• Asian-Australasian Journal of Animal Sciences
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• 제12권6호
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• pp.901-903
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• 1999

Twenty-four multiparous crossbred Friesian dairy cows (60-90 days in lactation) were randomly assigned into a $2{\times}2$ factorial arrangement in a randomized complete block design. Factors were two levels of concentrate supplementation (1:2, high vs 1:1.2, very high; concentrate:milk yield) and two levels of high-quality feed block (HQFB) supplementation (non vs ad libitum block licking). Ruzi grass (Brachiaria ruziziensis) was fed as a roughage throughout the 70 day feeding trial. High level of concentrate fed group resulted in higher roughage and HQFB intakes, compared with very high concentrate supplemented group. HQFB supplementation tended to increase roughage intake and significantly improved milk yield (2 kg/hd/d in high concentrate supplementation) and quality (% fat) which resulted in higher economical return. HQFB was recommended to be used as a strategic supplement in lactating dairy cows especially when fed on low-quality roughages or crop residues.

• Asian-Australasian Journal of Animal Sciences
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• 제21권6호
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• pp.769-775
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• 2008

This study was on the relative net income (RNI) for 18,286 Iranian Holstein cows from 799 herds, with first freshening between 1991 and 2000. Two kinds of production system, which differed mainly in milk pricing system and feed cost, were considered. Four different models adopted from the literature were examined to find the optimum model. They differed by the cost of rearing and growth after first calving and they needed different amounts of economic data at the farm level. Results showed that four measures of RNI were highly correlated (>0.96) and could be used equally to measure lifetime profitability of cows. Therefore, in herds without a regular system for recording economic and management data, use of the simplest model is recommended. Multiple regression analysis revealed that RNI was affected by age at first freshening, milk yield and days of productive life (DPL), regardless of production system, and a similar breeding goal could be defined for the two systems. Multiple regression analysis of RNI showed that in order to obtain an unbiased estimate of economic value for DPL, the per day milk yield, not total lifetime milk yield, should be included in the regression model along with DPL. Regression analysis suggested that it is possible to predict RNI using information on age at first freshening along with the length of first lactation and per day milk yield with a coefficient of determination ranging from 0.44 to 0.47.

• Asian-Australasian Journal of Animal Sciences
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• 제13권9호
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• pp.1235-1238
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• 2000

Thirty-six Holstein dairy cows were used to evaluate the effect of a rumen protected methionine supplement (RPMet). The cows were divided into two groups of 18 each (control/experimental). The experimental group was given 15 g/d of RPMet (Mepron $^{(R)}$M85, Degussa) from the 4th to the 26th week postpartum. All cows were fed a similar amount of forage including alfalfa silage, corn silage and timothy silage. Concentrate mixture was offered in proportion to the milk yield of each cow. Sufficiency of major metabolizable AAs was checked. Milk yield and milk composition was monitored for each individual cow. A metabolic profile test (MPT) was carried out at the 7th, 11th and 21st week postpartum. Without supplement, both methionine and leucine fell short of the daily requirement. Supplementation with 15 g/d RPMet was calculated to be within a sufficient margin of safety. Milk yield tended to remain higher in the supplemented group than in the controls during supplementation with RPMet. The differences in weekly milk production at the 17th, 18th, 19th and 22nd weeks postpartum were significantly high in the RPMet group (p<0.05). The average 305-d milk yield and the percentages of milk fat, milk protein and solids-not-fat were not affected by the treatment. No differences were observed in either the somatic cell count in the milk or the reproductive status. Judging from MPT, all the cows were in good health during lactation.

• Asian-Australasian Journal of Animal Sciences
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• 제19권3호
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• pp.305-308
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• 2006

A genetic study was conducted to elucidate the effect of alpha-Lactalbumin (${\alpha}$-LA) gene polymorphism on milk production traits involving total milk yield and daily milk yield during first lactation in two breeds of water buffaloes namely, Murrah and Bhadawari. Single strand conformation polymorphism (SSCP) was carried out to explore genetic polymorphism present at this locus. For this study, exon 1 region of ${\alpha}$-LA was analyzed. Finally, polymorphism data was associated with milk production traits by employing least square analysis. In Murrah buffalo, five genotypes such as AB, BB, BC, CC and CD and four alleles A, B, C and D were detected whereas in Bhadawari buffalo two genotypes namely, AB and BC and three alleles namely, A, B and C were found. Genotypes showed significant effects ($p{\leq}0.05$) on total milk yield and daily milk yield in Bhadawari buffalo but had non-significant effects on these traits in Murrah buffalo.

