• 한국축산식품학회지
• /
• 제42권2호
• /
• pp.210-224
• /
• 2022

The use of skim milk is a strategy to increase goat milk yogurt acceptability. However, it can negatively affect yogurt rheology because fat plays a vital role in dairy structural integrity. Thus, this study aimed to investigate the effects of fat replacers on the rheological, physical, and sensory parameters of low-fat cupuassu goat milk yogurts during refrigerated storage (28 days). Five goat milk yogurts formulations were carried out: whole yogurt (WY), skim yogurt (SY), skim yogurt with inulin (SIY), skim yogurt with maltodextrin (SMY), and skim yogurt with whey protein (SWY). Treatments were subjected to bacterial counts, chemical composition, pH, water holding capacity, instrumental color and texture, rheological and sensory analyses. All samples showed reducing pH values, water holding capacity, and L^* and b^* value during storage. Regarding texture, the firmness and consistency decreased during storage. On the other hand, the viscosity index significantly increased during refrigerated storage time. Moreover, all treatments exhibited viscoelastic behaviour. In addition, SIY and SMY showed the highest apparent viscosity. Furthermore, SIY, SMY, and SWY formulations exhibited positive sensory scores for appearance, color, aroma, texture, and viscosity. However, the overall acceptability and purchase intention did not differ statistically between WY and the fat-replacement treatments (SIY, SMY, and SWY). These results indicate that fat substitutes improved the quality of skimmed formulations. Thus, inulin and maltodextrin have the potential as functional fat replaces to produce low-fat goat milk yogurts.

• Asian-Australasian Journal of Animal Sciences
• /
• 제15권5호
• /
• pp.732-739
• /
• 2002

Milk samples with different phenotype combination of $\{kappa}$-casein and ${\beta}$-lactoglobulin and different preheating temperatures of 30, 70, 75 and $80^{\circ}C$ were used for cheesemaking under laboratory conditions. For the 853 batches of cheese, mean composition was 59.64% total solids, 30.24% fat and 23.66% protein, and the whey contained 6.93% total solids, 0.30% fat and 0.87% protein. Least squares analysis of the data indicated that heating temperature of the milk and ${\kappa}$-CN/${\beta}$-LG phenotypes had significant effects on cheese and whey compositions. The total solids, fat and protein contents of cheese were negatively correlated with preheating temperatures of milk. Cheese from BB/BB phenotype milk had the highest and those from AA/AA phenotype milk had the lowest concentrations of total solids, fat and protein. Mean recoveries of milk components in the cheese were 53.71% of total solids, 87.15% of fat, and 80.32% of protein. For the 10 different types of milk, maximum recoveries of milk components in cheese occurred with preheating temperature of $70^{\circ}C$ or $75^{\circ}C$ and lowest recoveries occurred at $80^{\circ}C$. The whey averaged 6.94% total solids, 0.30% fat and 0.87% protein. Losses of milk components in the whey were lowest for milk preheated at $80^{\circ}C$ and for milk containing the BB/BB phenotype.

• 한국축산식품학회지
• /
• 제26권1호
• /
• pp.121-126
• /
• 2006

Major milk proteins have considerable variane which comes from substitution and deletions in their amino arid sequences. Variants in genes that code for milk proteins, such as ${\beta}$-lactoglobulin (${\beta}-LG$) have been established as genetic markers for milk production and milk protein composition in dairy cattle. The effect of ${\beta}-LG$ variant on milk production traits, such as milk yield. fat yield, protein yield, fat percentage and protein percentage, was estimated for 482 Holstein cows in the first lactation. The ${\beta}-LG$ variants were determined by PCR-RFLP technique at the DNA level. Single trait linear model was used for the statistical analysis of the data. Results of this study indicated that ${\beta}-LG$ variants affected significantly protein yield (p<0.05) and fat percentage (p<0.05). Animals with the AA variant produced 31kg of milk protein more than animals with the BB variant. On the contrary, cows with the BB variant had fat percentage higher by 0.35 and 0.32% compared with cows with the AA and AB variants, respectively. No associations between the ${\beta}-LG$ variants and milk yield, protein percentage and fat yield were found Therefore, milk production traits could be improved through ${\beta}-LG$ typing by increasing the frequency of A variant for protein yield or the frequency of B variant for fat content in Holstein dairy cattle population.

• Asian-Australasian Journal of Animal Sciences
• /
• 제18권4호
• /
• pp.580-583
• /
• 2005

We have evaluated the application of spectroscopy using an insertion-type fiber-optic probe and a sensor at wavelengths from 400 to 1,100 nm to the measurement of milk fat content on dairy farms. The internal reflectance ratios of 183 milk samples were determined with a fiber-optic spectrophotometer at 5$^{\circ}C$, 20$^{\circ}C$ and 40$^{\circ}C$. Partial least squares (PLS) regression was used to develop calibration models for the milk fat. The best accuracy of determination was found for an equation that was obtained using smoothed internal reflectance data and three PLS factors at 20$^{\circ}C$. The correlation coefficients between predicted and reference milk fat at 5$^{\circ}C$, 20$^{\circ}C$ and 40$^{\circ}C$ were r=0.753, r=0.796 and r=0.783, respectively. The predictive explained variances ($Q^2$) of the final model, moreover, were more than 0.550 at all temperatures, and the regression coefficients of determination ($R^2$) were more than 0.6 (60%). Our results indicate that milk has different internal reflectance measured in the range of visible and near infrared wavelengths (400 to 1,100 nm), depending on its fat content.

