Evaluation of the sexual dimorphism in Mangalarga Marchador horses using discriminant analysis

This study used discriminant analysis to evaluate body measures and sexual dimorphism in Mangalarga Marchador horses. Discriminant analysis is a multivariate method that generates functions to classify animals using a prior criterion. In this study a prior criterion is male or female. The study analyzed 25 linear and 11 angular measures obtained from 25 stallions and 56 mares registered with the Mangalarga Marchador Brazilian Breeders Association. Knee girth, cannon girth, chest width, chest girth, back-loin length, hip width, distance from elbow to knee, hind limb hoof length, head width, shoulder length, and body length were found to be linear measures that provided evidence of sexual dimorphism. Angular measures with evidence of sexual dimorphism were shoulder–humerus, metacarpal–phalanx, coxae–femur, and femur–tibial angles. Stallions were larger than mares for almost all linear measures, except for back-loin length, hip width, and distance from elbow to knee. Shoulder–humerus and coxal–femur angles were larger in mares, while metacarpal–phalanx and femur–tibial angles were larger in stallions. Using linear measures, two mares were classified as stallions and three stallions were classified as mares. For angular measures, two other mares were classified as stallions and three other stallions were classified as mares. The discriminant functions can be useful for the selection of horses and to avoid registration of animals not meeting the phenotypic standards of the breed association.     

Effect of mixed maize-legume silages on milk quality and quantity from lactating smallholder dairy cows

The study investigated the effect of the following maize:legume (70:30) mixed crop silages: maize:cowpea, maize:velvet bean, and maize:lablab on milk production during the 2016 dry season. Using a 5?×?5 double Latin square design, five Holstein-Friesian crossbred cows in early lactation (30?±?15 days) and five Jersey crossbred cows in early lactation (25?±?10 days) were given the supplementary mixed crop silage diets at 0.5 kg/l of milk produced over 105 days. Commercial dairy meal and sole maize silage were used as positive and negative controls, respectively. Milk yield was significantly higher (P?< 0.05) in cows given the dairy meal compared to mixed crop silages; however, milk yield was also significantly higher (P?< 0.05) for cows given the three mixed crop silages compared to cows given sole maize silage. Cows given mixed crop silages produced milk of significantly higher protein content (P?< 0.05) than those given sole maize silage. There was no significant difference (P?> 0.05) in butterfat content of milk across all the dietary treatments. The dietary cost of producing 1 l of milk was highest at 0.31USD/l for cows given commercial dairy meal and lowest for cows given maize:velvet bean and maize:cowpea silage at 0.19USD/kg. The highest dietary gross margins of 68% were observed when cows were given maize:velvet mixed silage compared to commercial dairy meal (47%) and sole maize silage (57%). The 70:30 maize:legume mixed crop silages showed the capability to increase milk quantity and quality at very low production costs in smallholder dairy schemes.     

Silages in the form of diet based on spineless cactus and buffelgrass

This study was conducted to evaluate the fermentation pattern and the in situ dry matter degradability of silages in the form of diet. Five diets were formulated based on spineless cactus (Opuntia fícus-indica cv. ‘Gigante’) and buffelgrass (Cenchrus ciliaris). The experimental design was completely randomised, with five treatments and three replicates in which the diets differed in the proportion of buffelgrass (0%, 15%, 25%, 30% and 35%, on a fresh matter basis). There was significant difference (p < 0.05) in the chemical composition of the diets, with all dry matter contents being within the ideal range. Ammonia-nitrogen content was not affected (p > 0.05). There were significant differences (p < 0.05) in dry matter recovery across diets, which ranged from 96.28% to 99.93%. The pH values decreased as the time of opening (days) was extended. Organic acid contents differed across all diets; however, overall, all diets showed satisfactory lactic acid contents. As the proportion of buffelgrass in the diets was increased, the degradability of dry matter decreased. Based on fermentation profile, losses and chemical composition the diet with higher proportion of spineless cactus can be recommended for silage production.     

Performance and intestinal microbiota of chickens receiving probiotic in the feed and submitted to antibiotic therapy

The purpose of this study was to verify the ability of a probiotic in the feed to maintain the stability of the gut microbiota in chickens after antibiotic therapy and its association with growth performance. One thousand six hundred twenty 1‐day‐old Cobb male were housed in floor pens (36 pens, 45 birds/pen) and were fed corn‐/soya bean meal‐based diets supplemented with or without probiotic (Bacillus subtilis) during the entire rearing phase. From 21 to 24 days of age (three consecutive days), the chickens were submitted to antibiotic therapy via drinking water (bacitracin and neomycin) in order to mimic a field treatment and induce dysbiosis. Growth performance was monitored until 42 days of age. At 2, 4 and 6 days after antibiotic therapy, three chickens from each pen were euthanized and the contents of the small intestine and caeca were collected and pooled. The trial was conducted with four treatments and nine replicates in a 2 × 2 factorial arrangement for performance characteristics (with and without probiotic × with and without antibiotic therapy); for the intestinal microbiota, it was in a 2 × 2 × 3 factorial arrangement (with and without probiotic × with and without antibiotic therapy × 2, 4 and 6 days after the antibiotic therapy) with three replicates per treatment. Terminal restriction length polymorphism (T‐RFLP) analysis showed that the structure of gut bacterial community was shaped by the intestinal segment and by the time after the antibiotic therapy. The number of 16S rDNAs copies in caecum contents decreased with time after the therapeutic treatment. The antibiotic therapy and dietary probiotic supplementation decreased richness and diversity indexes in the caecal contents. The improved performance observed in birds supplemented with probiotic may be related to changes promoted by the feed additive in the structure of the intestinal bacterial communities and phylogenetic groups. Antibiotic therapy modified the bacterial structure, but did not cause loss of broiler performance.     

