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equipped with an automatic on-column injector (Agilent 7683 Series, Agilent Technologies, Inc., Wilmington, DE) and a flame-ionization detector (FID). The carrier gas was high purity hydrogen at a flow rate of 1.0 mL/min. The make-up gas used was high purity nitrogen, which was maintained at a flow-rate of 40 mL/min. High purity hydrogen (40 mL/min) and compressed air (450 mL/min) were supplied to the FID. The injector and detector temperatures were 250 and 300°C, respectively. The column oven temperature was programmed to hold at 100°C for 5 min, it was then increased from 100 to 250°C at 10°C/min and held at 250°C for 12 min. Calibration curves were prepared using a mixture of high purity (> 99%) FFA standards: C 4:0 , C 6:0 , C 8:0 , C 10:0 , C 12:0 , C 14:0 , C 16:0 and C 18:0 (Sigma-Aldrich, St. Louis, MO and Nu-Chek Prep, Inc. Elysian, MN) extracted through the whole procedure as for the cheese samples. As in the extraction of cheese samples, C 9:0 was used as an internal standard. Sensory Analysis Licensed Wisconsin cheese graders using a Wisconsin Cheese Makers Association World Championship Cheese Contest Form scored the cheeses for flavor defects, body, texture, appearance and color defects at 1, 3, 6, and 9 mo. RESULTS AND DISCUSSION Casein contents were 3.99, 3.97, and 3.72%, in milk from Groups I, II, and III, respectively (Table 1). The decrease in the casein content with increasing SCC was probably due to increased proteolysis; a similar trend is seen in mastitic bovine milk (Politis and Ng-Kwai-Hang, 1988b). Further evidence of enhanced proteolysis in high SCC milk can be seen in the decrease in the casein to true protein ratio (Table 1). Cheese yield at 1 d decreased from 16.03 to 15.97 to 15.09% with increasing SCC levels. Lower yields were attributed to lower casein and fat contents of the higher SCC milk (Table 1). Clotting time increased with higher levels of SCC (results not shown) probably due to the enhanced proteolysis in these milks; a similar trend is often seen in mastitic and late-lactation bovine milks (Lucey, 1996). Cheese yield decreased with the high SCC milk was possibly due to the lower casein and fat levels in these milks. In addition, nitrogen recovery was lowest in Group III milks (results not shown). The higher moisture contents in Group III cheeses (Table 2) probably reflect reduced synergetic ability caused by casein hydrolysis. There was no difference in the pH of all the cheeses over the entire ripening period (Table 3). There were slightly higher levels of 12% TCA soluble nitrogen at all stages of ripening in cheeses made from Group III milks (Table 4). Manchego cheeses made from milk in Groups I and II were judged to have more flavor defects at 6 and 9 mo (Table 5), although lipase flavor was detected in the cheese manufactured from Group III milk in the first month. Judges scoring for body and texture defects also noted more textural defects at 6 and 9 mo in the cheeses manufactured from milks with the two higher SCC levels (Table 6). Free nonanoic acid (C 9:0 ) is either found in ovine milk cheeses in trace quantities or to be totally absent (Sousa and Malcata, 1997). In our preliminary work (results not shown), only trace concentrations of C 9:0 were found in Manchego cheese and did not change significantly during ripening. Thus, C 9:0 was used as an internal standard. As moisture contents of the cheeses were changing with age, the fatty acid concentrations were expressed as g per kg of fat.
