The Experts below are selected from a list of 399 Experts worldwide ranked by ideXlab platform
Miguel Angel De La Fuente - One of the best experts on this subject based on the ideXlab platform.
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Animal performance and milk fatty acid profile of dairy goats fed diets with different unsaturated plant oils
2012Co-Authors: Martínez Marín A. L., Gómez-cortés Pilar, Juárez Manuela, Miguel Angel De La FuenteAbstract:El pdf del artículo es la versión pre-print.-- et al.The effect of supplementing a basal diet with 1 of 3 plant oils on productive efficiency and milk fatty acid composition was studied in dairy goats. Sixteen Malagueña goats were used in a 4 × 4 Latin square experiment with 21-d periods and 4 goats per treatment. The basal diet comprised 30% alfalfa hay and 70% pelleted concentrate. Experimental treatments were control (basal diet without added oil) and the basal diet supplemented with 48. g/d of high oleic sunflower oil (HOSFO), regular sunflower oil (RSFO), or linseed oil (LO). Dry matter intake and body weight were not affected by treatments. Milk production was higher in HOSFO treatment and milk fat content was higher in RSFO and LO treatments, although no differences in milk energy production or milk Renneting Properties were found. The RSFO and LO treatments increased the proportion of vaccenic acid in milk fat more so than the HOSFO diet, and rumenic acid followed the same pattern. The content of trans10-18:1 remained low in all experimental diets (
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animal performance and milk fatty acid profile of dairy goats fed diets with different unsaturated plant oils
2011Co-Authors: A Martinez L Marin, A Gomez G Castro, L Perez M Alba, Perez M Hernandez, Pilar Gomezcortes, Manuela Juarez, Miguel Angel De La FuenteAbstract:Abstract The effect of supplementing a basal diet with 1 of 3 plant oils on productive efficiency and milk fatty acid composition was studied in dairy goats. Sixteen Malaguena goats were used in a 4×4 Latin square experiment with 21-d periods and 4 goats per treatment. The basal diet comprised 30% alfalfa hay and 70% pelleted concentrate. Experimental treatments were control (basal diet without added oil) and the basal diet supplemented with 48g/d of high oleic sunflower oil (HOSFO), regular sunflower oil (RSFO), or linseed oil (LO). Dry matter intake and body weight were not affected by treatments. Milk production was higher in HOSFO treatment and milk fat content was higher in RSFO and LO treatments, although no differences in milk energy production or milk Renneting Properties were found. The RSFO and LO treatments increased the proportion of vaccenic acid in milk fat more so than the HOSFO diet, and rumenic acid followed the same pattern. The content of trans 10-18:1 remained low in all experimental diets (
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animal performance and milk fatty acid profile of dairy goats fed diets with different unsaturated plant oils
2011Co-Authors: A Martinez L Marin, A Gomez G Castro, L Perez M Alba, Perez M Hernandez, Pilar Gomezcortes, Manuela Juarez, Miguel Angel De La FuenteAbstract:The effect of supplementing a basal diet with 1 of 3 plant oils on productive efficiency and milk fatty acid composition was studied in dairy goats. Sixteen Malaguena goats were used in a 4×4 Latin square experiment with 21-d periods and 4 goats per treatment. The basal diet comprised 30% alfalfa hay and 70% pelleted concentrate. Experimental treatments were control (basal diet without added oil) and the basal diet supplemented with 48g/d of high oleic sunflower oil (HOSFO), regular sunflower oil (RSFO), or linseed oil (LO). Dry matter intake and body weight were not affected by treatments. Milk production was higher in HOSFO treatment and milk fat content was higher in RSFO and LO treatments, although no differences in milk energy production or milk Renneting Properties were found. The RSFO and LO treatments increased the proportion of vaccenic acid in milk fat more so than the HOSFO diet, and rumenic acid followed the same pattern. The content of trans10-18:1 remained low in all experimental diets (<0.7% of total fatty acid methyl esters) although HOSFO and RSFO diets increased it. The variations in the fatty acid profiles observed with the 4 diets, mainly the unsaturated fatty acid isomer contents, are extensively discussed. Compared with that in the control diet, the n-6:n-3 fatty acid ratio in milk fat substantially decreased with the LO, increased with RSFO, and did not change with HOSFO. The addition of moderate amounts of LO to the diets of dairy goats has favorable effects on milk fatty acid composition from the point of view of the human consumer, without negative effects on animal performance.
