چكيده لاتين :
The effects 0f transhumance on body growth and adaptation parameters in the Baladi goat, and testicular activity in bucks were studied over a period of one year. Thirty
two animals were allocated to 4 similar groups according to age (l00 days for 8 male and 8
female kids, and 3-4years for 8 bucks and 8 does) and sex. Goats were raised in a coastal
pasture area for the winter period (WP), then transhumed towards a mountainous area in
May for the summer period (Sp) . Every 21 days, animals were weighed and monitored for a
whole day to estimate the distance travelled; four does and four bucks were followed for two
successive days to evaluate the nature of the plants grazed by direct observation. Four
summer and two winter collections of these plants were subjected to proximate analysis;
Respiration and heart rates were recorded every two hours between 6:00 a.m. and 6:00 p.m.;
Testicular volume and semen quality were also measured. Animals traveled 1km/h in summer
period and 0.8 km/h in winter. Herbaceous plants formed 95% of the plants grazed in SP and
ligneous plants formed the majority of the plants ingested (80 to 95%) in WP. Protein
percentages decreased from 15.2 to 8,6% between the beginning and the middle of the SP
whereas it was around 11% in WP. Weight gain was greater during SP in comparison to WP
except for bucks (12, 7,6, 4.2 and -3.3 kg vs. 3.4, 1.8, - 7, 5 and 3.3 kg for male and female goat
kids, does and bucks, respectively) , Respiration and heart rates showed adaptation of animals
to walking long distances in both zones, stabilizing respectively at 47-50 breaths/min and 8390
beats/min after a 6 km walk. Decrease in semen concentration was observed at the end of
the animalיs stay in each zone, with values between 3.1 and 3.7 spermatozoa x 10^9/ml vs. 1,7
and 2.7 spermatozoa x 10^9/ml in SP and WP, respectively. The volume varied between 1.0 ±
0.2 and 1.6 ± 0.4 ml in SP, and decreased to 0.6 ±0.3 ml in WP. Transhumance is thus
beneficial for only two months, i.e. between the end of spring and beginning of summer; this
advantage is then reduced when dietary protein levels fall to 8%. Semen quality showed
acceptable seasonal fluctuations, with maximum spermatogenetic activity in the summer
period.
