Leche

Título: Cría artificial de corderos. Comparación de tres dietas líquidas
Autores: Kremer, R.; Barbato, G.; Rista, L.; Rosés, L. y Herrera, V.
Publicación: Primer Congreso Uruguayo de Producción Animal. 83-85. 1996.

Resumen

The experiment reported here was conducted to investigate lamb growth during artificial rearing under three feeding regimes: 1) ewe´s milk (LO), 2) dried cow´s full cream milk reconstituted to contain approximately 13% dry matter (LV) and 3) dried cow´s full cream milk reconstituted to contain approximately 13% dry matter plus 2% casein (LV+C). Thirty lambs were removed from their mother´s between 2-5 days old and stated on artificial rearing regimes until they reached an average weaning weight of 10 kg. Lo lambs reached the assigned weaning weight at 46 days old, while LV and Lv+C lambs at 57 days old. The lambs fed sheep milk had higher average daily gains and reached the assigned weaning weight earlier than the lambs in groups LV and LV+C. The results indicated that artificial rearing of lambs can be satisfactory carried out with ewe´s milk and cow´s milks.

Título: Dairy milk yield of east friesian and corriedale sheep
Autores: Kremer, R.; Barbato, G.; Rosés, L. y Rista, L.
Publicación: World Congress Animal Production, Porto Alegre, Brasil. October 26-31. CD. 2003.

Resumen

Sheep dairy industry is a non-traditional production in Uruguay. East Friesian and their crosses with non-dairy breeds is the main breed milked. The objective of this study was to evaluate dairy milk yield at farm level of East Friesian crosses. In one year, four populations were evaluated (about 1000 ewes). In all flocks, the ewes were running on pastures (native and/or implanted) with no significant supplementary feed. The sheep were mated in march, after parturition, they reared a lamb during 30 to 60 d (10 - 15 kg) and after weaning the ewes were milked twice daily by machine. The following data were collected for each sheep: breed (F1, East Friesian X Corriedale, n = 332; F2, East Friesian X F1, n = 387 and Corriedale, n = 93), number of milking (first or higher), age (estimated by number of teeth), milk produced during milking only period by monthly recording (CICPE, A4), and body condition (1 to 5). Dairy milk production corrected to 100 d was of 53.12+22.60 l, the main significant effects (P<0.01) were farm, breed and number of milking. F1 produced 54.9 % more than Corriedale (P<0.01) and F2 produced 67.6 % more than Corriedale (P<0.01). Ewes milked for first time, yielded 34.7 % less than milked for second time or higher (P<0.01). Age was non significant on milk yield. Average body condition during the milking period was 1.96 + 0.47, it was affected (P<0.01) by farm, breed and number of lactation.

Título: Aptitud al ordeño mecánico de ovejas corriedale en Uruguay
Autores: Kremer, R.; Rosés, L.; Barbato, G. y Rista, L.
Publicación: Avances en Producción Animal (Universidad de Chile). 25: 151-157. 2000.

Resumen

El objetivo de los experimentos que se reportan fue el de obtener datos básicos de la aptitud al ordeñe mecánico de la raza Corriedale. Los ensayos se realizaron en la lechería ovina que se encuentra en el Campo Exp. Nº 1, Migues, de la Facultad de Veterinaria. Se determinó en la semana 12 y 16 postparto (n=16), la cantidad y composición de las sucesivas fracciones obtenidas en el ordeñe: leche extraída a máquina (MAQ, que incluye la de apurado a máquina); leche de repaso manual (LRM), leche residual con ordeñe a mano luego de la inyección de oxitocina (LR). Se midió la duración del ordeñe (n=54) y el efecto de la supresión del ordeñe vespertino en la producción lechera en los 39 días finales del período (n=60). De la producción total diaria, la fracción MAQ fue en promedio 82.17%, la LRM 17.83% y la LR 8calculada sobre MAQ+LRM) fue 31.29%. La grasa en las fracciones LRM y LR fue en promedio un 30% superior al obtenido en MAQ. La duración del ordeñe a máquina fue promedialmente de 77.5 segundos en la mañana y 64.8 segundos en la tarde; el flujo de leche fue de 5.13 y 4.41 ml/s respectivamente. La eliminación del turno vespertino redujo en promedio, 25% (P<0.01) la producción de leche en ese período, sin afectar significativamente (P< 0.01) la producción total de leche estandarizada a 100 días. De los resultados mencionados se puede concluir que esta raza presenta características que el Corriedale integre un sistema productivo que incluya el ordeñe mecánico.

