الفهرس 
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Abstract
This study was conducted in three different farms in Beni-Suef governorate during the period from December 2010 to March 2012 to investigate the effect of some managerial practices on milking performance and cows’ behaviour.
Effect of pre-milking preparation techniques on milking performance and somatic cell count of dairy cows during early lactation in the three examined farms
The results of this study revealed that milking without udder preparation lead to a significant decrease in the milk yield/ milking (8.40 and 9.15kg) in farm I and farm II respectively, significant increase in the milking time (6.56 min.) in farm I, significant decrease in the average milk flow rate (1.61 and 1.22 kg/min.) in farm I and farm II respectively, significant increase in the amount of residual milk (3.45 kg) in farm II and significant increase in the milk SCC (49.44 and 52.36 x104 cells/ml) in farm I and farm II respectively
Moreover, the pre-milking oxytocin (OT) injection cause significant increase in milk yield/milking (12.74 and 12.65 kg) in farm I and farm II respectively, significant decrease in milking time (3.93 min.) in farm I only, significant increase in the average milk flow rate (3.06 kg/min. and 2.49 kg/min.) in farm I and farm II respectively, significant decrease in the amount of residual milk (0.28 kg) in farm II only and significant increase in the milk SCC (39.44 and 45.36 x104 cells/ml) in farm I and farm II respectively.
Furthermore, there wasn’t a significant difference in the milking performance and udder health between different duration of pre-milking preparation and intervals till teat cup attachment in both farm I and farm II except after 3 min. attachment delay which cause significant decrease in the milk yield/milking in farm I (8.67 and 8.44 kg) in case of short preparation and long preparation respectively, and also in farm II (9.35 and 9.65 kg) in case of short preparation and long preparation respectively.
Conversely, in the farm III there was no significant difference in the milking performance between different pre-milking udder preparation techniques, but the milk SCC was significantly increased (52.41x104 cells/ml) in cows milked without pre-milking udder preparation.
Effect of pre-milking preparation techniques on milking performance and somatic cell count of dairy cows during late lactation in the three examined farms
Milking without prestimulation in farm I resulted in a significant decrease in the milk yield/milking (6.00 kg), significant increase in the milking time (10.80 min.), significant decrease in the average milk flow rate (0.60 kg/min.) and a significant increase in the milk SCC (53.51 x104 cells/ml). Moreover, long preparation and 1.5 min attachment delay cause a significant increase in the milk yield/milking (9.45kg), significant decrease in milking time (4.10 min.) and significant increase in average milk flow rate (1.55 kg/min.) in this farm.
On the other hand, there wasn’t any significant difference in the milking performance between different pre-milking udder preparation techniques in farm II and farm III, but no pre-milking preparation cause a significant increase in milk SCC (52.46 and 56.58 x104 cells/ml) in farm II and farm III respectively.
Effect of different milking systems on milking performance, somatic cell count and milk cortisol level of dairy cows during early and late lactation.
There was a significant decrease in daily milk yield (13.10 and 10.30 kg) and milk yield/milking (6.25 kg and 5.15 kg), significant increase in the milking time (7.85 and 6.39 min.), significant decrease in the average milk flow rate (0.93 and 0.93 kg/min.) in early and late lactation respectively and significant increase in the amount of residual milk (1.88 kg) in early lactation. While the increase in the milk SCC (39.16 x 104 cells/ ml) was recorded only in early lactation in hand milked cows as compared with both machine milked groups (either parlor or portable machine milking).
Despite this significant decrease in the daily milk yield of hand milked cows the significant increase in the milk SCC, it was accompanied with a significant decrease in the milk cortisol level (2.21ug/dl) as compared with the other two machine milking systems.
