Simplification of the growth recording protocol for meat sheep applied in Morocco

Document Type : Original Research Article (Regular Paper)

Author

Institut Agronomique et Vétérinaire Hassan II, PO Box 6202, Rabat-Instituts, 10101 Rabat, Morocco

Abstract

The study aimed to simplify the actual sheep weight recording protocol used in Morocco that is based on weighing lambs at four different intervals of 21 days. The study was simulated using the weights of 1554 Timahdite lambs, born between 2008 and 2012 in four state farms. Nine simplified protocols were applied,,based on constant birth weight for all lambs or according to their type of birth and sex and number of weighings to be carried out. Comparison between the standard weights at 30, 70 and 90 days, calculated using the actual and simplified protocols, was based on the average bias, mean squared error and accuracy loss. Moreover, direct and maternal heritability estimates of the standard weights, calculated using the actual and simplified protocols, were compared. Similarly, the Spearman correlation coefficients between sheep rankings on the direct genetic indexes and correlation coefficients between sheep rankings on the maternal genetic indexes for weight at 30, 70 and 90 days, estimated using the actual protocol and each of the simplified protocols, were calculated. Based on these criteria, the closest standard weights’ estimation to those of the actual protocol was performed using protocols based on constant birth weight for all lambs or according to their type of birth and sex, and two controls at 42 and 84 days or three controls at 42, 63 and 84 days, with only lambs more than 21 days old being weighed at each control. It was concluded that ignoring one or two controls out of the four currently practiced would not alter the shape of the lambs' growth curve and would allow standard weights to be estimated without much loss of accuracy.

Keywords

Main Subjects

References

References
Ait Bihi, N., Boujenane, I., 1997. Contrôle de performances des ovins en milieu difficile : Cas du Maroc. Options Méditerranéennes, Série A 33, 11-34.
Atoui, A., Carabano, M.J., Abdennebi, M., Najari, S., 2020. Impact of simplified methods of growth recording on genetic parameter estimates of Tunisian local goat population under a low input production system. Italian Journal of Animal Science 19 (1), 222-229.
Ben Gara, A., Rouissi, H., Jurado, J.J., Bodin, L., Gabina, D., Boujenane, I., Mavrogenis, A.P., Djemali, M., Serradilla, J.M., 1997. Etude de la simplification du protocole de pesées chez les ovins à viande. Options Méditerranéennes, Série A 33, 11-34.
Ben Hamouda, M., Rekik, M., 2012. Contrôle de croissance des ovins allaitants en Tunisie. II. Perte de précision sur le calcul des performances à âge type selon un protocole simplifié alternatif au protocole officiel. Revue d’Elevage et de Médecine vétérinaire des Pays tropicaux 65, 41-47.
Boggess, M.V., Wilson, D.E., Rothschild, M.F., Morrical, D.G., 1991. National sheep improvement program: Age adjustment of weaning weight. Journal of Animal Science 69, 3190-3201.
Boldman, K.G., Kriese, L.A., Van Vleck, L.D., Van Tassell, C.P., Kachman, S.D., 1995. A Manual for Use of MTDFREML. A Set of Programs to Obtain Estimates of Variances and Covariances. USDA/ARS, Washington, DC, USA (Draft).
Boujenane, I., 2006. Reproduction and production performance of Moroccan sheep breeds. CAB Reviews: Perspectives in Agriculture, Veterinary Science, Nutrition and Natural Resources 1 (014), 18.
Boujenane, I., 2022. Comparison of nonlinear models for describing the pre-weaning growth of Timahdite lambs and genetic and non-genetic effects for curve parameters. Small Ruminant Research 216, 106800.
Boujenane, I., Kansari, J., 2002. Estimates of (co)variances due to direct and maternal effects for body weights of Timahdite sheep. Animal Science 74 (3), 409-414.
Boujenane, I., Ait Bihi, N., Boukallouche, A., 1995. Amélioration génétique des ovins au Maroc. Options Méditerranéennes 11, 109-119.
Gonzalo, C., Othmane, M.H., Fuertes, J.A., De La Fuente, L.F., San Primitivo, F., 2003. Losses of precision associated with simplified designs of milk recording for dairy ewes. Journal of Dairy Research 70, 441-444.
Kaps, M., Lamberson, W., 2004. Biostatistics for Animal Science. CABI Publishing, Mongewell, Wallingford, UK.
Naves, M., Menendez Buxadera, A., Alexandre, G., Mandonnet, N., 2001. Etude comparative sur la méthodologie d’estimation des poids à âges types avant sevrage appliquée aux caprins Créoles producteurs de viande. Revue d’Elevage et de Médecine vétérinaire des Pays tropicaux 54, 81-87.
Perret, G., Bibé, B., 1979. L’amélioration de la croissance et son contrôle chez les agneaux. In: 5èmes Journées de la recherche ovine et caprine: l’amélioration génétique des espèces ovine et caprine. Paris, France, INRA/ITOVIC, pp. 386-402.
Ricordeau, G., Boccard, R., 1961. Relation entre la quantité de lait consommé par les agneaux et leur croissance. Annales de Zootechnie 10(2), 113-125.
SAS, 2002. SAS User’s Guide, Version 9.2: Statistics. SAS Institute Inc., Cary, NC.
Tiphine, L., Bouix, J., Poivey, J.P., 2005. Proposition d’allègement du contrôle de performances en ovins allaitants. In: Proceedings 12èmes Rencontres Recherches Ruminants, Paris, France, 7-8 décembre 2005, pp. 349.

Files

Share

How to cite

Statistics