Impact of Variability Factors on Hair Cortisol, Blood Count and Milk Production of Donkeys.

The increased interest in donkeys because of their milk has led to changes in their farm management. Little is known about the effect of the farming systems on donkey health and welfare. Measuring hair cortisol concentrations is an emerging method to assess stress in animals. To the best of our knowledge, no cortisol assessment has been done on dairy donkeys; similarly, only a few studies have investigated donkey haematological values. The aim of this study was to evaluate the effects of the lactation phase, parity and season on blood parameters, milk yield and quality and hair cortisol in dairy donkeys. Individual samples of milk, blood and mane hair were taken from twenty jennies at 1, 6 and 10 months after parturition. Higher values of hair cortisol were found in the first sampling, suggesting temporary stress during the peri-parturition. The parity influenced the number of blood cells, which was lower in the pluriparous jennies. The season affected milk quality and mean corpuscular haemoglobin and mean corpuscular haemoglobin concentration. The latters might represent the adaptation to the environmental conditions. This study contributes to a better understanding of the biochemical processes occurring in lactating jennies, and to their physiological and wellbeing status.

Effects of month of kidding, parity number, and litter size on milk yield of commercial dairy goats in Australia.

The aim of this observational study was to identify the influence of key nongenetic factors such as month of kidding, parity, and litter size on milk yield and composition of Australian dairy goats throughout lactation. The study was conducted over 4 consecutive kidding seasons from June 2016 to March 2017. Data from 940 lactations of Saanen goats from a commercial herd were used to observe the effects of month of kidding, parity number, and litter size on total milk yield (L/goat) in early lactation (kidding to 90 d in milk; DIM), mid lactation (91-180 DIM), and late lactation (181-270 DIM), cumulative milk yield (from kidding to 270 DIM; CMY), average lactation length, proportion (%) of does reaching their target lactation length (270 DIM), somatic cell count (SCC), and percentages of milk fat and protein in early lactation. The mean herd responses throughout the entire study were as follows: CMY = 519 L/goat; lactation length = 233 d, with 70% of does reaching 270 DIM; milk fat = 4.2%; milk protein = 2.9%; and SCC = 6.2 × 105 cells/mL. Average milk production peaked in February and was lowest in June (2.4 vs. 1.8 L/goat per day, respectively). Milk yield was affected by month of kidding, parity number, and litter size in all phases of lactation. November kidders had the greatest CMY, and March kidders had the lowest CMY. March kidders had the shortest lactation length and the lowest proportion of does reaching 270 DIM. June kidders had the longest lactation length, whereas September kidders had the highest proportion of does reaching 270 DIM. Maximum milk yield was attained in third parity. Goats in fourth or greater parity had the shortest lactation length, the lowest proportion of does reaching 270 DIM, and the highest SCC. Goats delivering single kids had lower CMY, lower SCC, and higher percentages of fat and protein than does delivering multiple kids. Our findings indicate that milk yield was primarily influenced by month of kidding, and the effects of month of kidding on milk yield were accentuated during mid lactation. However, the effects of month of kidding on milk yield varied significantly among parities.

Comparative proteomic exploration of whey proteins in human and bovine colostrum and mature milk using iTRAQ-coupled LC-MS/MS.

Whey, an essential source of dietary nutrients, is widely used in dairy foods for infants. A total of 584 whey proteins in human and bovine colostrum and mature milk were identified and quantified by the isobaric tag for relative and absolute quantification (iTRAQ) proteomic method. The 424 differentially expressed whey proteins were identified and analyzed according to gene ontology (GO) annotation, Kyoto encyclopedia of genes and genomes (KEGG) pathway, and multivariate statistical analysis. Biological processes principally involved biological regulation and response to stimulus. Major cellular components were extracellular region part and extracellular space. The most prevalent molecular function was protein binding. Twenty immune-related proteins and 13 proteins related to enzyme regulatory activity were differentially expressed in human and bovine milk. Differentially expressed whey proteins participated in many KEGG pathways, including major complement and coagulation cascades and in phagosomes. Whey proteins show obvious differences in expression in human and bovine colostrum and mature milk, with consequences for biological function. The results here increase our understanding of different whey proteomes, which could provide useful information for the development and manufacture of dairy products and nutrient food for infants. The advanced iTRAQ proteomic approach was used to analyze differentially expressed whey proteins in human and bovine colostrum and mature milk.

