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Registro completo
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Biblioteca (s) : |
INIA Las Brujas; INIA Tacuarembó. |
Fecha : |
21/10/2014 |
Actualizado : |
11/10/2019 |
Tipo de producción científica : |
Artículos en Revistas Indexadas Internacionales |
Autor : |
PAGANONI, B.L.; FERGUSON, M.B.; FERRIO, S.; JONES, C.; KEARNEY, G.A.; KENYON, P.R.; MACLEAY, C.; VIÑOLES, C.; THOMPSON, A.N. |
Afiliación : |
CAROLINA VIÑOLES GIL, Instituto Nacional de Investigación Agropecuaria (INIA), Uruguay. |
Título : |
Early reproductive losses are a major factor contributing to the poor reproductive performance of Merino ewe lambs mated at 8-10 months of age. |
Fecha de publicación : |
2014 |
Fuente / Imprenta : |
Animal Production Science, 2014, v.54, no.6, p.762-772. |
ISSN : |
1836-0939 |
DOI : |
10.1071/AN13240 |
Idioma : |
Inglés |
Notas : |
Article history: Received 13 June 2013 / Accepted 26 February 2014 / Published online 9 April 2014. |
Contenido : |
ABSTRACT.
The reproductive performance of Merino ewe lambs is lower than that achieved by mature ewes and is highly variable. It is likely that embryo loss represents a major source of reproductive wastage in Merino ewe lambs, but to our knowledge no studies have attempted to determine when the major reproductive losses occur or identify predisposing factors that are likely to lead to high rates of pregnancy failures in ewe lambs. After characterising where reproductive losses occurred in Merino ewe lambs mated at 8-10 months of age, we tested the hypothesis that pregnancy failure in ewe lambs is influenced by nutrition and liveweight change around conception and the genetic potential for growth of the ewe lamb. Two-hundred and twenty-four Merino ewe lambs born from 10 sires with Australian Sheep Breeding Values were teased for 14 days using vasectomised rams, and then fed two different diets for 68 days during mating. All ewe lambs were weighed and the appearance of crayon marks on their rump was recorded most days. Blood samples for progesterone assay were collected on Days 5, 12 and 17 after the first record of a crayon mark. Ultrasonography using a trans-rectal probe was used to measure the number of corpora lutea present, as a proxy for ovulation rate, 9 days after the first record of a crayon mark during the mating period. A further trans-rectal ultrasonography was undertaken 30 days after marking from the entire ram to determine pregnancy status and count the number of embryos. Over the entire mating period 54% of ewe lambs were pregnant with 66 fetuses per 100 ewes mated. The average ovulation rate was 150% however up to 84% of this potential was lost by weaning and the major contributor to this apparent deficit was the loss that occurred during the first 17 days after mating. Pregnancy failure was not significantly related to nutrition or liveweight change during mating however, there were significant differences in pregnancy failure between different sire groups. Pregnancy failure was significantly less for ewe lambs from sires with higher breeding values for weight and fat at post-weaning age (8-10 months). Only 60% of ewe lambs had achieved puberty when rams were introduced and only 83% by 35 days after mating. In addition, almost half of the ewe lambs that were mated for the first time during the first 35 days after rams were introduced, but failed to get pregnant, then seemed to skip a cycle or did not cycle again before the end of the 68-day mating period. Liveweight at introduction of entire rams was positively related to fertility, ovulation rate and reproductive rate. This study confirms that selection of sires with higher breeding values for post-weaning weight and fat will increase the fertility and reproductive rate of Merino ewe lambs mated at 8-10 months. This response is due in part to enhancing the onset of puberty and increasing the proportion of ewe lambs cycling at the start of mating and reducing pregnancy failure.
© CSIRO 2014. MenosABSTRACT.
