular venipuncture. In weeks 6 and 20 the apparent dry matter digestibility (ADMD) and N balance were evalua-ted. At the end of the test the wool production and quality were mea-sured. The weight gain and wool quality were similar in both groups, while wool production was 37.4% higher in group Z. According to the first balance period, ADMD was similar in both groups, but the reten-tion of N was significantly higher in group Z than in group B (5.53 vs 4.03 g/day). In the second balance period there was a similar trend. There were no differencies between groups on hematocrit, hemoglo-bin concentration, red blood cells, total leukocytes, lymphocytes and neutrophils number. These results suggest that subclinical Zn defi-ciency reduces wool production, which may be related to lower pro-tein synthesis. O objetivo deste teste foi estudar o efeito da deficiência subclíni-ca de zinco (Zn) em cordeiros sobre variáveis de interesse produti-vo, o balanço de nitrogênio (N) e parâmetros hematológicos. Dez cordeiros da raça Corriedale, com peso médio de 10,09 kg, foram divididos aleatoriamente em dois grupos: Basal (B, 10 ppm de Zn) e Suplementado com 30 ppm de Zn (Z). O teste estendeu-se durante 20semanas e os animais foram pesados a cada 4 semanas. Também com essa frequência, foram obtidas amostras de sangue por punção da veia jugular. Nas semanas 6 e 20, foram avaliadas a digestibilidade aparen-te da matéria seca (DAMS) e o balanço de N. Ao final do teste, foram medidas a produção e a qualidade da lã dos cordeiros. O ganho de peso e a qualidade da lã foram semelhantes em ambos os grupos, enquan-to a produção de lã foi 37,4% superior no grupo Z. De acordo com o primeiro período de balanço, a DAMS foi semelhante nos dois grupos, mas a retenção de N foi significativamente maior no grupo Z do que no grupo B (5,53 vs 4,03 g /dia). No segundo período do balanço hou-ve uma tendência semelhante. Não houve diferenças entre os grupos no hematócrito, concentração de hemoglobina, contagem de glóbulos vermelhos, leucócitos totais, linfócitos e neutrófilos. Estes resultados sugerem que a deficiência subclínica de Zn reduz a produção de lã, o que pode estar relacionado com uma menor síntese protéica. EEA Mercedes Fil: Pechin, Guillermo Héctor. Universidad Nacional de La Pampa. Facultad de Ciencias Veterinarias; Argentina. Fil: Corbellini, Carlos Nicolas. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Mercedes; Argentina Fil: Denda, Silvina Soraya. Universidad Nacional de La Pampa. Facultad de Ciencias Veterinarias; Argentina.

Dividir la majada al destete en dos lotes, en función de la condición corporal (CC) de las ovejas, puede ser una estrategia para administrar de forma eficiente el pasto durante el verano y lograr que la mayoría de las ovejas lleguen al servicio con una CC de 3,0 puntos. La propuesta es evaluar la CC de las ovejas al destete, y separar las de condición CC inferior a 3,0 para realizar una alimentación diferencial para que logren la CC objetivo al servicio. EEA Balcarce Fil: Alvarado, Patricia I. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Veterinarias; Argentina.