Tropical foliages: effect of presentation method and species on intake by goats

Browse or browsing: Investigating goat preferences for feeding posture, feeding height and feed type

Goats naturally browse different forages in various postures; this differs from typical farm practice, thus there are opportunities to improve goat welfare by understanding what and how they like to eat. We investigated if feeding preference was related to posture, feeder height relative to the ground, and type of feed. Sixteen adult, Saanen cross females participated in two experiments comparing a floor-level feeder (grazing posture; farm standard), with an elevated feeder (browsing posture; Exp1) and a platform-level feeder (raised, grazing posture; Exp2), when two forages (leaves, grass) were offered. Measurements included feed intake (g of DM/feeder), feeder switching frequency, first feeder visited, latency to visit first feeder and exploration and non-feeding activity time. Effects of posture (Exp1), height (Exp2) and feed type were analyzed. Type of feed affected preference for feeding posture and height. All goats consumed leaves over grass (Exp1: POP: 188 ± 6.52 g, GRA: 20.3 ± 7.19 g; Exp2: POP: 191 ± 6.15 g, GRA: 0.231 ± 6.91 g; P < 0.001), and the feeder containing leaves was often visited first (Exp 1: GRA/POP: 94% of visits, P < 0.001, POP/GRA: 53%, P = 0.724; Exp 2: GRA/POP: 91%, P < 0.001; POP/GRA: 69%, P = 0.041). When goats received only leaves, they consumed more from the floor-level (162 ± 22.2 g) vs. elevated level (102 ± 21.9 g) feeder (P = 0.039). When goats received only grass, there was no posture or height preference; however, they changed feeders more frequently (at least 4x (Exp1) and 2x (Exp2) more than other combinations; P > 0.01). Feed intake was negatively affected by exploring time (Exp1 only: r = −0.541; P < 0.001) and performing non-feeding activities (Exp1: r = −0.698; P < 0.001; Exp2: r = −0.673; P < 0.001). We did not identify a preference for elevated feeding posture; however, we suggest that our short test (compared to previous work) encouraged goats to make choices based on line-of-sight and also that the elevated feeder design (replicated from previous work) made leaf access harder. Nonetheless, we highlight that some goats actively used the elevated feeder; this coupled with the clear preference for leaves over grass, suggests that offering feed type and presentation diversity would allow individuals to express their natural feeding behavior more fully.

Estimation of Grazing Activity of Dairy Goats Using Accelerometers and Global Positioning System

The recent development of advanced electronic sensors to monitor and record animal grazing activity provides a real opportunity to facilitate understanding of their behavioral responses. This study aimed to characterize the grazing activity and protein−energy requirements of grazing dairy goats in a Mediterranean woodland in northern Morocco by combining two sensors, the Global Positioning System (GPS) and three axis accelerometers. An experiment was conducted in a representative woodland with eight dairy goats. Measurements were undertaken during the three main grazing seasons (spring, summer, and autumn) for two consecutive and contrasting years. Grazing activity parameters were assessed using GPS collars and leg position sensors. The results showed that grazing time was higher in spring (57% and 59%) than in summer (39% and 36%) and autumn (41% and 45%), respectively, for the dry and wet years (p < 0.001). During the two studied years, the daily horizontal distance traveled by the goats increased from spring (about 4.5 km) to summer (about 6.5 km) and autumn (about 7.4 km), while greater daily vertical distances were recorded over similar distances during summer−autumn. Several protein−energy intakes that were insufficient to cover the requirements of the grazing goats were recorded, especially in summer. The combination of GPS collars and accelerometers contributed to a better understanding of the grazing activities of dairy goats in the studied Mediterranean woodland. These findings provide useful data on the protein−energy balances of dairy goats and offer additional information that could be useful for herders and managers to enhance goat-feeding strategies and guarantee high-performance in the semi-extensive traditional goat farming system.

