• Asian-Australasian Journal of Animal Sciences
• /
• v.15 no.3
• /
• pp.382-389
• /
• 2002

The aims of this study is to evaluate the effect of Aspergillus oryzae Fermentation Extract (AFE) on the performance of lactating cows in summer (May to July) and winter (December to February). The experiment was a completely randomized design (CRD) and dietary treatments were 1) basal diet without AFE, 2) basal plus 3 g/d AFE into the basal total mixed ration (TMR), 3) basal plus 45.4 mg AFE/kg the ensiling corn silage and 4) AFE inclusion in silage and TMR. Twenty-eight cows from each trial were selected and randomly allocated into the four treatment groups, confined in individual pens, and fed ad libitum for 8 weeks in both seasons of feeding trials. Results showed that AFE inclusion in corn silage significantly improved DM intake by 4.4% and milk yield by 3.1% (p<0.05) during summer. In the winter season, AFE inclusion in the diet significantly improved milk yield by 10%. Direct addition of AFE to the TMR even further significantly improved milk yield over the addition through corn silage by 7.4% in winter (p<0.05). An additive effect of AFE inclusion into TMR and through corn silage was also demonstrated in the winter-feeding. AFE inclusion however, did not improve DM intake during the winter trial. In the summer trial, inclusion of AFE showed an adverse effect on the percentage of milk fat, but did not impact on the milk fat yield. Adding AFE through corn silage showed a trend towards alleviating the negative effects of milk fat from direct AFE inclusion in TMR. The similar trend occurred in the winter trial. The inclusion of AFE through corn silage significantly lowered the milk protein content over direct AFE addition, but did not significantly impacted the milk protein yield in summer. AFE supplementation during the winter season significantly increased milk protein content. Adding AFE to the corn silage significantly increased milk protein content over direct AFE addition in winter although inclusion of AFE significantly decreased total milk solid content in the summer (p<0.005). During the winter season, inclusion of AFE required less DM to produce a unit of milk. Inclusion of AFE into corn silage required less DM, energy and protein to produce a unit of milk. But inclusion of AFE did not alleviate heat stress on the lactating cows.

• Asian-Australasian Journal of Animal Sciences
• /
• v.15 no.5
• /
• pp.650-657
• /
• 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.

• Journal of Veterinary Clinics
• /
• v.30 no.3
• /
• pp.178-185
• /
• 2013

This study evaluated the effects of milk yield on the postpartum health and reproductive performance of dairy cows. In total, data were collected from 1,060 cows on six dairy farms, including their milk production, body condition score (BCS), postpartum disorders, and reproductive performance. The lactation data were grouped based on the 305-day milk yield into control (< 10,000 kg, n = 445) and high milk yield (${\geq}$ 10,000 kg, n = 615) groups. The milk fat and protein, and BCS were lower during the first 5 months postpartum in the high milk yield group compared with the control group (p < 0.01). Ovarian cysts were more frequent (p < 0.0001) in the high milk yield group (28.6%) than in the control group (15.3%), whereas endometritis tended to be less frequent in the high milk yield group (29.6%) than in the control group (35.1%, p = 0.06). A higher proportion of cows tended to receive reproductive hormones (p = 0.06) in the high milk yield group (62.4%) than in the control group (56.6%). The probability of a pregnancy after first insemination tended to be lower (odds ratio = 0.78, p = 0.07) in the high milk yield group (30.2%) than in the control group (35.2%). Furthermore, the hazard of pregnancy by 210 days in milk was lower in the high milk yield group (hazard ratio = 0.84, p = 0.04) than in the control group, which resulted in a 20-day increase in the median interval to pregnancy. In conclusion, high milk yield was related to lower milk fat and protein, lower BCS, an increased incidence of ovarian cysts, and increased use of reproductive hormones, which resulted in decreased reproductive performance of dairy cows.