The reproductive performance of Merino ewe lambs is lower than that achieved by mature ewes and is highly variable. It is likely that embryo loss represents a major source of reproductive wastage in Merino ewe lambs, but to our knowledge no studies have attempted to determine when the major reproductive losses occur or identify predisposing factors that are likely to lead to high rates of pregnancy failures in ewe lambs. After characterising where reproductive losses occurred in Merino ewe lambs mated at 8-10 months of age, we tested the hypothesis that pregnancy failure in ewe lambs is influenced by nutrition and liveweight change around conception and the genetic potential for growth of the ewe lamb. Two-hundred and twenty-four Merino ewe lambs born from 10 sires with Australian Sheep Breeding Values were teased for 14 days using vasectomised rams, and then fed two different diets for 68 days during mating. All ewe lambs were weighed and the appearance of crayon marks on their rump was recorded most days. Blood samples for progesterone assay were collected on Days 5, 12 and 17 after the first record of a crayon mark. Ultrasonography using a trans-rectal probe was used to measure the number of corpora lutea present, as a proxy for ovulation rate, 9 days after the first record of a crayon mark during the mating period. A further trans-rectal ultrasonography was undertaken 30 days after marking from the entire ram to determine pregnancy status and count the number ... Presentar Todo |
Thesagro : |
COMPORTAMIENTO REPRODUCTIVO; CORDEROS; MERINO; OVINOS. |
Asunto categoría : |
L01 Ganadería |
Marc : |
LEADER 03985naa a2200301 a 4500 001 1051211 005 2019-10-11 008 2014 bl uuuu u00u1 u #d 022 $a1836-0939 024 7 $a10.1071/AN13240$2DOI 100 1 $aPAGANONI, B.L. 245 $aEarly reproductive losses are a major factor contributing to the poor reproductive performance of Merino ewe lambs mated at 8-10 months of age.$h[electronic resource] 260 $c2014 500 $aArticle history: Received 13 June 2013 / Accepted 26 February 2014 / Published online 9 April 2014. 520 $aABSTRACT. The reproductive performance of Merino ewe lambs is lower than that achieved by mature ewes and is highly variable. It is likely that embryo loss represents a major source of reproductive wastage in Merino ewe lambs, but to our knowledge no studies have attempted to determine when the major reproductive losses occur or identify predisposing factors that are likely to lead to high rates of pregnancy failures in ewe lambs. After characterising where reproductive losses occurred in Merino ewe lambs mated at 8-10 months of age, we tested the hypothesis that pregnancy failure in ewe lambs is influenced by nutrition and liveweight change around conception and the genetic potential for growth of the ewe lamb. Two-hundred and twenty-four Merino ewe lambs born from 10 sires with Australian Sheep Breeding Values were teased for 14 days using vasectomised rams, and then fed two different diets for 68 days during mating. All ewe lambs were weighed and the appearance of crayon marks on their rump was recorded most days. Blood samples for progesterone assay were collected on Days 5, 12 and 17 after the first record of a crayon mark. Ultrasonography using a trans-rectal probe was used to measure the number of corpora lutea present, as a proxy for ovulation rate, 9 days after the first record of a crayon mark during the mating period. A further trans-rectal ultrasonography was undertaken 30 days after marking from the entire ram to determine pregnancy status and count the number of embryos. Over the entire mating period 54% of ewe lambs were pregnant with 66 fetuses per 100 ewes mated. The average ovulation rate was 150% however up to 84% of this potential was lost by weaning and the major contributor to this apparent deficit was the loss that occurred during the first 17 days after mating. Pregnancy failure was not significantly related to nutrition or liveweight change during mating however, there were significant differences in pregnancy failure between different sire groups. Pregnancy failure was significantly less for ewe lambs from sires with higher breeding values for weight and fat at post-weaning age (8-10 months). Only 60% of ewe lambs had achieved puberty when rams were introduced and only 83% by 35 days after mating. In addition, almost half of the ewe lambs that were mated for the first time during the first 35 days after rams were introduced, but failed to get pregnant, then seemed to skip a cycle or did not cycle again before the end of the 68-day mating period. Liveweight at introduction of entire rams was positively related to fertility, ovulation rate and reproductive rate. This study confirms that selection of sires with higher breeding values for post-weaning weight and fat will increase the fertility and reproductive rate of Merino ewe lambs mated at 8-10 months. This response is due in part to enhancing the onset of puberty and increasing the proportion of ewe lambs cycling at the start of mating and reducing pregnancy failure. © CSIRO 2014. 650 $aCOMPORTAMIENTO REPRODUCTIVO 650 $aCORDEROS 650 $aMERINO 650 $aOVINOS 700 1 $aFERGUSON, M.B. 700 1 $aFERRIO, S. 700 1 $aJONES, C. 700 1 $aKEARNEY, G.A. 700 1 $aKENYON, P.R. 700 1 $aMACLEAY, C. 700 1 $aVIÑOLES, C. 700 1 $aTHOMPSON, A.N. 773 $tAnimal Production Science, 2014$gv.54, no.6, p.762-772.