Effects of Replacing Grass with Foliage on Growth Rate and Feed Intake in Goats-A Systematic Review and Meta-Analysis

Small ruminants such as goats have a higher preference for browse species than cattle and sheep. In a meta-analysis of 42 papers describing 117 experimental treatments found by a search performed in June 2021 in PubMed and Web of Knowledge, we examined the general effect of including foliage in the diet of goats, replacing grasses, on dry matter intake and average daily weight gain. The inclusion requirement for a paper was that it described a controlled trial with a control diet of grass and with grass replaced by foliage in the experimental diet. Publication bias was estimated by calculating the Fail-safe n. Random effects analyses were conducted, using effect size calculated as Hedges' d. The results showed that inclusion of foliage increased feed intake (Hedges' d = 1.350, SE = 0.388) and average daily weight gain (Hedges' d = 1.417, SE = 0.444) compared with a grass-based control. The positive effect of foliage inclusion on dry matter intake was associated with lower neutral detergent fiber (NDF) and higher crude protein (CP) in the foliage than in the grass it replaced. The positive effect on average daily weight gain was associated with higher CP concentration in the foliage than in grass. Foliage inclusion level showed a quadratic relationship with dry matter intake, with maximum dry matter intake achieved at a level of 50-60%. There was wide variation between the studies reviewed, and this variation was not reduced by subgroup analysis based on different kinds of foliage. In conclusion, the addition of foliage to goat diets can increase feed intake and daily weight gain, as an effect of the dietary preferences of goats and of generally higher nutritional value in foliage species compared with natural/semi-natural grass species.

Temporal Variations in Chemical Composition, In Vitro Digestibility, and Metabolizable Energy of Plant Species Browsed by Goats in Southern Mediterranean Forest Rangeland

Simple Summary

Mediterranean forest rangelands constitute essential feed resources for grazing goats. The objective of this study was to evaluate the temporal variations in chemical composition, in vitro digestibility, and metabolizable energy of browsed plant species by goats on forest rangelands of the Southern Mediterranean of northern Morocco. Overall, the nutritive value of the selected plant species was highest in spring and then steadily decreased through the summer and autumn. Most of the selected plant species present high levels of crude protein than the minimum required level for maintenance. This study provides a valuable and useful database to elaborate the seasonal grazing and feeding management plan for goat herds.

Abstract

Forest rangelands contribute largely to goat diets in the Mediterranean area. Information about browsed plant quality is essential for adequate feeding management. The purpose of this study was to evaluate the temporal changes in chemical composition and in vitro digestibility of the main plant species selected by goats in the Southern Mediterranean forest rangeland during two consecutive years; these were very contrasted (dry and wet). The browsed species were composed of herbaceous, eleven shrubs, and four tree species. Overall, large variability in chemical composition, in vitro organic matter digestibility (IVOMD), and metabolizable energy (ME) was observed among species, grazing season (spring, summer, and autumn), and years within each species. Crude protein (CP) content varied from 60 to 240 g/kg dry matter (DM). The fiber fractions, except for Quercus suber, increased significantly by advancing maturity. Due to the water stress, the lignin level presented a higher value during the spring of the dry year. Condensed tannin (CT) content varied from 2 to 184 g/kg DM. CP, IVOMD, and ME showed a negative correlation with lignin and CT. Based on the results presented herein, it is concluded that the nutritive value of the browsed plant species was highest in the spring and lowest during the summer and autumn of both studied years. With a good grazing management strategy, the selected plant species by goats could guarantee high-quality feeding resources throughout the year.

