• Animal Bioscience
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• 제34권9호
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• pp.1466-1478
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• 2021

Objective: Ruminants are completely dependent on their microbiota for rumen fermentation, feed digestion, and consequently, their metabolism for productivity. This study aimed to evaluate the rumen bacteria of lactating yaks with different milk protein yields, using high-throughput sequencing technology, in order to understand the influence of these bacteria on milk production. Methods: Yaks with similar high milk protein yield (high milk yield and high milk protein content, HH; n = 12) and low milk protein yield (low milk yield and low milk protein content, LL; n = 12) were randomly selected from 57 mid-lactation yaks. Ruminal contents were collected using an oral stomach tube from the 24 yaks selected. High-throughput sequencing of bacterial 16S rRNA gene was used. Results: Ruminal ammonia N, total volatile fatty acids, acetate, propionate, and isobutyrate concentrations were found to be higher in HH than LL yaks. Community richness (Chao 1 index) and diversity indices (Shannon index) of rumen microbiota were higher in LL than HH yaks. Relative abundances of the Bacteroidetes and Tenericutes phyla in the rumen fluid were significantly increased in HH than LL yaks, but significantly decreased for Firmicutes. Relative abundances of the Succiniclasticum, Butyrivibrio 2, Prevotella 1, and Prevotellaceae UCG-001 genera in the rumen fluid of HH yaks was significantly increased, but significantly decreased for Christensenellaceae R-7 group and Coprococcus 1. Principal coordinates analysis on unweighted UniFrac distances revealed that the bacterial community structure of rumen differed between yaks with high and low milk protein yields. Furthermore, rumen microbiota were functionally enriched in relation to transporters, ABC transporters, ribosome, and urine metabolism, and also significantly altered in HH and LL yaks. Conclusion: We observed significant differences in the composition, diversity, fermentation product concentrations, and function of ruminal microorganisms between yaks with high and low milk protein yields, suggesting the potential influence of rumen microbiota on milk protein yield in yaks. A deeper understanding of this process may allow future modulation of the rumen microbiome for improved agricultural yield through bacterial community design.

• Journal of Animal Science and Technology
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• 제56권2호
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• pp.5.1-5.5
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• 2014

The objectives of this study were thus to identify most significant factors that determine milk component yield (MCY) using a meta-analysis and, if possible, to develop equations to predict MCY using variables that can be easily measured in the field. A literature database was constructed based on the research articles published in the Journal of Dairy Science from Oct., 2007 till May, 2010. The database consisted of a total of 442 observed means for MCY from 118 studies. The candidate factors that determine MCY were those which can be routinely measured in the field (e.g. DMI, BW, dietary forage content, chemical composition of diets). Using a simple linear regression, the best equations for predicting milk fat yield(MFY) and milk protein yield (MPY) were $MFY=0.351({\pm}0.068)+0.038({\pm}0.003)$ DMI ($R^2=0.27$), and $MPY=0.552({\pm}0.071)+0.031({\pm}0.002)DMI-0.004({\pm}0.001)$ FpDM (%, forage as a percentage of dietary DM) ($R^2=0.38$), respectively. The best equation for predicting milk fat content (%) explained only 12% of variations in milk fat content, and none of a single variable can explain more than 5% of variations in milk protein content. We concluded that among the tested variables, DMI was the only significant factor that affects MFY and both DMI and FpDM significantly affect MPY. However, predictability of linear equations was relatively low. Further studies are needed to identify other variables that can predict milk component yield more accurately.

• Asian-Australasian Journal of Animal Sciences
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• 제17권5호
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• pp.670-677
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• 2004