Moreover, by comparing the two machine milking systems, the obtained results showed that parlor milking cause a significant increase in the daily milk yield (27.90 and 17.00kg), significant decrease in milking time (4.85 and 4.55 min.), significant decrease in the average milk flow rate (1.63 and 1.26 kg/min) in early and late lactation respectively and a significant decrease in the milk SCC (29.73 x104 cells /ml.) in early as compared with portable machine. Additionally, there was no significant difference in the milk cortisol level between the two machine milking groups.
additionally, there wasn’t a significant difference in the milk yield/milking either in early or late lactation, the amount of residual milk and milk SCC in late lactation between parlor and portable machine milking.
Effect of different milking systems on cow behaviour during milking
There was a significant decrease in the incidence of step behaviour (1.38 no/head), kick behaviour (1.05 no/head) and scraping behaviour (17.09 %) in hand milked cows as compared with both machine milked groups, but they show significant increase in the incidence of bellowing behaviour (9.16 %) during pre-milking udder preparation. Furthermore, there was no significant difference in the incidence of pawing and lip licking behaviours between the three groups.
Hand milking resulted in a significant decrease in the incidence of step behaviour (0.73 no/head) as compared with both machine milking. Moreover, hand milked cows continue in exhibiting a significant increase in the incidence of bellowing behaviour (6.25 %) during main milking. Additionally, there was no significant difference in the incidence of the other behavioural patterns between the three groups.
During final milking, there wasn’t any significant difference in the incidence of kick, scraping, pawing and lip licking behaviour patterns between the three groups, except for the bellowing behaviour in which hand milked cows show significant increased incidence of this behavioural pattern (3.13 %).
Effect of milking frequency on milking performance and somatic cell count of dairy cows in early and late lactation
Milking cows three times daily resulted in a significant increase in the daily milk yield (27.90 and 17.00 kg), significant decrease in milking time (4.49 and 4.55 min) and a significant increase in the average milk flow rate (1.63 and 1.26 kg/min) in early and late lactation respectively as compared with twice daily milking of cows which had daily milk yield, milking time and average milk flow rate values of (21.20 and 13.78kg), (6.68 and 5.58 min.) and (2.16 and 2.02 kg/min) in early and late lactation respectively. Moreover, cows milked trice/day had a significantly lowered milk SCC (29.73 x 104 cells/ml) as compared with those milked twice (34.53 x104 cells/ml) in early lactation.
In addition, there was no significant difference in the milk yield/milking in early or late lactation and in the amount of residual milk in early lactation between cows milked twice and those milked thrice.
Effect of milking frequency in the first week of lactation on calcium, phosphorous and glucose levels, phagocytic activity of neutrophils, average daily milk yield and somatic cell count of dairy cows
There was a significant increase in the calcium, phosphorous and glucose level of once-a-day (OAD) milking group as compared with (twice-a-day) TAD milking group in the treatment period and in the following 11 weeks of lactation.
There was no significant difference in the phagocytic activity of neutrophils between OAD milking group and TAD milking group. Moreover, there was no significant difference between both groups in the average daily milk yield during the treatment period and over the following 11 weeks of lactation.
The milk SCC was significantly increased in OAD milking group in the treatment period (1st week of lactation) (25.76 x104 cells/ml) as compared with TAD milking group (17.13 x104 cells/ml); moreover there was lack of significance in the following 11 weeks of lactation.
Effect of parity on calcium, phosphorous and glucose levels, phagocytic activity of neutrophils, average daily milk yield and somatic cell count of dairy cows
The blood levels of calcium, phosphorous and glucose wasn’t significantly different between primiparous and multiparous cows over 12 weeks of lactation except of higher calcium level of Primiparous cows in the period from 9-12 week postpartum (10.18 mg/dl) as compared with multiparous cows (8.92 mg/dl).
There was no significant difference in the phagocytic activity of neutrophils and average daily milk yield between primiparous and multiparous cows. Moreover, multiparous cows had a significant increased milk SCC (24.51 x104cells/ml) as compared with primiparous cows (19.31 x104 cells/ml).