Feed intake and behavior of dairy goats when offered an elevated feed bunk

Goats are browsers and select vegetation at various heights when foraging. On commercial farms, dairy goats are typically fed from low-level feed bunks. The objective of this study was to determine how feed intake and feeding behavior vary when goats are offered feed at variable heights, with the potential of evaluating the benefits of offering an elevated feeder to dairy goats. Thirteen Saanen X dairy goats were housed in a home pen with a lying area of wood shavings, where they were pre-exposed for 24 d to 3 feeder heights designed to result in differences in head height while feeding: floor level (head lowered relative to body), head level (head level relative to body), and elevated level (head and neck angled upward). Nine groups of 3 goats each were randomly selected and housed for 24 h in a test pen identical to the home pen except that it contained 1 of each of the 3 feeder heights. Each feeder contained ad libitum chopped alfalfa silage and a top-dressed corn-based supplement, refreshed twice daily. Refusals from inside and under each feeder were weighed to calculate intake. Feed intake increased with increasing feeder height (mean ± SE; 0.18, 0.29, and 0.34 ± 0.04 kg of DM/goat for floor-level, head-level, and elevated-level feeders, respectively). Total feeding time did not vary with feeder height, but feeding rate tended to be faster at the elevated-level feeder (14.5 ± 2.1 g of DM/min) compared with head-level (9.2 ± 2.3 g of DM/min) and floor-level (8.9 ± 2.1 g of DM/min) feeders. Goats visited the floor-level feeder (36.4 ± 8.4 visits/goat) less than the head-level (79.4 ± 8.4 visits/goat) and elevated-level (74.8 ± 8.4 visits/goat) feeders. The number of displacements per minute of feeding time (physical removal of another goat from the feeding place) was greater at the elevated-level feeder (0.46 ± 0.06 displacements/min) compared with the floor-level feeder (0.23 ± 0.06 displacements/min) and tended to differ from the head-level feeder (0.27 ± 0.06 displacements/min). We conclude that goats eat more from an elevated feeder and compete more to access this feeder.

Behavioral pattern of Rohilkhandi kids under different feeding systems

Aim:

The present study designed to evaluate the effect of different feeding systems on the behavior of local Rohilkhandi kids.

Materials and Methods:

A total of 21 growing goats (local goat of Rohilkhand region), weighing around 7-11 kg and aging 4-5 months, were used. These animals were kept in three groups. Group I was fed un-chopped green fodder in circular feeder (newly designed). Group II was fed un-chopped green fodder in linear feeder that was similar to the existing farm practice. Group III was fed chopped green fodder in linear feeder (modified version). Amount of concentrate and dry fodder fed was kept constant for all the three groups subject to equal increment in accordance with their increasing age. Adlibitum green fodder was made available to the animals. The experiment was conducted for 3 months. On-going behavior was recorded each day 4 h (2 h in the morning from 9:00 am to 11:00 am, after offering the feed, and same was repeated for 2 h in the afternoon, i.e., from 2:00 pm to 4:00 pm) was made between 9 am and 5 pm. The individual behaviors, viz., feeding, drinking, lying down, ruminating, idling, butting, pressing, pushing, frontal clashing, and physical displacement at feed barrier (active and passive: Without physical contact) of the goat were recorded using time-sampling method. Further, incidental activities such as defecation and urination were also recorded.

Results:

Among all the groups, butting, head to head, and pushing were the common agonistic behavior found but values did not differ significantly. The pushing while feeding was relatively less in Group II (0.22±0.04 min) which differed significantly (p<0.05) from the other two groups. The idling time was found significantly (p<0.05) lower in Group II (1.68±0.21) as compared to Group I (4.67±0.52) and Group III (4.27±0.56). Time spent in rumination near the feeding trough as well as away from the feeding trough was also significantly higher in Group I (p<0.05) than the other two groups. Other minor activities, viz., defecation and urination were negligible. No stereotypic activities were observed.

Conclusion:

It was concluded that provision of un-chopped fodder in circular feeder could only simulate natural feeding behavior of goat but did not give any added advantage. Further, feeding chopped fodder in linear feeding trough lead to increased consumption and more time is spent on feeding than on agonistic behavior as compared to the other two groups.

Feeding value of different levels of malt sprout and katikala atella on nutrient utilization and growth performance of sheep fed basal diet of Rhodes grass hay

