RESUMEN

Since lamb is a commodity, producers cannot control the price of the product they sell. Therefore, managing production costs is a necessity. We explored the study of elasticities as a tool for basing decision-making in sheep production, and aimed at investigating the composition and elasticities of lamb production costs, and their influence on the performance of the activity. A representative sheep production farm, designed in a panel meeting, was the base for calculation of lamb production cost. We then performed studies of: i) costs composition, and ii) cost elasticities for prices of inputs and for zootechnical indicators. Variable costs represented 64.15% of total cost, while 21.66% were represented by operational fixed costs, and 14.19% by the income of the factors. As for elasticities to input prices, the opportunity cost of land was the item to which production cost was more sensitive: a 1% increase in its price would cause a 0.2666% increase in lamb cost. Meanwhile, the impact of increasing any technical indicator was significantly higher than the impact of rising input prices. A 1% increase in weight at slaughter, for example, would reduce total cost in 0.91%. The greatest obstacle to economic viability of sheep production under the observed conditions is low technical efficiency. Increased production costs are more related to deficient zootechnical indexes than to high expenses.

RESUMEN

Avaliou-se o consumo alimentar residual (CAR) e a conversão alimentar (CA) de 20 cordeiros, com o objetivo de estimar as correlações entre essas variáveis com medidas de desempenho e com características in vivo da carcaça. Os animais tiveram o consumo de MS (CMS) mensurado por 65 dias e foram pesados a cada 13 dias para obtenção do ganho médio diário (GMD). Foram considerados o peso vivo inicial (PVI), o peso vivo final (PVF), o peso metabólico (PM), o GMD, a taxa de crescimento relativo (TCR), a taxa de Kleiber (TK), a CA, o CMS e o CMS em percentual do PV (CMSPV). As avaliações de carcaça foram realizadas por ultrassom. O CAR se mostrou correlacionado com o CMS (+0,81), o CMSPV (+0,90) e a CA (+0,63). Correlações significativas foram encontradas entre CA e GMD; CA e TCR; CA e TK; e CA e PVI (-0,63, -0,74, -0,75 e +0,51, respectivamente). O CAR e a CA não se mostraram correlacionados com características de carcaça, e, da mesma forma, não houve diferença entre as classes de CAR para essas variáveis. Confirmou-se o potencial do CAR como medida de eficiência alimentar para cordeiros em confinamento, sem existência de relações com o ganho de peso e o tamanho corporal e sem alterações na composição da carcaça.

The residual feed intake (RFI) and the feed conversion ratio (FCR) of 20 lambs was evaluated in order to estimate the correlations between these traits and performance measures and with in vivo carcass characteristics. The animals had their dry matter intake (DMI) measured over 65 days and they were weighed every 13 days to determine the average daily weight gain (ADG). Initial body weight (IBW), final body weight (FBW), metabolic weight (MW), ADG, relative growth rate (RGR), Kleiber ratio (KR), FCR, DMI and DMI in BW percentual (BWDMI) were considered. The carcass evaluation was performed by ultrasound. The RFI was correlated with the DMI (+0.81), BWDMI (+0.90) and with FCR (+0.63). Significant correlations were found between FCR and ADG; FCR and RGR; and FCR and KR; and FCR and IBW (-0.63, -0.74, -0.75 and +0.51 respectively). The RFI and the FCR were not correlated with carcass traits and similarly there was no difference between the RFI-classes for these variables. It was proved the RFI has potential as a measure of feed efficiency for housed lambs, without the existence of relations with weight gain and body size of animals and without changes in carcass composition.