Effects of pearl millet silage ammoniation with urea on carcass and meat quality of lambs

This study aimed to evaluate the effect of pearl millet silage ammoniated with urea on lamb carcass characteristics and meat quality. Thirty‐two noncastrated crossbred lambs at 4–5 months of age, with an average initial body weight of 17.39 ± 2.16 kg, were distributed into four treatments in a randomized block experimental design with eight animals per treatment. Experimental diets were composed of pearl millet silage ammoniated with four levels of urea (0%, 2%, 4% and 6%, on dry matter basis (DM). Carcass conformation and fatness decreased linearly (p < 0.05). Except for the fat content, the proximate composition was not influenced (p < 0.05) by the diets. Meat lightness and yellowness increased linearly (p < 0.05). There was no effect of diets (p > 0.05) on cooking losses or shear force. The levels of oleic and erucic fatty acid levels in the meat decreased linearly (p < 0.05), whereas linoleic and eicosadienoic acids, polyunsaturated fatty acids, PUFA:SFA ratio and ω6 contents increased (p < 0.05). Pearl millet silage ammoniated with urea allows for the production of good‐quality lamb meat, with greater concentrations of polyunsaturated fatty acids. However, lambs fed diets with pearl millet ammoniated with up to 6% lead to a reduction of carcass characteristics without significantly affecting loin‐eye area possibly associated with low palatability of the additive used. The lower acceptance of the silages with higher levels of urea is due to the ammonia retention in the material is attributed to the ammonization process. Thus, in spite of the benefits on lamb meat quality, it is suggested that the use of this additive in the ammonization of tropical forages be carried out with care, in limits of up to 6%.     

Variation of Soil and Water Volumes in Riparian Jungle Soils of Brazil

The objective of this work is to study the relation between humidity, density, porosity and shrinkage of the floodplain soil and riparian vegetation and their ability to store water. For this purpose, two locations for every type of soils were evaluated. Both were placed at the Agronomy University （Faculdade de Cidncias Agron6micas） in SAo Manuel, State of SAo Paulo, Brazil. The floodplain soil was vegetated with Southern Cattail （Typha domingensis）. In both places, soil samples were collected from several depths： 0, 30, 60 and 100 cm. Results show that lower soil density values （0.15 g/cm3） with organic texture and high porosities values （up to 86.2%） were found in samples with the highest organic material content in the floodplain soil. For this field experiment, flood plains soils （characterised as basin gley soils） presented high volumetric instability with a retratibility of 67.49% and higher water storage capacities compared to riparian stands soils （characterised as fluvic neosoils）.     

Assessing the resistance of collard greens genotypes to the cabbage aphid (Brevicoryne brassicae) (Hemiptera: Aphididae)

Phytoparasitica - Severe attacks&nbsp;of Brevicoryne brassicae (Hemiptera: Aphididae) on brassica crops may lead to a significant decrease in yield and can cause plant death. Host plant...     

Modelling black Sigatoka epidemics with seasonal dispersal of Mycosphaerella fijiensis ascospores over a banana plantation in the Ribeira Valley,São Paulo,Brazil

Knowing the patterns of Black Sigatoka development is essential to propose adequate disease management practices and evaluate their effects, which can be achieved through temporal analysis by integrating the evolving interactions of the pathosystem components, expressed by data on cumulative incidence and severity, and summarizing these data in a disease progress curve. Airborne spores are essential components for the progression of an epidemic in the context of a specific pathosystem. In this perspective, the spore count is an essential approach to assess and model an epidemic. This study evaluated the temporal dynamics of Black Sigatoka in a banana plantation in the Ribeira Valley, state of São Paulo, Brazil, while simultaneously performing a year-long evaluation of fungal spore aerobiology. The disease was intense during the rainy season, but the leaf emergence rate was high enough for quickly inverting the severity peak (between 169 and 197 days of evaluation). After that, the disease severity raised until reach the higher rates (around the score 7 out of 8). The disease progress curve of Black Sigatoka showed peaks of extreme severity, one in the rainy and another in the dry season, with high levels of ascospores in the air. The ascospore concentration and the severity of the disease correlated significantly on the same day of sampling and 15 days after ascospore sampling, corresponding to the average latency period of the disease in the region. The patterns of the disease progress curve in both peaks fitted the monomolecular model, with higher rates of disease increase in the rainy season.