Summary
Mastitis, the most common and expensive disease in dairy cows, implies significant losses in the dairy industry worldwide. Many efforts have been made to improve genetic mastitis resistance ...in dairy populations, but low heritability of this trait made this process not as effective as desired. The purpose of this study was to identify genomic regions explaining genetic variation of somatic cell count using copy number variations (CNVs) as markers in the Holstein population, genotyped with the Illumina BovineHD BeadChip. We found 24 and 47 copy number variation regions significantly associated with estimated breeding values for somatic cell score (SCS_EBVs) using SVS 8.3.1 and PennCNV‐CNVRuler software, respectively. The association analysis performed with these two software allowed the identification of 18 candidate genes (TERT, NOTCH1, SLC6A3, CLPTM1L, PPARα, BCL‐2, ABO, VAV2, CACNA1S, TRAF2, RELA, ELF3, DBH, CDK5, NF2, FASN, EWSR1 and MAP3K11) that result classified in the same functional cluster. These genes are also part of two gene networks, whose genes share the ‘stress’, ‘cell death’, ‘inflammation’ and ‘immune response’ GO terms. Combining CNV detection/association analysis based on two different algorithms helps towards a more complete identification of genes linked to phenotypic variation of the somatic cell count.
The aim of this study was to evaluate the effect of including calving age (CA) on genetic evaluation models for Holstein cattle. The evaluated models included the permanent environment, the sire-herd ...interactions, and the animals and residual effects as random. The fixed effects included the average production of milk, fat, and protein and the herd-year-season effect. The analyzed data included 603,521 records of milk production (in kg) corresponding to 438,098 animals from 527 herds. Additionally, there were 179,122 records of fat and protein components, corresponding to 148,930 animals from 137 herds. The records were classified by first lactation only (FL) and all available lactations (AL) for validation test (VT). The FL records corresponded to 275,487 milk production records with a mean of 10,874.1 ± 2773.9 kg at a mean CA of 25.6 ± 4.2 months. For FL, the milk components consisted of 78,955 records with a mean fat production of 392.86 ± 89.9 kg, a mean protein production of 362.8 ± 74.9 kg and a mean CA of 25.2 ± 4.1 months. For AL, the number of records was 603,521 for milk production with a mean of 10,802.8 ± 2905.9 kg and a mean CA of 35.6 ± 11.5 months. For the milk components, there were 179,122 records with a mean of 36.1 ± 9.5 months for CA and 388.3 ± 98.4 kg and 356.7 ± 82.6 kg for fat and protein, respectively. Three models were compared: the base model (M0) described above, and two alternative models that included CA in a linear and quadratic form (M1 and M2, respectively). Estimations of the variance components (VC) and breeding value (BV) were obtained using a repeatability animal model, with the same phenotypic and pedigree information used for all models. To select the best fit model for the data, a likelihood ratio test (LRtest) was used. A validation test (VT) was also applied to each model to evaluate the consistency of the genetic trends for females with information on AL and FL. The inclusion of CA in its linear form (M1) was the model that achieved the best results in the LRtest and an acceptable value for the VT. These results show that CA improves the model fit for BV prediction and reliability.
Two studies were done to study detoxification of aflatoxin (AF)-contaminated chick feed with Nocardia corynebacteroides (NC). In the first study, pathogenicity of the bacteria was studied; in the ...second, the nutritional value of detoxified feed was evaluated. Commercial corn was divided into 2 sublots, one of which was contaminated with AF. Both lots were divided into 2 parts; the first was inoculated with NC. Four corn-soybean diets were prepared from the 4 corn lots. A completely randomized design was used with 2 x 2 factorial arrangement in which the factors were AF contaminated or not and NC inoculated or not. One hundred Ross 308 chicks (1-d-old, male) were used in 4 treatments with 5 repetitions and 5 chickens per cage. Bird weight and feed consumption were recorded weekly. Each week, 1 chick per treatment repetition was killed for histopathologic analysis of liver, kidney, bursa of Fabricius, pancreas, and small intestine (duodenum, jejunum, and ileum) and for analysis by scanning electron microscopy of the 3 sections of the intestine. At 21 d (the end of both experiments), 1 chick per treatment repetition was killed, and moisture, lipid content, and residual AF in liver were detected. Results at 3 wk did not show differences between treatments (P > 0.05) in any of the variables. In the second study, the same methodology was used except that greater levels of AF were used (800 and 1,200 μg of AFB1/kg of feed). Results showed differences (P < 0.05) in body weight, lipid content, and residual AF in liver. Histopathologic studies showed statistical differences in lesion severity in liver, duodenum, and kidney. Scanning electron microscopy analysis showed severe lesions of intestinal mucosa that mainly affected tight junctions in AF treatments. It can be concluded that NC is safe for chicks and may be used to partly detoxify chicken feed contaminated with AF.
