Resumo em Inglês:

ABSTRACT The objective of this study was to determine the effects of egg quality characteristics (egg weight, egg width, egg height, and shape index) on fertility of eggs of Japanese quail with different colored feathers (yellow, white, grizzled, and normal), which are of economic importance for poultry production. For this purpose, 383 eggs of Japanese quail with various feather colors were used. In the study, usability of classification and regression tree (CART) data-mining algorithm as a classification tree method is necessary for poultry breeders to define proper cut-off values of egg quality characteristics that ensure Japanese quail eggs at good quality in fertility. Fertility as the dependent variable in the study was examined as a binary trait (fertile and infertile) and all the egg quality traits accepted as explanatory variables were continuous variables. Feather color was also included as a nominal categorical explanatory variable. The classification tree results showed that the highest fertility ratio of 90.9% was obtained from the eggs of Japanese quail of white, grizzled, and normal feather colors with 10.425 g ≥ egg weight, 24.565 mm ≥ egg width, or the fertility ratio of 88.2% of the eggs was observed with 10.425 g ≤ egg weight and 25.605 mm ≥ egg width. Consequently, usability of the tree-based CART algorithm is important in practice for properly establishing fertilized eggs, depending on feather color types of Japanese quail.

Resumo em Inglês:

ABSTRACT The objective of this study was to investigate the effects of insoluble granite-grit on growth performance and gut health status of broiler chicks. One hundred and sixty 14-day-old broiler chicks were allocated to experimental groups control and grit feeding. Each group included 80 birds divided by four replicates, each consisting of 20 birds, 10 males and 10 females. Feed intake, body weight gain, feed conversion ratio, carcass weight, dressing percentage, gut length, abdominal fat pad, and liver, heart, and gizzard weights were determined. Starter diet included 230 g crude protein (CP) kg−1 and 3.15 Mcal metabolizable energy (ME) kg−1 during the days 14 to 21; grower diet included 212 g CP kg−1 and 3.20 Mcal ME kg−1; and finisher diet included 190 g CP kg−1 and 3.20 Mcal ME kg-1. Control birds were fed broiler diets, while grit-fed birds were allowed to consume broiler diets, including 3% insoluble granite-grit. Grit feeding improved the final body weight (2268 vs. 2336 g) with better feed efficiency (2.03 vs. 1.95) and less feed intake (3780 vs. 3764 g). Grit feeding increased gizzard weight (31.63 vs. 48.00 g) without affecting carcass weight (1643 vs. 1708 g), dressing percentage (73.50 vs. 73.60%), liver weight (42.69 vs. 40.69 g), heart weight (12.00 vs. 11.63 g), abdominal fat pad (34.50 vs. 35.38 g), and gut length (229.3 vs. 220.7 cm) of broilers. Grit feeding affects daily gain, feed intake, and feed conversion ratio positively by increasing gizzard development and health.

Resumo em Inglês:

ABSTRACT An experiment was conducted to determine the required levels of supplementary vitamin D and calcium in meat-type quail (Coturnix coturnix sp) between 15 and 35 days old. The experiment was a 4 × 4 factorial design with four levels of calcium: 0.42, 0.58, 0.74, and 0.90% and four levels of vitamin D: 1,000; 2,000; 3,000; and 4,000 IU. Body weight and body weight gain increased linearly and feed conversion showed some linear improvement due to increased levels of Ca and vitamin D. The increased vitamin D levels resulted in a linear increase in feed intake. Calcium and vitamin D requirements in meat-type quail between 15 and 35 days of age is greater or equal to 0.90% Ca and greater or equal to 4,000 IU of vitamin D, probably because the experiment was conducted during the pre-laying phase.

Resumo em Inglês:

ABSTRACT The objective of this study was to analyze the antioxidant activities of chitooligosaccharides (COS) both in vitro and in high-fat diet (HFD)-mouse model. In antioxidant assays in HFD-mouse model, mice were administered with normal diet, HFD, or HFD with 0.5% COS for six weeks. The administration of HFD with 0.5% COS resulted in significant increase in the activity of superoxide dismutase, catalase, and glutathione peroxidase in stomach, liver, and serum of mice as compared with the HFD-fed group, which means that COS may have certain antioxidant activity and can restore the activity of the enzymes affected by the HFD. Through morphological measurements of the small intestinal mucosa, mice fed HFD showed decreased villus height compared with other groups. On the other hand, HFD with 0.5% COS group showed similar ratio of villus height to depth compared with control mice, indicating that intestinal integrity was improved when COS was added. Chitooligosaccharides have potent antioxidant activity that can protect mice from oxidative stress.