Thor Langsrud - One of the best experts on this subject based on the ideXlab platform.
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Extreme frequencies of the αs1-casein "null" variant in milk from Norwegian dairy goats-- implications for milk composition, micellar size and Renneting Properties
2011Co-Authors: T G Devold, Thor Langsrud, R Nordbo, Brian Christensen, T Adnoy, Cecilie Svenning, Margreet Jansen Brovold, Esben Sørensen, Gerd Elisabeth VegarudAbstract:Caprine alpha(s1)-casein polymorphism is one of the key factors which determines important technological Properties of milk, such as rennetability and cheese yield. The indigenous Norwegian goat breed is characterized by a remarkably high frequency (> 70%) of a "null" variant of alpha(s1)-casein unique to this population. This mutation, referred to as the exon 12 D allele, involves a single base deletion in exon 12 of the alpha(s1)-casein gene. The aim of this study was to provide more detailed information on how alpha(s1)-casein polymorphism affects composition and rennet coagulation Properties of milk from Norwegian dairy goats. Class of alpha(s1)-casein significantly affected milk composition; crude protein, casein and pH. The mean casein micelle size was larger in milks containing alpha(s1)-casein "null" variant when compared to "strong" milks; in contrast, the heat-induced changes in micelle size appeared to be least pronounced in this group. Compositional differences between "strong" and "null" milks may explain these differences. alpha(s1)-Casein class had a significant effect on gel strength recorded 30 min after the addition of rennet, with the "strong" milks giving the greatest firmness. However, a considerable fraction of the milk samples in this study were unable to form a strong clot, regardless of the alpha(s1)-casein variant. These results indicate that environmental and compositional factors not considered in this study may be important in the curd formation process.
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αs1 casein null in norwegian dairy goat herds implications on milk composition micellar size and Renneting Properties
2005Co-Authors: T G Devold, C Svenning, Thor Langsrud, R Nordbo, Jansen M Brovold, Esben S Sorensen, Brian Christensen, T Adnoy, Gerd Elisabeth VegarudAbstract:This study aimed at investigating effects of α s1 -casein polymorphism on milk composition, mean size of casein micelles and rennet coagulation Properties in individual milk samples form Norwegian Dairy Goats. A remarkable high frequency (70 %) of the α s1 -casein null variant was found among Norwegian Dairy Goats. The composition of strong milks was characterized by a significantly higher content of crude protein and casein, higher Ca-ion activity, lower milk pH, smaller casein micelles and higher gel strength (A30) than null milks.
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genetic variants of norwegian goats milk composition micellar size and Renneting Properties
1999Co-Authors: Gerd Elisabeth Vegarud, R Opheim, E Loeding, C Svenning, Sigbjorn Lien, Roger K. Abrahamsen, T G Devold, Thor LangsrudAbstract:Abstract A survey has been conducted of the allele frequency of genetic variants of various caseins, mainly α s1 -casein, in herds of Norwegian goats located in north, west and southeast Norway. In addition, identifying the variants, milk composition, micellar size and Renneting Properties of the milks have been determined.