Sixteen multiparous Holstein-Friesian crossbred cows in mid-lactation were blocked according to days in milk (DIM) and previous lactation and randomly assigned according to a Randomized Complete Block (RCB) design with four replications to receive four dietary treatments. The dietary treatments consisted of T1: No cassava hay (CH) or stylo 184 hay (SH) supplementation, supplementation of concentrate to milk yield at 1:2 (control), T2: Supplementation of 1 kg of CH/hd/d, supplementation of concentrate to milk yield at 1:2, T3: Supplementation of 1 kg of CH+SH/hd/d, supplementation of concentrate to milk yield at 1:2, T4: Supplementation of 2 kg of CH+SH/hd/d, supplementation of concentrate to milk yield at 1:3. All animals received Ruzi grass from a cut-and-carry system as roughage source. The feeding trial lasted for 9 weeks. The results revealed that DMI of concentrate of supplemented treatments were significantly lower (p<0.05) than those in the control, but there was no significant difference between T2 and T3. There was no significant difference in forage DM intake between the control and supplemented treatments. CP and NDF digestibility of supplemented treatments were significantly (p<0.05) greater than the control and there were no significant differences among supplemented treatments. Milk yield and 3.5% FCM (14.3, 14.5, 14.7 and 14.8; 13.9, 14.3, 14.3 and 14.6 kg/hd/d, respectively) were not significantly different among treatments. Milk protein percentage of supplemented treatments was significantly (p<0.05) higher than the control, but there were no significant differences among supplemented treatments. There was no significant difference in milk fat percentage between the control and supplemented treatments. However, milk fat percentage tended to be higher for supplemented animals as compared to the control group. There were also no significant differences in lactose, solids-not-fat and total solids percentages among treatments. Cows in supplemented treatments gave incomes over supplement cost (IOSC) of 2.72, 2.74 and 2.93 US$/hd/d, respectively which were greater than for cows on control treatment. Furthermore, IOSC were greatest for cows in T4 as compared to other treatments. Based on this study it was concluded that, feeding cassava hay solely or in combination with stylo 184 hay as a supplemental protein source could be a potential valuable strategy in small-holder dairy farming systems in the tropics. This strategic supplementation significantly reduced concentrate use, which resulted in improved milk yields and milk quality for the supplemented cows. Moreover, it resulted in higher economical returns through increased productivity and lower ratios of concentrate to milk yield, from 1:2 to 1:3.

• Asian-Australasian Journal of Animal Sciences
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• 제16권2호
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• pp.204-210
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• 2003

To see the effect of Beragfat T-300, a by pass fat, on the production and composition of milk, four primiparous crossbred cows in their early lactation were used in a $4{\times}4$ Latin Square Design. Each period was of 30 days including 15 days of adjustment period. The diets were formulated to contain 0, 2.5, 3.5 and 4.5% of Bergafat and were isonitrogenous and isoenergetic. The intake of DM, OM, CP, NDF, ADF, Cellulose and ADL were not affected, however, the EE intake was increased by the supplementation of Bergafat in the diet of cows. The digestibilities of NDF and EE remained unaffected, whereas the digestibilites of DM, OM and CP were reduced. Milk yield remained unaltered, while 4%FCM yield increased as a result of adding Bergafat in the daily ration. Bergafat upto 4.5% of the diet DM can be added in the diet of crossbred cows without any adverse effect on the DM intake and digestibilities of DM and NDF. Furthermore, Bergafat does not cause any butter fat depression in the milk of cows.

• Animal Bioscience
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• 제34권4호
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• pp.567-574
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• 2021

Objective: In this study we investigated the effect of seasonal thermal stress on milk production and milk compositions between Holstein and Jersey dairy cows under the temperate-climate in Korea. Methods: A total of 9 Holstein lactating dairy cows (2.0±0.11 parity) which had a daily milk yield of 29.77±0.45 kg, and days in milk of 111.2±10.29 were selected similarly at the beginning of the experiments in each season. Also, a total of 9 Jersey lactating dairy cows (1.7±0.12 parity) which had a daily milk yield of 20.01±0.43 kg, and days in milk of 114.0±9.74 were selected similarly at the beginning of the experiments. Results: Results showed that the average ambient temperature (℃) and temperature-humidity index (THI) were higher in summer, and were lower in winter (p<0.05). The average relative humidity (RH, %) was higher in autumn than that of other seasons (p<0.05). Milk production was significantly decreased (Holstein 29.02 kg/d and Jersey 19.75 kg/d) in autumn than in other seasons (Holstein 30.14 kg/d and Jersey 20.96 kg/d). However, the milk production was negatively correlated in Holstein cows, and positively correlated in Jersey cows with THI values increased from 16 to 80. In addition, milk yield was increased by 15% in Holstein cows and decreased by 11% in Jersey cows with the THI values increased from 16 to 20. The fat and protein content percentage was significantly higher in Jersey milk than in Holstein milk, furthermore the fat and protein content yield was higher in Jersey cow milk than that of Holstein cow's milk with all THIs. Conclusion: From the study results, we concluded that Jersey cows might be less adaptable to low temperature of the winter, and this would have a negative impact on dairy farmer income since Korea's milk price estimation system places a higher value on milk yield than on milk compositions or sanitary grades.