A substitution (Pherightward arrowIle) within the sodium channel gene sequence has been associated with pyrethroid resistance in Boophilus microplus. The aim of the present study was to analyze the ...inheritance of pyrethroid resistance and the mutant allele, on reciprocal crosses of a susceptible (SS) and a resistant (RR) strain. Bioassays and genotypes were determined to evaluate pyrethroid resistance. The resistance allele frequency of both parental strains were 100% and 2.27% for RR and SS, respectively. The reciprocal crosses show a predominance of the heterozygote genotype, in agreement with the significant decrease of the acaricide resistance to cypermethrin, deltamethrin, and flumethrin. However, the RS progeny showed a complete recessive survival (D ML = 0) for deltamethrin and flumethrin, suggesting a complete dominance of the susceptible allele and incomplete dominance for cypermethrin (D ML = 0.169). On the other hand, SR progeny showed a partially recessive survival for cypermethrin (D ML = 0.380), deltamethrin (D ML = 0.319), and flumethrin (D ML = 0.258), indicative of a partially dominant inheritance of the resistance. A possible maternal strain effect should be considered for practical purposes and prediction of acaricide resistance and further work needs to be done to elucidate the underlying inheritance of pyrethroid resistance and the sodium channel mutation in B. microplus.
The effect of a formulated diet (FD), a seaweed diet (SW), and a mixture of both (FD + SW) on growth, survival rate, and fatty acid content in the tissue of juvenile Haliotis fulgens abalone grown ...under commercial culture conditions, was analyzed over a 329-day period. Survival and growth rate in terms of length and weight were different with each of the diets evaluated, being significantly higher (P < 0.05) with the mixed diet (FD + SW), followed by SW and FD. Since feed intake was not evaluated in this preliminary study, differences in growth cannot be attributed to the dietary treatments; however, the importance of this work was to show the significant impact of the diet treatments on the tissue fatty acid profiles, suggesting that the treatments contribute to the composition of some fatty acids found in muscle. The polyunsaturated fatty acid (PUFA) 22:4n-6 was not detected in any of the diets, while 20:4n-3 was only present in SW and 22:5n-3 only in FD. However, after the feeding experiment all these PUFAs were present in abalone tissue. The possible synthesis of PUFAs from dietary n-3 and n-6 fatty acids of shorter hydrocarbon chain is discussed.
Acute pancreatitis (AP), a disease that commonly requires in-hospital treatment, has been associated with a high incidence of abnormal cardiovascular findings (ACFs). We conducted a prospective study ...to explore the association of these findings with severity of the disease.
Adult patients with AP diagnosis were prospectively enrolled in an observational study during an 8-month period in a tertiary care center. AP and its severity were defined according to the Revised Atlanta Classification of AP. Subjects were submitted to electrocardiographic, echocardiographic, and serologic testing during the acute period and a 3-month follow-up. The incidence of ACF was compared between two groups: (1) Mild and (2) moderate/severe cases.
Twenty-seven patients (mean age 48 ± 17 years) with AP were enrolled; 15 (55%) had mild and 12 (45%) had moderate/severe AP. During the acute episode, 67% had increased pro-brain natriuretic peptide levels; 52% had abnormal electrocardiographic findings; 48% had abnormal echocardiographic findings; and 18% had increased troponin I levels. There was no significant difference in the incidence of ACF between mild and moderate/severe groups. Nineteen patients (70%) had repeated follow-up testing, and most of the initial ACF did not persist.
ACFs occur in an important proportion of patients during AP episodes. Future research should continue to focus in the association of ACFs and the severity of the disease.