G. Matteo Crovetto - One of the best experts on this subject based on the ideXlab platform.
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effects of a nonforage diet on milk production energy and nitrogen metabolism in dairy goats throughout lactation
2001Co-Authors: Luciana Bava, G. Matteo Crovetto, L Rapetti, A Tamburini, A Sandrucci, G Galassi, G SucciAbstract:Abstract The objective of the experiment was to compare a silage-based control diet (C) with a nonforage diet (NF) in dairy goats throughout lactation in terms of animal performance and energy utilization. Eight Saanen goats were divided into two groups and fed C or NF, a commercial blend that included sunflower meal, cassava, coconut meal, and whole cottonseeds as the main ingredients that was characterized by a small particle size and a high crude protein content. In early, mid, and late lactation (44, 100, and 219 days in milk) the goats were individually tested for dry matter intake (DMI), digestibility, milk yield and composition, milk Renneting Properties, rumen and plasma parameters, and nitrogen and energy utilization (open circuit respiration chambers). During early and mid lactation, the NF fed goats had a very high DMI: 2946 and 2915 g/ d, respectively. Nevertheless, milk yield was similar for the two treatments: 4369 vs. 4342 and 3882 vs. 3841 g/d for goats fed diets C and NF during the first and second periods, respectively. Milk fat content was not statistically different between the two diets. The protein content and rheological parameters of milk were similar for the two diets. Nonprotein nitrogen and urea levels in milk of goats fed NF were significantly higher than goats fed C. Ruminal ammonia and plasma urea nitrogen were also significantly increased by diet NF, due to its high protein content. Plasma glucose, s-hydroxybutyrate, and nonesterified fatty acids and ruminal volatile fatty acids were not influenced by dietary treatment. Dietary NF significantly decreased energy digestibility (74.5 vs. 65.8%, on average for the lactation, for C and NF, respectively) and had a significantly lower metabolizability (metabolizable energy/intake energy; 66.6 vs 58.0%, on average); however, the efficiency of utilization of metabolizable energy was unaffected by the diet. In conclusion, goats were fed a nonforage diet during the entire lactation without detrimental effect on their health and productive performance.
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comparison of lucerne silage and ventilated hay in maize silage based rations for dairy cows for the production of milk destined for grana cheese
1999Co-Authors: G Colombari, Giorgio Borreani, G. Matteo CrovettoAbstract:Three experiments were carried out to study the effects of feeding lucerne silage (wilted to give different drymatter (DM) contents) and ventilated hay to dairy cows on milk production, milk quality, milk-Renneting Properties, clostridial spore content and the quality of cheese prepared from the milk. The lucerne, cut at vegetative or early-bud stages of maturity, was harvested from alternate windrows and conserved as silage or artificially dried hay. The lucerne was wilted until it reached different DM contents of 550, 360 and 432 g kg ‐1 in the three experiments, harvested, chopped with a selfloading forage wagon and ensiled in low and narrow clamps made up of transferable prefabricated walls. The organic acid content, pH, yeast and mould counts of the lucerne silage suggested that there was no aerobic deterioration. In each experiment, fifty Italian Friesian lactating cows were divided into two groups and fed two maize silage-based rations for 6 weeks, which only differed in the lucerne forage [silage (S) vs. ventilated hay (H)], in a cross-over experimental design. The lucerne in the rations represented 35%, 23% and 24% of the DM of the rations for the three experiments. The microbiological profiles of the ration were influenced more by the maize silage than by the lucerne silage. Individual daily DM intakes were similar for the two treatments in Experiments 1 and 3 (on average 18AE 7k g in Experiment 1 and 20AE3 kg in Experiment 3) and slightly lower for S cows in comparison to H cows in Experiment 2 (18AE0 vs. 19AE0 kg). Milk yields of S and H cows were 21AE0 and 20AE8, 20AE0 and 20AE 6( P <0 AE01), and 28AE4 and 27AE 9k g d ‐1 in Experiments 1, 2 and 3 respectively. Milk composition was similar for all the experiments for the two treatments, except that the protein content was lower and the fat content was higher in the silage treatment than in the hay. The Renneting Properties and microbiology of the milk were not influenced by the introduction of lucerne silage into the rations, although the season in which it was consumed had a greater effect on the microbiological content, in terms of standard bacterial counts, proteolytic, coli and lactic acid bacteria, and clostridia spores. The clostridial spore counts were always very low (< 400 per litre), thus fulfilling the requirements for top-quality milk for Grana cheese production. In the third experiment, the quality of Grana Padano cheese produced was examined, and no differences between treatments were observed after 12 months of maturation. These results show that lucerne silage can be included in the ration of dairy cows instead of ventilated lucerne hay, which is considered to be the top-quality hay available for the production of milk destined for Grana cheese, without any negative effects on milk and cheese quality.
