Effects of different storage conditions, the farm and the stage of lactation on renneting parameters of goat milk investigated using the Formagraph method

2011 ◽  
Vol 78 (3) ◽  
pp. 343-348 ◽  
Author(s):  
Michele Pazzola ◽  
Filippo Balia ◽  
Maria Luisa Dettori ◽  
Maria Consuelo Mura ◽  
Vincenzo Carcangiu ◽  
...  

This study evaluated the effect of storage on renneting properties of goat milk investigated using the Formagraph method. Milk samples from 169 goats in three farms (F1, F2 and F3) were analysed during an entire lactation (45, 75, 105, 135 and 165 days in milking DIM), to obtain renneting parameters, both from fresh milk and after storage with Bronopol and freezing at −20°C and −80°C. As regards fresh milk, mean values of clotting time were between 12·51 (45 DIM) and 13·29 min (105 DIM and F2), the curd firming time between 1·77 (45 DIM) and 2·15 min (F1) and curd firmness between 42·09 (165 DIM) and 49·55 mm (45 DIM). No statistical difference was recorded after storage. After regression analysis, all prediction models showed significance value at P<0·001 with the highest R2 value for clotting time, 0·710 (fresh vs. frozen milk at −20°C), and the lowest for clot firmness, 0·281 (fresh vs. frozen milk at −80°C). Results demonstrated that assessment of goat milk coagulation properties using the Formagraph method is also achievable after freezing or Bronopol addition.

2014 ◽  
Vol 83 (10) ◽  
pp. S3-S8 ◽  
Author(s):  
Lenka Necidová ◽  
Šárka Bursová ◽  
Alena Skočková ◽  
Bohdana Janštová ◽  
Pavla Prachařová ◽  
...  

The aim of this study was to compare Bacillus cereus growth rates and diarrhoeal enterotoxin production in raw and pasteurized goat, sheep, and cow milk in terms of storage conditions. Milk samples were inoculated with B. cereus (CCM 2010), which produces diarrhoeal enterotoxins. Enterotoxin production was tested by ELISA (Enzyme-Linked Immunosorbent Assay), and the count of B. cereus was determined by the plate method. With raw cow milk, B. cereus growth and enterotoxin production can be completely suppressed; in raw goat and sheep milk, enterotoxin was produced at 22 °C. In pasteurized cow, goat, and sheep milk, the B. cereus count increased under all storage conditions, with more rapid growth being observed at 15 °C (sheep milk) and 22 °C (cow and goat milk). Enterotoxin presence was detected at 15 °C and 22 °C, and with pasteurized cow milk also at 8 °C. Our model experiments have determined that B. cereus multiplication and subsequent enterotoxin production depend on storage temperature and milk type.


2008 ◽  
Vol 53 (No. 2) ◽  
pp. 55-63 ◽  
Author(s):  
J. Kuchtík ◽  
K. Šustová ◽  
T. Urban ◽  
D. Zapletal

The evaluation of the effect of the stage of lactation on milk composition, its properties and the quality of rennet curdling was carried out over the period of three successive years using milk samples (<I>n</I> = 162) obtained from a total of 27 ewes of the East Friesian (EF) breed, reared on a small sheep farm in Juřinka in the region of Wallachia. The stage of lactation had a highly significant effect on the contents of all milk components. However, only the contents of total solids (TS), solids non-fat (SNF), fat (F), protein (P) and casein (CN) gradually increased with the advancement of lactation. The stage of lactation also had a highly significant effect both on all the properties of milk and the rennet curdling quality (RCQ). All phenotypic correlations between the particular contents of TS, SNF, F, P, CN and urea nitrogen (UN) were positive and high (<I>P</I> ≤ 0.001). On the other hand, all phenotypic correlations between milk yield and particular contents of TS, SNF, F, P, CN and UN were negative and high (<I>P</I> ≤ 0.001). The majority of phenotypic correlations between rennet clotting time (RCT) and the other particular parameters was insignificant. However, the phenotypic correlations between lactose (L) and RCT and between pH and RCT were positive and high (<I>P</I> ≤ 0.001) whereas the phenotypic correlation between titratable acidity (TA) and RCT was negative and high (<I>P</I> ≤ 0.001). The majority of phenotypic correlations between the rennet curdling quality (RCQ) and the other particular parameters was insignificant. Nevertheless, the phenotypic correlations between pH and RCQ and between RCT and RCQ were positive and high (<I>P</I> ≤ 0.001) whereas the phenotypic correlation between TA and RCQ was negative and high (<I>P</I> ≤ 0.001).