• Asian-Australasian Journal of Animal Sciences
• /
• v.17 no.9
• /
• pp.1232-1235
• /
• 2004

In order to investigate the effect of recombinant bovine somatotropin (rbST) on blood metabolites and milk yield of lactating buffaloes, 30 lactating buffaloes after acclimatization for 30 days were divided into 2 groups as control (n=10) and experimental (n=20). Animals were injected 250mg of rbST (Boostin-250) on 0, $14^{th}$ and $28^{th}$ day subcutaneously at ischiorectal fosse, where as control animals were given placebo of 2 ml normal saline. Fortnightly blood samples were collected from 15 days prior to 60 days post injection to estimate different blood metabolites. Daily milk yield was recorded and weekly average yield of each animal was calculated. From this study, it was found that blood metabolites such as glucose, triglycerides, total proteins, albumin, globulin and electrolytes like sodium and potassium were not altered by rbST injection. However, there was a significant (p<0.05) decrease in blood urea nitrogen (BUN) concentration in experimental group as compared to that of control group. The weekly average milk yield was significantly (p<0.001) higher (25%) in rbST injected group over the control group.

• Asian-Australasian Journal of Animal Sciences
• /
• v.6 no.3
• /
• pp.395-400
• /
• 1993

Four sheep per treatment were fed either control or 3% calcium salts of long-chain fatty acids (Ca-LCFA) in a total mixed ration (TMR). Feed and free water intakes were not different, but digestibilities of crude protein and crude fiber were lower (p<0.05) and that of crude fat was higher (p<0.05) for sheep fed Ca-LCFA than for control sheep. Dry matter digestibility, ruminal pH and microbial protein yield were not different between treatments and ammonia-N concentration in the rumen was higher for sheep fed Ca-LCFA than for control sheep. A 60-day milk production trial was conducted with thirty lactation Holstein cows. Fifteen cows per treatment were fed TMR containing either control or 3% Ca-LCFA ad libitum. Feed intake was not different between treatments, but milk yield was significantly higher (p<0.05) for cows fed Ca-LCFA than for control cows. Milk fat percentage was slightly higher and milk protein was lower for cows fed Ca-LCFA than for control cows. Lactose and total solid contents in milk were not different between treatments.

• Asian-Australasian Journal of Animal Sciences
• /
• v.17 no.2
• /
• pp.153-158
• /
• 2004

Data containing 14,188 lactation and reproductive records of Korean Holstein cows at first parity distributed across 3,734 herd-year-season groups were analyzed to get genetic (co)variance estimates for milk yield, fat yield, calving ease, and days open. Milk and Fat yields were adjusted to 305 d. Heritabilities and genetic correlations were estimated in two different animal models on which were included direct genetic effects (Model 1) and direct+maternal genetic effects (Model 2) using REML algorithms. Milk and fat yields were affected by age at first calving as linear and quadratic. Heritability estimates of direct effects were 0.25 for milk yield, 0.17 for fat yield, 0.03 for calving ease and 0.03 for days open in Model 2. These estimates for maternal effects were 0.05, 0.08, 0.04 and less than 0.01 for each corresponding trait. Milk productions at first lactation were to show genetically favorable correlation with calving ease and days open for direct genetic effects (-0.24 - -0.11). Moreover, calving ease was correlated with days open of 0.30 for direct genetic effects. Correlations between direct and maternal effects for each trait were negatively correlated (-0.63 - -0.32). This study suggested that maternal additive genetic variance would be not ignorable for genetic evaluation of milk production as well as reproductive traits such as calving ease and days open at first parity. Furthermore, difficult calving would genetically influence the next conception.

• Asian-Australasian Journal of Animal Sciences
• /
• v.32 no.4
• /
• pp.459-466
• /
• 2019

Objective: This study assessed the possible existence of genotype by environment interactions for milk, fat and protein yields in Holstein cattle raised in one of the most important milk production basins in Brazil. Methods: Changes in the genetic parameters and breeding values were evaluated for 57,967 animals from three distinct regions of southern Brazil, divided according to differences in climate. The genotype by environment interaction was determined by genetic correlations between regions, estimated by the restricted maximum likelihood, considering the animal model. Bull rankings were investigated to verify the ratio of coincident selected animals between regions for each trait. Results: The estimates of heritability coefficients were similar between two regions, but were lower in the third evaluated area, for all traits. Genetic correlations between regions were high, ranging from 0.91 to 0.99 for milk, fat and protein yields, representing the absence of a genotype by environment interaction for productive traits. The percentage of selection error between regions for the top 10% of animals ranged from 0.88% to 2.07% for milk yield, 0.99% to 2.46% for fat yield and 0.59% to 3.15% for protein yield. Conclusion: A slight change in genotype between areas was expected since no significant genotype by environment interactions were identified, facilitating the process of selecting Holstein cattle in southern Brazil.