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Comparison of lucerne silage and ventilated hay in maize silage-based rations for dairy cows for the production of milk destined for Grana cheese
1999Co-Authors: G Colombari, Giorgio Borreani, G. Matteo CrovettoAbstract:Three experiments were carried out to study the effects of feeding lucerne silage (wilted to give different dry-matter (DM) contents) and ventilated hay to dairy cows on milk production, milk quality, milk-Renneting Properties, clostridial spore content and the quality of cheese prepared from the milk. The lucerne, cut at vegetative or early-bud stages of maturity, was harvested from alternate windrows and conserved as silage or artificially dried hay. The lucerne was wilted until it reached different DM contents of 550, 360 and 432 g kg-1 in the three experiments, harvested, chopped with a self-loading forage wagon and ensiled in low and narrow clamps made up of transferable prefabricated walls. The organic acid content, pH, yeast and mould counts of the lucerne silage suggested that there was no aerobic deterioration. In each experiment, fifty Italian Friesian lactating cows were divided into two groups and fed two maize silage-based rations for 6 weeks, which only differed in the lucerne forage [silage (S) vs. ventilated hay (H)], in a cross-over experimental design. The lucerne in the rations represented 35%, 23% and 24% of the DM of the rations for the three experiments. The microbiological profiles of the ration were influenced more by the maize silage than by the lucerne silage. Individual daily DM intakes were similar for the two treatments in Experiments 1 and 3 (on average 18.7 kg in Experiment 1 and 20.3 kg in Experiment 3) and slightly lower for S cows in comparison to H cows in Experiment 2 (18.0 vs. 19.0 kg). Milk yields of S and H cows were 21.0 and 20.8, 20.0 and 20.6 (P < 0.01), and 28.4 and 27.9 kg d-1 in Experiments 1, 2 and 3 respectively. Milk composition was similar for all the experiments for the two treatments, except that the protein content was lower and the fat content was higher in the silage treatment than in the hay. The Renneting Properties and microbiology of the milk were not influenced by the introduction of lucerne silage into the rations, although the season in which it was consumed had a greater effect on the microbiological content, in terms of standard bacterial counts, proteolytic, coli and lactic acid bacteria, and clostridia spores. The clostridial spore counts were always very low (< 400 per litre), thus fulfilling the requirements for top-quality milk for Grana cheese production. In the third experiment, the quality of Grana Padano cheese produced was examined, and no differences between treatments were observed after 12 months of maturation. These results show that lucerne silage can be included in the ration of dairy cows instead of ventilated lucerne hay, which is considered to be the top-quality hay available for the production of milk destined for Grana cheese, without any negative effects on milk and cheese quality
Gerd Elisabeth Vegarud - One of the best experts on this subject based on the ideXlab platform.
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Extreme frequencies of the αs1-casein "null" variant in milk from Norwegian dairy goats-- implications for milk composition, micellar size and Renneting Properties
2011Co-Authors: T G Devold, Thor Langsrud, R Nordbo, Brian Christensen, T Adnoy, Cecilie Svenning, Margreet Jansen Brovold, Esben Sørensen, Gerd Elisabeth VegarudAbstract:Caprine alpha(s1)-casein polymorphism is one of the key factors which determines important technological Properties of milk, such as rennetability and cheese yield. The indigenous Norwegian goat breed is characterized by a remarkably high frequency (> 70%) of a "null" variant of alpha(s1)-casein unique to this population. This mutation, referred to as the exon 12 D allele, involves a single base deletion in exon 12 of the alpha(s1)-casein gene. The aim of this study was to provide more detailed information on how alpha(s1)-casein polymorphism affects composition and rennet coagulation Properties of milk from Norwegian dairy goats. Class of alpha(s1)-casein significantly affected milk composition; crude protein, casein and pH. The mean casein micelle size was larger in milks containing alpha(s1)-casein "null" variant when compared to "strong" milks; in contrast, the heat-induced changes in micelle size appeared to be least pronounced in this group. Compositional differences between "strong" and "null" milks may explain these differences. alpha(s1)-Casein class had a significant effect on gel strength recorded 30 min after the addition of rennet, with the "strong" milks giving the greatest firmness. However, a considerable fraction of the milk samples in this study were unable to form a strong clot, regardless of the alpha(s1)-casein variant. These results indicate that environmental and compositional factors not considered in this study may be important in the curd formation process.
