Effect of stocking density on performance, infection by Eimeria spp., intestinal lesions and foot pad injuries in broilers with outdoor access under tropical conditions.

1. The study was carried out to evaluate the effect of stocking density on performance, litter moisture, Eimeria oocyst shedding, intestinal and foot lesions in broilers.2. A total of 192 1-d-old male Cobb broilers were distributed with three different stocking densities (6, 8 or 10 chickens/m2) with outdoor access and eight replicates in a completely randomised design over two periods. Productive parameters were measured from 3 to 7 weeks of age.3. Oocyst counts (OPG) in both excreta and litter were performed at 3, 4 and 5 weeks of age. Intestinal and foot pad lesions were evaluated at 7 weeks old. The stocking density of 6 birds/m2 had the highest body weights (P < 0.05) (2129 ± 37.67, 2759 ± 50.82 and 3167 ± 75.64 g at weeks 5, 6 and 7 of age, respectively).4. Feed intake decreased with increasing stocking density at week 3 (r = -0.57), 4 (r = -0.48), 5 (r = -0.84), 6 (r = -0.68) and 7 (r = -0.65) of age (P < 0.05). Birds with stocking densities of 8 and 10/m2 consumed, respectively, up to 11% and 19.5% less feed than the lower stocking density groups.5. Stocking density affected (P < 0.05) feed conversion (1.61, 1.49 and 1.46) and litter moisture (40.88, 52.60 and 56.19%) at 3 weeks of age. Neither carcase yield nor mortality was different between densities (P > 0.05). Likewise, there was no effect of stocking density on OPG neither in excreta nor in litter, intestinal lesions, or foot pad and hock injuries (P > 0.05).6. In conclusion, the higher stocking density decreased both the feed intake and the live weight in broilers, but there were no effects in the number of Eimeria OPG in excreta or litter, neither intestinal lesions nor in foot pad injuries.

Gymnopodium floribundum fodder as a model for the in vivo evaluation of nutraceutical value against Haemonchus contortus.

This study validated a protocol to identify the nutraceutical value of Gymnopodium floribundum (GF) foliage based on its effects on sheep nutrition, production and health and its impact on adult Haemonchus contortus. Thirty animals (17.8 ± 3.44 kg BW) were distributed into five experimental groups (n = 6). Groups T1-T3 received feed including 20%, 30% and 40% GF content, respectively, and group T4 received feed with 0% GF. Groups T1-T4 were all infected with 6000 H. contortus infective larvae (L3). Group T5 included six worm-free lambs fed a diet without GF. Feed intake, dry matter digestibility (DMD) and organic matter digestibility (OMD) were measured, in addition to the faecal excretion of eggs per gram (EPG) and total faecal egg count (TFEC) of H. contortus. On day 39 post-infection, lambs were humanely slaughtered to recover and count adult parasites and assess the length and fecundity of female worms. Higher levels of GF in the diet reduced DMD and OMD (P < 0.05), with the lowest values in T3 (40% GF) (P < 0.05). Body weight gain was similar for all groups (0.18 to 0.2 kg/day; P > 0.05). EPG and TFEC were lower in T1 and T3 than in T4 (P < 0.05), and the number of adult female worms was lowest in T3 (P < 0.05). In conclusion, GF leaf meal can be considered a nutraceutical when included at 40% (T3) in the diet of lambs, based on its ability to decrease the EPG and TFEC of H. contortus by reducing the female worm burden. A 40% inclusion level had no negative impact on lamb diet intake, production and health, although a reduction of digestibility was observed.

Impact of Dietary Condensed Tannins and Haemonchus contortus Infection in Growing Sheep: Effects on Nutrient Intake, Digestibility, and the Retention of Energy and Nitrogen.

PURPOSE: A controlled study evaluated the effect of condensed tannins (CT) from Gymnopodium floribundum leaf meal (GF), infection with Haemonchus contortus (I) and their interaction, on feed intake, diet digestibility and retention of N (NR) and energy (ER) in hair sheep lambs. METHODS: Thirty-six, worm-free hair sheep lambs (14.9 ± 1.56 kg body weight) were housed in metabolic cages. Eighteen animals were infected with 6000 H. contortus L3, while other 18 lambs were kept non-infected. On day 28th post-infection (PI), infected lambs were assigned to three diet groups: a diet without GF (I-NONGF), a diet with GF (I + GF) and a diet with GF + polyethylene glycol (PEG) (I + GF + PEG). Non-infected (NI) lambs were assigned to similar diet groups: NI-NONGF, NI + GF and NI + GF + PEG. The packed cell volume (% PCV), ante-mortem faecal egg counts and post-mortem worm burdens were also evaluated. RESULTS: Infection did not affect digestibility, NR and ER. Meanwhile, CT intake from the GF diet reduced the digestibility of dry matter, organic matter and crude protein, as well as NR, compared to lambs consuming the NONGF and GF + PEG diets (P < 0.05). Although, the digestible energy was similar between lambs consuming NONGF and GF + PEG diets, the ER was higher for lambs consuming the control NONGF diet. Diets did not affect the PCV, or the ante-mortem and post-mortem parasitological variables. CONCLUSION: The costs on N and energy metabolism were mainly associated with the CT content of the GF diet, but other features of the diet such as the high lignin content, seemed to affect animals consuming GF meal. Meanwhile, the H. contortus infection had a non-significant impact.

Nitrogen retention in hair sheep lambs with a gradient of Haemonchus contortus infection.

The impact of Haemonchus contortus infections on nitrogen retention (NR) of hair sheep lambs is unknown. This study estimated the feed intake, digestibility, NR, haematocrit (HT), and their relationship with the gradient of H. contortus infection in hair sheep lambs. Twenty-four hair sheep lambs, 3-4 months old, reared parasite-free were used (live weight (LW) 16.7 ± 1.7 kg). Six lambs were kept parasite-free, nine lambs received a dose of 300 H. contortus infective larvae (L3)/kg LW, and the remaining nine lambs received 500 H. contortus L3/kg LW. Infection doses ranged from 3870 to 9,500 L3. Lambs were individually fed for an average daily gain (ADG) of 100 g. On days 1 (P < 0.01) and 7 (P < 0.001) post-infection (PI), the L3 doses were positively associated with HT, possibly due to platelet recruitment. On week 1 PI, the infection (L3) reduced the crude protein (CP) intake (g/kg metabolic LW) (P < 0.05). A reduction of 1% HT corresponded to 1200 eggs per gram of faeces (EPG) for day 21 PI (P < 0.05), 2300 EPG for day 28 PI (P < 0.001), 2400 EPG for day 35 (P < 0.001), and 1300 EPG for day 41 PI (P < 0.001). However, the HT levels were never lower than 21 %. A lower CP digestibility was associated with EPG only on week 5 PI (P < 0.05). There was no significant association between EPG, Total egg in faeces, or worm burden (WB) with intake, dry matter digestibility (DMD), ADG or NR. The NR of lambs was positive along the different weeks of study irrespective of infection level. The WB was negatively associated only with HT on day 41 PI (P < 0.001), where a 1 % HT reduction was estimated for every 257 worms hosted. In conclusion, no relationship was found between H. contortus infection and DMD, ADG or NR in hair sheep lambs. The cost of H. contortus infection resulted only from the HT reduction and depended on the gradient and stage of the infection.