Título: Sistema lechero ovino. Potencial lechero del corriedale y efecto de la estrategia de destete y esquila
Autores: Kremer, R.; Barbato, G.; Rosés, L.; Rista, L.; Perdigón, F.; Herrera, V.; Sosa, L. y Fernández, G.
Publicación: Veterinaria, 134: 11-15. 1997.

Resumen

Se evalúa un sistema lechero ovino con ordeñe mecánico en Corriedale, durante 4 años, cuantificándose la producción de leche y el efecto de distintos momentos de destete y época de esquila. El régimen alimenticio era sobre praderas implantadas, con dotaciones que permitieran expresar el potencial productivo, 4 ovejas/há. La cantidad de leche obtenida durante el doble ordeñe diario fue de 69 litros en 100 d (n=297), siendo significativos los efectos año, edad de la oveja y ordeñe previo. El 26% de las ovejas paridas no completaron los 100 días de ordeñe, las principales causas de eliminación fueron: baja producción (menos de 300 ml/d) 13.4% y mastitis, 6.4%(mayoritariamente al inicio del período de ordeñe mecánico). Durante el período de destete parcial se obtuvieron 8 litros en 20 días, con un bajo contenido en materia grasa (3.13 y 1.77% en los dos años de registro). No hubo diferencia en producción de leche en 100 días en ovejas destetadas 48 horas postparto vs. destete brusco a los 30-35 días (n=67). La esquila a mitad del período de ordeñe no influyó sobre la producción de leche (n=66).

Título: Inducción de lactancia mediante tratamiento hormonal en ovinos corriedale
Autores: Rosés, L.; Perdigón, F.; Sosa, L.; Barbato. G.; Rista, L. y Kremer, R.
Publicación: Primer Congreso Uruguayo de Producción Animal. Montevideo. 2-4 de octubre. 249-251. 1996

Resumen

The objective of this study was to induce lactation through hormonal treatment in non-pregnat ewes. 14 adult Corriedale ewes (7 multiparous and 7 nulliparous) were inserted intravaginally with sponges containing medroxyprogesterone acetate and injected with estradiol-17? for 35 days. After withdrawal of the sponges, the ewes were given a dexametazone and oxitocin injection to initiate lactation. Individual milk production was recorded every 7 days. The results indicated that lactation was induced 100% of ewes treated by this method. Ewes were milked during 54 days reaching a milk yield of 12.67 litters per ewe in the period. No differences in milk production between nulliparous and multiparous ewes were noted, but differences in mammary growth were observed.

Título: Machine milk yield and composition of non-dairy corriedale sheep in Uruguay
Autores: Kremer, R.; Rosés, L.; Rista, L.; Barbato, G.; Perdigón, F. y Herrera, V.
Publicación: Small Ruminant Research. 19: 9-14. 1996.

Resumen

Milk production after total weaning was 71.05 L per lactation of 100 days. Total milk yied obtained by machine, including once a day milking during partial weaning and twice a day milking after total weaning to a level of 0.4 L per day (120 days), was 90 L per ewe. Average milk composition was: fat, 7.16%; protein, 6.32%; lactose, 5.27%; solid non-fat, 12.68%. Fat content during partial weaning ranged from 1.77 to 3.13%. Correlation between one recording after weaning and total milk yield was 0.79. It was concluded that the Corriedale breed adapted well to milk production and the animals appeared to be producing close to their genetic potential. Lamb growth was not a good indicator of dairy milk production; however, a single milking record taken early during lactation had a high correlation with total milk yield.

Título: Análisis y optimización económica de un sistema ovino lechero en Uruguay
Autores: Barbato, G. y Kremer, R.
Publicación: Veterinaria. 130: 15-19. 1996.