• Asian-Australasian Journal of Animal Sciences
• /
• v.8 no.4
• /
• pp.365-368
• /
• 1995

Lactation curves of dairy cows were generated using three models, namely; incomplete gamma function (model 1), polynomial inverse function (model 2) and non-linear regression (model 3). Secondary milk yield data of 27 cows which had completed 6 lactations were used in this study. Milk yield records (once a week) throughout the lactation and from the first three months of lactation were fitted to the models. Estimation of total milk yield by model 3 using the data once a week throughout the lactation resulted in smaller % bias and standard error than those generated from model 1 and 2. But, model 2 was more accurate in predicting the 305-day milk yield equivalent closer to actual yields with smaller bias % and error using partial records up to 3 months. Also, model 2 was able to estimate the time to reach peak yield close to the actual data using partial records and model 2 could be used as a tool to advise farmers on appropriate feeding and management practices to be adopted.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.35 no.3
• /
• pp.217-224
• /
• 2015

This study aimed to investigate the effects of Dandelion (Taraxzcum coreanum) supplementation on milk yield, milk composition and blood characteristics in lactating dairy cows. Eight lactating dairy cows were divided into two groups (control: TMR supplementation, treatment: TMR with Dandelion supplementation). The milk yield, milk fat, lactose, solids not fat (SNF) and somatic cells counts (SCC) were not significantly different between the control group and the treatment group, whereas milk protein, milk urea nitrogen (MUN) and free fat acid (FFA) were significantly higher in the treatment group compared to the control (p<0.05). The blood components of the treatment group were compared with those of the control group and only aspartate aminotransferase (AST) appeared significantly high (p<0.05). The other blood components were not significantly different in the two groups. Blood corpuscle components in the groups were not significantly different. Especially, all blood corpuscle components in the treatment group were within the normal range. However, the white blood cells (WBC), lymphocytes (LYM) and hematocrits (HCT) in the control group exceeded the normal range. Based on the above results, the addition of Dandelion to feed increased milk protein, MUN and FFA, but did not significantly affect the composition of the blood and corpuscle in Holstein milking cows.

• Asian-Australasian Journal of Animal Sciences
• /
• v.14 no.8
• /
• pp.1118-1124
• /
• 2001

Fifteen lactating crossbred cows were randomly allotted to three groups of 5 each, and fed three isoproteinous concentrate mixture varying in RDP and UDP ratios, viz. 71: 29 (T1) and 58: 42 (T2) and 44: 56 (T3), along with green maize and wheat straw given as 2/3 and 1/3 of total roughage respectively, for a period of 120 days. The DM intake (kg/d) differed significantly (p<0.01) among the treatments as well as among the fortnights over a period of 120 days. DMI (kg/d) progressively increased from first to eighth fortnight in all the treatments. The daily DMI (% BW) was significantly (p<0.01) lower in T1 (2.37) than those of T2 (2.82) and T3 (2.67). The body weights of cows decreased up to 4th fortnight in T1 and up to 3rd fortnight in T2 and T3, then it showed an increasing trend till the end of the experiment in all the treatments. Cows in T1 lost 10 kg body weight but cows in T2 and T3 gained 23 and 12 kg the body weight, respectively. Both the milk and FCM yield differed significantly (p<0.01) among the fortnights. The FCM yield increased up to 2nd fortnight in all the treatments and thereafter, the FCM yield declined gradually as the lactation advanced. The FCM yield (kg/d) was significantly (p<0.05) higher in T3 (10.47) than in T2 (9.81) and T1 (9.68), however, milk yield, SCM yield and milk energy yield did not differ among the treatments as well as among the fortnights. Fat and protein % in milk increased as the lactation advanced. However, fortnightly SNF % in milk showed an irregular trend. The % fat, protein, SNF and total solids in milk differed significantly (p<0.01) among the fortnights. The % fat and protein in milk varied significantly (p<0.01) among the treatments, being lowest in T1 and highest in T3. The feed efficiency for milk production showed a non-significant variation among the treatments as well as among the fortnights, but increased with the increase in UDP level. It is concluded that by increasing the UDP level from 29 to 56 per cent of CP in the diet of medium producing cows, the milk production increases and cost of milk production reduces.