Nadja Gomes Alves

Eficiências Reprodutiva e Produtiva em Vacas das Raças Gir, Holandês e Cruzadas Holandês x Zebu

To evaluate the reproductive efficiency and its relationship with productive traits and genetic composition of a herd, in tropical climate, 113 cows were ssigned to seven crossbreeding levels: 1/2, 3/4, 7/8, 9/16 and 15/16 Holstein x Zebu, crossbreed pure Holstein and Gir. The studied traits were: age at calving, calving season, interval from calving to first service, interval from first service to fertile service, number of services, service period, interval calving, reproductive efficiency, lactation period, milk production by lactation order and genetic groups of the herd. Analyses of multiple regression, variance and comparison of averages using Tukey test were performed in statistical software SAEG. The reproductive efficiency was influenced by the age at calving, lactation period, calving interval and genetic composition of the cows, but it was not influenced by milk production and season. The productive indexes were not influenced by the calving season, but were influenced by the genetic composition of the animals. In this study, the reproductive indexes were satisfactory, the zebu cows presented the smallest productive indexes and the taurine ones the smallest reproductive efficiency, probably by larger sensibility to handling.

Dinâmica folicular em cabras da raça Toggenburg em lactação tratadas ou não com somatotropina bovina recombinante

The effect of the r-bST injection was evaluated on the goats estrous cycles. Twenty-four Toggenburg does were used in two treatments: T1 (n=12) treated with r-bST; and T2 (n=12) treated with saline solution (control). After the first r-bST injection, the estrous cycles were checked between two estrus. The estrous cycle length and interovulatory period of the goats did not differ between treatments (P>0.05). Estrous cycles with two, three and four waves of follicular growth were observed. The number of waves during the estrous cycle were not affected by the r-bST treatment (P>0.05). The number of 3mm follicles was different between T1 and T2 (P 0.05) between treatments. The r-bST did not affect the ovarian response during the estrous cycle. The r-bST not affected the follicular dynamic of Toggenburg lactating does, but increased the number of emerging follicles ≥3mm during the estrous cycle.

Características do sêmen a fresco e descongelado de garanhões da raça Nordestina

Este estudo descreveu as caracteristicas seminais, da membrana plasmatica e do acrossoma de espermatozoide congelado/descongelado de 19 ejaculados de garanhoes da raca Nordestina. Os aspectos analisados incluiram os parâmetros fisicos do semen fresco; a motilidade e a longevidade do semen diluido e descongelado; a morfologia espermatica, integridade funcional e estrutural da membrana plasmatica do espermatozoide e a habilidade de ligacao do espermatozoide a membrana perivitelina da gema do ovo de galinha do semen descongelado. As variaveis foram avaliadas pela ANOVA com post hoc teste de Student Newman-Keuls (P<0,05). A MT e a MP foram maiores (P<0,05) no semen diluido do que no descongelado. A percentagem media de defeitos maiores, menores e totais foi muito inferior ao limite recomendado pelo CBRA. A porcentagem de reativos ao HOST foi de 14,21±1,12% e a porcentagem media de membranas integras detectadas pelo teste supravital de 62,22±9,06% e pela sonda SYBR-14 de 81,47±26,90. O numero medio de espermatozoides ligados a MPV apos a descongelacao do semen foi de 230,39±57,09. A MT e MP no tempo 0 min do TTR foi superior (P<0,05) em relacao a 150 min, nao diferindo nos tempos 10 min e 30 min. Os resultados demonstram que a utilizacao dos testes laboratoriais adicionais ajudam no processo de avaliacao das amostras, possibilitando a obtencao de informacoes mais confiaveis e precisas. Embora a criopreservacao tenha provocado queda na motilidade seminal, o uso de diluidor contendo amidas minimizou os danos osmoticos nas celulas espermaticas e manteve a integridade morfologica, funcional e estrutural da membrana plasmatica do espermatozoide. Estes resultados sao um referencial em estudos futuros uma vez que, inexistem dados comparativos nesta raca.

