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Restriction in energy or protein affects differentially behavior of lactating dairy cows
Feed restriction adversely affects feeding and social behavior in cattle. However, data on the effects of nutrient composition on these characteristics are limited. The objective was to quantify the effects of dietary energy and protein restriction on feeding and behavior in lactating Holstein and Jersey cows. Twelve cows in mid-lactation balanced for breed and days in milking were used in a Latin square design: 3 cows x 3 periods. Each experimental period lasted for 3 weeks and consisted of (1) adaptation, where all animals were fully fed according to their requirements, (2) restriction, where animals were fed to provide 50% of their daily energy and protein requirements, and (3) treatment, where animals were fed with one of the following diets: 100E+P, 50E+100P and 100E+50P, to provide 100% of energy + protein requirement, 50% of energy requirement, 50% of protein requirements, respectively. On the last day of the treatment period, cows were visually observed from 6 am to 9 pm. The behavioral attributes were recorded as time spent in feeding behavior and number social and adaptation events. Data were logarithmic transformed and submitted to analysis of variance considering main effects of diet, cow and period. Nutrient restriction did not change feeding and ruminating times or aggressive interactions. Energy restriction reduced time spent lying but increased tongue curling and licking events. Protein restriction reduced idling time, number o low intensity vocalizations and tended to reduce standing time. The data are consistent with the concept that cows react differently to limitations in energy or protein in the diet.
Attribute |
Diet |
P>F diet |
RSD (%) |
||
|
100% E+P |
50%E+100%P |
50%P+100%E |
|
|
Eating (min) |
276.1 |
254.1 |
278.7 |
ns |
2.2 |
Ruminating (min) |
116.6 |
129.1 |
145.2 |
ns |
6.7 |
Idling (min) |
243.1 a |
243.7 a |
182.6 b |
0.0094 |
4.3 |
Lying (min) |
203.7 ab |
176.6 b |
243.7 a |
0.0381 |
5.1 |
Standing (min) |
169.8 d |
130.0 de |
87.7 e |
0.0615 |
12.6 |
Aggressing (n°) |
0.9 |
1.6 |
2.9 |
ns |
300.6 |
Being aggressed (n°) |
1.9 |
1.2 |
1.6 |
ns |
257.7 |
Vocalizing (n°) |
0.5 a |
0.3 ab |
0.1 b |
0.0440 |
93.5 |
Licking the floor (n°) |
0.1 b |
1.7 a |
0.5 ab |
0.0271 |
217.0 |
Curling the tongue (n°) |
0.1 b |
0.2 a |
0.1 b |
0.0279 |
15.6 |
a,b means in the same row are different (lsmeans, DMS test, P<0.05).
d,e means in the same row tend to be different (lsmeans, DMS test, P<0.10).
RSD: relative standard deviation
Keywords: behavior, nutrient, restriction