Jacira Neves da Costa Torreão

Effect of multiple stress factors (thermal, nutritional and pregnancy type) on adaptive capability of native ewes under semi-arid environment

This study was conducted to evaluate the effect of multiple stress factors (thermal, nutritional and pregnancy type) on two different native track breeds of ewes as reflected by their adaptive capability under semi-arid environment. The multiple stressor experiment was conducted in twenty-four ewes (12 Santa Inês and 12 Morada Nova ewes). Both heat stress and pregnancy stress was common to all four groups. However, the animals were divided into further two groups within each breed on the basis of nutrition regimen. According the groupings were: Group 1 (Six Santa Ines ewes; heat stress; nutrition at 0.5% of BW; single pregnancy); Group 2 (Six Santa Ines ewes; heat stress; nutrition at 1.5% BW; twin pregnancy); groups Group 3 (Six Morada Nova ewes; heat stress; nutrition at 0.5% of BW; single pregnancy); Group 4 (Six Morada Nova ewes; heat stress; nutrition at 1.5% BW; twin pregnancy). All the animals in the experiment were pregnant. Heat stress was induced by exposing all animals to summer heat stress in outside environment while the nutritional regimen followed was at 0.5% and 1.5% level of body weight (BW) respectively in each breed. The experiment was conducted in a completely randomized design with two breeds, two nutritional treatments and two pregnancy types, 10 repetitions for physiological parameters and six for blood parameters, with repeated measures over time. Physiological parameters (respiratory rate, pulse rate and rectal temperature) were measured with the animals at rest in the morning and afternoon, 0600-0700 and 1300-1400h, respectively, every seven days. Blood samples were collected every 14d for determination of serum glucose, triglycerides, cholesterol, urea and creatinine. We found interaction effect between breed and pregnancy type on respiratory rate and rectal temperature with greater values in Santa Inês ewes than Morada Nova ewes. However, there was no significant fixed effect of pregnancy type and supplementation level on physiological responses of breeds. Environmental factor (period of the day) had influenced the physiological responses of ewes during all gestational period. Santa Inês ewes had greater serum glucose concentration at 105d and 120d of gestation compared to the Morada Nova ewes. Morada Nova ewes had greater concentrations of triglycerides, urea at 120d, 150d and also greater cholesterol at 105d, 135d and 150d of gestation compared with Santa Inês ewes. The present result indicates that thermal condition was most important factor that modified the physiological responses of ewes in a semi-arid tropical environment.

Relação materno-filial da raça Morada Nova recebendo dietas com três níveis de energia, ao final da gestação

The present work was carried out with the objective to evaluate the effects of different energy levels offered in the final third of gestation on the ewe-lambs behavior of animals from the Morada Nova breed. The experiment was divided into three treatments - three groups of eight ewes, fed isoprotein diets containing different energy levels (2.0, 2.4, and 2.8 Mcal ME/kg DM), with eight replicates each. There was effect of the treatment on the maternal behavior evaluated variables (vocalization, act of smell and lick the lambs and the position of the ewe - stand up or lying), in the ewes, but no difference was observed for the filial behavior (position of animal, time from the birth to the first time that the animal was up, time from the birth to the first sucking and total time sucking) of the lambs. The mobilization of reserves or the direct carrying of nutrients of the diet for normal fetal growth, in the groups fed with diets containing 2.0 and 2.4 Mcal ME/kg DM, minimized the possible effects on the filial behavior of lambs. The mobilization of reserves or direct carry of nutrients of the diet for normal fetal growth, in the groups fed with diets containing 2.0 and 2.4 Mcal ME/kg DM, minimized the possible effect on the filial behavior of lambs. Despite the interference in their relationship with the kids, ewes Morada Nova attained to keep the conditions of the lambs unchanged in all treatments.

