Seasonal variations in botanical and nutritive composition, forage availability and ingestive behavior of grazing goats in the semiarid region.

The aim of this study was to assess how the different seasons of the year impact the botanical composition, availability, and quality of forage in the caatinga, as well as the frequency of ingestion and ingestive behavior of goats in a semi-arid region. The experiment used four crossbred castrated males, with an average weight of 30.2 ± 4.76 kg and an average age of 20 months. The experimental period lasted for 12 months, encompassing two rainy seasons and one dry season within this timeframe, with three replications (data collection) per season. All collected forage was categorized based on its stratum (herbaceous, woody, and litter), and a chemical composition analysis was conducted. The goats' behavior was assessed by observing variables such as feeding time, idleness, rumination, displacement, social interaction, and water intake. The findings revealed clear seasonality in both availability and quality of forage, consequently influencing the botanical composition of the goats' diet and their ingestive behavior. In addition, during the grazing period, the goats showed a shift grazing habit, in which idle and feeding peaks were alternated with increased displacement during the morning and rumination in the afternoon. The seasons of the year strongly impact the availability and nutritional quality of forage in the caatinga biome, consequently influencing the ingestive behavior and dietary composition of goats in this ecosystem.

Effects of heat-stress-reducing systems on blood constituents, milk production and milk quality of Holstein and Jersey cows and heifers on pasture.

The objective of this study was to evaluate the influence of different heat-stress-reducing systems, i.e., sprinkler + artificial shade, shower + artificial shade, and artificial shade, on serum mineral, hormonal, hematological, and metabolite profiles, on milk production, and milk composition in lactating cows and pubertal heifers of Holstein and Jersey breeds. For this purpose, 12 animals were used: 3 Holstein cows with an average (mean ± SD) body weight of 600 ± 30 kg, 53 ± 11 months of age, and milk yield of 27 ± 3.5 kg/day; 3 Jersey cows with an average body weight of 370 ± 11 kg, 40 ± 6 months of age, and milk production of 11 ± 1.5 kg/day; 3 Holstein heifers (325 ± 25 kg and 16 ± 0.6 months of age); and 3 Jersey heifers (250 ± 25 kg and 13 ± 0.6 months of age). Animals were used in a replicated 3 × 3 Latin square design with a 3 × 2 × 2 factorial arrangement of treatments that included three treatments (sprinkler + artificial shade, shower + artificial shade, and artificial shade), two breeds (Holstein, Jersey), and two physiological stages (lactating cows, heifers). The experimental treatments influenced (P < 0.05) the concentrations of triiodothyronine, with the shower and shade systems showing greater and similar concentrations (99.5 and 96.3 µg/dL, respectively) when compared with sprinkler treatment (89.2 µg/dL). There was an effect (P < 0.05) of breed on the concentrations of Na + , K + , hemoglobin, hematocrit and mean corpuscular volume levels with the Holsteins having lower levels of Na + , K + , hemoglobin, hematocrit and mean corpuscular volume (101.1, 4.0 ng/mL, 11.2 g/dL, 24.7%, and 42.3 µm3, respectively) than the Jerseys (106.5 and 4.3 ng/mL, 12.4 g/dL, 27.7%, and 46.3 µm3, respectively. Total cholesterol and high-density lipoproteins were influenced by physiological stage (P < 0.05). Concentrations of cholesterol and high-density lipoproteins were higher for cows (94.1, and 56.9 mg/dL, respectively) than for heifers (56.9 and 42,9 mf/dL, respectively). Milk production and fat content were affected (P < 0.05) by breed (P < 0.05), with Holstein cows producing more milk (23.9 kg/day) than Jersey cows (12.0 kg/day), but Jersey cows had higher fat concentration (4.6%) than Holstein cows (3.0%). Therefore, the three different thermal-stress-reducing-systems tested were able to maintain the serum biomarkers within normal physiological ranges. However, the most appropriate thermal-stress-reducing-systems would be a sprinkler systema because it uses less water compared with the shower system.

Physicochemical and microbiological parameters of rumen fluid of lactating goats fed diets containing crude glycerin from waste frying oil used in biodiesel production.

Crude glycerin from the biodiesel industry is a alternative energy source used to replace part of the energy components of the diet, since the nutritional value of glycerol makes it suitable for use in ruminant diets. The objective was to analyze the effects including crude glycerin (CG) derived from the production of biodiesel from residual frying oil, in diets of lactating goats on the physicochemical and microbiological parameters of rumen fluid. Eight 2-year-old goats weighting approximately 42.06 ± 3.5 kg of body weight (BW) were kept in individual stalls, receiving diets containing 0, 7, 14 and 21% of CG (% DM). The experiment was carried out according to a double 4 × 4 Latin square and lasted for 80 days. Orthogonal contrasts were tested to determine linear and quadratic effects, as well as the effects of 0% CG in the diet in comparison to the other treatments. There was a linear decreasing effect on DM intake (P = 0.001) and neutral detergent fiber (P = 0.0001), as well as a quadratic effect (P = 0.0002) on ether extract (EE) intake with increasing level of CG in the diet. Including CG affected motility and density of the protozoa (P = 0.0001). Treatments had no effect on pH, N-NH3 concentration and percentage of protozoa in the rumen liquid. There was increasing linear effect on sedimentation and flotation time (P = 0.001). Therefore, including 14 and 21% CG in the diet as a source of glycerol decreased nutrient intake and altered the ruminal microbiota, but pH and N-NH3 were not affected. Thus, to avoid impairment to the physicochemical and microbiological parameters of the rumen liquid of goats, the inclusion of CG should not exceed 7% DM.