Sincronização de estro com CIDR reutilizado em cabras lactantes da raça Toggenburg tratadas com somatotropina bovina recombinante (r-bST)

The response of goats treated with r-bST in the estrous synchronization protocol was evaluated. Twenty-six Toggenburg females were divided in two treatments: T1 (n=13) treated with four injections of 250mg r-bST, at 14 days intervals, and T2 (n=13) treated with saline solution (control). The intravaginal device previously used by five days was inserted (day 0) one week after the last injection of r-bST and PGF2a (22.5µg) was injected in the animals of both treatments. The device was removed on day 6. All the females in estrus were bred by fertile bucks. The percentage of animals in estrus and the pregnancy rate were: 76.9 and 70, and 84.6 and 72.7% for goats in T1 and T2, respectively. The estrous cycle length; the interval from treatment to the onset of estrus; the ovulation number; and the intervals from the onset of estrus to ovulation, end of estrus to ovulation, and from device removal to ovulation were not affected by r-bST injection. The r-bST did not affect the diameter of the ovulatory follicles (P>0.05). Progesterone concentration showed similar values (P>0.05) among the goats of T1 and T2 during the treatment with device. The r-bST administration did not affect estrous synchronization.

Effect of urea in the diet on ovarian follicular dynamics and plasma progesterone concentration in Alpine goats

To evaluate the effect of using urea in the diet on ovarian follicular dynamics and plasma urea and progesterone concentration, an experiment was carried out with 29 Alpine goats randomly distributed into four diets, each one containing 0%; 0.73%; 1.46% or 2.24% of urea on total dry matter. The follicular dynamics was monitored daily by ultrasonography. The estrous cycles were characterized by occurrence of two, three, four or five follicular waves. The emergence day of the first follicular wave in cycles with two waves, the length of the third wave and the maximum diameter of the largest follicle of the third wave in cycles with three waves presented a quadratic behavior according to the percentage of urea in the diets. In cycles with four waves, the urea intake did not influence the follicular dynamics. The interestrus and interovulatory periods and the luteal and follicular phases length did not differ among treatments. The plasma urea concentration did not differ among diets neither among collection weeks. Plasma progesterone concentration on the estrus day and on the 11th day after estrus presented quadratic behavior, and on the 15th day after estrus, it linearly reduced acording to the percentage of urea in the diets. The supply of urea in diets at levels up to 2.24% in dietary dry matter did not influence the dry matter intake and the urea plasma concentration. For goats, the emergence day and the length of the waves, the follicular diameter and the plasma progesterone concentration on the estrus day and in the latter stages of diestrus were altered when there was supply of urea in the diet.

Effect of flushing with sources of protein with different degratability on ovulation in Santa Inês ewes

This study aimed at evaluating plasma concentration of urea nitrogen, the number of ovulations and the diameter of ovulatory follicle of Santa Ines ewes submitted to flushing with sources of protein with different ruminal degradabilities. Forty-four estrus-synchronized ewes were fed isoprotein diets composed of soybean meal (n = 24) or corn gluten meal and cottonseed meal (n = 20) for 28 days before ovulation. Animals were distributed in a block design in which the blocks were formed by three score ranges of body condition score. Body weight and body condition score gains, body weight and body condition score on the 28th experimental day, urea nitrogen plasma concentration, number of ovulations and diameter of the ovulatory follicle did not differ among ewes submitted to flushing with soybean meal or with corn gluten and cottonseed meal. Ewes under soybean meal flushing showed higher urea nitrogen plasma concentration on days seven and 14 and lower concentration on the 28th day when compared to those fed corn gluten and cottonseed meal (day vs. diet interaction). The supply of one diet with lower content of ruminal degradable protein does not reduce urea nitrogen plasma concentration neither alters the number of ovulations and diameter of ovulatory follicle.

Nursing regimens: Effects on body condition, return to postpartum ovarian cyclicity in Santa Ines ewes, and performance of lambs

The effects of nursing regimens on the body condition, onset of ovarian cyclicity postpartum and weaning weight of lambs were assessed in Santa Ines ewes. Thirty-two ewes were blocked according to parity, number of lambs, and body weight at lambing and within each block randomly allocated to treatments: continuous nursing (CN), controlled nursing (CN2) with two daily feedings for an hour after the 10th day postpartum, or early weaning (EW) with total separation from the lambs after the 10th day. The animals were evaluated from the 12th day postpartum until the first estrus or until 60th day. The dry matter and nutrients intake did not differ among treatments (P>0.05) but did differ over time (P<0.01). The weight, body condition score, serum concentrations of non-esterified fatty acids and prolactin, the percentages of ewes in estrus, of ewes that ovulated within 60th day and had ovulation silent, the period from lambing to estrus, ovulation and follicle with a diameter ≥5mm and the maximum follicular diameter did not differ (P>0.05) among the treatments. The percentage of ovulation until 30th day was greater (P<0.05) in the EW group. The percentage of short luteal phases was higher in the CN2 and EW groups (P=0.07) and normal luteal phases were higher in the CN group (P=0.01). Lamb weight weaning was lower in the EW group (P<0.05). It is possible to use CN to obtain lambing periods less than eight months in Santa Ines ewes, with the advantages of simpler management and higher lamb weaning weights.

