Abstract #M469

# M469
Calcium and phosphorus accretion rate in Saanen goat kids of different genders.
José Maurício dos Santos Neto*1, Kléber Tomás de Resende1, Márcia Helena Machado da Rocha Fernandes1, Izabelle Auxiliadora Molina de Almeida Teixeira1, Julian André Castillo Vargas1, Ana Rebeca Castro Lima1, Fernanda Oliveira de Miranda Figueiredo1, Rafael Fernandes Leite1, Paula Fernanda Varella dos Santos1, Carolina Isabel Soriano Oporto1, 1São Paulo State University (Unesp), Jaboticabal, São Paulo, Brazil.

Calcium (Ca) and phosphorus (P) constitute an essential part of goat diets, being necessary for adequate growth and physiological function; however, studies about their accretion rate in goats are still scant, especially regarding the differences among genders. In this sense, we evaluated and compared the Ca and P accretion rate in intact males, castrated males and females, weighting from 15 to 30 kg of body weight (BW). We used 58 Saanen goat kids (20 intact males, 20 castrated males and 18 females) fed ad libitum and housed in individual pens, with an initial BW of 15.85 ± 0.11 kg. The diet consisted of 45% forage (dehydrated corn plant) and 55% concentrate. The animals of different genders were assigned in a completely randomized design and slaughtered at 16.6 ± 0.40 kg BW, 23.1 ± 1.33 kg and 31.2 ± 0.58 kg BW. Allometric equations used to calculate the relationships between macromineral quantities and empty body weight (EBW) were generated and compared among genders by NLINMIX procedure (SAS Institute Inc., Cary, NC 9.4). The Ca and P accretion rate were estimated by the first derivative of these allometric equations. The Ca and P accretion rate did not differ among genders (P > 0.05) and decreased from 11.04 to 11.01 g of Ca and from 6.96 to 5.98 g P per kg of EBW gain, when kids grown from 15 to 30 kg BW, respectively. Because Ca and P mostly concentrate in skeletal tissue, absence of difference may indicate that bone development in Saanen goats are similar among genders, and presumably, those animals have reached bone maturity early in life.

Key Words: body composition, comparative slaughter, macromineral