Nonconventional agro-industrial by-products such as traditional liquor residues (locally called katikala atella) are widely used by livestock farmers in Ethiopia. The objective of this experiment was to evaluate the supplementary value of katikala atella and malt sprout (MS) on performance of sheep fed a basal diet of Rhodes grass hay. Thirty intact yearling male sheep with an average initial body weight of 17.4 ± 0.74 kg (mean ± SD) were assigned to the treatments in a completely randomized block design: atella alone (T1), 75 % atella + 25 % malt sprout (MS) (T2), 50 % atella + 50 % MS (T3), 25 % atella + 75 % MS (T4), MS alone (T5), and Rhodes grass hay alone (T6). Grass hay was fed ad libitum to all treatments. The total dry matter (DM) and organic matter (OM) intakes of sheep fed T4, T5, and T3 diets were the highest (P < 0.05), while sheep receiving T6 had the lowest DM intake. The highest (P < 0.05) total crude protein (CP) intake was for sheep fed T5 diet, while the lowest was for those fed T6 diet. Sheep receiving T3 diet had higher (P < 0.05) DM, OM, CP, neutral detergent fiber (NDF), and acid detergent fiber (ADF) digestibility as compared with those fed T1, T2, and T6 diets. Sheep supplemented with 50-100 % malt sprout had similar (P > 0.05) DM, OM, CP, NDF, and ADF digestibility. The highest (P < 0.05) average daily gain was for sheep fed T3, T4, and T5 diets, while sheep in T6 lost body weight. Sheep fed T5 diet had the highest (P < 0.05) nitrogen retention, while those fed T6 diet had the lowest. The study has shown that a mixture diet consisting of equal parts of katikala atella and malt sprout (T3) are found to be superior in most of the required nutrient characteristics.

Feed intake, digestibility, nitrogen utilization, and body weight change of sheep consuming wheat straw supplemented with local agricultural and agro-industrial by-products

Effects of supplementing sheep consuming wheat straw with local agro-industrial by-products on feed intake, growth, digestibility and nitrogen utilization were determined. Thirty 1-year-old local wethers, with a mean (+/-SD) live weight of 19.8 (+/-1.06) kg, were assigned to five treatments: wheat straw + atella (T1), wheat straw + atella + poultry litter (T2), wheat straw + atella + coffee pulp (T3), wheat straw + atella + coffee pulp + poultry litter (T4), hay + concentrate (T5). A 7-day digestibility experiment and a 112-day growth trial were conducted. Total dry matter (DM) and organic matter (OM) intake as well as body weight gain was similar for all treatments. The highest (P < 0.05) nitrogen (N) intake was in sheep fed T1 and T4 diets, while the lowest was in those fed T2 and T5 diets. Sheep fed T1 and T2 diets had greater (P < 0.05) DM and OM digestibility than those fed T4 and T5 diets. The highest (P < 0.05) digestibility of N was for the T2, T4, and T5 diets, while the lowest was for the T1 diet. The highest N retention was in T4 diet, whereas the lowest was in T3 diet. In conclusion, in urban and peri-urban areas where atella, poultry litter, or coffee pulp are available, smallholder farmers could feed the mixtures as a supplement to straw with a good performance without using concentrate feeds.

Performance of growing indigenous goats fed diets based on urban market crop wastes

The effect of feeding diets including market crop wastes (sweet potato vines (Ipomoea batatas) and scarlet eggplant (Solanum aethiopicum)) on growth and digestibility was studied using 32 indigenous intact growing male goats. Adding elephant grass (Pennisetum purpureum), maize bran and Leucaena leucocephala leaves, four isocaloric and isonitrogenous diets (Sweet potato vines, Solanum, Mixed and Control) were formulated. After the growth trial, 12 goats were randomly selected for a digestibility trial with the same diets, and 8 goats for a feed preference test comparing the market wastes and elephant grass. Crude protein (CP) intake was highest (P<0.05) for the Control (48 g/day) and lowest for the Sweet potato vines diet (23 g/day). Average daily gain was between 11.0 and 14.2 g/day, and similar between diets. The DM and CP digestibilities of the diets were 0.56 and 0.56 (Control), 0.62 and 0.56 (Mixed), 0.59 and 0.49 (Sweet potato vines), and 0.54 and 0.45 (Solanum), respectively. Faecal and urinary N excretions were highest in goats fed the Sweet potato vines and Solanum diets. Eggplant wastes were the least (P<0.05) preferred. On average the goats spent 5% of their 8-hour time eating eggplant wastes, 34% on sweet potato vines and 36% on elephant grass. Growth performance and N retention were low due to the low intake of feed, especially eggplant wastes.