El robalo Centropomus undecimalis y la especie localmente conocida como chucumite (Centropomus parallelus) se distribuyen naturalmente en el Golfo de México, tienen alto valor comercial y son ...explotadas en la captura de la pesca ribereña, principalmente en el estado de Veracruz, México. Con el objeto de estudiar el crecimiento de C. undecimalis y de C. parallelus en estanques rústicos de agua dulce, se capturaron crías de ambas especies con tallas de 5.5 cm de longitud estándar que fueron sembradas en tres estanques rústicos de 25.0 x 10.0 x 1.20 m, donde simultáneamente se sembraron reproductores de la tilapia (Oreochromis niloticus) como especie forrajera para alimentar al robalo y el chucumite a diferentes densidades 4:1, 1:1 y 3:2. Durante 14 meses del experimento se determinaron las tasas absolutas de crecimiento en longitud y en peso con máximos registrados de 26.43 ± 0.135 cm y 265.3 ± 0.623 g para el robalo y de 12.0 ± 0.105 cm y 55.1 ± 0.191 g para el chucumite; la tasa diaria de crecimiento fue de 0.062 cm para el robalo y de 0.028 cm para el chucumite. La relación talla-peso estimada (W= aLb) fue de 3.01 para el robalo y de 2.96 para el chucumite, presentando un crecimiento isométrico. Las condiciones de cultivo en agua dulce fueron monitoreadas durante todo el experimento: la temperatura de 26-34°C, oxígeno disuelto de 4.16.9 mg L-1 y pH de 6.9-7.5. Estas condiciones de cultivo resultaron favorables para el crecimiento de ambas especies, ya que las tallas y pesos alcanzados se encuentran dentro de los promedios reportados para ambas especies.
Kelp meal made from Macrocystis pyrifera is a common ingredient in abalone diets (Haliotis fulgens); however, a greater demand for this ingredient as feed supplement for domestic animals has led to a ...considerable increase in price and it has become costly to use in balanced diets. Hence, the aim of the present work is to study the possibility of replacing kelp meal in the abalone diet with a regional winery by-product. Five diets were formulated in which kelp meal was substituted from 0% to 100%, at a maximum of 33% of the total of ingredients; 375 abalone (15.09 ± 0.38 mm and 0.434 ± 0.03 g) were used, randomly distributed in fifteen 8-L plastic buckets. After 60 days of experimentation, significant differences were detected in the slopes of the different treatments for both length and weight. Since the inclusion of the winery by-product resulted in a lower feed ingestion but the feed conversion efficiency remained constant, a factor of low palatability can be attributed to the winery by-product and not an antinutritional factor. It is concluded that the winery by-product can be substituted for kelp meal in 16% of the total diet without having a negative effect on the growth of the organisms.
Juvenile green abalone
Haliotis fulgens (mean length
=
65.15 mm; mean weight
=
38.77 g) were fed a standard formulated diet for 15 days (acclimation period), and then starved for 27 days. Following ...the starvation period, wet weight loss was 13.4%. Crude protein and NFE accounted for 69.9% and 31.5%, respectively, of the total net loss in dry weight that was calculated to be a total loss of 3.57 kcal/organism. Lipid content of the tissue increased by 1.0% (dry weight) while protein content remained unchanged.
Plasma levels of free amino acid, soluble protein and glucose were determined on days 0, 7, 14, 21 and 27. The level of plasma glucose significantly decreased after the first 7 days, 34 to 10 μm/ml, and then leveled at 15 μm/mL. Soluble protein in the plasma decreased from 3.33 to 2.6 mg per ml during the starvation period. Taurine was the principal free amino acid among the plasma amino acids, comprising approximately 50–65% and showing a net decrease of almost 75% at 27 days. For the essential amino acids, gross levels of histidine and arginine decreased significantly and correspondingly produced substantially higher net decreases. For the non-essential amino acids, plasma levels of alanine, proline, tyrosine, glutamic acid, and serine decreased significantly by day 27 or earlier, but proportional composition remained similar.
After starvation, changes in the gross amounts (μg/mg total dry weight) of some essential and non-essential amino acids in the muscle and visceral tissue occurred, but their relative proportions remained essentially unchanged. The ratio of the concentration of non-essential to essential amino acids in both the muscle and viscera (∼
1.9) did not change after starvation. The mean net change of non-essential amino acid content per abalone (within muscle tissue) was higher (−
41.8) than that of the essential amino acids (−
8.9). In contrast to all other amino acids, little or no loss of arginine, histidine and threonine occurred.
Plasma levels of carbohydrates and protein in starved abalone dramatically decrease within the first two days and then decrease very slowly. Muscle protein is the principal source of energy, and non-essential amino acids are preferentially used. Retention of arginine in the muscle tissue may reflect its need in arginophosphate for muscle contraction. By converting the decrease in weight to energy loss, the amount of energy used for basal metabolism during starvation was estimated to be 2.99 cal g org
−
1
day
−
1
.
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