Author(s):  
Surya Pratap Singh Chauhan ◽  
Sanjay Kumar ◽  
D V Singh ◽  
R K Sharma ◽  
Jyoti Palod ◽  
...  

Goat is a versatile animal having short generation interval with lower investment cost and higher prolificacy. The present study was carried out at Goat farm, LPM, GBPUAT, Pantnagar. During the entire study the fresh milk samples of Pantja goats were taken according to lactation order and stage viz., 1st (Upto 30 days), 2nd (31 to 60 days) and 3rd (above 61 days) stage of lactation were analyzed for physico-chemical properties. The values of milk composition were significantly affected by lactation order and stage of lactation and their interaction. The color of Pantja goat milk was perfectly white in all the lactation order and lactation stages. The specific gravity and boiling point of milk increased significantly from 1st to 3rd lactation order and with advancement of lactation stage. The milk composition; fat, protein, total solids, solids not fat, total ash and chemical properties viz.titratable acidity of milk was increased significantly in advanced lactation order and stage of lactation except, pH, water and carbohydrate which showed a declining trend


Animals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 906
Author(s):  
María Isabel Berruga ◽  
Juan Ángel de la Vara ◽  
Carmen C. Licón ◽  
Ana Isabel Garzón ◽  
Andrés José García ◽  
...  

This study describes chemical, physical, microbiological and technological characteristics of red deer milk and the effect of lactation on these parameters in order to know their potential aptitude to elaborate dairy products. During 18 weeks, milk from five hinds was monitored for composition, bacteriology, somatic cell count (SCC), physical properties and rennet coagulation. Mean values (g/100 g) for fat, protein, lactose and dry matter were 10.4, 7.1, 4.3 and 24.2, respectively, and for urea, 265 mg/100 mL. Except for lactose, a significant increase in these components was observed (p < 0.01) as lactation progressed. The average values for bacteriology and SCC were 5.3 log cfu/mL and 4.7 log cells/mL, respectively. Regarding physical properties, conductivity (mean: 2.8 ms/cm), viscosity (3.1 Cp), coordinates L* (89.9) and a* (−3.1) and milk fat globule diameter (D4,3: 6.1 µm) increased along with lactation while density (1.038 g/mL) decreased (p < 0.01). The pH (6.7), acidity (22.9° Dornic), coordinate b* (8.4) and ethanol stability (66.6% v/v) were stable during the study period. The stage of lactation also has a significant impact on milk coagulation properties and mean curd yield was 3.29 g/10 mL. These results suggest that red deer milk could be a potential innovative source of milk for the dairy industry.


2019 ◽  
Vol 40 (5Supl1) ◽  
pp. 2261
Author(s):  
Luciana Florêncio Vilaça Lopes ◽  
Elizabete Cristina da Silva ◽  
Anidene Christina Alves de Moraes ◽  
Elizabete Rodrigues da Silva ◽  
Kleber Régis Santoro ◽  
...  

The objective of this study was to detect Mycoplasma agalactiae (Ma) and the Mycoplasma mycoides cluster (Mmcluster) in 373 goat milk samples of different breeds from herds located in Pernambuco and Paraíba states, as well as to evaluate somatic cell count (SCC) and milk composition from positive animals. For this, DNA extraction from milk samples was carried out, followed by generic and species-specific amplification by Polymerase Chain Reaction (PCR). Milk constituents were determined by medium infrared spectrometry and SCC by flow cytometry. Analyses of variance and tests of comparison of means verified the effects of positivity on the evaluated characteristics. The frequencies for Ma and Mmcluster were 43.21 and 5.70%, respectively. In all genetic groups, Ma was detected in all positive samples, whereas Mmcluster was only observed in samples from Moxotó, Parda Sertaneja, and that without a defined racial pattern. Statistical difference was observed (p < 0.05) between mean values of protein, casein and SCC in positive and negative Ma samples. In terms of Mmcluster there was only a statistically significant difference in the SCC parameter. The detection of Mycoplasma in samples of goat milk suggests an introduction of infected animals into the evaluated herds, as well as possible contact with the etiological agents at fairs and exhibitions.