Resumo em Inglês:

ABSTRACT Aiming at breeding heifers with 14-15 months of age, 100 Hereford calves were subjected to different feeding systems. Heifers grazed on a natural pasture in early winter, fed or not a supplement (14% crude protein; 72% total digestible nutrients), were transferred to a ryegrass pasture for 73 days, and then returned to a natural pasture for 15 days until the beginning of the breeding season. During the last 15 days on ryegrass pasture and the 15 days of the return to the natural pasture, half of the heifers of the two previous systems were offered the supplement, thereby establishing four feeding treatments. Heifers supplemented during the second period, independently of supplementation during the first grazing period, presented higher average daily gain and greater backfat values than the non-supplemented heifers. The breeding season extended for 75 days. At the start of the breeding season (November 18), heifers supplemented during both periods presented higher body condition score and body weight. The highest percentage of puberty was determined in heifers supplemented in the early winter. Heifers supplemented during both periods presented the highest pregnancy rate. Pregnant heifers presented higher average daily gain when fed the supplement during the second period, as well as higher relative pelvic area, body weight, and body condition score at the start and end of the breeding season. To an expressive pregnancy in 14- to 15- month-old heifers, higher weaning weights and pasture allowance are required to get a better answer to supplements offered.

Resumo em Inglês:

ABSTRACT The objective of the study was to assess the effects of including 0, 79.8, 159.8, and 240.0 g kg-1 crude glycerin in the total diet dry matter on the 84 days feedlot performance, nutrient digestibility, blood parameters, and carcass characteristics of crossbred dairy steers. Experimental diets were composed of 98.5 g kg-1 of sorghum silage and 901.5 g kg-1 of concentrate. Twenty-four crossbred dairy steers (337.3±39.8 kg body weight and 15 months of age) were distributed in a completely randomized design with four treatments and six replicates. The intake and digestibility of the dry matter and nutrients were not altered by including crude glycerin in the diet. Crude glycerol levels did not affect the final weight (430.2 kg), daily weight gain (1.38 kg day-1), total weight gain (97.2 kg), hot carcass weight (218.9 kg), cold carcass weight (215.2 kg), hot carcass yield (0.50 kg 100 kg-1 BW), longissimus dorsi area (62.86 cm²), subcutaneous fat thickness (4.05 mm), and carcass physical composition. Concentrations of serum glucose, triglycerides, total cholesterol, high-density lipoprotein cholesterol, and creatinine were not altered by including crude glycerin in the diet. Crude glycerin can be added to high concentrate diet up to 240 g kg-1 without changing the animal performance, apparent digestibility of nutrients, the main carcass characteristics, and blood parameters of finishing crossbred dairy steers.

Resumo em Inglês:

ABSTRACT This study was conducted to evaluate the influence of management tools - daily pasture allowance and corn silage supplementation - during periods of forage shortage on the metabolism of dairy cows grazing low-mass pasture in temperate regions. Forty lactating Holstein cows were used during an experimental period of seventy days (April 15 to June 23, 2012). Blood metabolites and milk production were determined in fall-calving dairy cows grazing under two daily pasture allowances (PA) (moderate, 17 kg vs. high, 25 kg dry matter (DM)) and supplemented with corn silage (CS) (low, 4.5 kg vs. high, 9.0 kg DM). All cows received 3 kg DM of concentrate. Plasma concentrations of β-hydroxybutyrate (BHBA), non-esterified fatty acids (NEFA), and urea were determined using an automated spectrophotometer, and milk production was electronically measured at each milking time during the trial. The experimental design was completely randomized using a 2 × 2 factorial arrangement of treatments. The increase in daily PA decreased plasma concentrations of BHBA (0.91±0.36 vs. 1.12±0.43 mmol L−1), provided an increase in milk yield (23.18±3.26 vs. 21.99±3.37 kg d−1), and did not modify the concentrations of NEFA and urea. The increased CS supplementation increased mildly the plasma concentrations of BHBA (1.07±0.36 vs. 0.96±0.44 mmol L−1) and NEFA (92.77±54.14 vs. 92.77±55.31 µmol L−1), and decreased the concentrations of urea (4.08±1.40 vs. 4.64±1.30 mmol L−1), but did not change milk production. The positive effect of increasing PA was associated with a high herbage intake, while the lack of response to increasing CS supplementation was attributed to a high substitution of pasture intake (0.9 kg DM pasture/kg DM CS). Low corn silage supplementation is recommended.

