Tairon Pannunzio Dias e Silva

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.

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.

Características morfológicas, qualidade nutritiva e produção de metano de gramíneas tropicais no Brasil

The objective of this work was to evaluate three tropical forage species for their in vitro methane (CH4) production and organic matter degradability, in order to determine the relationships between forage grass nutritive quality and CH4 production. Guinea grass (Megathyrsus maximus), palisade grass (Urochloa brizantha), and signal grass (Urochloa decumbens) were evaluated. Palisade grass showed the highest organic matter, neutral detergent fiber, acid detergent fiber, lignin, and lower-crude protein content. Signal grass had the highest values for hemicellulose and neutral detergent fiber-nitrogen, and the lowest-cellulose content. Guinea grass and signal grass showed a higher-total gas production than palisade grass. Besides, Guinea grass showed an increased CH4 production, and palisade grass showed lower value for truly degraded organic matter, and reduced partitioning factor, in comparison to signal grass. An increased CH4 production was observed in cases of lower hemicellulose and paratitioning factor. The nutritive value and CH4 production of forages may be employed as parameters, aiming at the sustainability of ruminant production.

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.

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.