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αs1 casein null in norwegian dairy goat herds implications on milk composition micellar size and Renneting Properties
2005Co-Authors: T G Devold, C Svenning, Thor Langsrud, R Nordbo, Jansen M Brovold, Esben S Sorensen, Brian Christensen, T Adnoy, Gerd Elisabeth VegarudAbstract:This study aimed at investigating effects of α s1 -casein polymorphism on milk composition, mean size of casein micelles and rennet coagulation Properties in individual milk samples form Norwegian Dairy Goats. A remarkable high frequency (70 %) of the α s1 -casein null variant was found among Norwegian Dairy Goats. The composition of strong milks was characterized by a significantly higher content of crude protein and casein, higher Ca-ion activity, lower milk pH, smaller casein micelles and higher gel strength (A30) than null milks.
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genetic variants of norwegian goats milk composition micellar size and Renneting Properties
1999Co-Authors: Gerd Elisabeth Vegarud, R Opheim, E Loeding, C Svenning, Sigbjorn Lien, Roger K. Abrahamsen, T G Devold, Thor LangsrudAbstract:Abstract A survey has been conducted of the allele frequency of genetic variants of various caseins, mainly α s1 -casein, in herds of Norwegian goats located in north, west and southeast Norway. In addition, identifying the variants, milk composition, micellar size and Renneting Properties of the milks have been determined.
Giuseppe Massimo Vacca - One of the best experts on this subject based on the ideXlab platform.
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variability of the caprine whey protein genes and their association with milk yield composition and Renneting Properties in the sarda breed 1 the lalba gene
2015Co-Authors: Maria Luisa Dettori, Michele Pazzola, Pietro Paschino, Maria Giovanna Pira, Giuseppe Massimo VaccaAbstract:: The variability of the promoter region and the 3'UTR (exon-7) of the BLG gene, encoding the β-lactoglobulin, was investigated by sequencing in 263 lactating Sarda goats in order to assess its association with milk traits. Milk traits included: milk yield, fat, total protein and lactose content, pH, daily fat and protein yield (DFPY), freezing point, milk energy, somatic cell count, total microbial mesophilic count, rennet coagulation time (RCT), curd firming rate (k20) and curd firmness (a30). A total of 7 polymorphic sites were detected and the sequence analysed was given accession number KM817769. Only three SNPs (c.-381C>T, c.-323C>T and c.*420C>A) had minor allele frequency higher than 0.05. The effects of farm, stage of lactation and the interaction farm × stage of lactation significantly influenced all the milk traits (P T and c.*420C>A (P T (P < 0.001). The c.-381TT homozygous goats showed lower pH, RCT and k20 than c.-381CT (P < 0.05). In conclusion the polymorphism of the goat BLG gene did not affect the total protein content of the Sarda goat milk, and only weakly influenced RCT and k20. On the other hand, an interesting effect on milk yields and DFPY emerged in two SNPs. This information might be useful in dairy goat breeding programs.
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effect of polymorphisms at the casein gene cluster on milk Renneting Properties of the sarda goat
2014Co-Authors: Michele Pazzola, Maria Luisa Dettori, Emanuela Pira, Antonia Noce, Pietro Paschino, Giuseppe Massimo VaccaAbstract:Abstract This study investigated the influence of casein genes polymorphism on Renneting Properties of milk from Sarda goats. Milk yield and composition, and Renneting Properties (rennet coagulation time RCT, firming time k20 and curd firmness a30) were evaluated in 200 multiparous goats from three farms, at monthly intervals from March to July. Animals were genotyped at CSN1S1 , CSN2 , CSN1S2 and CSN3 . Statistical analysis was performed by a repeated measures General Linear Model. CSN1S1 significantly affected milk traits with a lower fat content registered for goats carrying the F allele. The highest protein concentration was recorded for the CSN1S1 AB goats. Milk from CSN1S1 FF homozygote goats was characterized by a delayed k20 and the CSN1S1 AB showed a higher a30. All the parameters were influenced by the CSN2 locus, except milk yield. Polymorphism at CSN1S2 influenced only daily milk yield and a30. The CSN1S2 0 null allele was detected for the first time in this breed. The influence of genotype effect was particularly marked for CSN3 ; RCT and k20 were delayed in CSN3 BB goats and the highest level of a30, 47.88 mm registered for CSN3 AA goats, could be considered remarkable when compared to other goat breeds or populations. In conclusion, this study improved knowledge on the effects of goat casein genes on milk Renneting parameters, and could be useful in the future planning of breeding programs and specific dairy products linked to the Sarda breed (PDO/PGI).
