Effect of Long Daily Photoperiod on Milk Production of Dairy Goat
Date Issued
2006
Date
2006
Author(s)
Jen, Wei-Ping
DOI
zh-TW
Abstract
The long daily photoperiod (LP) has been proved to enhance dairy cattle production including growth and lactation through increasing the concentration of plasma IGF-I. However, its effect on dairy goat, a seasonal breeder, was unclear. In this study, we intended to elucidate the effect of long daily photoperiod on milk production of dairy goat. Ten multiparous and three primiparous Alpine dairy goats were evenly assigned to LP (16 h lighting per day, 0400 - 2000) or natural daily photoperiod (NP) according to parity, kidding date, and body condition. Light intensity was set more than 600 lux at goats’ eyes level. The experiment lasted for 22 weeks after kidding from Feb to Aug, 2005. Same diet, meeting nutrient recommendation for lactating dairy goat by NRC, was offered to both groups. Goats were milked twice daily, and offered half of daily ration after each milking. Milk, feed, and refusal were weighted and sampled on last two days each week. Results showed that LP had no effect on lactose and milk fat concentrations and raw milk total bacterial number (P > 0.05). The average concentration of plasma IGF-I was increased by LP treatment (P < 0.05). Milk yield on weeks 6 and 7 tended to be increased by LP (3.74 vs. 2.24 kg/d; 3.76 vs. 2.54 kg/d; P < 0.10). The 4% fat corrected milk (FCM) response was similar to milk yield. The LP treatment increased IGF-I, FCM and feed intake by 25.5%, 34.7% and 41.4% on average, respectively. In conclusion, photoperiod is an effective method to improve dairy goat production.
Subjects
乳山羊
延長光照
乳產量
Dairy goat
Long daily photoperiod
Milk production
Type
thesis
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