Abstract Feeding is a determining factor in the various characteristics of sheep meat and animal performance, the objectives were to evaluate the effect of supplementation of ewe lambs finished in different nutritional planes on the gene expression of CASP3, CAPN1, CAPN2 and CAST and its possible association with meat quality. Samples of the Longissimus lumborum muscle of 24 ewe lambs were used, distributed in 3 groups (n=8): P (pasture), PS (pasture and supplement) and F (feedlot). Physicochemical analyses were performed for centesimal analysis, pH, lipid oxidation, Warner-Bratzler shear force and RT-qPCR for the analysis of relative gene expression of the following genes: CASP3, CAPN1, CAPN2 and CAST. There is an increase in daily weight gain and ethereal extract values in the meat of confined animals, due to the greater energy intake in the nutrition of these animals. Animals kept only on pasture have lower lipid oxidation in meat than other treatments because of the lower percentage of lipids. The Warner-Bratzler shear force is considerably higher in the meat of animals kept only on pasture but is still considered tender. The different nutritional systems do not interfere with the gene expression of CASP3, CAPN1, CAPN2 and CAST in ewe lambs.

Resumen Este estudio evaluó los efectos de diferentes fuentes de energía, como sustitutos del maíz, sobre la calidad de la carcasa y la carne de los corderos. Se identificaron, pesaron y distribuyeron 24 corderos machos no castrados en cuatro tratamientos: maíz, pulpa de cítricos, salvado de arroz y cáscaras de soya. Los corderos fueron confinados en corrales de engorde y cuando alcanzaron los 30 kg de peso vivo fueron sacrificados. Para el análisis de resultados se utilizó un diseño completamente aleatorio con diferentes réplicas y se utilizó la prueba de Tukey-5%. Para las variables de peso de la carcasa caliente y fría, el salvado de arroz fue inferior a los otros tratamientos. Para el color rojo de la carne, la pulpa de los cítricos presentó un resultado superior al maíz, mientras que el color de la carne y la grasa, la ternura objetiva y el área del ojo del lomo no difirieron entre tratamientos. Las diferentes fuentes de energía utilizadas en las dietas de terminación de corderos no alteraron la composición química de la carne ni las características de calidad.

Abstract This study evaluated the effects of different energy sources, as corn substitutes, on the carcass characteristics and meat quality of lambs. Twenty-four intact ram lambs were identified, weighed, and assigned to one of four dietary treatments: corn, citrus pulp, rice bran, and soybean hulls. The ram lambs were confined in feedlots, and when they reached 30 kg of live weight, they were slaughtered. A completely randomized design with different replicates was used for the analysis, along with the Tukey-5% test. For hot and cold carcass weight, rice bran produced lower values than the other dietary treatments. For the red color content of the meat, citrus pulp presented superior values when compared to corn, whereas meat and fat color, loin eye area, and objective tenderness did not differ between treatments. Different energetic sources used to replace corn in ram lambs finishing diets did not affect the proximate composition and quality of the meat.

ABSTRACT The objective of this study was to evaluate the reproductive performance of ewes subjected to a short-term protocol for estrus induction using 1 mg of Norgestomet during the non-breeding season in Brazil. A total of 84 ewes were randomly divided into two equal groups (n = 42 per group). Controlled Internal Drug Release (CIDR) containing 330 mg progesterone was inserted into the vagina in the first 42 ewes, and for the other 42 ewes in the second group, 1 mg of Norgestomet was placed subcutaneously in the convex surface of the ear. Implants and devices were removed in both groups on day 6. Following the removal of implants and devices, 10 mg of PGF2α and 300 IU of eCG were injected in all the ewes. After 48 h of application, three fertile rams were added to the herd. Ewes and rams were kept together for four days. Rams were removed on day 12, and after 42 days, pregnancy was diagnosed by ultrasound scanning. Short-term protocols using either an intravaginal device or ear implant were similarly effective to estrus induction (95.23 vs. 92.85%), and all ewes from both groups had estrus manifestation within 72 h after implant removal (72±9 h). In addition, no significant difference in pregnancy rate was observed between ewes treated with the intravaginal device and ear implant protocols (52.38 vs. 57.14%). These results suggest that 1 mg of Norgestomet is a good alternative for short-term protocols for estrus induction/synchronization during the non-breeding season in ewes. It is possible to replace the progesterone-releasing intravaginal device by the ear implant and obtain the same reproductive effectiveness in ewes.