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the effect of long term freezing on Renneting Properties of sarda sheep milk
2013Co-Authors: Michele Pazzola, Maria Luisa Dettori, Gianpiera Piras, Emanuela Pira, Fabio Manca, Ornella Puggioni, Antonia Noce, Giuseppe Massimo VaccaAbstract:Summary Cold storage is a well-known strategy to limit concerns about seasonality for sheep dairy productions. Th e aim of this study was to investigate the eff ect of long-term freezing on milk Renneting Properties from the Sarda sheep, an autochthonous breed from Italy. Two-hundred milk samples from 50 pluriparous Sarda ewes were collected at monthly intervals throughout the lactation from April to July. Each sample of fresh milk was analysed for composition and subsamples were obtained and frozen for one, three and fi ve months. Renneting Properties, both from the fresh and frozen subsamples, were achieved using the Formagraph instrument and results were submitted to a mixed model statistical analysis. Th e storage eff ect signifi cantly aff ected (P<0.01) the Renneting parameters. A large amount of non coagulating subsamples was registered aft er a long-term frozen storage. Furthermore, milk clotting time was longer in frozen subsamples and curd fi rmness diminished aft er a freezing period of fi ve months. In conclusion, the remarkable decreasing of sheep milk Renneting characteristics aft er frozen storage can predict a worse yield and quality of cheese-making and suggests that freezing of Sarda raw milk should be limited to shorter periods.
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The Effect of Long-term Freezing on Renneting Properties of Sarda Sheep Milk
2013Co-Authors: Michele Pazzola, Maria Luisa Dettori, Gianpiera Piras, Emanuela Pira, Fabio Manca, Ornella Puggioni, Antonia Noce, Giuseppe Massimo VaccaAbstract:Summary Cold storage is a well-known strategy to limit concerns about seasonality for sheep dairy productions. Th e aim of this study was to investigate the eff ect of long-term freezing on milk Renneting Properties from the Sarda sheep, an autochthonous breed from Italy. Two-hundred milk samples from 50 pluriparous Sarda ewes were collected at monthly intervals throughout the lactation from April to July. Each sample of fresh milk was analysed for composition and subsamples were obtained and frozen for one, three and fi ve months. Renneting Properties, both from the fresh and frozen subsamples, were achieved using the Formagraph instrument and results were submitted to a mixed model statistical analysis. Th e storage eff ect signifi cantly aff ected (P
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higher somatic cells counted by the electronic counter method do not influence Renneting Properties of goat milk
2012Co-Authors: Michele Pazzola, Maria Luisa Dettori, Gianpiera Piras, Filippo Balia, V Carcangiu, Giuseppe Massimo VaccaAbstract:Abstract Laws of different countries regarding SCC of goat milk are not in agreement with each other and sometimes they fix a threshold for the enhancement of dairy products. The aim of this study was to assess if Renneting Properties of goat milk are influenced by higher somatic cell count (SCC) measured by an electronic cell counter. Milk samples, taken throughout the lactation of 169 goats from three farms, were analyzed for chemical, physical, hygienic and Renneting Properties. Samples were divided into three levels on the basis of their SCC: L: low level, samples with SCC lower than 10 6 cells/ml; M: medium, between 10 6 and 2 × 10 6 cells/ml; H: high, higher than 2 × 10 6 cells/ml. Milk clotting time was between 12.07 and 13.31 min, curd firming time between 1.68 and 2.05 min and curd firmness between 41.66 and 48.97 mm. All the three Renneting Properties were not affected by the SCC level but they were highly correlated with other factors as protein content and pH. Furthermore, the microbial count showed a high positive correlation with SCC. These results showed that in goat milk, contrarily to other dairy species, higher SCC did not affect Renneting Properties and that counting of somatic cells by using electronic cell counters might be not suitable for the improvement of dairy products.