الفهرس 
Impact of herd management on milk productionOnly 14 pages are availabe for public view
 |  | from | 140 |  |  |
| | | from | 140 | | |
Abstract
This study was conducted on 779 Holstein Friesian cows including 2 lactations belonging to El-Bayoumi dairy farms in Gamasa, Dakahila Governorate. Data were collected within the period between January 2016 to December 2016.
All Cows were fed on a mixture of TMR (Total Mixed Ration)
throughout the year with an emphasis on the quality of the feed materials involved in the mix. Feeds consisting of corn silage, hay and concentrate.
Cows were vaccinated regularly against Foot and mouth disease (FMD) every 4 months, Lumpy skin disease (LSD) every 6 months, 3 days sickness annually, Cattle master (IBR- PI3- BVD) every 6 months and Clostridia every 6 months.
All cows were housed in10 loose half shaded barns with clayey bedding and cooling systems (water spray and ventilators). Barn area reach 2340m2(78m length x 30m width) with 30m2 available space per cow. Barn cleaning out fulfilled monthly in summer and weekly in winter using loader, tractor and trailer
The main objective of this study was to investigate the effect of herd management criteria on milk yield (daily milk yield and 305DMY), milk hygiene (SCC, SPC and EC) and milk composition (daily fat, casein, whey protein and lactose yield).
The results can be summarized as following :
1- Influence of Herd management criteria on milk production a- Parity has a significant effect on daily milk yield and 305day milk yield whereas daily milk yield and 305DMY was lower in the first lactation 29.3 ± 0.2 kg/cow/day and 8948.5 ± 80 kg / 305DMY, respectively and then increase with advanced parities that reach in the maximum production in the third parity 31.9±0.5 kg/cow/day and 9753.7 ± 154 kg/305 day milk.
b- Cow cleanliness score has a highly significant effect on daily milk yield and 305DMY whereas daily milk yield for cows with clean score and dirty score were 30.58 ± 0.02 and 27.7 ± 0.1 kg, respectively. Also 305DMY were 9326.9 ± 111 and 8448.5 ± 126 kg for clean and dirty score, respectively.
c- overstocking management have a negative consequence on daily milk yield and 305DMY whereas daily milk yield for high density stocked cows (10-30 m2 /cow) decreased in daily milk yield by 20.2 kg milk compared with low density stocked cows (31-50 m2 /cow). Furthermore, 305DMY for high density stocked cows (10-30 m2 /cow) decreased by 66606
compared with low stocked cows (31-50 m2 /cow). Managing overstocking cows will be decrease the space for each cow in feeding trough which could be lead to decreasing feed intake and subsequently decrease milk yield.
d- Feeding regime has a highly significant effect (P<0.001) on daily milk yield and 305DMY whereas daily milk yield for cows with feeding regime in winter and summer were 31.8 ± 0.2 and 27.9 ± 0.2 kg ,respectively and 305DMY were 9712.2±120 and 8511.3±120 kg, respectively. Feeding components were different in winter than summer whereas food intake, kind and quality of fodder and the green feed was higher in winter than summer which leaded to producing high milk.
e- Three milking shifts were applied in the farms studied. There was no significant difference between milker’s shifts in daily milk and 305DMY. Whereas dairy milk yield for cows that milked by milker’s shifts (A, B and C) were 30.3± 0.1, 30.1 ± 0.5 and 29.9 ± 0.2 kg milk respectively. On the other hand 305DMY were 9241.5 ± 89, 9180.5 ± 102 and 9119.5 ± 113 kg milk, respectively.
f- All interactions within criteria studied on milk production were highly significant (P<0.001) except that between cow cleanliness score x parity which was only significant (P<0.005). It is obviously clear that the influence of all criteria studied interacting together on milk production. Managing such criteria are very difficult and complicated. Manager should be carefully handle with those criteria as an integrated task and not as individual one. The negative influence of overstocking on milk production was lower in winter than in summer. On the other hand feeding regime and cow cleanliness score interact highly significant (P<0.001) on daily milk yield and 305 DMY. Furthermore the interaction between feeding regime and parity interact highly significant (P<0.001) on daily milk yield and 305 DMY.