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INIA Las Brujas (LB) |
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Registro completo
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Biblioteca (s) : |
INIA Las Brujas. |
Fecha actual : |
17/09/2014 |
Actualizado : |
18/03/2022 |
Tipo de producción científica : |
Artículos en Revistas Indexadas Internacionales |
Circulación / Nivel : |
B - 1 |
Autor : |
CAPRA, G.; MARTÍNEZ, S.; FRADILETTI, M.; COZZANO, S.; REPISO, L.; MÁRQUEZ, R.; IBÁÑEZ, F. |
Afiliación : |
GUSTAVO ENRIQUE CAPRA CASSINONI, Instituto Nacional de Investigación Agropecuaria (INIA), Uruguay; MARIA FLORENCIA FRADILETTI DE ASPIRTARTE, Instituto Nacional de Investigación Agropecuaria (INIA), Uruguay; FACUNDO IBÁÑEZ SILVA, INIA (Instituto Nacional de Investigación Agropecuaria), Uruguay. |
Título : |
Meat quality of rabbits reared with two different feeding strategies: With or without fresh alfalfa ad libitum. |
Fecha de publicación : |
2013 |
Fuente / Imprenta : |
World Rabbit Science, 2013, vol.21, no.1, p.23-32. Doi: |
ISSN : |
1257-5011 |
DOI : |
10.4995/wrs.2013.1197 |
Idioma : |
Inglés |
Notas : |
Article history: Received March 2012 / Accepted October 2012. |
Contenido : |
ABSTRACT.
The aim of this study was to evaluate production performance, carcass characteristics and nutritive value of meat of rabbits reared under the 2 prevailing feeding strategies iiji Uruguay. One week after weaning, 96 purebred V line rabbits were randomly distributed between 2 treatments: (T1) commercial pelleted food ad libitum and (T2) commercial pelleted food ad libitum plus fresh alfalfa ad libitum. Each treatment included 12 cages containing 4 individuals each (2 males and 2 females). Growth performance characteristics (live weight evolution, commercial food consumption and food/gain ratio) were evaluated. The consumption of alfalfa was not measured. Rabbits were slaughtered at a live weight of 2500 g and carcass characteristics were evaluated. Samples of meat and dissectible fat were analysed to determine intramuscular fat content at muscle L. dorsi, dissectible fat and intramuscular fat composition, minerals (Zn, Fe, Mg and Na), vitamin E and purines. Sensory evaluations were conducted to assess the effect of treatments on the consumer's perception of differences and the existence of attributes determining preferences. Differences between treatments were significant for total commercial food intake (23356 vs: 20930 g/cage; P<0.001) and feed conversion ratio (3.82 vs. 3.41; P<0.01) for T1 and T2 respectively. No significant differences were found in average daily gain, age at slaughter and carcass characteristics. There were no significant differences in the intramuscular fat content. The fatty acid composition of dissectible and intramuscular fat was affected by the inclusion of alfalfa in the diet increasing the linolenic acid content (1.82 vs. 3.28% and 2.29 vs. 5.15% for T1 and T2 at intramuscular and dissectible fat, respectively; P<0.001), and improving the n-6/n-3 relationship (8.60 vs. 5.82 and 11.58 vs. 5.64 for T1 and T2 at intramuscular and dissectible fat, respectively; P<0.001). There were no significant differences in vitamin E, Fe or Zn content between treatments, but differences were significant in Mg (22.5 vs. 24.4 mg/100 g for T1 and T2; P<0.05) and Na (44.1 vs. 48.2 mg/100 g; P<0.05). In the sensory evaluation, panellists significantly perceived differences between treatments with 95% confidence.
© WRSA, UPV, 2003. MenosABSTRACT.