• Asian-Australasian Journal of Animal Sciences
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• 제16권7호
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• pp.983-987
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• 2003

Malpura and Kheri ewes (76) in their late gestation, weighing $34.40{\pm}0.95kg$ were randomly selected and divided into 4 groups of 19 each (G1, G2, G3 and G4). Ewes in all the groups were grazed on natural rangeland from 07.00 h to 18.00 h. Ewes in G1were maintained on sole grazing while ewes in G2, G3 and G4, in addition to grazing received concentrate mixture at the rate of 1% of their body weight during late gestation, early lactation and entire last quarter of pregnancy to early quarter of lactation, respectively. The herbage yield of the community rangeland was 0.82 metric ton dry matter/hectare. The diet consisted of (%) Guar (Cyamopsis tetragonoloba) bhusa, (59.2), Babool pods and leaves (17.2), Bajra (Pennisetum typhoides) stubbles (8.8), Doob (5.3), Aak (4.2) and others (5.3). The nutrient intake and its digestibility were higher (p<0.01) in G2, G3 and G4 as compared to G1 because of concentrate supplementation. The intakes of DM ($g/kg\;W{^0.75}$), DCP ($g/kg\;W{^0.75}$) and ME ($MJ/kg\;W{^0.75}$) were 56.7, 5.3 and 0.83; 82.7, 12.2 and 1.16; 82.7, 12.1 and 1.17 and 83.1, 12.3 and 1.18 in G1, G2, G3 and G4, respectively. The per cent digestibility of DM, OM, CP, NDF, ADF and cellulose was 57.9, 68.8, 68.7, 52.3, 37.5 and 68.4; 67.6, 76.1, 82.3, 60.6, 44.5 and 73.4; 67.6, 76.1, 81.5, 60.6, 44.8 and 74.5 and 67.6, 76.1, 82.3, 60.6, 44.7 and 73.3 in G1, G2, G3 and G4, respectively. The nutrient intake of G2, G3 and G4 ewes was sufficient to meet their requirements. The ewes raised on sole grazing lost weight at lambing in comparison to advanced pregnancy. However, ewes raised on supplementary feeding gained 1.9-2.5 kg at lambing. The birth weight of lambs in G2 (3.92) and G4 (4.07) was higher (p<0.01) than G1 (2.98), where as in G1 and G3 it was similar. The weight of lambs at 15, 45 and 60 days of age were higher in G2, G3 and G4 than in G1. Similarly, the average daily gain (ADG) after 60 days was also higher in G2, G3 and G4 than in G1. The milk-yield of lactating ewes in G2, G3 and G4 increased up to 150-250 g per day in comparison to G1. The birth weight, weight at 15, 30, 45 and 60 days, weight gain and ADG at 30 or 60 days was similar both in male and female lambs. It is concluded from this study that the biomass yield of the community rangeland is low and insufficient to meet the nutrient requirements of ewes during late gestation and early lactation. Therefore, it is recommended concentrate supplementation at the rate of 1% of body weight to ewes during these critical stages to enhance their production performance, general condition as well as birth weight and growth rate of lambs.

• Asian-Australasian Journal of Animal Sciences
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• 제25권3호
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• pp.311-319
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• 2012

This study examined the effects of supplementation of fish oil and canola oil in the diet on milk yield, milk components and fatty acid composition of Holstein dairy cows in early lactation. Eight multiparous early lactation Holstein cows ($42{\pm}12$ DIM, $40{\pm}6kg$ daily milk yield) were fed a total mixed ration supplemented with either 0% oil (Control), 2% fish oil (FO), 1% canola oil +1% fish oil (FOCO), or 2% canola oil (CO) according to a double $4{\times}4$ Latin square design. Each period lasted 3 wk; experimental analyses were restricted to the last week of each period. Supplemental oils were added to a basal diet which was formulated according to NRC (2001) and consisted of 20% alfalfa, 20% corn silage and 60% concentrate. Milk yield was similar between diets (p>0.05), but dry matter intake (DMI) was lower (p<0.05) in cows fed FO diet compared to other diets. Milk fat percentage and daily yield decreased (p<0.01) with the supplementation of fish and canola oil. The daily yield and percentage of milk protein, lactose and solids-not-fat (SNF) were not affected by diets (p>0.05). The proportion (g/100 g fatty acids) of short chain fatty acids (SCFA) decreased and polyunsaturated fatty acids (PUFA) increased (p<0.05) in milk of all cows fed diets supplemented with oil. The proportions of 6:0, 8:0, 10:0 12:0 and 14:0 fatty acids in milk fat decreased (p<0.01) for all diets supplemented with oil, but the proportions of 14:1, 16:0 and 16:1 fatty acids were not affected by diets (p>0.05). The proportion of trans(t)-18:1 increased (p<0.01) in milk fat of cows fed FO and FOCO diets, but CO diet had the highest proportion of cis(c)-11 18:1 (p<0.01). The concentration of t-10, c-12 18:2, c-9 t-11 18:2, 18:3, eicosapentaenoic acid (EPA, 20:5) and docosahexaenoic acid (DHA, 22:6) increased (p<0.05) in FO and FOCO diets in comparison with the other two diets. These data indicate that including fish oil in combination with canola oil significantly modifies the fatty acid composition of milk.

