Evaluation of dietary calcium requirements for laying Longyan shelducks

Abstract

To establish the dietary Ca requirements for laying ducks during their peak laying period, 5 Ca levels (2.8, 3.2, 3.6, 4.0, and 4.4%) were used, and laying performance, eggshell quality, serum variables, and bone quality were examined. A total of 1,620 Longyan shelducks with similar BW at 20 wk of age were fed for 13 wk in 5 treatment groups, each with 4 replicates of 81 birds. Dietary Ca increased egg production and egg mass (linear, P<0.01) and reduced the feed conversion ratio (FCR), but egg weight was not affected. Dietary Ca level did not affect eggshell properties or any reproductive organ index except for shell weight (highest with the 4.0% Ca diet, P<0.05). Serum concentrations of Ca and calcitonin increased with dietary Ca level (linear, P<0.01), and a quadratic response (P<0.01) was seen in alkaline phosphatase activity; the highest values were in ducks fed the 3.6% Ca diet. Tibial fresh weight was affected by dietary Ca (linear and quadratic, P<0.05) with tibiae from the 2.8% Ca ducks weighing less than those from ducks fed any other Ca level. Other tibial measurements were unaffected by dietary Ca. According to the regression model, the Ca levels required for laying Longyan shelducks during their peak laying period are 3.4 and 3.2% for maximal serum alkaline phosphatase activity and tibial fresh weight, respectively. The results showed that diets containing 3.2 to 3.6% Ca provide for superior productive performance and bone quality in laying Longyan shelducks during their peak laying period.

Nutritional requirements of meat-type and egg-type ducks: what do we know?

“…In White Pekin and Mule ducks, Ca deficiency can lead to rickets, low growth rate, low feed utilization, and a high mortality rate [ 35 , 36 ]. Xia et al [ 37 ] estimated the Ca requirements of Longyan laying ducks, from 20 to 33 wk of age, and recommended formulating diets containing 3.6% Ca with 0.40% available P to maximize egg production, egg mass, feed utilization, and enhance the bone characteristics. In addition, 0.806% Ca plus 0.403% non-phytate phosphorus and 0.796% Ca plus 0.379% non-phytate phosphorus were recommended to attain the highest daily weight gain and lowest FCR, respectively, in White Pekin ducks during the first 3 wk of age [ 38 ], whereas 0.72% Ca plus 0.37% non-phytate phosphorus were suggested to optimize daily weight gain from 3 to 6 wk of age in White Pekin ducks [ 39 ].…”

Calcium Intake Level as Factor of Influencing of the Eggshell Qualities in Laying Hens

“…On the other hand, Moreki et al (2011) showed that the shell weight and eggshell percentage increased when the diet calcium level increased from 1.5 to 2.5%, without data on the effects of other diet calcium levels on the same eggshell properties. In laying Longyan shelducks, different dietary calcium levels (2.8, 3.2, 3.6, 4.0, and 4.4%) did not affect eggshell properties or any reproductive organ index except for shell weight (Xia et al, 2015). This fact brings into question the species-dependence effects of diet calcium levels.…”

“…An increase of egg production was also reported by Sultana et al (2007) in Japanese quail fed on a 3% calcium diet vs. quail fed on 2.5 or 2.75% calcium enriched diets. Xia et al (2015) reported an increase in egg production and egg mass in Longyan shelducks fed on 2.8, 3.2, 3.6, 4.0, and 4.4% calcium-enriched diets. In contrast, Moreki et al (2011) reported increase of egg production (P < 0.0001) in broiler breeder hens from 36 to 60 weeks of age when dietary calcium was increased from 1.5% to 2.5% but no significant (P>0.05) differences were found in this variable in diets containing 2.5 and 3.5% calcium levels, the consecutive decrease of the protein and energy contents in these last diets being considered the reason.…”

The effects of dietary Se on productive and reproductive performance, tibial quality, and antioxidant capacity in laying duck breeders

“…The Longyan duck is a popular laying breed in China; originally, it is produced from crossing between the Longyan breed, Putian Black breed, and Putian White breed ( Lin et al., 2014 ). In southern China, more than 300 million birds are raised from such breed, producing around 80 billion eggs per year, with an average adult BW of 1.5 kg and 280 to 300 eggs per duck yearly ( Xia et al., 2015 ). Over the past 10 y, our group has been estimating nutrient requirements for the layers and breeders of Longyan duck breed, including CP, ME, amino acids, vitamins, and minerals ( Chen et al., 2015 , Xia et al., 2015 , Xia et al., 2019a , Xia et al., 2019b ).…”

“…In southern China, more than 300 million birds are raised from such breed, producing around 80 billion eggs per year, with an average adult BW of 1.5 kg and 280 to 300 eggs per duck yearly ( Xia et al., 2015 ). Over the past 10 y, our group has been estimating nutrient requirements for the layers and breeders of Longyan duck breed, including CP, ME, amino acids, vitamins, and minerals ( Chen et al., 2015 , Xia et al., 2015 , Xia et al., 2019a , Xia et al., 2019b ). As part of a systematic program for optimizing the performance of the highly productive laying duck breeders, this study aimed to estimate the optimal level of dietary Se, testing 6 graded levels, for maximal egg production, fertility, hatchability, tibial quality, and antioxidative status in Longyan duck breeders.…”