• Asian-Australasian Journal of Animal Sciences
• /
• 제25권5호
• /
• pp.659-664
• /
• 2012

The present experiment aimed to evaluate the effect of HMBi on the production performance and metabolism in dairy cows. Thirty multiparous Holstein dairy cows under similar conditions were randomly assigned to three dietary treatments; i) Control, a basal diet; ii) T1, a basal diet plus HMBi (0 g prepartum and 18 g postpartum); and iii) T2, a basal diet plus HMBi (10 g prepartum and 18 g postpartum). Treatments were initiated 21 d before expected calving and continued through 91 d postpartum. HMBi was top-dressed onto the total mixed ration of each cow. Treatments did not affect dry matter intake, plasma urea nitrogen, peak milk yield, days to peak milk yield, nonesterified fatty acid, glutamate pyruvate transaminase, glutamic oxalaetic transaminase, milk fat content, milk protein content, milk lactose content, and milk solid non-fat content. The milk composition yields were increased by the HMBi-supplemented treatment. The T1 and T2 treatments increased the yields of 4% fat-corrected milk yield, milk fat, milk protein, and milk lactose compared with the control. Although there was no difference in the milk composition of the control and T2-treated cows, the T2-treated cows exhibited higher milk fat yield (increased by 74 g/d), lower milk urea nitrogen (reduced by 3.41%), and plasma ${\beta}$-hydroxy butyrate than the control cows. The results indicate that HMBi supplementation to diet has beneficial effects, and that there is no difference between supplementation at prepartum and starting only at parturition.

• 대한수의학회지
• /
• 제41권2호
• /
• pp.243-252
• /
• 2001

Milk constituents and somatic cell count (SCC) were analysed for 4,059 milk samples from 178 dairy farms from April to December in 1999. Correlations among each milk constituents, milk urea (MU) concentration and SCC in association with lactation stage, milk yield and parity, and balancing status of nutrients' supplies were analysed, and the results are summarized as follows; Averages of milk fat percent, total solids percent and milk yield were $3.72{\pm}0.91%$, $12.50{\pm}1.31%$ and $23.80{\pm}8.54kg$, respectively, whereas those were significantly lower during the summer season. In contrast, average of MU concentration was $0.0361{\pm}0.0006%$ which was significantly higher during the summer season. With milk yield, concentrations of fat, protein and SCC in milk decreased but concentrations of lactose and urea in milk and body condition score (BCS) were not altered. Concentrations of fat, protein, lactose, total solids, SNF, and urea in milk were significantly affected by stage of lactation ($P{\leq}0.0001$) but SCC was not changed. Parity of dairy cows had a significant effect on concentrations of fat ($P{\leq}0.02$), lactose ($P{\leq}0.0001$), total solids ($P{\leq}0.002$), and SNF ($P{\leq}0.0001$) in milk and milk yield ($P{\leq}0.0005$) but did not change concentrations of urea and protein in milk. Somatic cell count had significant positive correlationship with percentages of fat, protein and total solids ($P{\leq}0.0001$), respectively, but had negative correlationship with percentages of urea and lactose in milk and milk yield ($P{\leq}0.0001$). Milk urea concentration was negatively correlated with concentrations of protein, fat, total solids, and SNF in milk and milk yield ($P{\leq}0.0001$) and, according to regression analysis using milk urea concentration and SCC, following equation was obtained; $Y(MU)=3.688{\times}10^{-2}-4.04{\times}10^{-7}{\times}X(SCC{\times}1,000)(r^2=0.0038$, $P{\leq}0.0001$). We studied balance between protein and energy supplies to dairy cows in each farm based upon milk urea and protein concentrations, and results showed that 137 of total 178 farms fed cows unbalanced amounts of dietary protein and energy.

• Asian-Australasian Journal of Animal Sciences
• /
• 제4권1호
• /
• pp.25-29
• /
• 1991

Performance and production of twenty lactating Holstein cows fed diets containing either soybean meal or fish meal as the primary protein source were compared in a continuous or split feeding scheme. At 1 wk prepartum four groups of five animals were placed on each experimental diet. Animals assigned to the continuous feeding scheme were continued on these diets for 10-wk postpartum. At 4 wk postpartum, the diets for the groups assigned to switching protein sources were changed. These treatments were continued for another 6 wk. Milk production and dietary intakes were recorded daily. Milk constituents were measured every 2 d. Cows weights, rumen fluid samples and jugular blood samples were collected weekly. Data showed no effect of early lactation diet on cow performance or milk characteristics. Overall, compared to the soybean meal diet, the fish meal diet lowered the milk fat percent and increased production of milk per unit of dry matter ingested. No differences were observed for volatile fatty acid content of rumen fluid, blood mineral content, milk protein, somatic cell count, 4%-fat corrected milk, dry matter intake, or body weight.

