Researcher H. Mazzuco at the institute, Embrapa Suínos e Aves at Concórdia in the Brazilian state of Santa Catarina and colleagues there and at Universidade Regional Integrada at Erechim in the state of Rio Grande do Sul have compared different methods of moulting laying hens and published their paper in the December 2011 issue of Poultry Science.

They explain that the purpose of their study was to evaluate alternative moulting protocols, assessing hen welfare and performance during and after moult.

Hyline W-36 pullets were housed at 15 weeks of age and their egg production was obtained during this first cycle.

When birds were 80 weeks old, one of the the following moulting treatments was applied:

• a conventional moult consisting of 10 days of fasting, followed by cracked corn for eight days and a pullet developer diet for 10 days

or one of four alternative moulting programmes:

• a soy hulls-based diet (12 per cent crude protein; 1,455kcal per kg of metabolisable energy and 1.38 per cent calcium) offered for 14 days followed by cracked corn for four days and a pullet developer diet for 10 days
• and three other moult regimens consisted of feeding soy hulls for four, eight or 12 days, followed by 10, six or two days, respectively, of a soy hulls-based diet and four days of cracked corn plus 10 days of a pullet developer diet.

A non-moulted group of birds was fed a laying hen diet during the experimental period.

Hen-day egg number was recorded daily for 56 weeks (between 80 and 136 weeks of age).

The researchers found that non-moulted hens laid fewer eggs (lower hen-day production) and fewer intact eggs and a higher number of cracked and shell-less eggs than the moulted hens (P<0.0001).

A significant treatment × age effect (P<0.0001) was observed for the variables of high-density lipoproteins and triglycerides. Control hens showed the lowest high-density lipoprotein concentration and the highest triglyceride levels at 84 weeks of age.

The lack of difference in heterophil-to-lymphocyte ratio during moult suggests little influence of moulting protocols on this variable, report Mazzuco and co-authors.

Regardless of the treatments, moulting was deleterious to bone quality. A high mobilisation of calcium through bone resorption for eggshell formation could explain the results obtained. Behavioural patterns coincided with a decline in frustration activities and an increase in alertness as moult proceeded until 83 weeks of age.

Mazzuco and co-authors concluded that alternative moulting diets consisting of soybean hulls were successful in providing acceptable post-moult egg production performance.

Reference

Mazzuco H., V.S. Avila, A. Coldebella, R. Mores, F.R.F. Jaenisch and L.S. Lopes. 2011. Comparison of the effect of different methods of molt: Production and welfare evaluation. Poultry Science, 90 (12): 2913-2920. doi: 10.3382/ps.2011-01670

Further Reading

-

You can view the full report (fee payable) by clicking here.

January 2012