• Asian-Australasian Journal of Animal Sciences
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• 제15권5호
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• pp.650-657
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• 2002

Two experiments were conducted to evaluate the effects of forage:concentrate ratios and feeding principles on milk yield, milk composition, body weight change, postpartum oestrus and feed cost. A total of 36 crossbred F1 cows (Holstein Friesian${\times}$Local Yellow) in the 8th week of lactation were used. In each experiment, animals were divided into three groups using a randomized block design according to the milk yield of the previous eight weeks. Cows were fed 30, 50 and 70% concentrate in the diet based on DM. In experiment 1 (Fc), cows were given the same amount of DM with constant ratios of forage and concentrate within treatments. In experiment 2 (Fa), cows were given the same constant amounts of concentrate as in experiment 1 and ad libitum forage. The forage consisted of a natural grass mixture based on 5 species of grasses with high nutritive values. There was no difference in total DM intake between treatments within experiments. However, cows fed forage ad libitum had higher DM intakes compared to cows fed constant forage (1.6, 4.5 and 9.5% for cows fed 70, 50 and 30% forage, respectively). Daily milk yield of cows fed forage ad libitum was higher than that of cows fed constant forage:concentrate ratio. Within experiment, milk yield was highest for cows fed 30% DM forage, followed by cows fed 50% and then cows fed 70% forage (11.17, 10.98 and 10.71 for the 30Fc, 50Fc and 70Fc cows; 11.73, 11.16 and 10.81 kg for the 30Fa, 50Fa and 70Fa cows, respectively). Decreased forage ratio in the diets resulted in decreased milk fat content and tended to increase milk protein. Increased concentrate ratio in the diet and feeding forage ad libitum increased body weight gain. The effect of forage:concentrate ratio on postpartum oestrus was not significant. The feed cost per kg milk produced was lowest for the cows fed 70% forage. It is concluded that increased ratio of concentrate resulted in increased body weight gain, milk yield, milk protein, and decreased milk fat. Feeding forage ad libitum increased feed intake, milk yield and body weight gain. The ratio of 50% forage is more suitable for milk production and animal condition, but in terms of feed cost and under the conditions of small dairy farmers, the 70% ad libitum forage feeding is recommended.

• Asian-Australasian Journal of Animal Sciences
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• 제18권1호
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• pp.48-53
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• 2005

Finger millet straw and rice straw are the major source of dry roughage in southern India. They distinctly vary in their morphological and nutritional characters. Hence an effort was made to study the nutrient utilization, milk yield and composition in crossbred dairy cows fed either finger millet (group 1) or rice straw (group 2) as a source of dry roughage. The cows in both the groups were fed as per requirement with concentrate, green fodder and straw in the ratio of 30:45:25 parts (DM). At the end of 50 days of preliminary feeding a digestibility trial was conducted for 7 days and pooled samples of feed, fodder, feces, urine and milk were analysed for macro and micro nutrient content. Finger millet straw contained more CP, Ca, P, Mg, Cu, Zn and Co than rice straw and rice straw contained higher ADF, ash and silica. The intake of DM, CP, EE, NDF, ADF and most micronutrients (Ca, P, Mg, Cu, Zn, Fe, Mn and Co) was significantly higher in cows fed finger millet straw. The digestibility of DM, CP, NDF and ADF was significantly higher in cows fed finger millet straw and the gut absorption of Ca, Cu, Mn and Co was significantly higher in cows fed finger millet straw. The dietary requirement of all micronutrients in both the group of cows could be met irrespective of the type of roughage fed except that of Ca, which was low (0.61 and 0.40%) in rice straw fed cows. The average daily milk yield (L/cow) was also higher (7.0 L) in cows fed finger millet straw as compared to cows fed rice straw (6.3 L). The average milk composition also did not differ except that of milk fat which was significantly (4.7 and 4.5%) low in cows fed rice straw. The overall results of this study have indicated that finger millet straw is a better source of dry fodder than rice straw and while feeding rice straw as the sole roughage to dairy cows there is need to supplement additional calcium as this could be one of the limiting nutrients for milk production.