Resumo em Inglês:

ABSTRACT The effect of supplementation with corn oil (CO) and its mixture with palm kernel oil (CO:PKO 75:25) to grazing cows on ruminal fermentation, milk yield, and its fatty acid (FA) profile was evaluated. The treatments were: one control treatment (C) without oil and two treatments with 720 g d−1/cow of CO or CO:PKO (ether extract: 22.7 g kg−1 for control treatment, 66 g kg−1 for CO, and 65 g kg−1 for CO:PKO). Six multiparous Holstein cows (6.3±1.8 yr, 597±11.5 kg body weight (BW), 160±29 d in milk; mean ± standard deviation) were assigned to a double 3 × 3 × 3 Latin square design. Cows grazed (3 kg DM/100 kg BW) a Cenchrus clandestinus (previously Pennisetum clandestinum) pasture and were supplemented with 0.9 kg d−1 DM corn silage, 4.2 kg d−1 DM concentrate, and 9 g Cr2O3. The mixture of concentrate and oils was offered twice a day. The addition of oils increased milk yield (kg d−1) (C: 21.4, CO: 23.6, CO:PKO: 23.9) and milk fat concentration (g kg milk−1) (C: 31.5, CO: 34.0, CO:PKO: 34.0). Compared with control, conjugated linoleic acid (18:2c9 t11 CLA) proportion (g 100 g−1 FA) in milk fat was higher for oil treatments (C: 0.68, CO: 1.56, CO:PKO: 1.01). Voluntary intake and digestibility were not different among treatments. The molar ratio of acetate, propionate, and butyrate was not different among treatments, but the molar concentration of volatile fatty acids (VFA) was lower for CO and CO:PKO, resulting in a lower estimated methane (CH4) production (mL/100 mol VFA) for CO and CO:PKO treatments. Supplementing CO and CO:PKO to grazing dairy cows increases milk yield without affecting voluntary intake or diet digestibility. The proportion of conjugated linoleic acid increases more for CO than for CO:PKO.

Resumo em Inglês:

ABSTRACT The objective of this study was to evaluate the effect of source of roughage and crude protein level on feeding performance and carcass traits of Majaheem camels (Camelus dromedarius). Forty-eight male calf-camels weighing 203.3±5.1 kg were equally assigned to a 2 × 3 factorial arrangement of two sources of roughage (Rhodes grass hay and dry salicornia biomass) and three dietary crude protein levels (12, 14.5, and 17%); the feeding trial lasted for 18 weeks. The results showed that slaughter and hot carcass weights, average daily gain, dry matter intake, feed efficiency, and separable fat from 9th-11th rib joint increased as the crude protein in the diets increased from 12 to 14.5%, whereas increasing crude protein to 17% resulted in no further changes. Slaughter weight, average daily gain, hot carcass weight, rib eye area, and separable lean did not differ between Rhodes grass and salicornia diets, but salicornia-fed camels had higher dry matter intake and produced heavier kidney fat and separable fat weights than camels fed Rhodes grass diets. It is suggested that the inclusion of salicornia biomass as a roughage ingredient up to 25% in the diet containing not greater than 14.5% crude protein can be utilized without adverse effect on feeding performance of calf-camels.

Resumo em Inglês:

ABSTRACT The avian embryo is a time-honored animal model for understanding vertebrate development. A key area of extensive study using bird embryos centers on developmental phenotypic plasticity of the cardio-respiratory system and how its normal development can be affected by abiotic factors such as temperature and oxygen availability. Through the investigation of the plasticity of development, we gain a better understanding of both the regulation of the developmental process and the embryo's capacity for self-repair. Additionally, experiments with abiotic and biotic stressors during development have helped delineate not just critical windows for avian cardio-respiratory development, but the general characteristics (e.g., timing and dose-dependence) of critical windows in all developing vertebrates. Avian embryos are useful in exploring fetal programming, in which early developmental experiences have implications (usually negative) later in life. The ability to experimentally manipulate the avian embryo without the interference of maternal behavior or physiology makes it particularly useful in future studies of fetal programming. The bird embryo is also a key participant in studies of transgenerational epigenetics, whether by egg provisioning or effects on the germline that are transmitted to the F1 generation (or beyond). Finally, the avian embryo is heavily exploited in toxicology, in which both toxicological testing of potential consumer products as well as the consequences of exposure to anthropogenic pollutants are routinely carried out in the avian embryo. The avian embryo thus proves useful on numerous experimental fronts as an animal model that is concurrently both of adequate complexity and sufficient simplicity for probing vertebrate cardio-respiratory development.