Intake, digestibility, milk yield and indicators of the metabolic status of native ewes fed supplemented diet under grazing system

This study aimed to evaluate the intake, digestibility, milk yield and indicators of the metabolic status of native lactating ewes supplemented under grazing system. In the present study 28 lactating ewes were selected: 14 Morada Nova (MN) and 14 Santa Inês (SI), distributed in a completely randomized experimental design, with a 2x2x2 factorial arrangement of two breeds, two supplementation levels and two experimental periods. Blood samples were collected from lambing to 70 days of lactation, with 14 days interval. Laboratory analyses consisted in determining serum glucose, triglycerides, cholesterol, urea and creatinine. Concentrate intake (g/day) during the lactation differed (P<0.05) between breeds. Total dry matter intake of ewes was affected (P<0.05) by breed and treatment. Morada Nova ewes presented lower intake than SI due to their smaller size. Serum glucose, triglycerides, cholesterol, urea and creatinine differed between breeds (P<0.05) with greater levels in SI ewes compared with MN. Concentrate supplementation did not affect (P>0.05) the serum levels of these metabolites. Indicators of the metabolic status were not affected by concentrate supplementation, which was effective for the maintenance of normal serum concentrations. However, these values differ between breeds within the permissible standards, indicating a high adaptation to postpartum.

Concentrate supplementation during pregnancy and lactation of ewes affects the growth rate of lambs from a variety of crosses

The objective of this study was to determine how concentrate supplementation during late third gestation and lactation affects ewe and offspring performance from birth to weaning. Thirty-six ewes and their offspring (n = 32) were used. Eighteen Morada Nova and 18 Santa Ines ewes were artificially inseminated with semen from Dorper ram and distributed in a completely randomized factorial arrangement (2 × 2) consisting of two supplementation levels (5 and 15 g kg-1 of BW) and two breeds (Morada Nova and Santa Ines) or two crosses (Dorper × Morada Nova and Dorper × Santa Ines). The ewes were weighed, their body condition was evaluated during pregnancy, and the weaning weight of the lambs at up to 70 days old was measured. There was no effect of breed or supplementation on the prolificacy or type of birth. The Santa Ines ewes had a faster rate of development, although the weight loss during lactation was lower in the Morada Nova ewes. The weight development of the Dorper × Santa Ines lambs during the maternal-dependent phase was 34 g/100 g higher than that of the other cross, with no difference in the maternal-independent phase. Dorper × Santa Ines lambs gain more weight during the 70 days of development. However, the Dorper × Morada Nova lambs show a better response in terms of production efficiency when comparing the weight of the lambs with the weight of the sheep.

Maternal and neonatal behavior as affected by maternal nutrition during prepartum and postpartum period in indigenous sheep

ABSTRACT An intensive period of behavioral interaction between the ewe and the newborn lambs occurs during parturition, usually associated with specific physiological changes. This study was conducted to evaluate the maternal–filial behavior of native breeds given concentrate supplementation, prepartum and postpartum, and outcomes for their crossed Dorper lambs. A total of 52 crossbreed lambs from 36 hair ewes, 20 Santa Ines (SI), and 16 Morada Nova (MN), crossed with a Dorper ram were distributed in a completely randomized design in a 2 × 2 factorial arrangement with 2 breeds (MN and SI) and 2 treatments (0.5% and 1.5% of concentrate supplementation based on body weight). There was no effect (P > 0.05) of breed and concentrate supplementation on total lambing time (P > 0.05) or placental expulsion time (P > 0.05). Concentrate supplementation did not influence (P > 0.05) lamb survival at birth and weaning for either breeds. SI ewes had greater maternal behavior scores (MBSs) than did MN ewes indicating better care at the time of lamb identification. The lower MBS for MN ewes may be attributed to complications during the birth. SI and MN ewes had high similarity in several aspects of maternal and neonatal behavior. The level of concentrate supplementation did not affect the ewe behavior, but 0.5% concentrate promotes similar offspring survival at birth and at weaning compared to 1.5% concentrate supplementation.