Effects of extruded urea levels on the productive performance and carcass and meat characteristics of Nellore cattle.

Because the non-protein nitrogen sources can be an option for a ruminant diet to replace true-protein sources, we hypothesized that using extruded urea in increasing levels by reducing soybean meal in the diet can maintain or improve the productive performance of beef cattle in a feedlot. It was aimed to evaluate the effects of extruded urea levels on the productive performance and carcass and meat characteristics of Nellore steers in feedlot. Twenty-four Nellore steers, with an average age of 22 months and an average initial weight of 333.5 kg, were used. A completely randomized design was used with four treatments: 50, 60, 70, and 80 g/100 kg BW of extruded urea. There was no effect of extruded urea levels on nutrient intake. The final weight and average daily gain were adjusted by a quadratic equation, with maximum estimated values of 479.18 kg and 1.02 kg/day with the inclusion of 59.71, 54.14, and 54.16 g/100 kg BW of extruded urea, respectively. There was no effect (P > 0.05) of extruded urea levels on hot carcass weight (233.3 kg), carcass yield (53.2%), ribeye area (72.7 cm2), and subcutaneous fat thickness (5.3 mm). Likewise, there was no effect (P > 0.05) of extruded urea levels on meat chemical composition, shear force (8.9 KgF), cooking losses (28.2%), pH (5.6), and meat color parameters. We recommended the use of 70 g/100 kg BW of extruded urea in the diet for finishing Nellore steers in confinement.

Chemical composition, fermentative characteristics, and in situ ruminal degradability of elephant grass silage containing Parkia platycephala pod meal and urea.

This study aimed to evaluate the effects of the addition of Parkia platycephala pod meal (PP) and urea on the chemical composition, fermentation characteristics, and in situ ruminal degradability of elephant grass silage. A completely randomized design with a 4 × 2 factorial arrangement was adopted, with four levels of pod meal (0, 10, 20, and 30%) and two levels of urea (0 and 1.5%) on as fed basis. The produced silages were evaluated in terms of dry matter (DM), crude protein (CP), mineral matter (MM), neutral detergent fiber (NDF), acid detergent fiber (ADF), hemicellulose, ammonia nitrogen, pH, short chain fatty acids, and in situ ruminal degradability. For the study of degradation, four Santa Ines rumen fistulated sheep, with average weight of 45 ± 2.5 kg were used. The association of the additives increased (p < 0.05) DM, CP, DM degradability, fractions a, b, and effective degradability at all passage rates (2, 5, and 8%/h) and reduced NDF and ADF contents. DM disappearance increased (p < 0.05) during the incubation time, especially for the silages containing the two additives. The interaction in the rumen environment is essential for microbial multiplication. Thus, the use of additives such as PP and urea contributed to the availability of digestible fractions of the feed and greater use by ruminal microorganisms. The association of Parkia platycephala with urea improves the fermentation characteristics, chemical composition, and degradability of elephant grass silage.

Resilience of cactus pear genotypes in a tropical semi-arid region subject to climatic cultivation restriction.

The cactus pear has demonstrated productive potential in arid and semi-arid regions due to its photosynthetic process of crassulacean acid metabolism. Thus, this study aimed to evaluate agronomic characteristics and chemical composition of three genotypes of cactus pear at different locations of a tropical semiarid region classified as non-suitable for cactus pear cultivation. A completely randomized design in a factorial arrangement (3 × 7) (three genotypes of cactus pear [Miúda, Baiana (Nopalea cochenillifera) and Orelha de Efefante Mexicana - OEM (Opuntia stricta)] and seven locations) was used. The climatic conditions characterized an environment that restricts the growth of cactus pear genotypes, mainly due to the air relative humidity values. All morphological characteristics of the cactus pear genotypes were influenced by the interaction genotype x location, with higher expression of the characteristics on the different genotypes under hot semi-arid climate and tropical wet and dry climate. An effect of the interaction genotype x location was observed (p < 0.05) on water use efficiency, water accumulation and carrying capacity, where the highest values were observed for genotype Baiana at location 1. Also, there was influence of the interaction genotype x location over the chemical composition of the cactus pear. The cultivation of cactus pear is recommended under restricted climatic conditions in semi-arid tropical regions, especially the genotype Baiana, based on growth factors, biomass production and chemical composition.

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.

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.