ABSTRACT This study aimed to determine the histological features of the endometrium of bitches, as well as the cell proliferation at specific moments of diestrus, 10, 20, 30, 40, 50 and 60 days post ovulation, correlating the endometrial thickness with the uterine cell proliferation and the metabolic state (weight, blood glucose and plasma cholesterol) of the animals. Therefore, the right and left uterine horns of 26 clinically healthy bitches submitted to ovariohysterectomy were histologically analyzed 10, 20, 30, 40, 50 and 60 days post ovulation. The hematoxylin-eosin and AgNOR staining techniques were performed. All parameters were evaluated by ANOVA and post-hoc Tukey test (p<0.05). The correlation between endometrial thickness and uterine cell proliferation, weight, blood glucose and plasma cholesterol of animals was observed using the Pearson method (p<0.05). In the present study, it is concluded that endometrial thickness does not differ at any of the moments analyzed in diestrus. The endometrial thickness is not influenced by hormones, weight, blood glucose or serum cholesterol of bitches in this phase of the estrous cycle. However, there is greater cell proliferation in the endometrium at day 40 compared to day 60 post ovulation under the influence of the endocrine profile.

O objetivo do presente trabalho foi testar a indução e sincronização do estro em ovelhas utilizando-se diferentes períodos de permanência do progestágeno, dose única de PGF2α ou efeito macho. Para tanto dois experimentos foram realizados: no experimento 1, as ovelhas (n=48) receberam esponjas vaginais impregnadas com MAP (medroxiprogesterona) e foram divididas em 2 grupos: G-9 e G-14, ou seja, MAP por nove ou 14 dias com aplicação de PGF2α na retirada do progestágeno e detecção de estro com reprodutores. Não houve diferenças (p<0,05) na manifestação no estro (69,6 % e 80%), na porcentagem de prenhez (34,8% e 44%) ou de concepção (50% e 55%) nos grupos G-9 e G-14, respectivamente. No experimento 2, as ovelhas (n=151) foram aleatoriamente divididas em 3 grupos: G-6, cada ovelha recebeu MAP por seis dias e aplicação de PGF2α na retirada do progestágeno; G-PGF, cada ovelha recebeu dose única de PGF2α e G-EM para avaliar o efeito macho foram introduzidos machos entre ovelhas previamente separadas dos mesmos. A porcentagem de manifestação de estro foi maior (p<0,05) nos grupos G-6 (58%) e G-PGF (39%) quando comparados ao G-EM (11%). Concluímos ser possível diminuir o tempo de permanência do progestágeno, porém o uso de luteolítico, em período de transição da estacionalidade reprodutiva, sem o progestágeno, resulta em baixa manifestação de estro.

The objective of this study was to evaluate the effects of progestagen treatment of different duration, PGF2α and ram effect on estrus induction synchronization in ewes. In Experiment I, ewes (n=48) received vaginal sponges with MAP (medroxyprogesterone) for nine or 14 days (G-9 and G-14, respectively), followed by PGF2α treatment and estrus detection. There were no differences in estrus (69.6 and 80%), conception (50 and 55%), and pregnancy rates (34.8 e 44.0%) between G-9 and G-14, respectively. In Experiment II, ewes (n=151) were divided into three groups: G-6 received vaginal sponges with MAP for 6 days, followed by PGF2α treatment and estrus detection, G-PGF received only PGF2α treatment, and G-EM were only exposed to males after a period of separation. Estrus rates were greater (p<0.05) in G-6 and G-PGF groups (58 and 39%, respectively) than in G-EM group (11%). In conclusion, it was possible to reduce the duration of progestagen treatment; however, the use of PGF2α during the breeding season transition without progestagen seemed to reduce estrus rates.