Fermentation ◽  
2020 ◽  
Vol 6 (4) ◽  
pp. 100
Author(s):  
Eleni Kamilari ◽  
Dimitrios A. Anagnostopoulos ◽  
Photis Papademas ◽  
Marina Efthymiou ◽  
Svitlana Tretiak ◽  
...  

In general, it is a common practice among dairy producers to store the milk in the refrigerator directly after milking, in order to preserve it and prevent the development of spoilage microbes. However, the impact of keeping the milk in the refrigerator overnight on milk microbial diversity has been poorly investigated. This study aimed to provide a snapshot of the bacterial composition of goat milk after direct storage at −80 °C and after being kept overnight at 4 °C and then in storage at −80 °, using high-throughput sequencing (HTS). Goat milk samples from four different farms were analyzed, to reveal that milk bacterial diversity differed between the two different storage conditions. Goat milk directly stored at −80 °C was characterized by the presence of the Gram-negative contaminants Pseudomonas and Acinetobacter, in addition to the genera Corynebacterium, Chryseobacterium, Bacteroides and Clostridium. Milk samples that were kept overnight at 4 °C were characterized by a reduction in their bacterial biodiversity and the predominance of the Gram-negative, aerobic Phyllobacterium. Overall, HTS methodologies provide an in-depth identification and characterization of the goat raw milk microbiome. Further, they offer a better understanding of the contribution of cold storage conditions to milk microbiota formation. This study may assist dairy producers in improving raw milk and raw milk cheeses quality and guaranteeing consumers’ safety.


1992 ◽  
Vol 59 (1) ◽  
pp. 21-28 ◽  
Author(s):  
Despina Kalogridou-Vassiliadou ◽  
Konstantinos Manolkidis ◽  
Afrodite Tsigoida

SummaryBacteriological analyses, cell counts using the Fossomatic method and California Mastitis Test were performed on 1523 goat milk samples taken aseptically at monthly intervals throughout lactation from three goat herds. Of the goat udders, 81·4% were infected, minor pathogens being the most frequent isolates (65·7%). Differences in the level of infection by minor pathogens were found betwccn herds. Cell counts were influenced by stage of lactation and intramammary infection. Cell counts < 106 cells/ml were found in 80% of milk samples infected by major pathogens and in 45% infected by minor pathogens. About 81% of udders infected with major pathogens gave California Mastitis Test scores of 2 and 3, compared with 20% for uninfected goats. A high proportion (65%) of udders infected with minor pathogens also produced scores of 2 and 3. A significant positive correlation was found between the California Mastitis Test and cell counts. The use of cell counts for the detection of abnormal goat milk is discussed.


2002 ◽  
Vol 47 (1) ◽  
pp. 57-73
Author(s):  
Snezana Jovanovic ◽  
Ognjen Macej ◽  
Jelena Djurdjevic-Denin

The influence of pH (6.5 and 5.8), amount of added CaCl2 (0, 200 and 400 mg/l)), coagulation temperature (30?C and 35?C) and heat treatment of milk (65?C/30 min and 87?C/10 min) on the rate of rennet induced milk coagulation (s) were investigated. The time (s) from rennet addition to onset of gelation (as indicated by the first visible floccules) was measured. The milk samples heat-treated at 87?C/10 min, with 400 mg/l added CaCl2, which were coagulated at 35?C and pH 5.8, coagulated 23.28-fold faster than the same samples without added CaCl2, which were coagulated at 30?C and pH 6.5. The results of investigations related to the influence of particular coagulation factors on the coagulation rate of heat-treated milk showed that at pH 6.5 the most pronounced influence was demonstrated by the amount of Ca2+ and temperature of coagulation. At pH 5.8, different amounts of Ca2 and used temperatures of coagulation did not influence coagulation rate regardless of the used heat treatment of milk. The influence of used heat treatment of milk was particularly pronounced during coagulation of samples without added CaCl2 that coagulated at 30?C and pH 6.5. The used heat treatment of milk practically did not influence the milk coagulation rate at pH 5.8. The greatest influence on milk coagulation rate was showed by pH. This influence was the most marked in coagulation of samples in which the coaggregates were formed, regardless of the amount of added Ca2+ and used coagulation temperatures.