The FFA concentrations generally increased as ripening progressed for all the three cheeses, although the increase was not constant in all cases. Similar trends for fatty acid concentrations were observed in Groups I and II. Cheeses made from Group III milks had the highest total as well as individual FFA levels at all stages of maturation (Table 7). The main FFA observed during maturation were butyric (short-chain), capric (medium-chain), myristic acid (mediumchain) and palmitic (saturated long-chain). A similar trend has been observed by other authors during ripening of Manchego cheese (Pavaia et al., 2000, Poveda et al., 2000). The most abundant FFA in all the three cheeses, irrespective of SCC levels and ripening time, was palmitic acid (representing 30-32 % of total FFAs). Short-chain FFA comprised 17-22% of the total FFA, of which butyric was the main short-chain fatty acid, accounting for 7-10% of the total FFA. Although the short-chain fatty acids are found in low amounts, they contribute more to cheese flavor than the long-chain FFA (De la Fuenta et al., 1993, Poveda et al., 2000). Higher SCC levels affected the concentration of both individual and total FFA (C 4:0 -C 18:0 ). The cheese made from Group III milk contained the highest concentration of FFA compared to the other two SCC groups over the entire ripening period. Although there was only a slight increase in the FFA concentrations with increasing the SCC from Group I to II, the cheese made from the Group II was judged to have more flavor defects. This probably was due to the concentrations of FFA in the higher SCC cheeses being sufficiently higher than the aroma threshold. The results demonstrated that high SCC in ovine milk results in lowered cheese yields due to lower casein, fat and solids levels in the milk. Flavor defects such as increased rancidity were noted by licensed Wisconsin cheese graders and verified from testing individual and total free fatty acid concentrations. Even moderate differences in SCC showed a difference in total free fatty acid content at 1, 3, 6, and 9 mo. Acknowledgements The authors would like to thank the following Wisconsin Center for Dairy Research personnel for their help with this project: Amy Dikkeboom, Bill Hoesly, Kristen Houck, Cindy Martinelli, Juan Romero, Marianne Smukowski, Bill Tricomi, and Matt Zimbric. The Wisconsin Center for Dairy Research funded this project. References Anifantakis, E. M. 1986. Comparison of the physico-chemical properties of ewes’ and cows’ milk. Pages 42-53 in Proc. of the IDF seminar on the production and utilization of ewe’s and goat’s milk. IDF Bull. 202. International Dairy Federation, Brussels, Belgium. Association of Official Analytical Chemists. 1995. Official Methods of Analysis. 16th ed. AOAC, Arlington, VA. Barbano, D. M., R. R. Rasmussen and J. M. Lunch. 1991. Influence of milk somatic cell count and milk age on cheese yield. J. Dairy Sci. 74:369-388. Bencini, R. and G. Pulina. 1997. The quality of sheep milk: a review. Aus. J. Exp. Agric. 37:485-504. De la Fuente, M. A., J. Fontecha and M. Juárez. 1993. Fatty acid composition of the triglyceride and free fatty acid fractions in different cows-, ewes- and goats-milk cheeses. Z. Lebensm. Unters Forsch. 196:155-158. Food and Agriculture Organization. 1998. Food and Agriculture Organization of the United Nations. FAOSTAT Database Collections. Green, W.C. and K.K. Park. 1980. Comparison of AOAC, microwave and vacuum oven methods
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Proceedings of the 7 th Great Lakes
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ORGANIZING COMMITTEE 7 TH GREAT LAK
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Thursday, November 1 Noon Registrat
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SPEAKERS Dr. Juan-José Arranz, Dpt
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Table of Contents (continued) Lates
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eeding and were created to have hig
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Disease in the U.K. and subsequentl
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sheep production conditions in Wisc
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Pinelli, F., P. A. Oltenacu, G. Ian
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Bucket milking and elevated platfor
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Throughputs in different parlors No
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1 - Stand up as straight as possibl
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Roques J.L.. 1997. Traite des brebi
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Grade B milk quality is as follows:
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(c) Not Applicable (d) At least 10
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TOILET AND WATER SUPPLY 7. Toilet (
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(c) Drugs and medicinals shall be l
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FARMSTEAD CHEESE AND MARKETING Stev
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5. Cheese is delivered in person, w
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to participate with us, we are enga
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The key points to this plan were: Y
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Milk is supplied in two major forms
Page 45 and 46: MANAGEMENT OF A DAIRY SHEEP OPERATI
Page 47 and 48: 4 3.5 3 2.5 2 1.5 1 0.5 Chart 1: Mi
Page 49 and 50: Facilities and Equipment The requir
Page 51 and 52: from the ewes at 12 to 24 hours of
Page 53 and 54: COMPARISON OF EAST FRIESIAN AND LAC
Page 55 and 56: two-year-olds in 2001. East Friesia
Page 57 and 58: Reproduction. Table 4 compares the
Page 59 and 60: six ewes were sired by Lacaune ram
Page 61 and 62: FACTORS AFFECTING THE QUALITY OF EW
Page 63 and 64: Sheep Genetic factors breed and gen
Page 65 and 66: Genetic factors The breed and genot
Page 67 and 68: Physiological factors affecting she
Page 69 and 70: Management factors affecting the qu
Page 71 and 72: sheep with one peak of milk ejectio
Page 73 and 74: An important aspect of dietary fibr
Page 75 and 76: References Alais C. (1974). Science
Page 77 and 78: Bufano G., Dario C. and Laudadio V.