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RESUMEN

Avaliou-se o efeito da adição de plasma seminal ovino ao sêmen descongelado sobre a taxa de prenhez de ovelhas em rebanho comercial. Cento e setenta e quatro ovelhas cruza Texel foram distribuídas em quatro tratamentos: T1) inseminação artificial cervical (IAC) com sêmen descongelado (SD) diluído em solução tampão fosfato salino (PBS); T2) IAC com SD e adição de plasma seminal ovino; T3) grupo-controle I: IAC com sêmen fresco diluído em PBS; T4) grupo-controle II: inseminação artificial por laparoscopia com SD diluído em PBS. Para indução de cio, utilizaram-se esponjas impregnadas com acetato de medroxiprogesterona (MAP) por 12 dias, com aplicação intramuscular de 400 UI de eCG (Novormon®) e de 37,5µg de cloprostenol sódico (Sincrocio®), no dia da retirada das esponjas. O aparecimento de cio foi monitorado com rufiões vasectomizados a partir da retirada das esponjas até a inseminação artificial em tempo fixo - 54 a 60 horas. A taxa de prenhez do tratamento com adição de plasma seminal ao sêmen descongelado (7,0%) não diferiu (P>0,05) do tratamento sem adição de plasma (4,3%), entretanto foi menor (P<0,05) se comparada à taxa de prenhez dos grupos-controle I inseminação via cervical superficial com sêmen fresco diluído (50,0%) e II inseminação via laparoscopia com sêmen descongelado (39,4%). A inseminação artificial por via cervical superficial com adição de plasma seminal ao sêmen descongelado não elevou o percentual de prenhez em valores que justifiquem a indicação desta biotecnologia em rebanhos comerciais de ovinos.

The effect of seminal plasma addition to thawed-frozen ram semen on the pregnancy rate of commercial herd ewes was evaluated. One hundred and seventy-four crossbred Texel sheep were allocated to four treatments: T1) cervical artificial insemination (CAI) using frozen-thawed semen (FTS) diluted in phosphate buffered saline solution (PBS); T2) CAI using FTS diluted in ovine seminal plasma; T3) control group I: CAI using fresh semen diluted in PBS; T4) control group II: laparoscopic insemination using FTS diluted in PBS. Estrus induction was performed with medroxiprogesterone acetate (MAP) impregnated sponges for 12 days, followed by intramuscular injection of 400 IU of eCG (Novormon®) and 37.5µg of sodium cloprostenol (Sincrocio®) on the day of sponge removal. Estrus was monitorated with vasectomized rams, beginning at the time of the sponge removal until the fixed time artificial insemination - 54 to 60 hours. The pregnancy rate of FTS diluted in seminal plasma treatment (7.0%) did not differ (P>0.05) for the treatment without addition of seminal plasma (4.3%), however it was lower (P<0.05) when compared to the pregnancy rate of the cervical inseminated control I group with PBS diluted fresh semen (50.0%) and laparoscopic inseminated control group II with PBS diluted FTS (39.4%). The cervical artificial insemination with the addition of seminal plasma to frozen-thawed semen did not increase the pregnancy rate at acceptable values to make this biotechnology useful on commercial herds.

Asunto(s)

RESUMEN

Avaliou-se o efeito da adição de plasma seminal ovino ao sêmen descongelado sobre a taxa de prenhez de ovelhas em rebanho comercial. Cento e setenta e quatro ovelhas cruza Texel foram distribuídas em quatro tratamentos: T1) inseminação artificial cervical (IAC) com sêmen descongelado (SD) diluído em solução tampão fosfato salino (PBS); T2) IAC com SD e adição de plasma seminal ovino; T3) grupo-controle I: IAC com sêmen fresco diluído em PBS; T4) grupo-controle II: inseminação artificial por laparoscopia com SD diluído em PBS. Para indução de cio, utilizaram-se esponjas impregnadas com acetato de medroxiprogesterona (MAP) por 12 dias, com aplicação intramuscular de 400 UI de eCG (Novormon®) e de 37,5µg de cloprostenol sódico (Sincrocio®), no dia da retirada das esponjas. O aparecimento de cio foi monitorado com rufiões vasectomizados a partir da retirada das esponjas até a inseminação artificial em tempo fixo - 54 a 60 horas. A taxa de prenhez do tratamento com adição de plasma seminal ao sêmen descongelado (7,0%) não diferiu (P>0,05) do tratamento sem adição de plasma (4,3%), entretanto foi menor (P<0,05) se comparada à taxa de prenhez dos grupos-controle I inseminação via cervical superficial com sêmen fresco diluído (50,0%) e II inseminação via laparoscopia com sêmen descongelado (39,4%). A inseminação artificial por via cervical superficial com adição de plasma seminal ao sêmen descongelado não elevou o percentual de prenhez em valores que justifiquem a indicação desta biotecnologia em rebanhos comerciais de ovinos.(AU)