2021 ◽  
Vol 12 (1S) ◽  
pp. 204-211
Author(s):  
Noor Syaheera Ibrahim ◽  
Farida Hani Ahmad Tajuddin

Milk is an important elements due to its high nutritious and balanced in human diet. In Asian, goat milk is the most consumed because of the unique taste, more nutritious than cow milk. However, milk production and composition values differ at every stage of lactation in goats. Thus, determining the highest milk production and producing the best quality goat milk is essential to satisfy the local market demands. The objective of the present study is to determine the milk yield and milk composition at different lactation stages and to evaluate the lactation curves in Saanen goats. The lactation stages can be categorized into three, early (less than 80 days), mid (80 – 140 days) and late (over 140 days) days in milk (DIM). In total, 90 milk samples were collected from 15 goats representing early (n=5), mid (n=5), and late (n=5) stages of lactation. The Saanen goats were raised under the same conditions, and milking was done early in the morning (9.00am).The milk yield from Saanen goats were collected and measured weekly at each stage of lactation. Milk samples were analyzed for fat, protein, solid non-fat, and lactose. Current result illustrated, there were significant different (p ˂ 0.05) among three stages of lactation in milk yield, solid non-fat, fat, protein and lactose. In terms of food regulation, the Saanen goats almost fully met the standard requirements for milk production and composition. In addition, this study also observes the lactation curves in Saanen goats and analyse the curve shapes and patterns. The average milk yields from three different stages develops a concave downward curve. The results indicated that mid yield increased from early to mid- lactation and decreased thereafter until the end of lactation.


2020 ◽  
Vol 44 (2) ◽  
pp. 195-205
Author(s):  
F. O. Ahamefule ◽  
N. J. Ekanem ◽  
U. U. Uka ◽  
K. Ikwunze

The milk yield and compositions of twelve lactating does comprising six each of West African Dwarf (Fouta djallon) and Red Sokoto (Maradi) were compared in a 21-week study. The does in their second parity were monitored over a full lactation. The goats received daily basal grass and browse fodder in addition to a concentrate supplement in a 2 × 3 factorial experiment. The does were hand milked and milk yield (g/d) was quantified daily. Milk samples were analyzed weekly for total solids (TS %), butter fat (BF %), solids-not-fat (SNF %), crude protein (CP %) and total ash (TA %). Lactose concentration (LC %) was analyzed daily immediately after sampling. Macro-minerals in milk samples were determined by dry ash extraction method specific for each mineral element. Milk yield was influenced significantly (p<0.05) by both breed and stage of lactation. The WAD produced more milk (97.34 g/d than RS (87.01 g/d). For both breeds, the average mid lactation milk yield (119.04 g/d) was significantly (p<0.05) different than either early (88.35 g/d) or late (69.14 g/d). The highest milk production was by WAD does in mid lactation (125.10 g/d) and the least was by RS in late lactation (47.07 g/d). The TS, BF, SNF, CP and LC concentrations in milk were not influenced (P>0.05) by breed. The TA was significantly (P<0.05) higher in WAD milk (0.89 %) relative to RS milk (0.88 %). Also, stage of lactation significantly (P<0.05) influenced the concentrations of TS, BF, TA and LC in WAD and RS goats milk. Total solids was significantly (P<0.05) higher in late (13.47 %) than in early (12.53 %) lactation for both breeds. The BF and LC in milk followed similar trend, recording 4.45, 3.89 and 4.13 and 3.98 % in late and early stages of lactation respectively. On the other hand, The TA decreased with advancing lactation and the highest value was obtained in the early (0.92 %) than in mid (0.89 %) and late (0.86 %) lactation in both WAD and RS goat milk. TA was highest in WAD milk in early lactation (0.92 %) and least in RS milk in late lactation (0.85 %). All macro minerals were influenced (p<0.05) by lactation stage and breed differences, except potassium (K) and sodium (Na) which were only influenced by the stage of lactation. The milk of both WAD and RS goats yielded more calcium (Ca) than K, which was attributed to the nutrients in the diets.


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