Plasma urea nitrogen and progesterone concentrations and follicular dynamics in ewes fed proteins of different degradability

The effects of overfeeding with protein of different degradability on body condition, plasma urea nitrogen and progesterone concentrations, ovulation number and follicular dynamics were assessed in Santa Ines ewes. Twelve ewes were assigned to a randomized block design according to body weight and received overfeeding with soybean meal or with corn gluten meal or maintenance diet for 28 days before ovulation and during the next estrous cycle. Blood samples were taken on days 7, 14, 21, and 28 after the beginning of treatments for analysis of plasma urea nitrogen and on days 3, 6, 9, 12, and 15 into the estrous cycle for analysis of plasma urea nitrogen and progesterone. Follicular dynamics was monitored daily by ultrasound during one estrous cycle. Dry matter and crude protein intake, weight gain, plasma urea nitrogen concentration before ovulation, number of ovulations, diameter of the largest follicle of the 1st and of the 2nd waves and the growth rate of the largest follicle of the 1st wave were higher in the ewes that received overfeeding. The growth rate of the largest follicle of the 3rd wave was higher in the ewes fed maintenance diet. The back fat thickness, plasma urea nitrogen before ovulation and progesterone concentrations, diameter of the largest follicle of the 2nd wave and growth rate of the largest follicle of the 3rd wave were higher in ewes that received overfeeding with soybean meal. The growth rate of the largest follicle of the 1st wave was higher in ewes that received overfeeding with corn gluten meal. Overfeeding with protein-rich feeds may increase the ovulation number and with soybean meal, it may be effective in increasing plasma progesterone concentration in ewes.

Performance and carcass characteristics of lambs fed diets with fat and vitamin E

This experiment aimed to determine the influence of diets with inclusion of protected fat and vitamin E on performance, yield and carcass characteristics of feedlot lambs with different weights. Thirty-two non-castrated Santa Ines lambs were fed diets with a ratio of 40% forage and 60% concentrate ad libitum, with presence or absence of protected fat and/or vitamin E, in a total of four diets. Two weights of early containment were also considered: between 20 and 25 kg and between 30 and 35 kg. All animals were slaughtered at 84 days of confinement. Animals fed diets without addition of protected fat, regardless of the use of vitamin E, had the highest intakes of dry matter, crude protein, neutral detergent fiber and ash, and decreased intake of ether extract. The variables investigated did not affect daily weight gain and total gain. Feed conversion was better for the lighter confined animals not fed protected fat. The heavier feedlot lambs fed diets with vitamin E showed higher cold carcass. The warm carcass for the lighter animals confined fed with vitamin E, and the heavier ones, fed with protected fat and vitamin E, showed the best yields of cold carcass. Objective measures of the carcass cold had the highest mean for heavier feedlot lambs. The addition of fat in the diet reduces the intake of dry matter and increases the ether extract. Although the inclusion of vitamin has no effect on intake of nutrients, it protects the carcasses from losses during cooling, and weight differences at containment directly reflect the measures of the carcasses.

Embryo development and follicular status of Toggenburg does fed urea diet

Objetivou-se investigar os efeitos da ureia na producao, qualidade e estadio de desenvolvimento embrionario e status folicular ao inicio do tratamento superovulatorio de animais alimentados com ureia na dieta. Dezoito cabras da raca Toggenburg foram distribuidas equitativamente para receberem dietas: sem ureia (controle, n=8) e 2,4% de ureia na materia seca total da dieta (n=10) UMS. Os embrioes foram recuperados entre o 7o o 8o dia apos o estro pela tecnica transcervical e classificados pela qualidade e pelo estadio de desenvolvimento. O status folicular foi determinado por ultrassonografia transretal no dia da aplicacao da primeira dose de FSH. O numero e a qualidade dos embrioes nao foram influenciados pela concentracao de ureia na dieta. Embrioes em estadio avancado de desenvolvimento foram recuperados do tratamento com 2,4% de ureia. A concentracao de ureia testada (2,4%) diminui o numero de foliculos com menos de 5 mm de diâmetro, categoria que se correlaciona positivamente ao numero de embrioes coletados e ao numero e a porcentagem de embrioes excelentes e bons.