• Asian-Australasian Journal of Animal Sciences
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• 제30권3호
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• pp.363-369
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• 2017

Objective: The current study compared the effects of dietary levels of two phase stoned olive cake (OC) in form of silage (OCS) on milk production and quality of Saanen goats. Methods: The OCS included in total mixed ration (TMR) at dry matter proportions of 0.0 (OC0), 0.10 (OC10), and 0.20 (OC20). The TMR were fed to a total of 18 goats in a completely randomized design for a period of 5 weeks. Results: Dietary treatments had no effect on the milk yield of Saanen goats, but the daily milk fat production was greater (p<0.05) at feeding OC20. The total phenolic (TP) compounds contents increased (p<0.01) in each increment of OCS in TMR and this was also reflected in the TP contents of milk. The C8:0, C10:0, C12:0, and C14:0 saturated fatty acids (FAs) in milk fat decreased (p<0.01) with increasing dietary level of OCS, but the decrease (p<0.001) in C16:0 and the increase (p<0.01) in C18:0 in milk fat occurred similarly at each inclusion level of OCS. Only OC20 reduced (p<0.05) the total saturated FA, yet the reduction (p<0.01) in n6/n3 ratio and atherogenicity index occurred in both OC10 and OC20. Conclusion: Two phase stoned OCS increases milk quality not only through modifying the milk FA composition, but also by increasing the milk TP content. These favorable changes in milk quality are closely associated with the dietary level of OCS.

• Asian-Australasian Journal of Animal Sciences
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• 제31권8호
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• pp.1259-1266
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• 2018

Objective: This study was carried out to investigate the possible application of Broussonetia papyrifera (B. papyrifera) silage as a functional feeding stuff in dairy cattle. Methods: Seventy-two Holstein cows were divided into four groups randomly and allocated to 6 pens with 3 individuals in each group and fed the original total mixed ratio (TMR) in the dairy farm or the new TMR with 5%, 10%, and 15% B. papyrifera silage, separately. Feed intake were recorded, milk and blood samples were collected, and milk composition, blood metabolites and milk fatty acids composition were measure at the end of the experiment. Results: Dry matter intake of cows decreased when they fed on diet with B. papyrifera, but no differences were observed in body condition score, milk yield, milk protein and lactose, feed efficiency and serum metabolites between groups. Both 10% or 15% of B. papyrifera silage in the diet significantly increased the immunoglobulin A (IgA) and IgG in serum, 15% of B. papyrifera silage increased the content of serum catalase, superoxide dismutase, total antioxidant capacity, and decreased the content of 8-hydroxy-2'-deoxyguanosine. Furthermore, 10% or 15% of B. papyrifera silage resulted in a significant decrease in the milk somatic cell count, and increased the polyunsaturated fatty acids content in the milk. Conclusion: The diets with 10% to 15% of B. papyrifera silage might enhance the immune and antioxidant function of dairy cows and increase the polyunstaturated fatty acid concentration in the milk.

• Asian-Australasian Journal of Animal Sciences
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• 제33권5호
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• pp.825-835
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• 2020

Objective: The aim of the present study was to investigate the effect of dietary zinc supplementation of Friesian cows on chemical-nutritional and aromatic properties of Caciocavallo cheese after 7 days (C₇) and 120 days (C₁₂₀) of ripening. Methods: Twenty eight Friesian cows, balanced for parity, milk production and days in milk, were randomly assigned to 2 groups. The control group (CG) was fed with a conventional complete diet, while the experimental group (zinc group, ZG) received a daily zinc supplementation of 60 mg for kg of dry complete feed. During the experimental period, the milk yield was monitored and samples of milk and caciocavallo cheese were collected and analyzed for chemical-nutritional composition and aromatic profile. Results: The enrichment of dairy cows diet with zinc, did not influence milk yield and composition, however a marked reduction of somatic cell count was evidenced. Both in milk and cheese the ZG samples were characterized by a lower concentration of satured fatty acids and an increase in oleic, vaccenic and rumenic acids. The aromatic profile of dairy products was also positively affected by dietary zinc intake, with an increase in concentration of carboxylic acids, esters and lactones. Conclusion: The present results suggest a positive role of dietary zinc intake in improving the quality of bovine milk and related cheese, in particular for the increase in concentration of bioactive fatty acids such as rumenic acid. The changes evidenced in cheese through the analysis of the volatile profile, would be consistent with the development of interesting organoleptic properties, although further evaluations should be performed to confirm the consumer acceptability of these changes.