The effect of seminal plasma addition to thawed-frozen ram semen on the pregnancy rate of commercial herd ewes was evaluated. One hundred and seventy-four crossbred Texel sheep were allocated to four treatments: T1) cervical artificial insemination (CAI) using frozen-thawed semen (FTS) diluted in phosphate buffered saline solution (PBS); T2) CAI using FTS diluted in ovine seminal plasma; T3) control group I: CAI using fresh semen diluted in PBS; T4) control group II: laparoscopic insemination using FTS diluted in PBS. Estrus induction was performed with medroxiprogesterone acetate (MAP) impregnated sponges for 12 days, followed by intramuscular injection of 400 IU of eCG (Novormon®) and 37.5µg of sodium cloprostenol (Sincrocio®) on the day of sponge removal. Estrus was monitorated with vasectomized rams, beginning at the time of the sponge removal until the fixed time artificial insemination - 54 to 60 hours. The pregnancy rate of FTS diluted in seminal plasma treatment (7.0%) did not differ (P>0.05) for the treatment without addition of seminal plasma (4.3%), however it was lower (P<0.05) when compared to the pregnancy rate of the cervical inseminated control I group with PBS diluted fresh semen (50.0%) and laparoscopic inseminated control group II with PBS diluted FTS (39.4%). The cervical artificial insemination with the addition of seminal plasma to frozen-thawed semen did not increase the pregnancy rate at acceptable values to make this biotechnology useful on commercial herds.(AU)

Asunto(s)

RESUMEN

Avaliou-se o consumo alimentar residual (CAR) e a conversão alimentar (CA) de 20 cordeiros, com o objetivo de estimar as correlações entre essas variáveis com medidas de desempenho e com características in vivo da carcaça. Os animais tiveram o consumo de MS (CMS) mensurado por 65 dias e foram pesados a cada 13 dias para obtenção do ganho médio diário (GMD). Foram considerados o peso vivo inicial (PVI), o peso vivo final (PVF), o peso metabólico (PM), o GMD, a taxa de crescimento relativo (TCR), a taxa de Kleiber (TK), a CA, o CMS e o CMS em percentual do PV (CMSPV). As avaliações de carcaça foram realizadas por ultrassom. O CAR se mostrou correlacionado com o CMS (+0,81), o CMSPV (+0,90) e a CA (+0,63). Correlações significativas foram encontradas entre CA e GMD; CA e TCR; CA e TK; e CA e PVI (-0,63, -0,74, -0,75 e +0,51, respectivamente). O CAR e a CA não se mostraram correlacionados com características de carcaça, e, da mesma forma, não houve diferença entre as classes de CAR para essas variáveis. Confirmou-se o potencial do CAR como medida de eficiência alimentar para cordeiros em confinamento, sem existência de relações com o ganho de peso e o tamanho corporal e sem alterações na composição da carcaça.(AU)

The residual feed intake (RFI) and the feed conversion ratio (FCR) of 20 lambs was evaluated in order to estimate the correlations between these traits and performance measures and with in vivo carcass characteristics. The animals had their dry matter intake (DMI) measured over 65 days and they were weighed every 13 days to determine the average daily weight gain (ADG). Initial body weight (IBW), final body weight (FBW), metabolic weight (MW), ADG, relative growth rate (RGR), Kleiber ratio (KR), FCR, DMI and DMI in BW percentual (BWDMI) were considered. The carcass evaluation was performed by ultrasound. The RFI was correlated with the DMI (+0.81), BWDMI (+0.90) and with FCR (+0.63). Significant correlations were found between FCR and ADG; FCR and RGR; and FCR and KR; and FCR and IBW (-0.63, -0.74, -0.75 and +0.51 respectively). The RFI and the FCR were not correlated with carcass traits and similarly there was no difference between the RFI-classes for these variables. It was proved the RFI has potential as a measure of feed efficiency for housed lambs, without the existence of relations with weight gain and body size of animals and without changes in carcass composition.(AU)

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