Length-weight relationship of European catfish (Silurus glanis L.) fry reared at different stocking densities under controlled conditions

V. Krasteva*, M. Yankova

Institute of Fisheries and Aquaculture, 4003 Plovdiv, Bulgaria

(Manuscript received 14 October 2020; accepted for publication 18 January 2021)

Abstract. The present paper investigates the body length and weight, and the size-weight variations of one-month-old European catfish reared at 4 variants of stocking density: Variant 1 – 5 spec/l; Variant 2 – 10 spec/l; Variant 3 – 15 spec/l and Variant 4 – 28 spec/l. The experiment is carried out at the Institute of Fisheries and Aquaculture, Plovdiv for a period of 16 days, using a production system consisting of tubs with continuous water flow (0.7 l/min). At the end of the experiment, the fish from each variant are sorted in three size-weight groups: A – large, B – medium and C – small. The number of fish in each group is established. From the group of the medium- and small-sized fish, 150 speciments are measured, while from the group of the large specimens, which are the smallest in number, all specimens are measured for the biometric parameters body weight (BW, g) and total body length (TL, cm). The results from the study show small variations in the length and weight of the fish reared at the lowest stocking density (Variant 1). As the density increase, the size-weight differences between the specimens from Group A also increased, while of those from Group B they decrease. The number of the medium-sized fish decrease (p≤0.001) while the number of large specimens (p≤0.01) and small fish increase (p≤0.001).

Effect of Gmelina leaf meal diets on productive and physiological parameters of West African dwarf goats

P.C. Jiwuba1*, W.N. Amaduronye2, R.C. Akazue1

1Department of Animal Production Technology, Federal College of Agriculture, P.M.B. 7008, Ishiagu,
Ebonyi State, Nigeria.
2Department of Animal Breeding and Physiology, Michael Okpara University of Agriculture, Umudike, Nigeria

(Manuscript received 21 June 2020; accepted for publication 2 October 2020)

Abstract. West African Dwarf (WAD) goat plays an important socio-economic role, hence the effect of 82 days of feeding Gmelina leaf meal (GLM) diets on feed intake, body weight change and blood indices of WAD goats were investigated. A total of 36 WAD goats averaging 9.04 kg in weight were randomly divided into four groups of nine goats each with three goats constituting a replicate. The groups were randomly assigned four experimental diets (T1, T2, T3, and T4, containing GLM at 0%, 12%, 24% and 36%, respectively) in a completely randomized design. Results indicated significant (p<0.05) improvement for body weights and feed conversion ratio for T2, T3, and T4. There was significant difference (p<0.05) for all the haematological parameters except packed cell volume (PCV). White blood cells (WBC) increased in their number (p<0.05) with incremental levels of GLM in the diets. All the serum biochemical indices showed significant (p<0.05) difference with glucose and cholesterol concentration reduced (p<0.05) with incremental levels of GLM. It could be concluded that GLM can be included in the diets of goats up to 36% without deleterious effects on the productive and physiological indices of WAD goats.

Characterization of testicular and epididymal parameters in Algerian Arabia bucks

N.A. Ouchene-Khelifi*, N. Ouchene, A. Dahmani

Institute of veterinary sciences, Saad Dahlab University Blida 1, Road of Soumaa, BP 270, Blida-09000, Algeria

(Manuscript received 20 June 2020; accepted for publication 24 September 2020)

Abstract. In goat production, the reproductive efficiency of bucks must be taken into account. Testicle size is the most appropriate parameter to directly improve the reproductive performance of females. In this study, body weight (BW), body condition score (BCS) and testicular and epididymal parameters of Arabia goats were studied. A total number of 200 bucks wеre randomly selected and classified into three age categories (6-12 months, 13-24 months and >2 years). BW, BCS, mean scrotal circumference, testicular volume, testicular diameter, testicular length, testicular weight, testicular density, epididymal weight, epididymal length, epididymal tail length, caput weight, corpus weight, caudal weight, Gonadosomatic Index, Epididymosomatic index and Epididymal-Testicular weight ratio were measured. A highly significant correlation was found between all parameters (p<0.05). The values of all parameters increased significantly with age, with the exception of the gonadosomatic and epididymosomatic indices, which decreased with age (p<0.05). These results provide data that can be used to anticipate an adequate ante-mortem sperm reserve based on testicular size in the preliminary selection of breeding males from the local sexually mature population.