• Asian-Australasian Journal of Animal Sciences
• /
• 제27권12호
• /
• pp.1705-1711
• /
• 2014

The objective of this study was to evaluate the effect of ruminally protected amino acids (RPAAs) and ruminally protected fat (RPF) supplementation on ruminal fermentation characteristics (in vitro) and milk yield and milk composition (in vivo). Fourteen mid-lactating Holstein dairy cows (mean weight $653{\pm}62.59kg$) were divided into two groups according to mean milk yield and number of days of postpartum. The cows were then fed a basal diet during adaptation (2 wk) and experimental diets during the treatment period (6 wk). Dietary treatments were i) a basal diet (control) and ii) basal diet containing 50 g of RPAAs (lysine and methionine, 3:1 ratio) and 50 g of RPF. In rumen fermentation trail (in vitro), RPAAs and RPF supplementation had no influence on the ruminal pH, dry matter digestibility, total volatile fatty acid production and ammonia-N concentration. In feeding trial (in vivo), milk yield (p<0.001), 4% fat corrected milk (p<0.05), milk fat (p<0.05), milk protein (p<0.001), and milk urea nitrogen (p<0.05) were greater in cows fed RPAAs and RPF than the corresponding values in the control group. With an index against as 0%, the rates of decrease in milk yield and milk protein were lower in RPAAs and RPF treated diet than those of basal diet group (p<0.05). In conclusion, diet supplemented with RPAAs and RPF can improve milk yield and milk composition without negatively affecting ruminal functions in Holstein dairy cows at mid-lactating.

• 한국식품영양과학회지
• /
• 제30권5호
• /
• pp.933-936
• /
• 2001

본 연구는 건강한 20대 한국 성인의 장에서 내산성과 내담즙성이 강한 비피더스균을 분리하여 비피더스균의 형철 콜레스테롤 저하 효과를 알아보기 위하여 체중 200g 정도 되는 Sprague-Dawley 종 희준 숫컷을 대상으로 우유, 비피더스균을 첨가항 우유, 캡슐화된 비피더스균을 첨가한 우유와 비피더스균에 의해 발혀된 발효유를 투여한 결과 우유, 비피더스 균을 첨가한 우유와 캡슐화된 비피더스균을 첨가항 우유를 투여한 실험군에서 혈청 콜레스테롤 저하 효과가 나타나지 않았으나 비피더스 발효유를 먹인 실험군에서 혈청 콜레스테롤 저하시키는 효과를 볼 수 있었으므로 혈청 콜레스테롤 저하 효과를 나타내는 것은 발효유에 있는 젖산균 그 자체가 아니라 발효유라는 결과를 얻었다.

• Asian-Australasian Journal of Animal Sciences
• /
• 제22권11호
• /
• pp.1504-1512
• /
• 2009

A feeding trial was conducted to examine the effect of high-temperature-micro-time (HTMT) processing of diets containing extruded soybean (ESB) in high quantity on milk fat production, metabolic responses, and the formation of conjugated linoleic acid (CLA) and trans-vaccenic acid (TVA). Twenty-one multiparous Holstein cows in mid-lactation were blocked according to milk yield in the previous lactation. Cows within each block were randomly assigned to either normal concentrate or HTMT treated diets containing ESB (7.5% HTMT-ESB and 15% HTMT-ESB). It was hypothesized that the HTMT-ESB would affect the undegradable fatty acids in the rumen and, thus, would modify the fatty acid profile of milk fat. Both 7.5% and 15% HTMT-ESB did not affect milk yield, fat, protein, lactose and solid-not-fat (SNF), but the proportion of cis-9, trans-11 CLA in milk fat was significantly increased by these treatments. Content of TVA in milk fat was not affected by HTMT-ESB. The HTMT-ESB influenced the fatty acid profile in milk fat, but there was little difference between 7.5% and 15% of supplementation. HTMT-ESB feeding significantly decreased the concentration of plasma insulin and glucose, while plasma growth hormone (GH), triglyceride (TG), non-esterified fatty acid (NEFA) and HDLcholesterol were increased by 7.5% and 15% ESB-HTMT supplementation in comparison to the control group (p<0.05). However, no significant difference was observed in plasma LDL-cholesterol, insulin like growth factor (IGF)-1, T3, T4, and leptin concentrations among treatments (p>0.05). The present results showed that cis-9, trans-11 CLA production was increased by HTMT treatment of dietary ESB without reduction of milk fat, and the unchanged milk fat and yield was assumed to be associated with the constant level of thyroid hormones, leptin, and IGF-1.