Desempenho de ovinos de corte mantidos em re-gime intensificado de reprodução no semiárido.

• Autor(a) principal: Oliveira, Flávio Gomes de
• Data de Publicação: 2018
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UFPB
• Texto Completo: https://repositorio.ufpb.br/jspui/handle/123456789/18975
• topic: Cordeiro.; Fertilidade.; Índices.; Intervalo de parto.; Ovelhas.; Pesos.; CNPQ::CIENCIAS AGRARIAS::ZOOTECNIA::PRODUCAO ANIMAL

The present research had the objective of evaluating the reproductive efficien-cy, productivity and productivity indexes of Santa Inês and F1 Dorper ewes subjected to the intensified reproduction model of three births every two years in the semiarid region, as well as the growth characteristics of lambs. A total of 120 sheep, 80 Santa Inês and 40 F1 Dorper were used, maintained in semi-intensive regime during five productive cycles from August 2012 to December 2015. To evaluate the reproductive and productive efficiency of the ewe, fertility, prolificity, total birth weight (PTCN), total weight of weaned lambs (PTCD) and three productivity indexes were calculated, wherein index I expressed the total weight of lamb weaned lambs, index II expresses grams of lamb produced per kilogram of live weight of ewes, and index III expresses the weight of lamb produced per kilogram of sheep's metabolic weight. While for the growth characteristics of the lambs we studied weight at birth (PN), weight at 28 days (P28), weaning weight (PD), daily mean weight gain (GPMD) and total weight gain at weaning (GPTD). For analysis of the studied variables they have been ob-served a total of 565 records of a database from the 120 ewes, of which 437 observations for fertility, 391 observations for prolificacy, 366 observations for (PTCN), 312 observations for (PTCD), 205 observations for sheep productivity indexes and 482 observations for perfor-mance characteristics of lambs. In the mathematical models used in the statistical analyzes were included, the fixed effects of the ewe genetic group and the lamb genetic group, produc-tive cycle, calving type, lamb sex, body condition score classes, age and lamb weight at co-variate and all possible interactions. There was an effect (P <0.05) of the genetic group of ewes in relation to fertility at calving and PTCD, with mean values for F1 Dorper ewes of 89.00% and 24.80 kg and for Santa Inês ewes of 74, 25% and 19.55 kg. There was a signifi-cant effect (P<0.05) of the productive cycles on fertility, prolificity and PTCN, with mean values varying from 80.09% to 92.56%, 1.29 to 1.60 and 4.36 kg to 6,03 kg. There was a sig-nificant effect (P <0.05) of the body condition score (ECC) on coverage on fertility and ECC to childbirth about prolificity, highlighting at ewe with ECC ≤ 2,5 in the mating being the highest fertility (88.7%) and with ECC ≤ 2.0 at to childbirth greater prolificacy (1.75). There was a significant interaction between the genotypes and the sheep body condition score to the fertility cover. The index I was influenced (P <0.05) by the effects of the genetic group of the sheep, productive cycles and type of childbed with mean values varying from 3.34 kg to 4.65 kg. The indexes II and III were influenced (P <0.05) by the effects of the productive cycle, type of childbed and body condition score (ECC) to childbed with mean values varying from 490 ga to 640 g and 1.35 kg to 1.74 kg respectively. All lamb growth characteristics were significantly influenced (P <0.05) by the evaluated effects. The highest weight at birth (PN), weight at 28 days (P28) and weaning weight (PD) were for lambs ¾ Dorper x Santa Santa Inês, with mean values of 3.98 kg, 9.98 kg and 17, 59 kg respectively. The lambs born from simple birth were heavier with mean values of 4.41 kg for (PN), 10.38 kg for (P28) and 18.49 kg for (PD) in relation to multiple births, as well like, male lambs were heavier than females. Ewes with ECC> 3.5 produced lambs with the highest PN, P28 and PD with mean values of 4.65 kg, 10.25 kg 20.39 kg respectively. The F1 Dorper ewes presented better reproductive efficiency, as well as a higher productivity index per ewe year compared to the Santa Inês ewes. High fertility and prolificacy rates can be achieved for sheep with a body condition score below 2.5. Although, for growth characteristics, F1 Dorper sheep with a body score above 3.5 produce lambs with the highest birth weight at weaning.