• Asian-Australasian Journal of Animal Sciences
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• 제15권9호
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• pp.1267-1272
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• 2002

The present research was undertaken to monitor the effects of restricted and ad. libitum feeding during last trimester of pregnancy on the performance of crossbred dairy cows and their calves. For this purpose two groups of crossbred cows having eight animals in each group were put into two plane of nutrition during their last three months of pregnancy. Dietary energy level in one group was calculated as per Ministry of Agriculture, Fisheries and Food, (MAFF, UK) and the cows on other group received ad. libitum feeding (concentrate level similar to MAFF, recommendation+ad. libitum roughage). After calving, the cows of both groups were given same diet (ad. libitum) to study the effect of feeding during pregnancy on subsequent lactation performance of the cows. It was observed that during pre-calving period cows on ad. libitum feeding gained significantly (p<0.05) more body weight than that of cows on restricted feeding ($38.50{\pm}6.04$ vs $21.37{\pm}8.04kg/cow$). There was no significant differences between the birth weight of calves of restricted ($21.31{\pm}2.18kg$) and ad. libitum ($20.31{\pm}3.27kg$) groups. Dietary energy intake of ad. libitum group ($50.22{\pm}4.24$ MJ ME/d/cow) was significantly higher (p<0.01) than that of restricted group ($39.76{\pm}1.03$ MJ ME/d/cow). During lactation period cows that were on restricted feeding produced little more milk (3.06 lit/cow/day), than that of the cows on ad. libitum feeding (2.84 lit/cow/day). Although growth rate of the calves of restricted group upto one month ($0.23{\pm}0.09kg/calf/d$) was significantly (p<0.01) higher than that of ad. libitum group ($0.17{\pm}0.08kg/calf/d$) but after four months the growth rate of the calves of two groups become nearly similar ($0.35{\pm}0.02$ vs $0.37{\pm}0.03kg/calf/d$) and difference between them was non-significant. During lactation period cows of restricted group gained little weight but cows of ad. libitum group lost significantly (p<0.05) more weight. Per day metabolizable energy intake in both group during lactation period was nearly similar (67.54 vs 69.58 MJ ME). It is concluded that ad. libitum feeding during last trimester of pregnancy is neither economic for getting maximum milk yield nor for calf growth rate and MAFF, recommended level of dietary energy during that period could be applied on our pregnant crossbred dairy cows.

• Asian-Australasian Journal of Animal Sciences
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• 제5권3호
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• pp.475-480
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• 1992

The effect of mechanical factors and season of the year on milking characteristics (milk yield, time of milking, rate of milk flow, stripping time and tripping milk) were studied on 26 Holstein Friesian cows, raised under Saudi Arabia environmental conditions. Cows were in the third and fourth lactation and reached the peak. Cows milked twice a day with equal intervals. Three vacuum levels (34, 38 and 42 cfm) and two pulsation ratios were used to form six vacuum-pulsation combinations. The study was carried during two seasons Autumn-Winter (S1) and Spring-Summer (S2). After absorbing the cow equations least square analysis was used to analyze the data. Vacuum level 38 cfm and pulsation ratio 70:30 was the best among all combinations of vacuum level-pulsation ratio. No significant effect (p < .01) for season, up to the seventh half minute, on the rate of milk flow. However, season of the year has a significant effect on total milk yield, stripping time and stripping milk.