Dietary supplementation for Santa Inês hair ewes on pasture at pre- and postpartum periods: dry matter intake, digestibility, milk production, and mineral metabolism

The aim of this study was to evaluate the impact of different levels of dietary supplementation and reproductive stages on dry matter intake, digestibility, milk production, and mineral metabolism in Santa Inês hair ewes. Two dietary supplement levels of 0.5 and 1.5%, based on body weight, were used. A total of 12 hair ewes (six subjected to 0.5 and six subjected to 1.5% of concentrate supplementation based on body weight—BW) of the Santa Inês breed were evaluated in a completely randomized design with fixed effects of supplementation level, period, and its interactions. Dry matter intake, digestibility, milk production, and mineral metabolism (calcium (Ca), phosphorus (P), magnesium (Mg), alkaline phosphatase (ALP), type I insulin-like growth factor (IGF-I), parathyroid hormone (PTH), and osteocalcin (OC)) were assessed. Dry matter digestibility was affected by the supplementation level (during both pregnancy and lactation), with higher values in ewes fed at a level of 1.5% of BW. A significant interaction between treatment × reproductive stages was found for the Mg concentration. A period effect (P < 0.05) on serum concentrations of P, Ca/P, Mg, and IGF-I was observed. Serum P concentrations were influenced (P < 0.05) by treatments and reproductive stages. There were significant differences in the Ca/P ratio among the reproductive stages. The enzymatic activity of ALP and serum IGFI differed among reproductive stages. Ewes supplemented at a level of 1.5% of BW produced 18.5% more milk than ewes supplemented at a level of 0.5% of BW. The use of 0.5% of body weight in concentrate supplementation is recommended for the reduction of production costs, without having an effect on the mineral metabolism of Santa Inês hair ewes.

The role of diet on the rhythm of physiological responses of lactating ewes under heat stress

ABSTRACT The aim of this study was to evaluate the role of diet on the rhythm of physiological responses of lactating ewes under heat stress. Twenty-four hair ewes, twelve Santa Inês (SI) and twelve Morada Nova (MN) were used. The data were analyzed using a factorial arrangement in a completely randomized design with two periods, two treatments and two breeds. Physiological responses and thermal variables were obtained at weekly interval, during eight weeks of lactation. Severe (morning) and extremely severe (afternoon) heat stress were observed. Results showed a high correlation between physiological responses with thermal variables. The interaction among breed x supplementation level x week of lactation had effect (P < 0.05) on plasma cortisol, with higher levels in SI (0.5 and 1.5 % BW) and MN ewes subjected to 1.5 % compared to MN ewes subjected to 0.5 % concentrate supplementation. An effect (P < 0.001) of interaction between breed x period of the day were seen on respiratory rate with higher values in the afternoon and SI ewes that received 1.5 % of concentrate supplementation. Heat stress and level of concentrate supplementation, in semiarid environment, promoted changes in physiological responses of lactating ewes.

Efeitos dos Níveis de Energia no Período Gestacional Sobre o Crescimento de Cordeiros Morada Nova

A viabilidade e o desenvolvimento pos-natal dos cordeiros sao diretamente influenciados pelo nivel de energia ofertado a ovelha no pre-parto. Com este trabalho objetivou-se avaliar a influencia do aporte energetico da dieta de ovelhas Morada Nova, no terco final da gestacao, sobre o desenvolvimento dos cordeiros na fase materno-dependente. O experimento foi conduzido na Estacao Experimental da UFPB, no municipio de Sao Joao do Cariri, Paraiba, tendo tres tratamentos com diferentes niveis energeticos no terco final da gestacao (2,2; 2,8 e 3,4 Mcal de EM/dia) com oito repeticoes cada. O desenvolvimento ponderal, na fase em estudo, nao apresentou variacao significativa (P>0,05) entre os niveis de energia ofertados, podendo-se atribuir tal comportamento a capacidade de mobilizacao de reservas corporais pelas ovelhas com menor oferta de energia ou mesmo devido ao carreamento de nutrientes da dieta para crescimento fetal, com reflexos no desenvolvimento pos-natal.