The aim of this study was to evaluate production performance, carcass characteristics and nutritive value of meat of rabbits reared under the 2 prevailing feeding strategies iiji Uruguay. One week after weaning, 96 purebred V line rabbits were randomly distributed between 2 treatments: (T1) commercial pelleted food ad libitum and (T2) commercial pelleted food ad libitum plus fresh alfalfa ad libitum. Each treatment included 12 cages containing 4 individuals each (2 males and 2 females). Growth performance characteristics (live weight evolution, commercial food consumption and food/gain ratio) were evaluated. The consumption of alfalfa was not measured. Rabbits were slaughtered at a live weight of 2500 g and carcass characteristics were evaluated. Samples of meat and dissectible fat were analysed to determine intramuscular fat content at muscle L. dorsi, dissectible fat and intramuscular fat composition, minerals (Zn, Fe, Mg and Na), vitamin E and purines. Sensory evaluations were conducted to assess the effect of treatments on the consumer's perception of differences and the existence of attributes determining preferences. Differences between treatments were significant for total commercial food intake (23356 vs: 20930 g/cage; P<0.001) and feed conversion ratio (3.82 vs. 3.41; P<0.01) for T1 and T2 respectively. No significant differences were found in average daily gain, age at slaughter and carcass characteristics. There were no significant differences in the in... Presentar Todo |
Thesagro : |
CARNE DE CONEJO; MINERALES; PURINES. |
Asunto categoría : |
L40 Estructura animal |
URL : |
http://ojs.upv.es/index.php/wrs/article/view/1197/1522
http://www.ainfo.inia.uy/digital/bitstream/item/3172/1/Capra-G.-2013-WRS-v.211-p.23-32.pdf
|
Marc : |
LEADER 03101naa a2200265 a 4500 001 1050351 005 2022-03-18 008 2013 bl uuuu u00u1 u #d 022 $a1257-5011 024 7 $a10.4995/wrs.2013.1197$2DOI 100 1 $aCAPRA, G. 245 $aMeat quality of rabbits reared with two different feeding strategies$bWith or without fresh alfalfa ad libitum.$h[electronic resource] 260 $c2013 500 $aArticle history: Received March 2012 / Accepted October 2012. 520 $aABSTRACT. The aim of this study was to evaluate production performance, carcass characteristics and nutritive value of meat of rabbits reared under the 2 prevailing feeding strategies iiji Uruguay. One week after weaning, 96 purebred V line rabbits were randomly distributed between 2 treatments: (T1) commercial pelleted food ad libitum and (T2) commercial pelleted food ad libitum plus fresh alfalfa ad libitum. Each treatment included 12 cages containing 4 individuals each (2 males and 2 females). Growth performance characteristics (live weight evolution, commercial food consumption and food/gain ratio) were evaluated. The consumption of alfalfa was not measured. Rabbits were slaughtered at a live weight of 2500 g and carcass characteristics were evaluated. Samples of meat and dissectible fat were analysed to determine intramuscular fat content at muscle L. dorsi, dissectible fat and intramuscular fat composition, minerals (Zn, Fe, Mg and Na), vitamin E and purines. Sensory evaluations were conducted to assess the effect of treatments on the consumer's perception of differences and the existence of attributes determining preferences. Differences between treatments were significant for total commercial food intake (23356 vs: 20930 g/cage; P<0.001) and feed conversion ratio (3.82 vs. 3.41; P<0.01) for T1 and T2 respectively. No significant differences were found in average daily gain, age at slaughter and carcass characteristics. There were no significant differences in the intramuscular fat content. The fatty acid composition of dissectible and intramuscular fat was affected by the inclusion of alfalfa in the diet increasing the linolenic acid content (1.82 vs. 3.28% and 2.29 vs. 5.15% for T1 and T2 at intramuscular and dissectible fat, respectively; P<0.001), and improving the n-6/n-3 relationship (8.60 vs. 5.82 and 11.58 vs. 5.64 for T1 and T2 at intramuscular and dissectible fat, respectively; P<0.001). There were no significant differences in vitamin E, Fe or Zn content between treatments, but differences were significant in Mg (22.5 vs. 24.4 mg/100 g for T1 and T2; P<0.05) and Na (44.1 vs. 48.2 mg/100 g; P<0.05). In the sensory evaluation, panellists significantly perceived differences between treatments with 95% confidence. © WRSA, UPV, 2003. 650 $aCARNE DE CONEJO 650 $aMINERALES 650 $aPURINES 700 1 $aMARTÍNEZ, S. 700 1 $aFRADILETTI, M. 700 1 $aCOZZANO, S. 700 1 $aREPISO, L. 700 1 $aMÁRQUEZ, R. 700 1 $aIBÁÑEZ, F. 773 $tWorld Rabbit Science, 2013, vol.21, no.1, p.23-32. Doi:
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