• Asian-Australasian Journal of Animal Sciences
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• 제15권10호
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• pp.1445-1452
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• 2002

The present experiment was carried out to study the utilization of substrates in the mammary gland of crossbred Holstein Friesian during feeding on different types of roughage. Sixteen pregnant crossbred Holstein heifers consisted of two breed types of eight animals each; Holstein Friesian${\times}$Red Sindhi (50:50=50%HF) and Holstein Friesian${\times}$Red Sindhi (87.5:12.5=87.5%HF). Animals were divided into four groups of the same breed type in each group which were fed with either rice straw treated with 5% urea or pangola hay (Digitaria decumbens) as the source of roughage throughout the experiments. Four consecutive experimental periods were carried out in late pregnancy (20-23 days before parturition), early lactation (30 days postpartum), mid-lactation (120 days postpartum) and late lactation (210 days postpartum). Measurement of mammary blood flow in combining with measurement of AV difference was performed for the mammary uptake of substrates. In the period of lactation, udder blood flow was nearly three times higher than that of late pregnant period (p<0.05) in both 50%HF and 87.5%HF feeding on either hay or urea treated rice straw. During mid- and late lactation of both groups of 87.5%HF animals, mammary blood flow and milk yield showed decrease when compared to those during the early lactating period while the trends for persistency were apparent in both groups of 50%HF animals throughout experimental periods. The mean arterial plasma concentrations of glucose, acetate, $\beta$-hydroxybutyrate and free glycerol in each group remained constant throughout experimental periods. During late pregnancy in all groups, the AV difference and extraction ratio of glucose, $\beta$-hydroxybutyrate and triacylglycerol across the mammary gland markedly lowered (p<0.05), which coincided with a lower net uptake by the mammary gland in comparison to the early lactating period. The mean arterial plasma concentration, AV difference and extraction ratio for acetate showed no significant differences between late pregnancy and the early lactating period. The AV difference of free glycerol showed apparent release from mammary tissue during late pregnancy in all groups. In mid- and late lactation, the mammary uptake for glucose, acetate and $\beta$-hydroxybutyrate in both groups of 87.5%HF animals showed apparent decrease as compared to that in the early lactating period, whereas no appearances were observed in 50%HF animals feeding either hay or urea treated rice straw. The mean arterial plasma concentrations for free fatty acid (FFA) and triacylglycerol (C16 to C18) were higher in late pregnancy than in early lactation in both types of crossbred animals. The values of AV difference and the net uptake by the mammary gland for FFA were variable during late pregnancy and lactating periods in all groups. There were no significant differences for AV difference, extraction ratio and net uptake of triacylglycerol during lactation advance in both groups of 50%HF and 87.5%HF animals feeding either hay or urea treated rice straw. These results suggest that the adaptations to either hay or urea treated rice straw by the mammary gland of crossbred HF animals allow for an adequate nutrient supply during pregnancy and lactation. There is no difference in the mode of mammary uptake of substrates in the same crossbred animals in response to feeding hay or urea treated rice straw. The differences in utilizing nutrients by the mammary gland for milk production between 87.5%HF and 50%HF animals would be dependent on changes in both intra-mammary factors and extra-mammary factors.

• Asian-Australasian Journal of Animal Sciences
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• 제15권5호
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• pp.675-681
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• 2002

Among Italian buffalo farmers, it is widely held that administering diets with high energy and protein concentrations is an effective way to increase milk production. In order to assess the validity of this opinion, we verified milk yield and physico-chemical characteristics from buffaloes that, from the $5^{th}$ month of lactation, were fed two total mixed rations (TMRs) which, given the same intake, should have led to satisfaction of protein requirements though with a slight energy deficit (diet A) or excessive amounts of energy and protein (diet B). Estimate of the energy and protein value of the diets and that of the corresponding requirements was carried out both by using two software programs derived from the Cornell Net Carbohydrate and Protein System (1992), and with the method set up by INRA researchers (1988). The results obtained show that the two diets administered did not result in significant changes to the quantity of milk produced. However, with Diet B the protein concentration in the milk was significantly (p<0.01) higher, although this was partly offset by the higher concentration (p<0.05) of non-protein nitrogen (NNP). The Group B buffaloes also showed significantly higher blood urea levels (p<0.01), with concentrations exceeding those considered physiological for lactating buffaloes. Finally, while administering Diet A the Body Condition Score (BCS) was close to 6.5 (Wagner et al., 1988), whereas in buffaloes which used Diet B it sometimes increased by over 0.5 points. As regards which of the two methods compared is more suitable for expressing dietary energy and protein value and corresponding requirements, we feel that due to the high variability in the Italian Mediterranean buffalo's milk production aptitude, it would be premature to express a judgement on methods which rest on a common scientific base and do not differ substantially.