Page 79 and 80: Cowan R.T., Robinson J.J., McHattie
Page 81 and 82: Folman Y., Volcani R. and Eyal E. (
Page 83 and 84: Kalantzopoulos G. (1994). Influence
Page 85 and 86: McHattie I., Fraser C., Thompson J.
Page 87 and 88: Peart J.N. (1970). The influence of
Page 89 and 90: Ranieri M.S. (1993). La variazione
Page 91 and 92: Treacher T.T. (1970). Effects of nu
Page 93 and 94: EVALUATION OF SENSORY AND CHEMICAL
Page 95: ing, the cheeses were brined for 18
Page 99 and 100: Table 1. Composition of pasteurized
Page 101: Table 6. Body and texture scores 1
Page 104 and 105: Present Development of Selection Sc
Page 106 and 107: Breed Usage in Europe Crossbreeding
Page 108 and 109: nearly 1. As a consequence this cha
Page 110 and 111: Table 5. Repeatabilities and phenot
Page 112 and 113: percentage is not expected to resul
Page 114 and 115: Improved AI technique Artificial in
Page 116 and 117: Identifying major genes or QTL rela
Page 118 and 119: Figure 5. Half-sib families and QTL
Page 120 and 121: In the case of cheese the problem i
Page 122 and 123: Emanuelson, U., Danell, B., Philips
Page 124 and 125: Rothschild, M. F., Soller, M. (1997
Page 126 and 127: teat placement in dairy ewes (Fern
Page 128 and 129: that of the average milking time. M
Page 130 and 131: 1988) and active expulsion of fat f
Page 132 and 133: References Barillet, F., and F. Boc
Page 134 and 135: Table 1. Least squares means ± SEM
Page 136 and 137: Table 3. Simulation of parlor throu
Page 138 and 139: EFFECT OF REDUCING THE FREQUENCY OF
Page 140 and 141: Individual ewe milk production (mor
Page 142 and 143: dimanche soir sur les brebis de rac
Page 144 and 145: A B A Morning milk yield, kg B Adj.
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Background and History: Most sheep
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Percent 100 80 60 40 20 0 87 Effect
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Fall Lambing Percentage 100 90 80 7
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THE EFFECT OF GROWTH RATE ON MAMMAR
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After puberty, the mammary gland re
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Many trials have examined the mamma
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From these results the authors conc
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Onset of Puberty and Reproductive P
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Similarly, calves, heifers, and cow
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McCann, M. A., Goode, L., Harvey, R
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DISCUSSION Stability of Frozen Raw
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analyzed for titratable acidity, sy
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411-416. Wendorff, W.L. 1998. Updat
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Recent Outbreaks involving Cheddar
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testing on raw milk at the farm. Th
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THE AUSTRALIAN SHEEP DAIRY INDUSTRY
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The University of Western Australia
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Heterosis did not seem to intervene
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Lambs The problem of weaning lambs
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GROUP BREEDING SCHEME: A FEASIBLE S
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Where: h = square root of heritabil
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Second step. All members enroll in
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The structure and movement of anima
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CAN THE OVARY INFLUENCE MILK PRODUC
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dividing the amount of milk obtaine
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the CL there were significant diffe
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etween milkings. Finally, this woul
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Table 1. Least squares means ± SEM
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A Daily milk yield (kg) A B Milk fl
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Progesterone (ng/ml) 8 6 4 2 0 CLY:
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milk volume within the cistern (Mar
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Results Treatment milk yield increa
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Reports in dairy cattle concerning
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Muir, D.D., D.S. Horne, A.J.R. Law,
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Milk yield (kg) 1.4 1.2 1.0 0.8 0.6
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A Milk protein (%) A A Milk protein
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TAPPE FARM TOUR Jon & Kris Tappe, T
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a little special attention every da
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