Comparative proteomic analysis of milk-derived exosomes in human and bovine colostrum and mature milk samples by iTRAQ-coupled LC-MS/MS.

Exosomes are membranous vesicles found in biological fluids with important functions. However, milk-derived exosome proteins from humans and bovines have not been studied in detail. The advanced iTRAQ proteomic approach was used to analyze milk-derived exosomes in human and bovine colostrum and mature milk samples. A total of 920 milk exosome proteins were identified and quantified. Among these, 575 differentially expressed exosome proteins (P<0.05) were found. Multivariate analysis, gene ontology (GO) annotation and the KEGG pathway were used to interpret the identified proteins. The major biological processes involved were: response to stimulus (22%), localization (16%), establishment of localization (14%), and cellular component organization (14%). Cellular components engaged in intracellular (31%) and intracellular part (31%). The most prevalent molecular function mainly touched upon binding (52%). Milk exosome proteins participated in several KEGG pathways containing ribosome, regulation of actin cytoskeleton, glycolysis/gluconeogenesis, leukocyte transendothelial migration, aminoacyl-tRNA biosynthesis, pentose phosphate pathway, galactose metabolism and fatty acid biosynthesis. These results provide important information on human and bovine milk exosomes, and increase knowledge on the proteomes of these exosomes across different lactation stages, which could provide potential directions for newborn milk powder, biological markers and functional foods.

Proteínas do soro lácteo de vacas da raça Jersey durante a lactação / Whey proteins from Jersey cows during lactation

Para avaliar as proteínas do soro lácteo durante a lactação, o soro obtido a partir de 48 amostras de leite coletadas de 12 vacas da raça Jersey antes da ordenha foi estudado. Os animais foram distribuídos em três grupos: terço inicial (30-120 dias de lactação), terço médio (121-210 dias de lactação) e terço final da lactação (mais de 211 dias de lactação). O proteinograma consistiu da concentração de proteína total do soro lácteo, determinado pelo método de biureto e da eletroforese em gel de poliacrilamida (SDS-PAGE). A diminuição gradual e significativa de algumas frações do soro de leite foi observada durante a lactação, albumina, lactoferrina, imunoglobulinas, β-lactoglobulina e α-lactoalbumina. Os valores de normalidade obtidos para as proteínas do soro do leite de vacas Jersey foram: proteína total do soro de leite 569,0-713,0mg/dL, lactoferrina 36,0-49,0mg/dL, albumina 24,0-34.0mg/dL, cadeia pesada de imunoglobulina 38,0-51,0 mg/dL; cadeia leve de imunoglobulina 59,0-95,0mg/dL, β-lactoglobulina 207,0-256,0mg/dL, α-lactoalbumina 117,0-157,0mg/dL, proteína com 226 KDa 5,80-12.0mg/dL, e proteína com 118 kDa 2,30-6.80mg/dL.

To evaluate the whey proteins during the lactation, whey obtained from 48 milk samples collected from 12 Jersey cows before milking were studied. Cows were distributed into three groups as follows: early (30-120 days), middle (121-210 days) and end of lactation (more than 211 days). The proteinogram consisted of total proteins concentration determined by biuret method and polyacrymalide gel electrophoresis (SDS-PAGE). A gradual and significant decrease of some fractions of the whey was observed during the lactation cycle albumin, lactoferrin, immunoglobulins, β-lactoglobulin and α -lactoalbumin. The normal ranges obtained for the whey proteins of Jersey cows were: whey total proteins 569.0 to 713.0mg/dL, lactoferrin 36.0 to 49.0mg/dL, albumin 24.0 to 34.0mg/dL, immunoglobulin's heavy chain 38.0 and 51.0mg/dL; immunoglobulin's light chain 59.0 to 95.0mg/dL, β-lactoglobulin 207.0 to 256.0mg/dL, α-lactoalbumin 117.0 to 157.0mg/dL; protein with 226 KDa 5.80 to 12.0mg/dL, and protein with 118 KDa 2.30 to 6.80mg/dL.