Effect of milking frequency and nutritional level on aspects of the health and welfare of dairy cows

Abstract

The objective of this experiment was to investigate the effect of milking frequency and nutritional level on some aspects of animal health. Holstein-Friesian cows (n ¼ 60) were assigned post calving to a factorial arrangement of treatments; twice a day (TAD) milking on a high or low nutritional level; once a day (OAD) milking on a high or low nutritional level. Milking characteristics were recorded daily. Blood samples to evaluate changes in the composition of the blood cells, milk leakage, udder tension and locomotory ability were measured on four occasions. Teat-ends were classified for hyperkeratosis (HK) monthly post partum. TAD had longer daily milking times (P , 0.001) compared with OAD cows. There was no effect of milking frequency or nutritional level on morning milking time, time to milk letdown or peak milk flow rate (P . 0.05). High nutritional level cows had higher average flow-rates (P , 0.05) than low nutritional level cows. Neither milking frequency nor nutritional level affected HK (P . 0.05). However, HK values were positively correlated with daily milking time for OAD cows for 6 months of lactation (P , 0.05). This correlation was significant (P , 0.01) for cows milked OAD on high nutrition during the peak lactation period. OAD cows had higher levels of milk leakage compared with TAD cows during the month of May (P , 0.01). Cows on high nutrition milked OAD showed higher udder firmness scores than cows milked once or twice daily at the low nutrition level in June and July (P , 0.05). OAD cows had higher locomotion scores compared with TAD cows (P , 0.001). Locomotion and udder firmness scores were significantly correlated for OAD in June (P , 0.05). OAD cows had lower blood lymphocyte counts, numerically higher counts of neutrophil and a higher monocyte count at peak lactation compared with TAD cows suggesting that OAD cows had altered immune responses. The increase in milk leakage, higher udder firmness and locomotion scores in conjunction with changes in blood cells, suggests that OAD milking may have caused some discomfort to the cows during peak lactation. A reduction in the concentrate input to OAD cows during this period could ameliorate this problem.

Management factors and cow traits influencing milk somatic cell counts and teat hyperkeratosis during different seasons

“…Teat-end condition deteriorated during lactation; this is partially in contrast with the observations of other authors Gleeson et al, 2007) who reported an increase in teat-end callosity until 4-5 months of lactation and a decrease thereafter.…”

Teat End Condition and Hyperkeratosis at Different Lactation Periods

“…This is presumably due to the increased frequency of milking. Results are similar to the research results of [3]; [6] which states that changes in teat end condition of dairy cattle in older lactation are worse than dairy cow in earlier lactation. Associated with [7] theory which stated that cattle are said to be in a problem if more than 20% of cattle have teat end with rough keratin ring or more than 10% with very rough keratin ring, therefor by looking at Table 1 it can be said that dairy cattle at sixth and seventh lactation faces problems.…”

Milking frequency affects the circadian body temperature rhythm in dairy cows

“…Finally, as there was no difference in the concentration of glucocorticoid metabolites in the faeces with milking frequency before or after the switch, nor any changes in behaviour indicative of discomfort , it is unlikely that the contrasting circadian body temperature rhythms in cows milked 2x or 1x could be interpreted as a sign of physiological stress per se. Other groups have found more lameness and udder firmness early in 1x lactation (Gleeson et al, 2007), and it could be useful to look at body temperature early in lactation or in cows producing more milk, both situations when discomfort might be a greater risk.…”

“…Cows milked 1x accumulate a large volume of milk in their udder over 24 h (Davis et al, 1999), which may result in udder distension and compromise their comfort as found at peak lactation by Gleeson et al (2007). Our objective was to investigate milking frequency as a potential physiological stressor in dairy cows milked 2x and 1x at peak lactation, and in response to a change from 2x to 1x at mid-lactation.…”