Resumen

Se realiza un estudio económico de un tambo ovino en Uruguay teniendo en cuenta las variables producción de leche por lactancia y número de animales en ordeñe por año. Se calculan los ingresos brutos, el resultado operativo total y por hectárea y la rentabilidad. La importación de la leche en el total de los ingresos varió entre 32 y 65% según el nivel de productividad (50 y 200 litros por oveja). Con producciones por animal bajas (50 lt/oveja en ordeñe/lactancia), el resultado operativo es cercano a cero con menos de 150 ovejas en ordeñe. Los mayores cambios en el resultado operativo y la rentabilidad ocurren con la mejora en la producción de leche por oveja más que con el aumento del número de ovejas en ordeñe.

Título: Producción lechera de ovejas corriedale. Efectos ambientales y estrategias de destete
Autores: Kremer, R.; Barbato, G.; Rosés, L.; Perdigón, F.; Rista, L. y Herrera, V.
Publicación: Revista Argentina de Producción Animal. Memorias de la XIV Reunión Latinoamericana de Producción Animal. Vol. 15 Nº 3/4. 870-873. 1995.

Resumen

Since 1987 the milking of sheep has become a new enterprise in Uruguay, mainly due to the fall of the international wool prices. The present experiment has therefore the aim to: quantify the milk yied of Corriedale ewes milked by machine, to estimate the environmental factors that affect milk production and to evaluate two alternatives for the initiation of milking. Milking records were obtained every 21 days and the ewes were dried off when producing less than 300ml/d. In 1993 and 1994, on average 15.3% of the ewes were discarded during the first 50 days of the milking period due to: low production and mastitis. The total milk mean production corrected to 100 days was 68.75 litres. Milk yield was observed to increase from 2 to 6 years old and thereafter to decrease (p<0.05). Also an increase on the milk obtained by machine on the successive milkings was found to be significant (p<0.05). No differences on milk yield were found between the initiation of lactation at 48 hours post-partum or at 30-35 days postpartum. It is concluded that the Corriedale breed adapted well to a dairy system of production and that in spite of their milk yield being smaller than that observed in dairy breeds, it is considered enough to undertake both selection or crossbreeding programmes.

Título: Observations on corriedale as a dairy sheep in Uruguay
Autores: Kremer, R.; Larrosa, J.R.; Perdigón, F.; Rosés, L.; Rista, L. and Fernández, G.
Publicación: Journal of the British Sheep Dairying Association. Vol. (10) 2: 22-24. 1993.

Resumen

Data on milk production and composition as well as early weaning of Corriedale lambs are presented. The Corriedale ewes 70 of 4 age group were grazed during lactation on clover predominant cultivated pastures. Lambs were partially weaned from 17 to 37 days of age, the ewes were milked by machine oce a day at that moment and twice daily from there to 146 days postpartum. These ewes had never been used before as daily sheep. Average milk production was 73.9+19.81 in 121 days of milking. Milk composition was (%): total solids, 19.85; fat, 7.45; protein, 6.35 and lactose, 5.07. Weaning on clover pastures was at 37 days (11.91+1.95 Kg), the man liveweight achieved at 145 days was 28.61+5.29 Kg. Dairy milk production obtained was found to be higher than expected for a breed specialised in wool production.

Título: Sincronización de celos en ovejas corriedale fuera de estación en un tambo ovino
Autores: Perdigón, F.; Sosa, L.;Barbato, G. y Bonzi, T.
Publicación: Primer Congreso Uruguayo de Producción Animal. 246-248. 1996.

Resumen

Since 1987 the milking of sheep has became a new enterprise mainly due the fall of the international wool prices. Corriedale were used as dairy ewes since their represent 70% of the whole uruguayan flock. Corriedales show oestrus from late January up to June and are mainly bred between February and March and milked from September to December. This assay was planned to demonstrate the presence of ovarian activity of its absence and to try to obtain oestrus during spring (October) in lactating sheep. 20 lactating and 20 open ewes were divided in to halves each, and one of each groups was treated with vaginal pessaries containing 40 mgr of PMA during 12 day. At the withdrawal of the pessaries 350 UI of PMSG were injected. The ewes were blood sampled from 7 days before the pessaries implant up to 7 days after their withdrawal to measure progesterone serum concentration by RIA. and vasectomized rams were used for heat detection. The efficacy of the treatment was about 72% and milk yield was not affected during it.